GT4 Tuning - An interesting little test - Results & Discussion Thread

  • Thread starter Der Alta
  • 23 comments
  • 1,893 views

Der Alta

Official GTP Bouncer
Staff Emeritus
9,209
DerAlta
This thread is the results thread from here: GT4 Tuning - an Interesting little test - Volunteers needed.

I'd also like for Testers to post up in here, fully discussing or expanding upon their testing results and experience.

In addition, I think this should be a "follow-up" thread, as each tester (I think) would like to tweak their choice of settings and see where improvements might be gained, or attributed to. As we all know, "To each, his own" holds very true to settings. In this case, I'd like to see it posted here.
 
Set-up A:

contestant:
When I setup the car with these setting's I though that they looked a little weird, but as I said
I would help I went and setup the car just like it said. My first impression was how well it turned
under braking. Because for me most cars don't turn very good with these tire's when your on the
brake's. I also found that the car also had good accelertion and didn't spin the wheels too much. That is
another thing for me that is weird. But I found that the best thing I liked about this setup is how smooth
the car handled. I found that the limit of the car was wide and easy to keep in the limit's and not lose
control. The setup would allow me to set one lap after another and get almost the same lap time's.

_________ T1 _______ T2______ Total ____

Setup 1 - 00:000 00:000 0:00:000
-------------------------------------------------------------------------
contestant:

* Understeers into turns. Pretty bad into some, not too bad into others.
* Oversteers out of turns if not Very careful with throttle application. Can easily get out of control, which resulted in several ruined laps.
* Normal brakes require earlier braking & then trying to get back on the throttle as early/aggressively as possible without losing the rear end.
* Gearing requires less shifting than the other Set-Up but is a compromise is some turns. Hard to decide whether or not it worth downshifting to a lower gear sometimes & risk losing the rear end coming out of the turn, or just gingerly carry the higher gear through the turn. Had most success with the later.
* Best Lap: 1'21.448

--------------------------------------
contestant:

Setup A

I felt this setup was quite unpredictable in nature. In low speed corners, it oversteered, and understeered in high speed corners (particulary through the esses).

The transition from understeer to oversteer (and vice versa) was very sharp - one minute the car would be oversteering, the next understeering sideways. Again, this was most noticeable through the esses - I even spun at the exit three times.

The use of a LSD initial torque value of 5 (effectively open diff) caused rather copious amounts of wheelspin on the exit of corners.

Coming over the hill to the start/finish line, the car was quite unstable - at one stage I had a big twitch while cresting the hill. The car also suffered from 4th, even 5th gear wheelspin through here.

The braking performance of this setup was, basically, hopeless. For the first corner, I had to brake at about the 150-metre mark to make the turn. The car also understeered on the brakes.
------------------------------------------------------------------------------
contestant:

Setup A

Lap time: 1'23.690 (T1 – 0'26.626 ; T2 – 0'52.184)
Mileage: 46.5 km

My first thought when I drove Setup A was that the car had significant problems with understeer. As I approached any corner the front was struggling for grip, and it gave me no confidence in the car. Looking at replays it appeared as though the front tyres were bouncing when the suspension was under high load.

In addition, if I hit the rumble strips the car would bounce and I would lose a lot of grip.

For my style of driving, this setup was uncomfortable. Due to the understeer it was difficult to position the car properly. I also had less of the track to use because the bumps unsettled the car so much. To me it seems like the extreme damper settings are responsible for this behaviour.

I found Setup A to be fairly unstable at speed, despite the understeer. Twice I found myself struggling to get the car straight after a high speed corner.

The gearing seemed okay, but the car could not match Setup 1 in a straight line. I’m not sure if this is due to Setup A not having a racing flywheel, or whether Setup 1 makes better use of the engines power band… Whatever the case, Setup A really suffered in acceleration.

Observations from the Data Logger
Setup 1 has a top speed of 241kph, while setup A only reaches 226kph. Is this the lack of flywheel in Setup A showing itself, or is Setup 1 taking advantage of the power band better?
In general, when I was driving Setup1 I was able to use 100% throttle earlier than I was with Setup A. It seemed like Setup 1 was taking advantage of the LSD, and Setup A was making me waste time feathering the throttle to slow the wheel spin.
Corner speed was similar, but Setup 1 had an advantage of over 10kph on the exit of the high speed chicane (turns 3 and 4). It was also generally Setup 1 that had the higher corner speed, even if the difference was marginal at times.
--------------------------------------------------
contestant
This setup is very poor under brakeing and looses a bit over a second for not using the Racing Brakes and Flywheel, but is still not as good as Setup 1 under brakeing when using these mods. This setup is also a bit understeery particularly under brakeing making it hard to get to the Apex of the corners.

T1/25.516 T2/50.088 Time/1'20.627
Top Speed Across The S/F Line: 143MPH
--------------------------------------------------
Contestant
Set-Up A:
This setup’s main weaknesses were substandard brake setup, excessive understeer and lack of acceleration. Turn #1 was difficult because if the brakes didn’t get you then the understeer would, and the same could be said for turn #5 in many cases. The remaining turns faired OK apart from the final turn into the tunnel where understeer again played its part in preventing a good exit. However, it was clear to me that the tuner really attempted to reduce the loss of rear wheel traction/wheelspin when tuning this car and should be commended for that effort. Again however, the car lacked the required acceleration that was needed for decent lap times and if the extra acceleration was initially applied I wonder how his attempt to stem the loss of rear wheel traction/wheelspin would’ve faired.
All in all, I actually enjoyed the fact that the wheelspin was reduced and therefore made for an exciting ride in terms of trying to tame the beast’s remaining shortcomings in a fast and controllable manner.

Lap Time: 1’20.9
-----------------------------------------------
contestant
Setup A didn't really feel as if it was attached to the road. You had to be very delicate with the throttle, but even with that there was still a lot of wheelspin. Coming over the crest onto the start finish straight caused the car to lose traction until after the start/finish line. The esses up the hill onto the S/F straight were a lottery every lap. It was flat, just, if you were lucky. Touch the inside kerb, or hit a bump at the wrong time, and all to often you were saying hello to the pit wall on a regular basis.

The car had a tendendancy to understeer on corner entry. I used 2nd coming out of the haipin into the tunnel at the end of the lap, but had to press the throttle gingerly or else the rear end wanted to overtake the front.

The normal brakes were weak, and really needed an upgrade.

Best lap - 1'23.904
---------------------------------------------------
T1: 0'25.553
T2: 0'50.518

Total: 1'21.180

Initial turn-in is ok, though the braking must happen earlier than you would expect. It almost feels like there is not enough weight transferring to the front of the car to allow the front to bite. Cadence braking seems to help wipe off speed. Mid-corner understeer seems to be a problem, the car is reluctant to turn once it has taken a "set". Then, on exit, there is oversteer, which seems to be a combination of wheelspin but also "roll oversteer", like the inertia of the car is overcoming the suspension control and grip. Overall the car feels unbalanced, like the front is fighting the rear, leading to unpredictable on-limit behaviour. The driver must also make sure not to touch kerbs because the front-end will bounce away from the apex. It is more difficult to set consistent lap times with this setup than with setup 1.

Also, setup A was consistently 4-7 km/h slower at the s/f line than setup 1, and the need to be earlier on the brakes cost another 5-10 km/h.
--------------------------------------------------
contestant
Setup A

Lap time: 1:21.719
V-Max: 242.5 km/h

Very twitchy. Soft rear end helps make traction from short gears, but those short gears and soft rear are, ultimately, a handicap. Stock flywheel only perceptibly hurts acceleration near V-Max. Those short gears make it fidgety from mid-corner to exit, inducing oversteer unless you modulate the throttle. Less understeer off-throttle than stock. Good amount of snap-oversteer under braking, making it very easy to set-up for corners… lack of racing brakes means that the braking threshold is lower, but it only pushes your braking points back a few meters (heck, the way I drive, it’s hard to tell sometimes)... While it rotates very quickly, the overly aggressive gearing and loose rear end hamper your ability to capitalize on this.

With this set-up, there’s no safety net of understeer to lean on. You need more countersteer and common sense to achieve a clean lap. You can drift it, with a little respect, but this obviously doesn't produce fast laps. Might produce a better lap than stock with better gears and a racing flywheel.
----------------------------------------------------
contestant
Setup A:
The worse of the two. While none was an absolutely fantastic setup, and both had their flaws, this one 'felt' worse. It was not as direct as I wanted it to be. However, keeping in mind that those are N3s, the car still felt very grippy. The brakes, however, were not that effective, so it lost a fair bit on the braking part. Plus, it was not very 'spinny', and needed total attention to throttle, since even in 4th it managed to spin the rears, on a straight. Also, the turn-in was not sharp enough, and the exit under power tended to be a bit chaotic - either straight, or extremely oversteery. Because of that understeer and twitchy character, it lost quite a bit of time on the hairpin, and on turns 3&4 (Right-left sweepers before T1), since more lift was required on 3&4, and the 'bite' needed to move the car into the hairpin wasn't sharp enough. Not all was bad, though: The car was the quicker of both in the looong left-hander before T2, and was easier to keep 'in-line' there - mid-turn handling was good, since as soon as the car 'accepted' the turn, it did it very well. Getting into the out of the corners was the problem.
----------------------------------------------------
contestant
Setup A:
- Understeer on high speed corners.
- LOTS OF WHEELSPIN!!!
- Late braking on turn 1 induces heavy understeer, and early braking leads to pretty low corner exit speeds.
- I liked that the understeer could be corrected by a slight blip of the throttle, but then must be controlled/corrected immediately as to avoid excessive wheelspin and not lose control of the car
- I guess it makes a good drift setup

quickest lap time: 1'23.294
mileage: 55.4
---------------------------------------------------
Contestant
Splits: 27.236 / 53.273 / 1.25.565

This set up offered a good initial turn-in but is spoiled by the fact that the brakes are so poor you need to be braking deep into the apex (and beyond) to even hope to get the car around the turns - turning under heavy braking was also quite difficult. Traction out of the turns was poor and continued to be so down the straights until the change to 5th arose. The car did behave well over the curbing however. The car handled quite predictably whilst oversteering (most of the lap) which made the longer turns quite enjoyable.

Overall quite an 'entertaining' ride, more suited for drifting than racing IMO. My lap time for this car is from one of the few laps that i managed to keep the car on the tarmac.
-------------------------------------------------------
 
Set-up 1:
contestant:

When setting up this car it looked alot like the setup's I use so nothing looked too strange. When driving this car I also found that it tuned well under braking. But the accelertion was not as good because the car had alot more wheel spin. And this also had affected the handling too. Because when I was driving the car it was harder to find the limit of the car. So I found my self spinning out of control when I tried to push the car hard. But it's not to say the car was slow, because it was faster than Setup A. But only because Setup A didn't use the same part's(Racing Flywheel and Racing Brake's). Even though Setup 1 was faster, I fell that if Setup A would have used the same part's as Setup 1 it would have been better and most likely faster as well. At lease that's what I think.

So that's what I think of the setup's. If the part's would have been the same I think Setup A would have been faster than Setup 1. I have both ghost replay's if needed. I also have the lap time's but because we aren't compairing lap time's I will only show the different's between them. Here they are.

Setup A - +0.248 +0343 +1.285
-------------------------------------------------------------
contestant:

Set-Up 1:
* Understeer into turns is significantly reduced. Actually turns in very nice in several turns.
* Oversteer coming out of turns is reduced since the Racing brakes allow much later braking, and the improved turn in characteristic allows you to get on the throttle earlier & more aggressively. Potential to lose the rear coming out of turns is significantly reduced.
* Best Lap: 1'21.334

Summary:
Set-Up 1 is more forgiving & much easier to drive more aggressively & more consistently. Good lap times are possible lap after lap. Set-Up A can give a similar best lap, but only once in a while & requires much more touch & control. Since that difference isn't obvious when simply comparing the Best Laps, I drove each car for a 15 lap session & noted every lap time (Since the car is "Special" & can't be entered into any races. ).
Set-Up A Set-Up 1
21'19.352 21'11.581 Total for 15 laps (7.771 diff)
1'25.290 1'24.772 Average lap (0.518 diff)
2 0 Blown laps over 1'30
Overall, I preferred driving Set-Up 1 since it's more forgiving/consistent & encourages more aggressive driving. If I had to pick one to drive in a race, it would be Set-Up 1 hands down. I think the brakes & gearing are the biggest things holding back Set-Up A. The suspension settings probably aren't making as much of a difference, although being a Development Engineer for Bilstein, I don't like the way the damping looks for Set-Up A.

FWIW, with my typical suspension settings & gearing applied to Set-Up 1, I was able to manage a 1'20.751 within 10 laps.
-------------------------------------------------
contestant:

Setup 1

This setup was much more balanced than setup A. It didn't suffer from much understeer - this setup was more oversteer-biased.

On power, the car had a tendency to oversteer, but it was relatively easy to catch, and bring back in line. Through the esses, despite some oversteer on exit, the car was pretty much neutral (unlike setup A).

There was less wheelspin (than A) on the exit of corners, due to the LSD having a higher initial torque value (10 as opposed to 5); I felt the reduction of the LSD Acceleration effect from 40 to 20 was a bit much, but wheelspin on exit was better controlled than setup A, despite this.

Cresting the hill, a problematic spot for setup A, this setup was much more composed, but still suffered from a bit (read: not a lot, but still enough to be noticeable) of wheelspin on exit. This setup didn't suffer from the twitchiness over the hill that setup A had.

I felt this setup was, overall, more controllable, more neutral and more entertaining than setup A. It also suited my own driving style (brake & turn to apex, full beans on exit) better than A did. It was also easier to recover when oversteer surfaced.


Overall
While both setups left much to be desired, I felt setup 1 was better - it was more user-friendly, more predictable, more controllable and more entertaining.

It also proved to be faster - almost 3 seconds between the best laps of both setups, in fact.
--------------------------------------------------------
contestant:

Setup 1

Lap time: 1'20.997 (T1 – 0'25.544 ; T2 – 0'50.706)
Mileage: 29.1 km

Setup 1 was reasonably well balanced. The car generally had a feeling of slight understeer, but it was okay because it felt almost neutral. The car could be positioned where I needed it to be, and it allowed me to drive reasonably close to the limit comfortably.

However, the high speed right-left ‘flick’ of turns 3 and 4 seemed to unbalance the rear of the car, causing fairly extreme oversteer at times. It was easy to control, though, and the car didn’t do anything nasty like snap back when I applied counter-steer. This oversteer was probably a good thing, as I was able to carry a lot of speed through turn 4 – over 10kph faster than Setup A through turn 4.

The car suffered fairly pronounced understeer on entry to the hairpin towards the end of the circuit. Despite this, the lowest speed it reached during the corner was 63kph – 4kph faster than Setup A through the same corner.

The gearing felt as if it was not tuned for this circuit, 6th gear was too long. It has the advantage of being a more flexible car in different circuits, but I felt the car could have accelerated a little faster if the gears were a bit shorter.
---------------------------------------------
Contestant
Setup 1:

Far superior under braking to Setup A, oversteers enough to allow you to get the car to the Apex of the corner fairly consistantly. This Setup is also alot better under acceleration although it has a tad more wheel spin.

T1/25.013 T2/49.119 Time/1'18.866
Top Speed Across The S/F Line: 146MPH
---------------------------------------------
contestant
Set-Up 1:
This setups only mayor weaknesses was excessive rear traction loss/wheelspin and the very unforgiving nature of the cars wheelspin whilst exiting a number of corners. However, turn #1 was a joy, although there were issues with wheelspin into and after turn #2 that left the driver wondering if it was best to do an early gear change or chance his arm and go for the full monty up to turn #3. Coming out of turn #4 was very unforgiving if the driver’s line wasn’t exactly right and turn #5’s exit was also a battle of wills in trying to keep traction up to turn #6. Again however, this setup boasted more acceleration and a lot less understeer than Set-Up A and thus resulted in much faster lap times. It appeared to me that either the tuners attempt to reduce wheelspin was tampered by the cars superior acceleration over Set-Up A, or the main objective was speed that in turn would result in better lap times, and therefore ignoring any issues with traction.
All in all, this setup was clearly the faster car and no matter how much I enjoyed driving Set-Up A I still have to say that this was also the better car even if rear traction was an issue.

Lap Time 1’18.9
------------------------------------------------
contestant

Setup 1 faired better than Setup A, but I was still dissappointed with it. The car did feel more planted, understeer was less evident and full throttle was attainable earlier. The uphill esses onto the S/F straight were easily flat with this setup. Traction was still broken by the crest, but the resultant wheelspin didn't last as long as it did using Setup A. The car could be driven over kerbs better than Setup A, but care was still required.

The brake setup was vastly superior, and worked well. Late braking was easy to do and didn't unsettle the car for corner entry.

Best lap - 1'20.491

Both setups cause massive vibrations on the DFP in anything other than a straight ahead position, so neither setup gave an easy drive for me.
---------------------------------------
contestant
Setup 1:

T1: 0'24.614
T2: 0'49.017

Total: 1'19.022

The car is stable under brakes, but suffers from turn-in understeer. It also struggles to turn in when off the throttle mid-corner, one needs to apply some throttle to get the rear of the car involved. On exit, there is some power oversteer, which seems primarily to be a result of wheelspin. The car is fast if one can balance it on the throttle and carry a few degrees of drift through the long corners, but this requires a bit of skill and can be hard to replicate. Overall the car feels balanced and progressive in losing grip, but the driver must be very smooth with their inputs.
---------------------------------------------
contestant
Setup 1

Lap time: 1:20.720
V-Max: 247 km/h

Initially feels more like the stock car, a bit understeery, with longer gears than Setup A. Wheelspin is better controlled than stock, despite the shorter gearing, but seems more than in Setup A, likely due to the stiffer rear end and larger camber settings. The upside to this is that it resists throttle-induced oversteer very well. The downside is more off-throttle understeer than Setup A. It’s very stable under braking, and easy to control mid-corner to exit. Snap under braking is good, and it’s easy to point the nose at the apex with the brakes. Requires a more deliberate approach than Setup A, but is ultimately more stable, faster and much better geared than either stock or Setup A, with better punch between 100 and 200 km/h. Only slows appreciably at speeds above 200 km/h, where aerodynamics play a larger role, which is why V-Max isn’t far off from “stock” gearing. No comment on LSD, so it’s doing its job, I guess. Definitely better than stock, in many ways, but the handling advantage is more qualitative than quantitative. Makes for more easily repeatable laps than the other set-ups.
-------------------------------------------
contestant
Setup 1:
My prefered setup. I wouldn't call it brilliant, since it still didn't leave me wanting to continue racing it for days, but it was far superior to the other setup. It felt more 'direct' during cornering, probably because of the added stiffness of the rollcage. Braking was easy and controllable, and enabled the use of trail-braking. Turn-in was sharp, and the exit, as long as it was done smoothly, was very neutral. One flaw of this car was keeping the line in mid-turn, such as during the long left-hander before T2, where it went wider, even when I kept the speed of 110Km/h, which kept the other setup 'in-line'. Oversteer was easy to obtain, and was very controllable, too - especially under the first tunnel, where letting the tail out a little, and clipping the inside was very easy. But more importantly, fun aside, this setup was seriously quicker. With a little courage (from the driver's side), this car was able to produce consistent and quick laptimes - mostly 1.5 seconds quicker than the best lap on the other setup, but the best was even 2.5 seconds quicker.

Times (A - 1):

T1: 0'26.614 - 0'25.883 (+0.731)
T2: 0'52.230 - 0'50.866 (+1.364)
Lap: 1'24.167 - 1'21.448 (+2.719)

Epilogue:
While I was pretty dissappointed with Setup A, and Setup 1 was very good, I felt neither were good enough, and they both lacked a bit. None was a true 'Fireblade'. They both felt a little unfinished, and Setup A could definetely be re-made, because perhaps this style of extreme-settings doesn't work on such a car. Setup 1 felt much more 'polished', but I think it was still not as perfected as one might want it to be. But, this is a comparison and not an objective rating, and therefore Setup 1 wins my vote. After all, a 2.5 seconds lead and better consistency/driveability are very clear - and the better 'feel' only adds to this victory.
-----------------------------------------------------
contestant
Setup 1:
- Showed minimal to moderate understeer under late braking. technically, it benefitted from the racing brake package.
- Wheelspin is a bit more controlled; however, still bothersome and intrusive.
- As with "Setup A", this setup was easy to get back in line when understeering by giving a slight blip of the throttle.
- Nice control under oversteer

quickest lap time: 1'20.503
mileage: 49.9

In closing, i had fun trying out other peoples setups!
------------------------------------------------------
Contestant
Set-up 1:

Splits: 25.864 / 50.683 / 1.21.764

First impressions of this set-up were that it felt much more stable than 'Set-up A'. The car had a little lift-off understeer, but thats no bad thing for such a tail happy car. I found this set-up a little less predictable during oversteer and more prone to initial understeer, often having to provoke the tail out a little to get it through certain bends. The transition of coming off the brakes and onto the throttle could be done much quicker and cleaner than 'A'. The main difference with this set-up was the brakes. I was braking a good 50-60m later into the first turn which gives you a second off your lap time straight away.

This was a much more forgiving set-up for the car in this specification. I felt i could lean on the cars limits more and spent much less time fighting traction with throttle imputs, which naturally leads to quicker lap times. Much more of a race-style set-up than the first one.
 
First I'd like to thank everyone who took part in this test, its been a great help (and I must admit a nervous few days waiting for the results to go up).

Its helped to confirm a few thoughts I've had in regard to set-ups and how personal they are, as well as general approaches to tuning.

I am fully intending to post my comments up here, but need a bit of time to read all of them and compose a reply worthy of the feedback received. Out of interest if anyone does have there own set-ups for this car and track combo (and is happy sharing them) I would be extremely interested to give them a go.

In closing (for now) I would also like to extend special thanks to sucahyo (for agreeing to take part) and DA for giving so much of his own time in running all this and putting together the feedback.

Thanks

Scaff

Edited to add - One of the main reasons that I (and I would have to assume Suchayo) battled to find the right balance between reducing wheel spin and retaining good levels of acceleration was down to the rather large power to weight ratio these cars have (around 680b hp per tonne). Not normally a problem if you have some weight to help out (which we didn't) or nice sticky S or R tyres (which again we didn't), all in all it added up to quite a challenge.

A number of people did comment in the original discussion about the lack of full tuning on the cars, which gives around 290bhp, I did try this but with the tyres in question the resulting 865bhp per tonne really would have needed race rubber to gain any traction above 1/2 throttle or crippling the gearbox, neither of which I wanted to do. Had we been running different tyres I would have almost certainly done so.
 
Der Alta
In addition, I think this should be a "follow-up" thread, as each tester (I think) would like to tweak their choice of settings and see where improvements might be gained, or attributed to. As we all know, "To each, his own" holds very true to settings. In this case, I'd like to see it posted here.

So you would like to see what each tester would change on the setting's to fit them?
If that's so I will get to work on it tomorrow.
 
Im still learning when it comes to tuning a car but I have a setting that I think both Setup A and 1 will benifit from (particularly Setup A). It is to reduce the LSD Deceleration setting down to 5. This makes steering while brakeing a bit easy (particularly on cars with long brakeing zones) and I find this to be an effective way to reduce understeer under braking.
 
Im still learning when it comes to tuning a car but I have a setting that I think both Setup A and 1 will benifit from (particularly Setup A). It is to reduce the LSD Deceleration setting down to 5. This makes steering while brakeing a bit easy (particularly on cars with long brakeing zones) and I find this to be an effective way to reduce understeer under braking.

I would agree with this.

When I was mucking around with baseline runs (before receiving the setups) I installed a simple 1-way LSD, so it's only active when power is applied. You get the benefit of the traction under power without compromising the car's ability to turn under brakes, something I found very helpful for my preferred driving style.
 
I just sent my results to Der Alta... was held up and couldn't send them till now...

One point of interest... has anyone else driven these two against a "stock" set-up?

I did about a dozen laps each... more with Set-up A, obviously, as it's trickier to learn... and I did a lot of laps before and after with a car with "stock" settings on a full-racing suspension, racing brakes, weight reduction, etcetera, but no LSD, Brake controller or Rollcage.

The results were interesting, to say the least. It did help me to appreciate the changes resulting from Set-up A and Set-up 1, and it kinda helped defined what antics (understeer, oversteer, etcetera) were due to the set-ups and which ones were due to the natural state of the car.
 
This was a fun test! It was interesting to see other peoples' approach to Set-Up & how it affects the reactions of the car. Thanks to everyone involved!

FWIW, here are my settings that I ran for 10 laps after ~80 laps each with Set-Ups A & 1. Content was otherwise the same as Set-Up 1.
Suspension
7.5/5.0
60/60
3/3
6/6
4.0/3.0
1/0
6/4
Brake Contoller
6/4
Trans
Default Final Gearing: 3.270
Auto Set: 9
Driving Aids
0
0
0
LSD
5
5
5
Best Lap: 1'20.751
 
Oh well, since Der Alta doesn't seem to be on... here's my take:

Stock (no cage, all power adders including racing flywheel and brakes, no LSD, brake controller or gearbox mods)

Lap time: 1.21.273
V-Max: 247 km/h

Lap characterized by more wheelspin than modified cars, but long gearing helps translate that into acceleration. The long first and second gears allow you to ride out wheelspin, and help make low speed handling more predictable. More off-throttle understeer than either modified set-up. Braking with no controller means snap under braking isn’t quite enough to help set up for turns, but braking distances are shortened by racing brakes. Moderate understeer under constant power and relatively benign throttle response allow you to keep speeds high in long sweepers, and aid in straight-line stability, with the trade-off of a wider line through the tighter corners.

Setup A

Lap time: 1:21.719
V-Max: 242.5 km/h

Very twitchy. Soft rear end helps make traction from short gears, but those short gears and soft rear are, ultimately, a handicap. Stock flywheel only perceptibly hurts acceleration near V-Max. Those short gears make it fidgety from mid-corner to exit, inducing oversteer unless you modulate the throttle. Less understeer off-throttle than stock. Good amount of snap-oversteer under braking, making it very easy to set-up for corners… lack of racing brakes means that the braking threshold is lower, and you can't turn under braking as early as with the other set-up, because you're locked up for a bit longer... (heck, the way I drive, it’s hard to tell sometimes)... While it rotates very quickly, the overly aggressive gearing and loose rear end hamper your ability to capitalize on this.

With this set-up, there’s no safety net of understeer to lean on. You need more countersteer and common sense to achieve a clean lap. You can drift it, with a little respect, but this obviously doesn't produce fast laps. Might produce a better lap than stock with better gears and a racing flywheel.

Setup 1

Lap time: 1:20.420
V-Max: 247 km/h

Initially feels more like the stock car, a bit understeery at speeds, with longer gears than Setup A. Wheelspin is better controlled than stock, despite the shorter gearing, but seems more than in Setup A, likely due to the stiffer rear end and larger camber settings. The upside to this is that it resists throttle-induced oversteer very well. The downside is more off-throttle understeer than Setup A. It’s very stable under braking, and easy to control mid-corner to exit. Snap under braking is good, and it’s easy to point the nose at the apex with the brakes. Requires earlier turn-in than Setup A, but is ultimately more stable, faster and much better geared than either stock or Setup A, with better punch between 100 and 200 km/h. Only slows appreciably at speeds above 200 km/h, where aerodynamics play a larger role, which is why V-Max isn’t far off from “stock” gearing. No comment on LSD, so it’s doing its job, I guess. Definitely better than stock, in many ways, but the advantage is more in handling "feel" than outright speed. Makes for more easily repeatable laps than the other set-ups, and is very very easy to drive in either "drift" or "grip" style.
 
Yep, I did indeed put his up yesterday.

I've added one more to the list this morning, and figure its time to announce who's is whos.

Set-up A, is sucahyo

Set-up 1, is Scaff
 
So did you want us to post up our ideas for improvements, or our settings if we have settings we prefer, or is this it?
 
So did you want us to post up our ideas for improvements, or our settings if we have settings we prefer, or is this it?
I'd like to use this experiment as a basis for follow-up experiments. By all means, post up your thoughts and adjustments. In particular, why the adjustments you've made have helped your lap times on the car.

I've run one car, but haven't set foot in the second. Hopefully tonight, when I hand Lady_DA $200 and tell her to go shopping again.
 
Yep, I did indeed put his up yesterday.

I've added one more to the list this morning, and figure its time to announce who's is whos.

Set-up A, is sucahyo

Set-up 1, is Scaff

D'oh... my bad. Thought it would be added at the end... didn't read through the middle of your post.

Kind of figures. Scaff's set-up is well thought-out and stable, and seems well-suited to racing. While it might not be the fastest set-up possible, it's a great one for competitive racing, with enough built-in safety nets to keep you from messing up. I could pull multiple laps at full pace without messing up in this car.

Sucahyo's set-up is unconventional... seemingly tuned around GT4's quirks rather than with real-world tuning in mind. By working around GT4's engine, it does solve some of the handling sins of the stock car, but has problems of its own (particularly with the drivetrain). This is more of a time attack or drift set-up, too twitchy for actual racing.
 
Yep, I did indeed put his up yesterday.

I've added one more to the list this morning, and figure its time to announce who's is whos.

Set-up A, is sucahyo

Set-up 1, is Scaff

As an occasional tuning-competition judge, that was obvious. I was tempted to add: "Sucahyo, what worked well on your Holden Monaro didn't work on this car" (I'm referring to the extreme dampers-stabilizers-toe settings)...
 
Thanks everyone, all of your evaluation give me something to learn. Thanks for the tip Gingiba.

I am surprise that racing brake really make a difference in car this light. I thought that by using N3 tire I don't even need racing brake.

Although racing flywheel can increase wheel spin, gearing can be used to make up for that, so I guess I have should equip my car with fly wheel and change the gear.

Move final drive to 4.830, then move auto to 1, then move final drive to 2.500, and use this gearing
4.171
3.266
2.619
2.151
1.807
1.553

This method of gearing has much lower first gear ratio (this 1st gear = previous 2nd gear, this 6th gear = previous 6th gear) which should help traction in low speed corner.

Another tweak maybe by reducing front spring rate to 5.0 and changing damper to 9/1 9/1. The LSD suggestion seem ok, so LSD to 15/30/5
 
Thanks everyone, all of your evaluation give me something to learn. Thanks for the tip Gingiba.

I am surprise that racing brake really make a difference in car this light. I thought that by using N3 tire I don't even need racing brake.
In regard to the racing brakes, in my own testing (straight line stopping distances) they make little or no difference with N and S tyres (details of the tests can be found in the GT4 & Brakes thread or the first of my guides). I tried my car with and without racing brakes and it made (for me) no real difference. My final set-up only really included them as I cut and pasted the mods from another set-up which ran R3's.

The problem for your car was highlighted by a few of the drivers...

Initial turn-in is ok, though the braking must happen earlier than you would expect. It almost feels like there is not enough weight transferring to the front of the car to allow the front to bite

...and...

This setup is very poor under brakeing and looses a bit over a second for not using the Racing Brakes and Flywheel, but is still not as good as Setup 1 under brakeing when using these mods.

...even with racing brakes fitted your set-up suffers because the front does not load up quickly enough, the delay is caused by the high front damper values initially resisting the load and losing you grip when the brakes are first applied. The frontward load transfer is delayed by the additional resistance the stiff dampers give.



Another tweak maybe by reducing front spring rate to 5.0 and changing damper to 9/1 9/1.
So you are suggesting softening the front end to give more compliance in the front end?

On a side note a quick question. Sucahyo, you used camber (both front and rear) in this set-up, rather than your norm of zero camber front and rear. As you have so strongly argued in the past against the use of any camber at all, can I ask why you used it in this set-up?


Regards

Scaff
 
even with racing brakes fitted your set-up suffers because the front does not load up quickly enough, the delay is caused by the high front damper values initially resisting the load and losing you grip when the brakes are first applied. The frontward load transfer is delayed by the additional resistance the stiff dampers give.
...
So you are suggesting softening the front end to give more compliance in the front end?
For me, in GT4, stiff spring increase grip but also make it faster/easier to slip. When at limit car end with stiffer spring rate will loose traction first. When braking Caterham front which has stiffer spring rate will loose traction first. So even when the grip increase, it don't help braking. But the increased grip can help drifting, more grip when sliding.

SOme problem like:
- heavy understeer when braking
- twitchy behaviour
- front tyres were bouncing when the suspension was under high load

can be cured by reducing front spring rate stiffness, but I don't know how bad it increase understeer on constant radius corner.

I reduce damper in an attempt to reduce/stop "front tyres were bouncing when the suspension was under high load" but still keeping it high to maintain "Less understeer off-throttle".

I just notice that apply throttle oversteer is a problem, so I guess lower front rebound or higher rear bound damper value. But since rear jittering is a problem I think lower front rebound would be better. so damper to 9/1 1/1.

On a side note a quick question. Sucahyo, you used camber (both front and rear) in this set-up, rather than your norm of zero camber front and rear. As you have so strongly argued in the past against the use of any camber at all, can I ask why you used it in this set-up?
Which past? I usually don't use camber in GT4 tuning competition since I don't have time to do it. When I want to tune camber I will use the method that I post in Are you using too much camber thread.

For this car I use feel method, which is basically an iteration of doubling or halving camber value. This will take much time, so I don't usualy use it.

And I see camber prevent me to see how the car react when I change other suspension part. I will usually keep camber zero when tuning other suspension part. Only after I satisfied with other suspension tuning I start tuning camber.
 
One more evaluation added, and I realized I never posted the original settings to anyone other than the testers. So here they are.

Track: Midfield (normal)
Car: Caterham Seven Fireblade

Set-up A:
Race Exhaust & Air Filter, Brake Controller, Port Polish, Engine Balancing, Racing Chip,
Fully Customisable Transmission, Triple Clutch, (Stock Flywheel), Variable LSD, Carbon Driveshaft, Supercharger kit, Fully Customisable Suspension
N3/N3 tire, Weight Reduction Stage 3.
Oil Change

Suspension
Spring Rate: 7.0 / 3.8
Ride Height: 70 / 90
Bound: 10 / 1
Rebound: 10 / 1
Camber: 1.5 / 0.5
Toe: 0 / -4
Stabilizers: 1 / 7

LSD
Initial: 5
Acceleration: 30
Deceleration: 15

Downforce
Amount: - / -

Driving Aids
ASM Oversteer: 0
ASM Understeer: 0
TCS: 0

Brake Controller
Brakes: 7 / 4

Transmission
move final drive to 5.500, after that move auto setting to 14

Ballast
Weight: 0
Location:0

Set-up 1:
Racing Exhaust, Brake Balance Controller, Port Polish, Engine Balance, Racing Chip, FC Transmission, Triple Plate Clutch, Racing Flywheel, FC LSD, Carbon Fibre Propshaft, Supercharger, Racing Suspension, N3 Tyres, Weight Reduction Stage 3
Stiffness / Roll-cage, Racing Brakes, Oil Change,

Suspension
Spring Rate F 7.0 / R 5.5
Ride Height F 75 / R 80
Bound F 2 / R 2
Rebound F 3 / R 3
Camber F 2.5 / R 1.5
Toe F 0 / R +1
Stabilisers F 1 / R 3

LSD
Initial – 10
Accel – 20
Decel – 20

Brakes
Brake Balance Controller F 5 / R3

Transmission
Auto - 13
 
I just notice that apply throttle oversteer is a problem, so I guess lower front rebound or higher rear bound damper value. But since rear jittering is a problem I think lower front rebound would be better. so damper to 9/1 1/1.
I think a LOT of your disagreement with and inability to grasp the commonly-held opinions on GT4 tuning are highlighted right in your words above.

Extreme values at EITHER end of the range are VERY likely to cause unpredictable handling effects. Every time I hear a sentence like "softening the front suspension makes less understeer" I automatically add the words "TO A POINT" in my head. Much too soft or much too firm can often cause the same problem for a given setting. It seems from your liking for extreme setting values that you haven't fully understood this point.
 
Thanks Der Alta.


Duke, about extreme or not. I find even at the lowest setting the Caterham spring rate is far too stiff, I consider that even at the lowest spring rate value, it still extreme (extremely stiff). And my main obstacle when using soft spring rate in GT4 is the reduced grip when tire at limit or in slipping condition (unlike other game).

About stabilizer extreme, I can't feel much rolling difference when using extreme setting in GT4, unlike when we do it in Viper Racing or GPL.

About damper extreme, I can't feel as much different behaviour in GT4 as in GT1 and Viper Racing. I believe high damper value make the tire hold the road better when not vibrate too much, so I try to use high value as much as possible and using spring to reduce vibration.

For caterham, I want much lower spring rate value and higher damper value, maybe lower stabilizer value too.

When I have more time tuning, I usually find non extreme value too.


I try to compare stock vs racing brake in caterham yesterday, the braking performance difference is really significant:
red line using stock brake, blue line using racing brake, my car setting, N3/N3 tire using BBC: 12/12



as comparation, the difference in braking performance in Lotus Elise is small:
red line using stock brake, blue line using racing brake, fully modded Elise, N3/N3 tire using BBC: 12/12



Conclution, on Caterham using N3/N3 tire, racing brake is a must. Thanks to everyone to make me notice this.
 
I try to compare stock vs racing brake in caterham yesterday, the braking performance difference is really significant:
red line using stock brake, blue line using racing brake, my car setting, N3/N3 tire using BBC: 12/12


as comparation, the difference in braking performance in Lotus Elise is small:
red line using stock brake, blue line using racing brake, fully modded Elise, N3/N3 tire using BBC: 12/12



Conclution, on Caterham using N3/N3 tire, racing brake is a must. Thanks to everyone to make me notice this.

Interesting, however on the screen-shot for the Caterham data-logger, the entry speed before braking differs for the two traces, the red trace (stock brakes) has a much higher speed at the braking point. Unfortunately I've found that this can be an issue when running brake tests.

Straightline braking from a fixed speed is one of the easiest ways of testing this (the GT4 and brakes thread has many examples of this from many different members), that way you can ensure that the initial speed is as constant as possible.

Results from those tests (and we certainly did not test every car in the game) seemed to indicate that racing brakes made little or no difference in overall straight line stopping on anything less than racing tyres.

FIDO69's First test
Lazydog's First test
Racing Brakes - Test 1
Racing Brakes - Test 2
Racing Brakes - A test with racing tyres

As you can see the testing has been quite varied, but given the total number of cars in GT4, testing each and everyone is unlikely. After all in reality if your brakes are already up to the job, then fitting bigger discs, pads, etc will not stop you quicker in a single braking situation (but it will help with brake fade, life, feel, modulation, etc).

All that said, given how cheap the racing brake upgrade is in GT4 its better to be on safe side and fit them anyway.

Regards

Scaff
 
I finally got round to attempt to improve these setups (yes, I know it's a bit late :guilty: ).

Racing Exhaust, Brake Balance Controller, Port Polish, Engine Balance, Racing Chip, FC Transmission, Triple Plate Clutch, Racing Flywheel, FC LSD, Carbon Fibre Propshaft, Supercharger, Racing Suspension, N3 Tyres, Weight Reduction Stage 3, Racing Brakes, Oil Change

Suspension
Spring Rate F 5.9 / R 6.5
Ride Height F 77 / R 74
Bound F 2 / R 3
Rebound F 2 / R 3
Camber F 2.6 / R 1.4
Toe F +1 / R -1
Stabilisers F 2 / R 3

LSD
Initial – 25
Accel – 55
Decel – 10

Brakes
Brake Balance Controller F 5 / R 4

Transmission
Tranny Tricked, Final Drive 3.600

:) Lap time was 1'20.750 (nearly a second quicker than what I managed in the faster of the two setups [Scaff's, for reference])
 
Back