Tune-ups effectiveness

[Patruck GT2]

Hi everyone,
after spending about 2 hours this evening trying to set up an used Corvette C4 ZR1 to have a decent handling, I've got some doubts about the tuning effectiveness.
I started with the stock config, changed the braking to 5/3 and felt some progress, made some adjustments to suspension, and my time got 1'36.4 with a good handling feeling (Trial Mountain). Then, only to be sure I had done something useful, I switched back to the default settings and I found the car actually better then the one I had made and even faster of 0.1 secs. So I remade the tune up from scratch and obtained a 1'36.1, then, after a few modifications, 1'35.8. Which to me seems quite disappointing.
So I wanted to ask to anyone, especially to people who have some experience with tune-ups, what's the gap between the car in its stock configuration (for stock I mean with the same parts but with default values, eg pro suspension left untouched) and the finished car? I'd really want to understand if a 0.5 secs gap in a 1'30 course is normal or extremely low, as I suspect.

P.S.: I know this may seem a thread that could be resolved with the "search" function, infact I used it before posting, but couldn't find anything similar. Maybe I'll post a thread about my search function effectiveness...

 

[VTiRoj]

It varies from car to car, but on average I find that after adjusting the suspension from the default settings, the laptimes improve by about 2 seconds.

Maybe the C4 Vette just has good default settings?

 

[Patruck GT2]

It varies from car to car, but on average I find that after adjusting the suspension from the default settings, the laptimes improve by about 2 seconds.

Maybe the C4 Vette just has good default settings?

That's an interesting theory. In fact, I have to say, my fastest setup has a quite similar suspension setting, although the LSD is completely different. The problem with this is that I also tried a very different LSD/Suspension setup (eg., stock dampers is 4/4, mine was 3/7, 3/8 or so, and the same amount of difference was in the rates, etc) and it proved to be just as fast as the stock one. Maybe I've taken the wrong car to tune and this hasn't significant gaps, but, considering as you say the suspension settings give 2 seconds avg, there's probably something which has to be fixed in that car...
By the way, thank you: 2 seconds seems to me a lot more "reasonable" than that feeble 1/2 seconds.

 

[JackWilson]

It varies from car to car (I think), but I would say 2-3 seconds, possibly more.
A very good transmission setup could probably shave off 6 tenths.
A good LSD setup could shave between 0.5-1.0 second.
And the suspension maybe another 0.5-1.0 second.

 

[Patruck GT2]

Forgot to say, I didn't touch the stock transmission.

 

[CyKosis1973]

Basing your impressions purely on laptimes isn't doing tuning justice.

Do the same thing again using a car that's been put together by someone who knows what they're doing (I don't count myself in that category, I'm distinctly amateur). You'll find not only are you faster, but you'll be consistently faster and the car will be far easier to drive.

I can post fast times in a crappy car, but it can be hard work. Using a properly sorted car, I can post fast laps over and over again...

 

[CSLACR]

Hi everyone,
after spending about 2 hours this evening trying to set up an used Corvette C4 ZR1 to have a decent handling, I've got some doubts about the tuning effectiveness.
I started with the stock config, changed the braking to 5/3 and felt some progress, made some adjustments to suspension, and my time got 1'36.4 with a good handling feeling (Trial Mountain). Then, only to be sure I had done something useful, I switched back to the default settings and I found the car actually better then the one I had made and even faster of 0.1 secs. So I remade the tune up from scratch and obtained a 1'36.1, then, after a few modifications, 1'35.8. Which to me seems quite disappointing.
So I wanted to ask to anyone, especially to people who have some experience with tune-ups, what's the gap between the car in its stock configuration (for stock I mean with the same parts but with default values, eg pro suspension left untouched) and the finished car? I'd really want to understand if a 0.5 secs gap in a 1'30 course is normal or extremely low, as I suspect.

P.S.: I know this may seem a thread that could be resolved with the "search" function, infact I used it before posting, but couldn't find anything similar. Maybe I'll post a thread about my search function effectiveness...

Very much depends on the track, and especially the car. Some cars are very good with default settings, and others can gains leaps and bounds.
https://www.gtplanet.net/forum/showthread.php?t=225427

A thread on the gains found, very different results from person to person, car to car, and track to track shown here.

 

[klevrah]

very good question, I personally am a drift tuner myself, and with drifting I tune to get the most control over a slippery car. I'll have a look into this myself and post a vid of it all.

 

[Patruck GT2]

Hi
After seeing your answers, confident, I found an old BMW Z3 coupè with stock settings and hard tyres and brought it to Tsukuba for some testing; first, started with a 10-lap practice with the stock settings, obtaining some 1'08.3. Then, seeing my time wasn't going to improve (at least, I believed so), I started with the tune and changed it to get a more oversteering character. I got 1'07.7 and then, after some modifications, 1'07.5 and finally 1'07.3. Having improved of one second, I was quite sure nothing was going to happen to my record time, but that wasn't the case.
After 1 (ONE) lap I had got back to the standard settings, I got a 1'06.7. Quite confused, switched to "SET C" and tried to break the car's handling derliberately using "stupid" settings, such as +40 front height and -20 rear, ultra soft springs on the rear, ultra hard on the front. I thought that had to be some slower. And it was: a disappointing 0.2 seconds slower and 0.4 faster than my tune record.
Now, I've got some theories:
- Tuning in GT5 is almost uneffective, a real hoax in which everyone seems to believe sharing tuning impressions and tuned car projects (got some doubts about this);
- This car, as well as the other one, was in its (nearly for the C4) stock condition, so the chassis hadn't really much problems coping with the standard amount of power: as a consequence, there's not much difference between the various set-ups;
- I'm not able of changing tune sets and I always used the good one, A;
- I can't properly feel and tune a car.

the last one seems to me the most likely, but in that case I must say tuning in GT5 has a lot less consequences than in GT2, for example. Adjusting a spring rate in GT2 meant the car DID change its behaviour. Adjusting spring rates, dampers, everything in GT5 and even comparing it with a deliberately dumb setup means if noone said me I couldn't even see the difference.

Is there something I don't know about switching A-B-C tunes? Please, tell me so. In any other case, I'm afraid Gt5 will lie on its shelf for a while...

 

[Motor City Hami]

I can find between 2 and 4 seconds per lap on most any car. I think I know why you are struggling to learn how to tune. Nowhere have you mentioned changing LSD settings. I believe that the LSD is the "super adjustment." If the LSD isn't right, no other suspension setting will make sense. Some tuners have found ways around the LSD's affect by using a "ride height glitch" of lowering the rear and raising the front. The LSD as the super tune showed up in GT4 and has carried into GT5.

You need to learn how to tune the LSD. There are two links in my signature below. One is to my tuning garage which contains three tuning guides; for the non-tuner, beginning tuner and advanced tuning - plus a bunch of cars that I've tuned. The second link is about LSDs - containing the current best thinking about what the LSD actually does in GT5.

I wish you luck. There is definately more speed to be found in most cars.

 

[JackWilson]

So 1st run with stock settings you get a 1:08, then with your tuning you get a 1:07, then you go back to stock settings and get a 1:06?

 

[Patruck GT2]

So 1st run with stock settings you get a 1:08, then with your tuning you get a 1:07, then you go back to stock settings and get a 1:06?

Correct. After I had made a tune, I used, in the previous versions of GT, to go back to the standard one and see if the improving was real or it simply was due to more practice. the fact is, I was quite sure I couldn't get anything under 1'07.3 then I switched to the stock to check the progress and actually found out that it effectively was only practice.

 

[Patruck GT2]

An advice for this evening: should I use low performance tyres for tuning? I'm saying, since it seems hard to me to clearly see differences between one setup and another, should I use comfort tyres in order to make handling faults appear clearer?

 

[XDesperado67]

An advice for this evening: should I use low performance tyres for tuning? I'm saying, since it seems hard to me to clearly see differences between one setup and another, should I use comfort tyres in order to make handling faults appear clearer?

Using a lower grade of tires for tuning can be helpful at times. That said you don't want to go to low as the suspension will need adjustment for great differences in tire grades. I'd suggest only droping a two or three grades from what you intend to run the car on when tuning. So if you plan to use Racing Softs then tuning with Racing Hards or Sports Soft tires could be helpful but Comfort tires would require to great a change to the suspension, LSD etc. to really be of use other than perhaps to illustrate the cars basic handling characteristics.

 

[savage_80]

LSD setting in my ruf took a 5 seconds thats the biggest improvement i have ever had from one change. But i would say normaly about 3-5 seconds fully tuned but you really have to put in a good 7 laps to get used to the car in its settings.

 

[Johnnypenso]

Every track/car/tire/pp combination will produce different results. In my opinion, Tsukuba is not a good track for tuning and testing because it basically only has two types of corners, it's short and flat and it offers lots of grip compared to most tracks. A gain of a full second at Tsukuba is in fact huge, and could be 2 or more seconds at Deep Forest or Trial Mountain or other larger tracks.

I suggest keeping at it, you'll get the hang of it eventually and you'll be surprised at the difference tuning can make. Took me some time to figure it out, and I'm still learning. It's also important to note that tuning involves the combination of suspension, LSD/Drivetrain and Transmission and gains can be had in all three areas. They should also be tuned together for maximum gain.

 

[Patruck GT2]

I suggest keeping at it, you'll get the hang of it eventually and you'll be surprised at the difference tuning can make. Took me some time to figure it out, and I'm still learning. It's also important to note that tuning involves the combination of suspension, LSD/Drivetrain and Transmission and gains can be had in all three areas. They should also be tuned together for maximum gain.

I'm keeping. Just re-downloaded the Scaff guide I had taken some basic notes from and I'm going to study it over again. My results sound like I need to adopt a more "scientific" method. During these days I'll figure out the suspension thing and then I'll try LSD.

I'll try Trial Mountain instead of Tsukuba, as well. The good thing of Tsukuba was that you had the last corner which seemed to be useful to understand how the car did perform in the central section of a corner.

 

[Motor City Hami]

During these days I'll figure out the suspension thing and then I'll try LSD.

I would do that in the opposite order. Read just the opening post of the LSD guide summary thread in my signature below. It includes Scaffs LSD information. The LSD holds so much power in GT5. Everything works together as JP said, but you'll go nowhere without getting the LSD in the ballpark.

 

[esoxhntr]

...and here's the ballpark for RWD (i don't have much experience with fwd or awd) cars in the 450p-550pp range using a DS3.

Init - 8-12
Accell - 18-25
Decel - 5 to 8

there will always be exceptions.

 

[CSLACR]

So 1st run with stock settings you get a 1:08, then with your tuning you get a 1:07, then you go back to stock settings and get a 1:06?

Correct. After I had made a tune, I used, in the previous versions of GT, to go back to the standard one and see if the improving was real or it simply was due to more practice. the fact is, I was quite sure I couldn't get anything under 1'07.3 then I switched to the stock to check the progress and actually found out that it effectively was only practice.

All this "proves" is that one of two things may have happened.
1. You improved as you drove, and the tuning had no great effect, because you're still learning the track.
1. You tuned poorly, hence it didn't improve the car.

You can never "prove" tuning doesn't help improve lap times, you can only prove that what you tried didn't help you.

I linked a thread to show you gains people have made. Quite frankly, this is a second thread (3rd technically) about exactly the same thing.

 

[ADRENALIN-EDGE]

Im not home untill late tonight but am willing to test my zr1 on the same track. if my laptime is faster than yours i will post my tune friday around this time. only if u reply.

 

[Poontanir]

As was said earlier and I'm going to re-word; a good driver can give you a hot lap, a good tuner can give you a race of hot laps. A good tune makes the game a cake walk. The hard thing is when you make a spring change you may need to make a damper, ARB or camber change. It used to take me hours to get to a good baseline, then I found some helpful equations here, made a calculator and added some missing equations. Having built the calculator I find a baseline without driving and immediately start fine tuning (that is unless I picked a bad baseline). The info we get from GT5 is minimal making it hard to tune the cars, a race team has large amounts of data on every track they visit and the car they're running. By having all this info the team can have a solid baseline that many would kill to have as a final tune. Being a numbers guy I love the calculator I built (do you think I'm biased). However you go about tuning if you make changes that work against each other you will never make progress.