Best approach for Performance Point Tuning

[chuyler1]

I typically race at the 450pp level but I guess the approach would be the same for higher levels. I have a few questions on optimizing a car for a given PP.

1) Do you detune an over pp car or modify an under pp car?

2) Do you over tune a car so you can use the performance limiter? If so, how much performancing limiting is desirable? 1% to maximize the restrictions? 100% to flatline your HP curve?

3) What mods do you pick first? Do certain mods give you more HP/torque per Performance Point?

4) Can you improve P/w ratio with weight reduction or is it best to leave cars their stock weight?

5) If you've matched another driver in cornering stability but he pulls on you in the straights, what can you do to get more speed? Are there suspension/ LSD changes that can improve straight line acceleration? Or is it just a factor of your car's power band?

6) In low power situations, are there suspension mods that will reduce drag? Has anyone tested top speed runs with a suspension height of -20 vs 0?

Sorry for all the questions...I am just finding myself out powered on tracks moreso than out driven...and I'm curious as to whether cars can be modded in a way that will make them superior. Example...the NSX is quicker than anything I've raced with...but why is that? ...and why can't I tune another car to be competitive against it?

 

[PawnBoy]

I typically detune an over pp car, mostly out of convenience (no menu dancing) more than anything else. And when I do detune, I simply limit the power as opposed to adding ballast or decreasing downforce.

 

[RA1D3R]

I fully tune all my cars I race online. When I limit a street car I only take away horsepower but I don't like to go below 70% of the max power because the power/weight ratio really suffers. On race cars I'll set the downforce to the default setting and then tune the horsepower because they handle just fine in the turns anyway so downforce is super important to me. I would rather run someone down on a straight than pass in a turn cause people online can't race very clean for some reason.

 

[Rotary Junkie]

It depends on the car mostly...

If it's a car that can hit the PP target fairly easily I'll usually install engine stage 3, racing exhaust, and the sports cat then choke it down a small bit to keep it at the PP cap. Usually a ~15% limiter is about perfect, the car can spend all of its time at peak power while having peak power actually be high enough to be useful.

If you massively overtune and then choke power via the limiter you wind up with less power at the same PP as removing as much stuff that doesn't raise maximum RPM as possible before choking it down... The game takes into account your maximum torque when calculating PP.

 

[chuyler1]

Ok, so you value engine stages, exhaust, and cat over ecu and intake mods?

I will try the 15% rule. Typically I mod so i use about 3% but I've been doing more experimenting lately.

So I guess the idea is to focus on the high rpm improvements. You want to cap the HP across the rpm range you use, but not so much that the line is flat across rpms you don't use.

I wish you could do side-by-side comparisons with the graph. It would make this a lot easier and intuitive.

 

[RA1D3R]

It depends on the car mostly...

If it's a car that can hit the PP target fairly easily I'll usually install engine stage 3, racing exhaust, and the sports cat then choke it down a small bit to keep it at the PP cap. Usually a ~15% limiter is about perfect, the car can spend all of its time at peak power while having peak power actually be high enough to be useful.

If you massively overtune and then choke power via the limiter you wind up with less power at the same PP as removing as much stuff that doesn't raise maximum RPM as possible before choking it down... The game takes into account your maximum torque when calculating PP.

I think i get what you are saying, but i thought it would be better to have a 500hp car tuned down to 375hp and have 375hp from lets say 6,000rpm to 8,000rpm instead of peaking 375hp at 7,500rpm.

 

[chuyler1]

I've been doing some experimenting. I think it really depends on the car, but most importantly, what the torque curve looks like to begin with.

But for most cars, The goal I think is to have a flat line for HP across the usable RPM range. If the redline is 7500rpm and when you shift the needle drops to 6200rpm, you'll want to reach peak hp at 6200rpm and have it flat across the top. It's better to have say 250hp flat over 1000rpm range than to peak at 251-252 rpm. However there is no sense in flat lining the hp below the usable range.

However, some low displacement cars don't have much torque near redline so you may want to flatline hp at a lower rpm so you can short shift and take advantage of the torque.

Two examples that run similar lap times at Trial Mountain:
'86 Toyota MR2 Supercharger [upgraded supercharger]
238HP/5300rpm - flat to redline
247ft-lb/5000rpm - decreasing to redline
I upshift at 6300 rpm to stay within the torque band. Transmission set at a much higher top speed to keep the engine running slow.

'86 Toyota MR2 [base mode with stage 3 turbo]
240HP/7200rpm
179ft-lb/6900rpm
I upshift at redline or run it in automatic and it will run the same lap times as the supercharger edition.

I have tried running the supercharger edition to redline but it is 2-3 seconds slower per lap, I have also tried not using the power reduction and instead removing parts...still slower. This was my basis for feeling slow and now that I'm running manual and shifting earlier I think I have gained 1-2 seconds per lap at Trial Mountain. I will see how it fairs online next week. For tracks where I don't want to run manual (if I'm not familiar with them) it will be better for me to run the base model since the automatic tranny shifts to keep it in the power band by default.

 

[Rotary Junkie]

I think i get what you are saying, but i thought it would be better to have a 500hp car tuned down to 375hp and have 375hp from lets say 6,000rpm to 8,000rpm instead of peaking 375hp at 7,500rpm.

It seems to more often be a difference between 370hp from 6000-8000 or 400+ from 6500-8000.

 

[Rusi]

'86 Toyota MR2 Supercharger [upgraded supercharger]
238HP/5300rpm - flat to redline
247ft-lb/5000rpm - decreasing to redline

This car is god tier and if you want a fast car with a low PP and low HP that will reck havoc then buy this and spend time tuning it.