Suspension - Track and Daily

[bmxr]

I am looking for advice from anyone that has already been through the process up upgrading a MY17+ PP car step by step as I am, for use as a daily and HPDE car. My philosophy has been to:
1) keep it as close to stock ride quality as possible
2) focus on seat time rather than cubic dollars spent
3) make small changes one at a time and learn from each of them

After about two dozen track days (over two years), I have RCE yellows, camber bolts, Apex 17x9 wheels (wheel and tire combo weigh the same as stock), and a Perrin oil cooler (30 degrees cooler oil temp across the board). Of course, I have gone through tires and brake pads, rotors, and fluid.

I have run stock tires, Firestone Indy 500's, and am now on R-S4s, so I think I am at the end of the tire upgrade route for now. I think the Hankook's are very good. I went through Carbotech XP10's and am on my second set of XP12's. Still on my first set of DBA rotors with no measurable wear. The brakes work great and do not fade, but pad wear has doubled as my lap times dropped (>10 seconds at Sebring). If there was an easy vent kit, I'd run it. I have the Porsche air deflectors.

So my next move is to try and dial out some of the understeer the car tends toward. I was thinking rear sway, but don't want to waste my money going way too hard. I want to balance the car and continue to work on lap times, not make a drift car! I am not sure what the effect of a Perrin 16mm vs 19mm would be, or the Whiteline 16mm vs 18mm I guess that first hand experience is what I am looking for. Both 16mm bars are supposed to be stiffer than stock at their lowest settings. I would have opted for camber plates first, but the tires already rub the spring perches ever so slightly (-1.7 deg camber with the Whiteline bolts).

I understand swapping to coilovers would be a shortcut, but I want to keep the stock dampers until they are actually worn out. They work really well and I cannot spend $2k on good coilovers right now.

What do you guys think?

[strat61caster]

Camber plates will add camber without reducing tire to strut clearance, I'd guess you could balance the car with some more front camber, I liked -3.2 up front with the rest of the suspension stock.

[Mr.ac]

I would take that $2k and just dump it on more track time.

[bmxr]

Originally Posted by strat61caster

Camber plates will add camber without reducing tire to strut clearance, I'd guess you could balance the car with some more front camber, I liked -3.2 up front with the rest of the suspension stock.

Gotcha. Makes sense. I got confused about that. Thanks.

[bmxr]

Originally Posted by Mr.ac

I would take that $2k and just dump it on more track time.

I agree and I’m not spending $2k. The question is about dialing out a little push for as little $ as possible.

[Nuts & Bolts Performance]

Also have a 17 PP and have tracked the car for 2yrs. This car really needs -3* camber upfront. The next best step would be camber plates.

As you, and others, have already said, seat time is next.

Do you use data at all? Harry's, Aim, etc?

Sent from my Pixel 3 using Tapatalk

[bmxr]

Originally Posted by Nuts & Bolts Performance

Also have a 17 PP and have tracked the car for 2yrs. This car really needs -3* camber upfront. The next best step would be camber plates.

As you, and others, have already said, seat time is next.

Do you use data at all? Harry's, Aim, etc?

Sent from my Pixel 3 using Tapatalk

Yes, it's pretty clear that -1.7 with just the bolts is not ideal. Not terrible (based on wear pattern and feel) but far from perfect.

I always have either Harry's or Track Addict running. Harry's gives good data via excel download and TA does a lot of things graphically better. I have not started using Race Render with it though.

[86TOYO2k17]

Originally Posted by bmxr

I am looking for advice from anyone that has already been through the process up upgrading a MY17+ PP car step by step as I am, for use as a daily and HPDE car. My philosophy has been to:
1) keep it as close to stock ride quality as possible
2) focus on seat time rather than cubic dollars spent
3) make small changes one at a time and learn from each of them

After about two dozen track days (over two years), I have RCE yellows, camber bolts, Apex 17x9 wheels (wheel and tire combo weigh the same as stock), and a Perrin oil cooler (30 degrees cooler oil temp across the board). Of course, I have gone through tires and brake pads, rotors, and fluid.

I have run stock tires, Firestone Indy 500's, and am now on R-S4s, so I think I am at the end of the tire upgrade route for now. I think the Hankook's are very good. I went through Carbotech XP10's and am on my second set of XP12's. Still on my first set of DBA rotors with no measurable wear. The brakes work great and do not fade, but pad wear has doubled as my lap times dropped (>10 seconds at Sebring). If there was an easy vent kit, I'd run it. I have the Porsche air deflectors.

So my next move is to try and dial out some of the understeer the car tends toward. I was thinking rear sway, but don't want to waste my money going way too hard. I want to balance the car and continue to work on lap times, not make a drift car! I am not sure what the effect of a Perrin 16mm vs 19mm would be, or the Whiteline 16mm vs 18mm I guess that first hand experience is what I am looking for. Both 16mm bars are supposed to be stiffer than stock at their lowest settings. I would have opted for camber plates first, but the tires already rub the spring perches ever so slightly (-1.7 deg camber with the Whiteline bolts).

I understand swapping to coilovers would be a shortcut, but I want to keep the stock dampers until they are actually worn out. They work really well and I cannot spend $2k on good coilovers right now.

What do you guys think?

did you put the camber bolt in the lower hole and the oem lower hole bolt in the top hole? I got -1.8 on RCE yellow but they said they could have done a lot more if i wanted.
What is your offset? if you are rubbing or close to it you will need camber adjustment at the top hats, but you could run up to a 4mm spacer and still have 8 1/2 turns on the lugs and that could add enough clearance for more camber from the bolts.

[TommyW]

Get -2 up front and don’t be afraid of bars as they’re adjustable.

[Racecomp Engineering]

As other's have said, you're camber challenged at the moment.

I recommend against only adding a larger rear sway bar. Sounds counter-intuitive for your problem, but a larger front sway would probably be a net improvement. In some use cases, a front and rear set works well for a car that's not on aftermarket coilovers.

- Andrew

[DarkSunrise]

I think -3* is the minimum camber you want to shoot for. Even at -2.4, I was still getting noticeably more tire wear on the outer shoulder.

[TommyW]

If you have understeer first look at your driving style such as where in the corner is it pushing? You need to review this before messing with the car. Many time just a bit slower entry or not going back to Power too soon will fix the problem

[bmxr]

Originally Posted by 86TOYO2k17

did you put the camber bolt in the lower hole and the oem lower hole bolt in the top hole? I got -1.8 on RCE yellow but they said they could have done a lot more if i wanted.

No, installed per instructions. I'm already not crazy about the eccentric so I'm choosing not to use the undersized bolt trick and I'm already out of clearance inboard anyway.

Originally Posted by 86TOYO2k17

What is your offset?

17x9 et42 Apex wheels running 245s. Firestone and Hankook both rub very slightly.

Originally Posted by 86TOYO2k17

if you are rubbing or close to it you will need camber adjustment at the top hats, but you could run up to a 4mm spacer and still have 8 1/2 turns on the lugs and that could add enough clearance for more camber from the bolts.

Agreed. The top hats are the conclusion so far. No need to spend the money on spacers if I do. I am running APR 3" wheel studs so spacers are a possibility if I ever want/need them.

[bmxr]

Thanks for the feedback, everyone!

Originally Posted by TommyW

Get -2 up front and don’t be afraid of bars as they’re adjustable.

-2 takes plates to do correctly, so I'll be shooting for more like -2.5 to -3.0.


I am not afraid of bars. More like asking if I will get the desired results with 16mm bars or 18/19mm bars. My concern is that the heavy bars are way stiffer than stock at their softest settings and conversely, the 16's might not be enough. This is with stock suspension, RCE springs and 200TW tires.

Originally Posted by Racecomp Engineering

As other's have said, you're camber challenged at the moment.

I recommend against only adding a larger rear sway bar. Sounds counter-intuitive for your problem, but a larger front sway would probably be a net improvement. In some use cases, a front and rear set works well for a car that's not on aftermarket coilovers.

- Andrew

That IS counterintuitive! It was also what my alignment guy suggested (@Apex Alignment), so I think you both might be on to something


That said, it seems like plates should clearly be step 1 at this point.

Originally Posted by TommyW

If you have understeer first look at your driving style such as where in the corner is it pushing? You need to review this before messing with the car. Many time just a bit slower entry or not going back to Power too soon will fix the problem

I am driving to account for a barely perceptible understeer, but it's not really a problem. I just want the car a little looser. If a sway bar would do that, it seems like a very easy fix. I think I am going to go with more front grip rather than less rear grip.


Thanks again everyone!