Tire recommendation for HPDE

[tosha]

Province regulations and pebble-throwing aside, it's a look that you can actually get used to because it is right for the car's and your hardest driving. Just sayin' . . . scroll my sig pic down a bit).


Norm

Airborne pebble is what I'm mostly concerned about. It's very easy to unexpectedly end up on a gravel road in Ontario unfortunately

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[tosha]

Meh. The S550 chassis needs the front 305 tire to turn well on track. I’d be ok with a 305/315 or something but 10mm isn’t worth loosing the ability to rotate IMHO.

The 1LE Camaro doesn’t have as much room in the front wheel wells to shove a 305 in there without tearing up the fender liners, which might have more to do with why you don’t see more 305s on the front of those cars.

The issues with a blower on track aren’t so much about controlling the power (that part is just good fun), but what it actually takes to cool the extra heat generated. Its no fun to get 2 good laps and then have to pit or drive like a granny to cool it back into reasonable temp range. Also you’d need a lot of brakes to shed the extra speed. Take a look at the GT500 brake calipers and rotors.

285/35 (or 275/35) if you want to get your money’s worth, but I’d want 305 square myself for the track. 305 is definitely overkill for the street.

I wouldn’t choose smaller front tires to control oversteer personally. I would select swaybars to control oversteer tho.

Hmm.. seems that I need 6 wheels at the end of day

Maybe that's the way to go and I can get rid of stock pp1 wheels then

I was thinking about heat factor and it's a valid concern. In Canada though, you have a good selection of events that run at cooler times of year. I have no interest in drag racing and autocross is not on my list in this car, so it would be purely occasional track weekends. I might still need to add more engine cooling and rear diff would be an issue for sure.

 

[NightmareMoon]

Hmm.. seems that I need 6 wheels at the end of day

Maybe that's the way to go and I can get rid of stock pp1 wheels then

I was thinking about heat factor and it's a valid concern. In Canada though, you have a good selection of events that run at cooler times of year. I have no interest in drag racing and autocross is not on my list in this car, so it would be purely occasional track weekends. I might still need to add more engine cooling and rear diff would be an issue for sure.

If you really want to track a car with FI on it, find someone whos' doing that and talk to them about what it takes. It takes a lot.

The stock cooling system is engineered to cool ~400hp to the wheels, not 600, 800 or more. If you increase power 150%, you need to shed about that much additional excess heat. Its not so easy to take a system designed for one job to do 150% of that job, let alone 200% or more.

I've done that on other non-mustang cars. Doubled the power and then my track days got a lot less fun, because I always had one eye on the temperature gauge and was always concerned about getting the engine too hot and doing damage to something. Kind of spoiled some of the fun. I eventually put enough effort into radiators, oil coolers, and other cooling mods to get the car to survive 15 minutes on track, and yeah the power is a real hoot, but most sane track rats don't drive blown cars unless the car was engineered at the factory that way.

 

[luc]

Usually narrower tires in front is a manufacturer decision to promote understeer ( on a front engine car) because understeer is safer for the average driver
Here is my experience with my 17 gtpp1 track car:
1/ Stock was awful, way to soft suspension, a ton of understeer and not much traction with the factory tires
2/ installed ford PP2, ford racing suspension, 19x10,et 35 wheels with nt01 285/35/19 tires, a world of difference but still too much understeer and not enough grip
3/ apex 18x11 et 52 wheels with ford racing hubs and 25mm spacers and 305/35/18 squared nt01 and ford racing camber plate with -2.8 camber….. now it’s a real track car
Amazing what more camber and 20mm tires can do
Was at Laguna yesterday and schooled quite a few Porsche on what a well setup and driven S550 can do…
I also added a huge Harrop oil cooler

 

[tosha]

If you really want to track a car with FI on it, find someone whos' doing that and talk to them about what it takes. It takes a lot.

The stock cooling system is engineered to cool ~400hp to the wheels, not 600, 800 or more. If you increase power 150%, you need to shed about that much additional excess heat. Its not so easy to take a system designed for one job to do 150% of that job, let alone 200% or more.

I've done that on other non-mustang cars. Doubled the power and then my track days got a lot less fun, because I always had one eye on the temperature gauge and was always concerned about getting the engine too hot and doing damage to something. Kind of spoiled some of the fun. I eventually put enough effort into radiators, oil coolers, and other cooling mods to get the car to survive 15 minutes on track, and yeah the power is a real hoot, but most sane track rats don't drive blown cars unless the car was engineered at the factory that way.

Thanks, appreciate the insights and will definitely think about it more. Maybe I will end up with a different car for tracking, if I start doing this seriously. This one was never intended for this to be honest and was spec'd to be a nice grand tourer. There is no good reason to pay for leather seats, premium interior and electronic dashboard in a track focused car, but the track bug bites hard...

 

[Steve68Cougar]

I've have my SC'd car on the track one time so far and it was in 95 degree weather. It was made obvious to me that my driving style is not nearly as aggressive as it could be. It dropped a little power (I've got the 700hp Roush tune), but it was still way faster than anything I've driven. I just got back from the alignment shop after putting 305/30-19s on the car. Right now it's set at 2.6 degrees of negative camber and 0 toe on the front. I haven't noticed any rubbing, but so far I haven't had an opportunity to push it hard. I'll be autocrossing it this weekend, so I'll find out if the 2.6 degrees is enough. Fortunately the camber is easy to set, and before they set it I was at 3.7 degrees, so I know I can get to wherever I need. One interesting thing, the car was still set in the rear as it came from Roush. It showed 2 degrees of negative camber from the factory (and slight toe in). I'll be at Gingerman for the Mohawk Track Experience in August, and that should give me a better idea of where I am with the cooling system. I'm thinking I'll eventually put most or all of the Roush cooling package on the car (not too sure about cutting vents in the side of the car, though). Autocrossing doesn't seem to heat up the car enough to be a problem. I typically do the little trick with the brake and speed control + button to help cool the car between runs.

BTW, the tires are Falken RT660s.

 

[TundraOnKings]

I’ve only tracked my new 2020 Magneride PP1 A10 once, and overheated the engine oil, trans, and rear diff.
I can’t imagine trying to cool a Forced Induction setup with 200+ more HP.

I’m waiting on the Steeda dual rate springs, have their camber plates, and looking for wheel/tire setup.
The 19” Apex SM-10’s are 3 months out. But sounds like the 18” Apex’s are the best for track? Is there an 18” setup where I don’t need hubs or spacers to run 305 wide?

 

[TeeLew]

I'm sure that similar discussions have gone on at Ford.

Still, it does seem that 20 mm stagger is a good place to stop where handling performance has at least equal weight with appearance. For forced induction front engine/RWD cars, anyway.

Norm

If we're starting from stratch, the total amount of tire needs(among other things) to be a function of grip and rolling resistance requirements. For handling, the F/R tire width debate needs to begin with a look at the weight distribution of the car. The tire width distribution needs to reflect the weight distribution of the car with a nod toward providing a certain amount of inherent understeer during limit conditions. Rear, mid and front engine cars will all end up different splits due to their different weight distributions. If we're putting wings on the car, they'll end up with different downforce distributions for the same reason.

So the 20mm tire stagger that makes sense on a 700 HP ZL1 would be a disaster to drive on a 700 HP Porsche GT2.

 

[shogun32]

Is there an 18” setup where I don’t need hubs or spacers to run 305 wide?

none that I've seen. In 19" I have the MRR M600/SVE GT7 with et24 and et52. There might be a few left on ebay but it's slim pickings.

It's gouche but you can run something like the ESR RF2 19x10.5 et30 or et22 up front and some other brand's 19x11 et50 on back. Their 18x10.5 *might* fit over the 6-pots if you can work with an outfit that will let you test fit.

 

[NightmareMoon]

I’ve only tracked my new 2020 Magneride PP1 A10 once, and overheated the engine oil, trans, and rear diff.
I can’t imagine trying to cool a Forced Induction setup with 200+ more HP.

I’m waiting on the Steeda dual rate springs, have their camber plates, and looking for wheel/tire setup.
The 19” Apex SM-10’s are 3 months out. But sounds like the 18” Apex’s are the best for track? Is there an 18” setup where I don’t need hubs or spacers to run 305 wide?

19” or 18” thr only thing that matters for spacers or not is your wheel width and the offset. Apex does offer a no-spacer fir for the 19”, I haven’t checked if that front wheel offset is also offerent in the 18” size. Either way me and most others running 11” wide wheels with 305s square are using slip on one piece spacers over replacement extended studs. Its kind of the easiest. Ost flexible way to do it and the one time cost isn’t that bad compared to the costs of good tires and/or wheels. If you step down to some more affordable SVE 11” wheels you miggt be able to get the studs and spacers and wheels for the same cost as the SM-10s

18” tire selection (for wide tires) offers different and generally slightly fewer options than 19” so stepping down in wheel diameter might bite you.

 

[TeeLew]

If you want to run racing tires instead of street oriented tires, then 18's are pretty much a necessity, but for autocross, you can find a lot of good options on 19's. The exception is Yokohama, which has a great selection of 18's, but damned few 19" tires.

 

[TundraOnKings]

19” or 18” thr only thing that matters for spacers or not is your wheel width and the offset. Apex does offer a no-spacer fir for the 19”, I haven’t checked if that front wheel offset is also offerent in the 18” size. Either way me and most others running 11” wide wheels with 305s square are using slip on one piece spacers over replacement extended studs. Its kind of the easiest. Ost flexible way to do it and the one time cost isn’t that bad compared to the costs of good tires and/or wheels. If you step down to some more affordable SVE 11” wheels you miggt be able to get the studs and spacers and wheels for the same cost as the SM-10s

18” tire selection (for wide tires) offers different and generally slightly fewer options than 19” so stepping down in wheel diameter might bite you.

Yeah, I was trying to stay away from swapping out the studs. I don’t mind running spacers. When moving to longer studs, is it all of them (F/R) or just front?
Any issue with moving back to say, a 20” wheel? I’d guess if they had center caps, the center caps won’t fit.
I do want the best track performance out of a tire (HPDE). I was pricing the Apex SM-10’s with 285/35/19 PS4’s - invoice was $3400 damnit lol. The PS4’s sure seemed expensive. Was hoping to find a good tire (pretty much track only) for cheaper. Guess that would determine what wheel to go with.
And I don’t want to go Hoosiers, because I do want the ability to drive it on Friday’s around town :-)

 

[luc]

Yeah, I was trying to stay away from swapping out the studs. I don’t mind running spacers. When moving to longer studs, is it all of them (F/R) or just front?
Any issue with moving back to say, a 20” wheel? I’d guess if they had center caps, the center caps won’t fit.
I do want the best track performance out of a tire (HPDE). I was pricing the Apex SM-10’s with 285/35/19 PS4’s - invoice was $3400 damnit lol. The PS4’s sure seemed expensive. Was hoping to find a good tire (pretty much track only) for cheaper. Guess that would determine what wheel to go with.
And I don’t want to go Hoosiers, because I do want the ability to drive it on Friday’s around town :-)

Nt01 fits that description.
Also the 305/18 is almost $100 cheaper than the 305/19

 

[Steve68Cougar]

Yeah, I was trying to stay away from swapping out the studs. I don’t mind running spacers. When moving to longer studs, is it all of them (F/R) or just front?
Any issue with moving back to say, a 20” wheel? I’d guess if they had center caps, the center caps won’t fit.
I do want the best track performance out of a tire (HPDE). I was pricing the Apex SM-10’s with 285/35/19 PS4’s - invoice was $3400 damnit lol. The PS4’s sure seemed expensive. Was hoping to find a good tire (pretty much track only) for cheaper. Guess that would determine what wheel to go with.
And I don’t want to go Hoosiers, because I do want the ability to drive it on Friday’s around town :-)

I just did the stud swap last week. It's a matter of getting the brakes out of the way, getting them pressed out and new ones in. I used a ball joint removal tool ( https://www.harborfreight.com/3-4-q...r-99849.html?_br_psugg_q=ball+joint+separator ) to remove them. I just had to remove a bit of material for head clearance. For pulling the new ones in, just get a 14mm nut from the hardware store along with some spacers and crank down until they're seated (I used an impact). It really wasn't very difficult. I still have my 20" Roush wheels that will go back on when I'm going long distances. The only difference in fit is that the narrower wheels (mine are 9.5" wide) don't need the 25mm spacer, and the extended studs require open ended lug nuts on the front. No reason to change anything on the rear. Several of the 200tw tires are actually cheaper than the PS4s.

 

[TeeLew]

I did the wheel stud change on the front for function. I changed them on the rear so they'd all be the same. If you're using ARP's, there are two lengths. The longer is for use with spacers on the front & shorter is without spacers for the rear. It bugged me having the two ends of the car different and it's not that big of a job.

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