Carpokes

The new forged Apex 19" SM-10RS wheels are now on the car along with new MSPC2 tires w/fronts up to 265/35 from OEM 245/35. It will make a difference. Fresh alignment. Soul Performance OAP's are installed. (The car sounds great!) From Flat 6, M-Engineering's M-Tuner Suite ECU tuning rec today. I'll have everything ready for a day at NCM this weekend. (Gonna be hot but what the heck - gotta give the new setup a whirl.)

Looking good Tim! 265s look great on there, remind me please, how wide are your front wheels again?

It seems you are track ready!

With my PS4S tires I would aim to come off the track at 34-35 PSI on each tire. If it is was cool I would start at around 30, and if it was a hot afternoon I would start at 28 but adjust through the day as the PS4S definitely started to get greasy at 37 or so.

I assume the Cup2s are similar, curious what your experience will be. I just did some reading on the subject and some said a target of 29/33 is what they shoot for. I have not yet tried setting the fronts lower but that is on my list of things to try soon.

Hi Jeremy,

Apex fronts are 19" x 9" and rears are 19" x 11". The front 5mm spacers come off when using the Apex wheels with the 265 tires.

Had the OEM 20" wheels straightened - they have had some slight out-of-round for awhile now from a lot of track use, not bad for non-forged wheels which is apparently what Porsche puts on the GT4. Corner cutting I guess. I put Michelin Pilot Sport 4 All-Season UHP's on the OEM's for winter off-track driving. Can use the car year-round now.

For track I start at 26 to 27 at all four corners but I think I'm going to try 28 this weekend and shorten the first outing if pressures get too high. Same as you, I'll use a bit higher starting out on cold days (45° or thereabouts). The 30 lbs that you use on cool days sounds about right.

When I come off track, I wait about 10-minutes and then bleed all four down to 29. I'll do the same routine a second or third time and then I am usually set. However, because NCM is so hard on left front tires, I am going to try keeping the left front a couple of pounds higher this weekend and see how the handling is and see if wear is lessened a bit on that tire.

I never like to be higher than 33 - 34 when the tires are at their hottest, although they occasionally get a bit higher and I can tell when that happens. The lowered pressures I like to run are probably contributing to faster wear. Just a guess. Don't know what to expect this weekend if I run the left front 2 lbs higher. I may just go up 1 or 1.5 lb. for the test.

Edit: I actually like to keep my tires at 32 when hot. 33 and up is more than I prefer but that might be better all things considered.

With the heat I would sure go back to your 26 or 27 lbs start as that was my go to pressure on a Mustang Mach 1 and years back a Viper ACR. With the weather beyond warm this weekend, I would stick to your regular pressures.

I took my battery out of my GT4 because it ran out of juice and now I am waiting till labor day sale to cop a Lithium Battery

blueline wrote: Mon Aug 21, 2023 9:11 pm The new forged Apex 19" SM-10RS wheels are now on the car along with new MSPC2 tires w/fronts up to 265/35 from OEM 245/35. It will make a difference. Fresh alignment. Soul Performance OAP's are installed. (The car sounds great!) From Flat 6, M-Engineering's M-Tuner Suite ECU tuning rec today. I'll have everything ready for a day at NCM this weekend. (Gonna be hot but what the heck - gotta give the new setup a whirl.)


2021 GT4 2023-08-21 Apex wheels #1.jpg


2021 GT4 2023-08-21 Apex wheels #2.jpg

What is the purpose of the tape lines, to line up the car in the mirrors as you park?

DomTheBomb wrote: Tue Aug 22, 2023 4:12 pm I took my battery out of my GT4 because it ran out of juice and now I am waiting till labor day sale to cop a Lithium Battery

Looking forward to seeing which battery brand and model you select.

DomTheBomb wrote: Tue Aug 22, 2023 4:13 pm

blueline wrote: Mon Aug 21, 2023 9:11 pm The new forged Apex 19" SM-10RS wheels are now on the car along with new MSPC2 tires w/fronts up to 265/35 from OEM 245/35. It will make a difference. Fresh alignment. Soul Performance OAP's are installed. (The car sounds great!) From Flat 6, M-Engineering's M-Tuner Suite ECU tuning rec today. I'll have everything ready for a day at NCM this weekend. (Gonna be hot but what the heck - gotta give the new setup a whirl.)


2021 GT4 2023-08-21 Apex wheels #1.jpg


2021 GT4 2023-08-21 Apex wheels #2.jpg

What is the purpose of the tape lines, to line up the car in the mirrors as you park?

Lol. Yes, except I don't use the mirrors or backup cameras. I open my door and look down as I back up. All three garage spaces are marked for the cars they hold. No car of mine is left misaligned in its space!

The tape is a bit ragged looking - time to replace it. (Gaffer's tape - marvelous stuff.)

@DomTheBomb

By the way, welcome to Carpokes!! Glad you found the site and glad that you signed up!

Yes, please share which battery you have selected. The lithium battery selection seems like a minefield, quality is all over the board. Very tempting based on weight though.