[glamcem]

looking forward to hearing your feedback

[tx6g1le]

Full report after my Track Night on 305/30r20 square:

Cons first:
1. As you can imagine shoving an extra amount of tire under the wheel wells was an issue. The shop I took it too recommended 10mm spacers, which did not come in in time. I overnighted 5 mm spacers and clearance ended up being very close to the lower spring perch. The first hard braking zone at 115+ trimmed the innermost side of the tire about 1/2 mm, clearance solved! I kept an eye on it and managed to run all 3, 20 minute sessions without issue.
2. Also, on the highway cruise to the track the car tends to wallow on the highway without any reason. Not to the point it scares you, but it makes you pay attention.
3. I ran with my PSSs and it felt neutral, I'm thinking with real rubber like the Sport Cup 2s in my garage you might get quite a bit of oversteer.

Pros:
1. I did not crash! The understeer I felt initially at the AutoX was completely based on the pea gravel lot we ran on. I was consistently turning in with more force and exiting faster than almost every car out there. The super-light prepped Miatas and S2000s couldn't even keep up in the bends. In fact, at the beginning of the highlights on my video, a 2-door ATS-V on R888s couldn't lose me in the most technical portion of the track.

Overall impressions - Was this better than the OEM tire set up? IMHO, I don't think it was a significant change. In fact I'm ordering a 285/30 front set of Cups 2s to run on the next track day to see if really good rubber will offset the square set up.

Hope you guys enjoy the video!

[7stringtheory]

Something I am going to try once I wear out the OEM tires that someone mentioned on another thread is running a square 295/30/20 setup on the OEM 1LE wheels. He says they fit with no issues whatsoever and do not require spacers. If you run the wheel calc it shows that on the OEM wheels up front, replacing the 285/30/20 with a 295/30/20 instead of a 305/30/20 gives you 5mm more clearance on the suspension. Basically negating your 5 mm spacer that you used, and meaning that using a 5mm spacer (if you felt it was needed) would put you at the OEM suspension clearance.

[7stringtheory]

Probably going to get the RE71Rs in 295/30/20 for the square setup.

[7stringtheory]

Also I remember glamcem saying that he would not be comfortable driving anything above a 5mm spacer on a track, so be careful if you choose to go that route.

Edit : one more thing is that according to the response that I got from John an engineer that apparently helped to design our cars, using a square setup on a car that is a designed from factory as staggered, while may give you performance (cornering) benefits at the cost of some steering stability, it would likely requiring altering the suspension setup from the factory recommended specs to optimize for the square setup.

[tx6g1le]

Originally Posted by 7stringtheory

If you run the wheel calc it shows that on the OEM wheels up front, replacing the 285/30/20 with a 295/30/20 instead of a 305/30/20 gives you 5mm more clearance on the suspension. Basically negating your 5 mm spacer that you used, and meaning that using a 5mm spacer (if you felt it was needed) would put you at the OEM suspension clearance.

Rapid fire man! Thank you for all the input too!

The problem with the 305/30r20 size on the front isn't the width it's the height. Once put on, they are overall taller than the OEM 285/30 so it rubs on the bottom spring perch. The 5mm spacer is really just to push it away from the perch so it doesn't rub (which it did under heavy braking). I still need some room obviously for it to work efficiently.

Originally Posted by 7stringtheory

Probably going to get the RE71Rs in 295/30/20 for the square setup.

I like this idea and I think it's a good overall setup. If you're interested I'll have my 10mm spacers coming in and I can give you my 5mm to ensure clearance.

Originally Posted by 7stringtheory

Also I remember glamcem saying that he would not be comfortable driving anything above a 5mm spacer on a track, so be careful if you choose to go that route.

I 100% agree it's not ideal to run a spacer if you can get around it and I'm still on the fence about it. BUT, I had custom hubcentric ones made and ordered the custom, longer studs from ARP. Worse comes to worst, I'll end up selling them on here or to a local AutoXer who wants to run a wider setup on their gen5 or gen6.

[tx6g1le]

Just for reference here's a shot before the 5mm spacer.

[AZ_1LE]

FWIW, I don't think it's ideal running a 305 on a 10" wheel. PSS's like to be stretched a little bit, and that's probably where you getting that "wallowing" feeling from.

[7stringtheory]

Originally Posted by tx6g1le

Rapid fire man! Thank you for all the input too!

The problem with the 305/30r20 size on the front isn't the width it's the height. Once put on, they are overall taller than the OEM 285/30 so it rubs on the bottom spring perch. The 5mm spacer is really just to push it away from the perch so it doesn't rub (which it did under heavy braking). I still need some room obviously for it to work efficiently.



I like this idea and I think it's a good overall setup. If you're interested I'll have my 10mm spacers coming in and I can give you my 5mm to ensure clearance.



I 100% agree it's not ideal to run a spacer if you can get around it and I'm still on the fence about it. BUT, I had custom hubcentric ones made and ordered the custom, longer studs from ARP. Worse comes to worst, I'll end up selling them on here or to a local AutoXer who wants to run a wider setup on their gen5 or gen6.

Well going from a 305/30/20 to a 295/30/20 gives you 5mm clearance away from the suspension but also gives you 3mm of vertical clearance as well.

305 : 6mm vertical from OEM and 10mm towards suspension from OEM
295 : 3mm vertical from OEM and 5mm towards suspension from OEM

if the 5mm spacer barely rubbed on your setup with 305s I imagine based on these numbers that the 295s would not cause any issues whatsoever, and possibly fit better on the 10" wheel.

[7stringtheory]

Also the importance of the comment I paraphrased from the engineer, (which I posted in another thread but I can post here if you want) is that in order to get the most out of your square setup you are going to need to alter your suspension. The way you will do this is by obtaining a tire pyrometer, going out on the track running hot laps, then pitting and immediately checking your temps in different parts of the tire. I'm not 100% of exactly how to apply the results from the pyrometer just yet but I know it can be a good basis for determining optimal tire pressures and suspension adjustments.

Point is I dont think you can really just switch to the staggered cup 2 setup and compare it with your experience with the square setup and make any useful determination as to which is better because you would need to finely tune your square setup first to really see what its capable of.

[glamcem]

Originally Posted by tx6g1le

I 100% agree it's not ideal to run a spacer if you can get around it and I'm still on the fence about it. BUT, I had custom hubcentric ones made and ordered the custom, longer studs from ARP. Worse comes to worst, I'll end up selling them on here or to a local AutoXer who wants to run a wider setup on their gen5 or gen6.

If you're already getting longer studs and hub centric rings, why don't you consider getting the Apex wheels that I got and put some 19s on them and more importantly save ~9lbs on each corner during the process? They're also dirt cheap and will probably save thousands of dollar down the road. I always calculate the long term consumable costs

Also may I learn where you got those custom/hub centric rings from? I can send you a PM this also. I like the idea of hub centric rings so that I can use with aftermarket wheels. Do you recall the specs of those hubcentric side?

Oh and have you ever consider other alternatives to the Cup 2 tires? my friend who used them on his Gen 5 1LE hated them and it gave him all sorts of issues. Same reported with a few other local track guys. They're very expensive also not sure why

[tx6g1le]

Originally Posted by glamcem

If you're already getting longer studs and hub centric rings, why don't you consider getting the Apex wheels that I got and put some 19s on them and more importantly save ~9lbs on each corner during the process? They're also dirt cheap and will probably save thousands of dollar down the road. I always calculate the long term consumable costs

Also may I learn where you got those custom/hub centric rings from? I can send you a PM this also. I like the idea of hub centric rings so that I can use with aftermarket wheels. Do you recall the specs of those hubcentric side?

Oh and have you ever consider other alternatives to the Cup 2 tires? my friend who used them on his Gen 5 1LE hated them and it gave him all sorts of issues. Same reported with a few other local track guys. They're very expensive also not sure why

I actually ordered a set of 19" FF01s from HRE around Christmas. I decided against the set because they didn't match the OEM width and wanted to run A street in AutoX this year. But your Apex wheels look great and I know they're a viable option.

The spacers are on order from a local track oriented shop in Ft. Worth and I can find out where they're being made at and get back with you ASAP.

I have run the gamut on tires over the past few years. My particular favorite has been the RE-71s. The reason for the Sport Cups is honestly... I've never tried them before. Several of the local Corvette and GTR guys swear by them so I decided why not try them

[booyaa56]

305 Square setup RE-71 on FS01 MRR wheels works just fine

[glamcem]

Originally Posted by tx6g1le

I actually ordered a set of 19" FF01s from HRE around Christmas. I decided against the set because they didn't match the OEM width and wanted to run A street in AutoX this year. But your Apex wheels look great and I know they're a viable option.

The spacers are on order from a local track oriented shop in Ft. Worth and I can find out where they're being made at and get back with you ASAP.

I have run the gamut on tires over the past few years. My particular favorite has been the RE-71s. The reason for the Sport Cups is honestly... I've never tried them before. Several of the local Corvette and GTR guys swear by them so I decided why not try them

The peak performance of the two should be really similar but of course the Cup 2 should be more consistent and less prone to overheating. They don't last that much though so the cost is very big compared to say for instance NT01s or R888s. NT01s will definitely a lot better in terms of longevity you can simply run them till the cords and they provide the same grip (in fact even better just before you cord them lol)

If you need to run OEM width (10/11") you probably don't even need a spacer and so longer studs upfront because of the offsets.

Originally Posted by booyaa56

305 Square setup RE-71 on FS01 MRR wheels works just fine

wheel specs?