Track forum general chit chat.

[kyippee]

All this talk about wider fitments, but has anybody experienced rubbing in the rear passenger corner?

A friend of mine was running 18x10 ET25 wheels with 265/35/18 A052 and rubbed through the fender liner and damaged his fuel filler mechanisms. Car wouldn't accept anymore fuel until he replaced parts.

It looked like he was rubbing due to heavy compression at Laguna Seca's corkscrew. He had softened the suspension in the rear to combat oversteer. I looked at my own car, with 18x10 ET25 with 275/35/18 NT01 and I do have a tiny little bit of rub marks in that spot too!

[kyrix1st]

I'm contemplating tracking my E92 or E36 on Suzuka today or tomorrow since it is holiday for us this week (お盆休み）but it will be 35C~40C ambient temp.

What do you guys say?

[Bartledoo]

Originally Posted by slicer

In my experience I needed et17 to clear the KW perch. I later installed a shorter main spring to avoid all of the hassle. I highly recommend doing that.

I routinely run 10 et15 E88's on the front of my car. You could go to a 10mm spacer. However a shorter Eibach spring isn't much more expensive that a set of spacers.

Yea, I'll be doing the shorter spring conversion, but my car is stored 20-30 minutes from my apartment (and I can't really do much work at the storage facility or my apartment garage) so it would be a pain to get done and then mess with ride height afterwards, especially with only a week between track days. So, I'm just going to do it over winter break when I have more time to deal with it.

Originally Posted by kyrix1st

I'm contemplating tracking my E92 or E36 on Suzuka today or tomorrow since it is holiday for us this week (お盆休み）but it will be 35C~40C ambient temp.

What do you guys say?

Um...yes...

[admranger]

Originally Posted by SYT_Shadow

I'm never going to run a Nankang tire, it's chinese. I'm done experimenting after the R888R, what a waste of $1300 and a track weekend! I'll run RE71Rs until something else gets tested to be very superior.

10" and 275 square is a good setup, but just swap the wheels to 10.5 and keep the 275 tires and you get some extra width out of the same tires for free.
And as Apex mentions, the 10.5 gives you options of running fatter tires if the mood strikes like the 285/30 which would be properly supported by the 10.5 but not the 10.

Just give in to the dark side and put slicks on.

Happily spending other people's money on track upgrades since 1994.

[gmx]

Originally Posted by OG Shark

That's a big spacer... My M2 is also has a bit of this going on. Really had to figure out tires first (street & track, now & future) before getting the wheels. Ended up with 18 x 9.5F, 10.5R & very happy with the setup. Square was just too much of a compromise on the rear to match the front. And like you said the payoff just isn't there to try to make it work sometimes.

I did the same, compromised on a 9.5 and 10.5 stagger. Offset and relative track width makes a difference to the balance of the car too. I run offsets that make the front track/scrub radius a little bit wider however the rear is practically the same. Balance is awesome to my liking.
All the F8x and even E9x are much faster with staggered setup round here.
The F8x esp in the hands of raceteams in strict race classes... could never get the square setup working or chased their tail adjusting setup for it. It was just faster, and more stable with staggered, end of story.

Imo, square is for economy.

[dparm]

Originally Posted by CarPoor

Bring beer. That way it’s clear when you’ve had enough.

Good way to replenish carbs at the end of the day, seriously.

[admranger]

Originally Posted by gmx

I did the same, compromised on a 9.5 and 10.5 stagger. Offset and relative track width makes a difference to the balance of the car too. I run offsets that make the front track/scrub radius a little bit wider however the rear is practically the same. Balance is awesome to my liking.
All the F8x and even E9x are much faster with staggered setup round here.
The F8x esp in the hands of raceteams in strict race classes... could never get the square setup working or chased their tail adjusting setup for it. It was just faster, and more stable with staggered, end of story.

Imo, square is for economy.

I had the 9.5/10.5 setup on the E90 and it worked really well in my opinion. I wasn't running dogbone levels of power or aero or brakes or, well, anything, but it was very neutral on track. Weakest link was the driver.

[dogbone]

Originally Posted by kpewpew

All this talk about wider fitments, but has anybody experienced rubbing in the rear passenger corner?

A friend of mine was running 18x10 ET25 wheels with 265/35/18 A052 and rubbed through the fender liner and damaged his fuel filler mechanisms. Car wouldn't accept anymore fuel until he replaced parts.

It looked like he was rubbing due to heavy compression at Laguna Seca's corkscrew. He had softened the suspension in the rear to combat oversteer. I looked at my own car, with 18x10 ET25 with 275/35/18 NT01 and I do have a tiny little bit of rub marks in that spot too!

The Corkscrew loads up the driver's side, not the passenger side. At Laguna, Turn 6 does load up the passenger side quite heavily if you take it fast enough. Here I am in Turn 6.



From instances like Turn 6, I have rubbed the fuel filler, but only by running super fat rear tires like the Yokohama A005 300/650/18. I had to roll the rear fenders to fit that monster under the car.

So, if you lower your car and run a super fat rear tire, the fuel filler is ask risk of being rubbed.

I don't have any issues with the Pirelli 305/645/18. The 305 Pirelli is significantly narrower than the 300 Yoko.....ah the joys of tire sizing.

[derbo]

Originally Posted by dogbone

The Corkscrew loads up the driver's side, not the passenger side. At Laguna, Turn 6 does load up the passenger side quite heavily if you take it fast enough. Here I am in Turn 6.



From instances like Turn 6, I have rubbed the fuel filler, but only by running super fat rear tires like the Yokohama A005 300/650/18. I had to roll the rear fenders to fit that monster under the car.

So, if you lower your car and run a super fat rear tire, the fuel filler is ask risk of being rubbed.

I don't have any issues with the Pirelli 305/645/18. The 305 Pirelli is significantly narrower than the 300 Yoko.....ah the joys of tire sizing.

Turn 6 or possible Turn 9 too.



My rear fender liner on the passenger side has worn the hell out from Laguna.

[derbo]

I test fitted a friend's 18x10.5 ET 20 TE37SL with 275/35/18 Dunlop Z3. It fits my MCS with an Eibach tender spring, barely but doable.

edit: Spring is 6" 400lb + 1.75" 150lbs spring.

[kyippee]

Originally Posted by dogbone

The Corkscrew loads up the driver's side, not the passenger side. At Laguna, Turn 6 does load up the passenger side quite heavily if you take it fast enough. Here I am in Turn 6.

From instances like Turn 6, I have rubbed the fuel filler, but only by running super fat rear tires like the Yokohama A005 300/650/18. I had to roll the rear fenders to fit that monster under the car.

So, if you lower your car and run a super fat rear tire, the fuel filler is ask risk of being rubbed.

I don't have any issues with the Pirelli 305/645/18. The 305 Pirelli is significantly narrower than the 300 Yoko.....ah the joys of tire sizing.

Oh yeah good catch - probably not the corkscrew as you said. Maybe 6, I get pretty low there too

[OG Shark]

Originally Posted by gmx

I did the same, compromised on a 9.5 and 10.5 stagger. Offset and relative track width makes a difference to the balance of the car too. I run offsets that make the front track/scrub radius a little bit wider however the rear is practically the same. Balance is awesome to my liking.
All the F8x and even E9x are much faster with staggered setup round here.
The F8x esp in the hands of raceteams in strict race classes... could never get the square setup working or chased their tail adjusting setup for it. It was just faster, and more stable with staggered, end of story.

Imo, square is for economy.

Agree on the F87 it just wasn't worth trying to get anything bigger than a 9.5 to fit the front. And that barely cleared with Ohlins R&T - spring perch is on the larger size. Stagger lets me run 275F, 295R R7's & the balance/grip is excellent. Turning up the wick a bit too so think the extra rear grip will be even more helpful.

On the E9x's there - what stagger are you seeing the faster cars running? On mine being able to run 10.5 square without any issues is pretty nice. 295 square (or 285 or 305 depending on the tire) felt really balanced and had good grip. My car is going to be coming back a little leaner & meaner - that's kind of when I wonder if trying to go even wider in the rear will help. Being able to cram a 315 back there might be kind of fun If my suspension didn't allow for 10.5 in front then would definitely go staggered for a lowest time setup.

[OG Shark]

Originally Posted by dogbone

The Corkscrew loads up the driver's side, not the passenger side. At Laguna, Turn 6 does load up the passenger side quite heavily if you take it fast enough. Here I am in Turn 6.



From instances like Turn 6, I have rubbed the fuel filler, but only by running super fat rear tires like the Yokohama A005 300/650/18. I had to roll the rear fenders to fit that monster under the car.

So, if you lower your car and run a super fat rear tire, the fuel filler is ask risk of being rubbed.

I don't have any issues with the Pirelli 305/645/18. The 305 Pirelli is significantly narrower than the 300 Yoko.....ah the joys of tire sizing.

What would you say the equivalent width to the Pirelli 305/645/18 would be in the Yoko's? Going to be trying out both of those soon. Thanks!

[gmx]

Originally Posted by OG Shark

Agree on the F87 it just wasn't worth trying to get anything bigger than a 9.5 to fit the front. And that barely cleared with Ohlins R&T - spring perch is on the larger size. Stagger lets me run 275F, 295R R7's & the balance/grip is excellent. Turning up the wick a bit too so think the extra rear grip will be even more helpful.

On the E9x's there - what stagger are you seeing the faster cars running? On mine being able to run 10.5 square without any issues is pretty nice. 295 square (or 285 or 305 depending on the tire) felt really balanced and had good grip. My car is going to be coming back a little leaner & meaner - that's kind of when I wonder if trying to go even wider in the rear will help. Being able to cram a 315 back there might be kind of fun If my suspension didn't allow for 10.5 in front then would definitely go staggered for a lowest time setup.

265/285 either in Z221 or 265/295 A050. Not sure of the actual wheel width and offset, although I'd assume within the range of the tyre manufacturer.
Keep in mind, something you change/do at the front will affect the rear and vice versa.

[ThunderMoose]

Originally Posted by OG Shark

What would you say the equivalent width to the Pirelli 305/645/18 would be in the Yoko's? Going to be trying out both of those soon. Thanks!

What kind of times does your car run now at COTA?

[OG Shark]

Originally Posted by gmx

265/285 either in Z221 or 265/295 A050. Not sure of the actual wheel width and offset, although I'd assume within the range of the tyre manufacturer.
Keep in mind, something you change/do at the front will affect the rear and vice versa.

You're absolutely right - which will lead me to the if it ain't broke then don't fix it debate. If the 10.5 square is good on my new setup - do I spend the money experimenting going wider in the rear? Expensive mistake if there is no benefit

[OG Shark]

Originally Posted by ThunderMoose

What kind of times does your car run now at COTA?

Right now I think I could put down a solid 8 minute lap on the back of a flatbed. If I really got at it maybe break into the 7's.







Personal best of 2:30 at the build level before the current work started. I'm hunting a 2:24 when we get to ST/TT3 trim... I think the car will be capable - not sure about the driver

[Richbot]

Please don't put the bodywork back on, that looks awesome

[OG Shark]

Originally Posted by Richbot

Please don't put the bodywork back on, that looks awesome

Considering it... might have a hard time passing tech though

[dogbone]

Originally Posted by OG Shark

What would you say the equivalent width to the Pirelli 305/645/18 would be in the Yoko's? Going to be trying out both of those soon. Thanks!

The closest thing to Pirelli 305 in the Yoko line would be the Yoko 280/650/18. Normally, I prefer to talk about tread width, but in the case of worrying about fitting, let's look at Section width:

Pirelli DH 305/645/18: 12.3"
Yoko A005 280/650/18: 11.9"
Yoko A005 300/650/18: 13.3"

The Yoko 300 is crazy fat. Without a widebody kit, there is no way you'd get that Yoko 300 in the front. And like I said, I had to roll the rear fenders to fit the 300 on a 10.5" rim (it would be even worse on a wider rim), and then it rubbed the fuel filler when the suspension compressed.

So, in the Yoko line, given OEM body trim, I'd say 280 is your best bet.

[OG Shark]

Originally Posted by dogbone

The closest thing to Pirelli 305 in the Yoko line would be the Yoko 280/650/18. Normally, I prefer to talk about tread width, but in the case of worrying about fitting, let's look at Section width:

Pirelli DH 305/645/18: 12.3"
Yoko A005 280/650/18: 11.9"
Yoko A005 300/650/18: 13.3"

The Yoko 300 is crazy fat. Without a widebody kit, there is no way you'd get that Yoko 300 in the front. And like I said, I had to roll the rear fenders to fit the 300 on a 10.5" rim (it would be even worse on a wider rim), and then it rubbed the fuel filler when the suspension compressed.

So, in the Yoko line, given OEM body trim, I'd say 280 is your best bet.

Wow, that's quite a difference. Gotta love that standard tire measuring system - really makes it easy!

How did you feel about the height? 650 pretty accurate - or did they have they same guy that measured the width measure the height too? Hopefully its not a ~ 29" tall tire

Thanks!

[CorruptCommie]

Pardon the crappy driving and cycled out slicks