[Nugget]

ET45 would be better on the back and et35 would be better on the front.
If you don't mind running a 5-10mm spacer on the front my suggestion would be get et45 all around, use up the standard tyres then get 245s all around.

[greenpeter]

So you're saying, 8.5 et45 with 5mm spacers on the front won't rub?
And without the 5mm spacer? will it touch the suspension? (Currently I have the adaptive m)

[ovekvam]

Notice that 5-10 mm spacers can cause centering issues. Very thin spacers will allow the wheels to be centered on the hub, and thick spacers will have a dedicated centering lip on the spacer.

[Nugget]

Good point about spacers, a 5mm spacer will just be a slip on on but should leave enough of the hub lip to be hubcentric. If you go with 10mm get a good quality hubcentric set.

Originally Posted by greenpeter

So you're saying, 8.5 et45 with 5mm spacers on the front won't rub?
And without the 5mm spacer? will it touch the suspension? (Currently I have the adaptive m)

et45 may rub on the suspension, et40(5mm spacer) shouldn't, et35 (10mm spacer) won't.

[BillyO]

G'day all!

I'm about to be a proud owner of an M140i and coming out of 2 previous Golf R's which I would track about 3-4 times year and use the car as a daily drive for work.

Mods will be kept basic for a while but first up im thinking;

- dedicated track wheesl in 18in, maily due to available tyre options, thinking R888, AD08, RS3/4 etc depending on availability and price.
- dedicated set of brake rotors and pads which i will change out when fitting wheels. High temp fluid as well of course.

I've been reading this and other threads trying to get my head around the best set wheel size combo for the second set of dedicated track wheels with the aim of fitting wider tyres all round.

There seems to be front tyre width limitations and talk of using spacers which i dont want to use. The wheels im getting come in 18x8.5 & 18x9.5, front and rear respectively. I can get the offset to my liking which is ideal so that i dont have to use spacers.

I would like 235/40/18 up front & options of 255/265/275/35/18 on the rear.

Question is, what offsets should i be aiming for to clear the struts and guards and not rub without the use of spacers?

[ovekvam]

I think the F20 understeers with 225/245 tyres, and works better with 225/225. Going to 265 or 275 in the rear is too much, in my opinion. I also think that the stock brake rotors will work fine, changing only the brake pads for track duty.

I think the stock BMW front wheel offset will work for 235 tyres. In the rear, you will probably have to use a slightly lower offset than stock, but I am not sure how much.

[BillyO]

After watching this I’m thinking 235f & 255r then try a 265r next time round.
I would go a 245f if there’s enough room. Test driver notes that the wider tyres have a better ability to deal with heat too.

I used to run a 225 square set up on my Golf R and I know that was limiting grip.

As for brakes, I just can’t see stock rotors being up for the abuse I’ll give them them and last thing I want is to leave a track day with stuffed rotors or suffer more fade than necessary on the day. Brakes Direct in Qld offer DBA T3 4000 rotors for $180 each which is a bargain really. Seems there aren’t too many after market options for a reasonable price.

[Nugget]

Originally Posted by BillyO

Question is, what offsets should i be aiming for to clear the struts and guards and not rub without the use of spacers?

18x8.5 et35-40 on the front
18x9.5 et50 on the rear.

My current set up
18x8.5 et35 with 225/40 AD08R (probably should have gone 235)
18x9 et52 with 255/35 AD08R

Pic below.

Ad08R run pretty big, next tyres I will probably get something less track focused and go 245/265.


I have run 9.5et50 on the rear previously and that was pretty bang on, not much room to go further in or out.
I really only changed because I wanted these specific wheels.

[BillyO]

Originally Posted by Nugget

18x8.5 et35-40 on the front
18x9.5 et50 on the rear.

My current set up
18x8.5 et35 with 225/40 AD08R (probably should have gone 235)
18x9 et52 with 255/35 AD08R

Pic below.

Ad08R run pretty big, next tyres I will probably get something less track focused and go 245/265.


I have run 9.5et50 on the rear previously and that was pretty bang on, not much room to go further in or out.
I really only changed because I wanted these specific wheels.

Cheers thanks Nugget. Your wheels are similar to ones I had on an S14. I’m actually looking at dished wheels too. Old school Simmons FR1’s.

Is that a harness you’re wearing too?

[ovekvam]

Originally Posted by BillyO

After watching this I’m thinking 235f & 255r then try a 265r next time round.
I would go a 245f if there’s enough room. Test driver notes that the wider tyres have a better ability to deal with heat too.

I think 245 up front is possible, unless you pick a wide tyre model. I heard one guy needed to roll the fenders a bit to fit them on his car, but the offset was probably not perfect in his case.

[BillyO]

I prefer not to roll the guards so will give 235’s a go first and if there’s room I’ll try 245 after that.

[Nugget]

Originally Posted by BillyO

Cheers thanks Nugget. Your wheels are similar to ones I had on an S14. I’m actually looking at dished wheels too. Old school Simmons FR1’s.

Is that a harness you’re wearing too?

I am partial to Japanese wheels, those are Advan GTs, previous set was Volk TE37s.

And yes that is a Schroth Quick Fit Pro.
Holds you in the seat and means I can use my HANs device.

There is some more info here
http://f87.bimmerpost.com/forums/sho...5#post23115055

[BillyO]

Originally Posted by Nugget

I am partial to Japanese wheels, those are Advan GTs, previous set was Volk TE37s.

And yes that is a Schroth Quick Fit Pro.
Holds you in the seat and means I can use my HANs device.

There is some more info here
http://f87.bimmerpost.com/forums/sho...5#post23115055

I actually have one of those Schroth units but for a Golf. Will definetly get one again!

[ovekvam]

Originally Posted by BillyO

I actually have one of those Schroth units but for a Golf. Will definetly get one again!

I also had a Schroth Quickfit harness in an E36 323ti. While it is nice for keeping you in the seat, I am slightly worried about what would happen if you have a rollover, and the ceiling caves in. The F20/21 surely has a more robust roof than the E36 Compact, but maybe it is still a bit risky without a roll cage?

I ended up selling the harness, and driving without it in the newer BMWs I have had. It is not hard to stay in the sport seats anyway, as I currently don't have R-compound tyres.

[BillyO]

I guess that’s what the helmet and air bags are for...

Rollover is also much less likely to happen than other incidents whereby the harness would work better than a belt and I’m confident they’re better than they are worse overall.

It’s a street car being thrown around the track and not a dedicated track car.

Also hate being thrown around the seat in corners.

[ovekvam]

Originally Posted by BillyO

I guess that’s what the helmet and air bags are for...

Rollover is also much less likely to happen than other incidents whereby the harness would work better than a belt and I’m confident they’re better than they are worse overall.

It’s a street car being thrown around the track and not a dedicated track car.

Also hate being thrown around the seat in corners.

Helmet and air bags will not protect your neck when your upper body is locked in position as the ceiling caves in. I agree that it is rather unlikely, but maybe worth worrying about.

The Schroth harness is superior when it comes to holding you in the seat during spirited driving, but I am but I am not convinced that it works better in a crash. After all, the stock seat belt has pyro tighteners and stretch links to stop you with the right force.

Would you use the Schroth harness in public traffic? And if not, why?

My personal preference is to keep the track day setup as close to street driving as possible, with brakes, tyres, pressures, seat belts, driving position and so on. This way the practice is more relevant. Besides, keeping the car consistent, will fine tune your reflexes and instincts to a higher level.

(I have also been down the modification road earlier, aiming for more of a race car, with bucket seat and missing interior.)

[BillyO]

I’m no seatbelt engineer so not worth arguing. Either way we’re speculating about an unlikely scenario.
No I wouldn’t wear a harness on the street as they restrict movement. I like to move around and be able to reach for things and being 6’3 with long legs, I can barely reach the volume knob when strapped into my Golf.
Harness’ are also fixed so it’s likely going to sit too tight for daily driving or too loose to be completely effective. If they made the with retractable straps that work just like a seatbelt then maybe I’d consider it...

[Nugget]

This harness discussion has been had 1000s of times. I'm not going to make recommendations on safety equipment and encourage everyone to do their own throrough research.

I made the decision to use one so I could wear a HANS device.

My E36 is set up properly with fixed back seats and cage.