[Track Tested] Fitmen info - 19" 325R 275F

[David0ff]

Nobody: "crickets"

David0ff: Here is an extreme tire/wheel/spacers combo which works for me
Wheels: Apex SM10
Tires: Indy 500
F- 19x10+ 25 & 15mm Spacer 275/35/19
R- 19x11 +44 & 10mm Spacer 325/30/19

Suspension
Oem EDC Shocks
GC front plates
GC Coils F -550 R- 750

Alignment
F- C= -3.3 T=0
R- C= -1.7 T= slight in

Height
As in pix

Does not rub on anything under compression or jumping curbs. 100% Track proven and safe.

When the front 275/35/19 is new, on wheel max lock in parking spaces there is a slight rub on the front inner fenders.

Hope this helps someone

Also as all tires are different this may not apply 100% to different brands, some are wider,narrower,squarer edged, rounder edges etc.

[Expert@ApexWheels]

Thanks for the post! 325/30-19 is quite aggressive in the rear especially with a 10mm spacer! Are your rear fenders completely untouched?

-Tom

[MJ6]

Originally Posted by Expert@ApexRaceParts

Thanks for the post! 325/30-19 is quite aggressive in the rear especially with a 10mm spacer! Are your rear fenders completely untouched? -Tom

I was going to ask the same question. With a 10mm spacer that basically equates to an ET34 offset. From what I've seen even a 305/30 profile is close to sitting flush with a 35 offset, so I can't imagine having an extra 10mm of width to deal with.

[erictrainer]

FWIW That 325/30/19 Indy500 tire he is using only has an 11.4" tread width, I say "only" because a 305/30/19 P4S has 11.5".

As OP clarified it works for this particular wheel/tire combination, your results may vary based on tire choice.

[David0ff]

Originally Posted by Expert@ApexRaceParts

Thanks for the post! 325/30-19 is quite aggressive in the rear especially with a 10mm spacer! Are your rear fenders completely untouched?

-Tom

Hi Tom,

No fenders will not get touched with this setup

I did however slightly rub my inner plastics, vertical sections though while messing around with different heights and alignment settings

If I lower the car ~1/2" more in the rear and have a lot of toe in, it will rub on curbs and bumpy track sections.

Now that I have it dialed in well it does not rub at all

Also as mentioned the tire section width is key here.

I also ran a set of ar1s at the begging of the season with the same settings and same spacers.
265F and 305R, the Indy 500s practice tires take more room Than the ar1s.
The 500s are rounder around the edges while the ar1 are squarer.

Also I don't think I can run a MPSS 325 in the rear as the tires is super square and has more contact patch than the 500

[David0ff]

In this pic I was slightly lower than what I initially posted, and had 2x the toe In I have now. This setup caused slight brushing of inner fender vertical section but not wheel

Also no spacers in the pic

[MJ6]

Originally Posted by erictrainer

FWIW That 325/30/19 Indy500 tire he is using only has an 11.4" tread width, I say "only" because a 305/30/19 P4S has 11.5".

Originally Posted by David0ff

Also as mentioned the tire section width is key here.
Also I don't think I can run a MPSS 325 in the rear as the tires is super square and has more contact patch than the 500

That makes a lot more sense now that I stop and think about it: if the Firestones run smaller than the Michelins, especially given the difference between the rounded and square contact patches, a 305 in one brand could easily be equivalent to a 325 in another.

It's like posting up your gains on a dyno: without something to compare it against, it's just numbers.

[David0ff]

Originally Posted by MJ6

That makes a lot more sense now that I stop and think about it: if the Firestones run smaller than the Michelins, especially given the difference between the rounded and square contact patches, a 305 in one brand could easily be equivalent to a 325 in another.

It's like posting up your gains on a dyno: without something to compare it against, it's just numbers.

Yup, something like that, also the reason why I gave all the data I have to make future comparisons easy.

[FriedPiston]

325/30/19 has been a proven fitment since 2014, it almost doesn't make sense why people insist on running 305/30/19; see: https://f80.bimmerpost.com/forums/sh....php?t=1012136

I'm personally running 325/30/19 PS4S on 19x11.5 ET45, -1.9 * rear camber, with absolutely no rubbing at full load (5 people in car). My setup looks like there's room for at least ~5mm clearance towards the outside fender.

275/35/19 also fits up front, but will rub slightly on the plastic liner.

[David0ff]

Originally Posted by FriedPiston

325/30/19 has been a proven fitment since 2014, it almost doesn't make sense why people insist on running 305/30/19; see: https://f80.bimmerpost.com/forums/sh....php?t=1012136

I'm personally running 325/30/19 PS4S on 19x11.5 ET45, -1.9 * rear camber, with absolutely no rubbing at full load (5 people in car). My setup looks like there's room for at least ~5mm clearance towards the outside fender.

275/35/19 also fits up front, but will rub slightly on the plastic liner.

When I originally got my GC adjustable kit the front was a 450lb spring, with the 450 at my current height even at -3camber you can rub all kinds.

Ever since I swapped the front 450 to a 550 all rubbing is gone and I like the car's behaviour better.

In early 2021 I'm supposed to receive my Voltex rear park bench, I'll see how the 750R springs handle that.

[AlterZgo]

Originally Posted by FriedPiston

325/30/19 has been a proven fitment since 2014, it almost doesn't make sense why people insist on running 305/30/19; see: https://f80.bimmerpost.com/forums/sh....php?t=1012136

I'm personally running 325/30/19 PS4S on 19x11.5 ET45, -1.9 * rear camber, with absolutely no rubbing at full load (5 people in car). My setup looks like there's room for at least ~5mm clearance towards the outside fender.

275/35/19 also fits up front, but will rub slightly on the plastic liner.

Hi. What rim width and offset is best to minimize plastic liner rub w/ 275/35/19 or 275/30/20? Thanks.

[FriedPiston]

Originally Posted by AlterZgo

Hi. What rim width and offset is best to minimize plastic liner rub w/ 275/35/19 or 275/30/20? Thanks.

See David0ff's comment above for a workaround. Don't believe offset is a factor for the slight rubbing with the liner, but more to do with the OD of 275/35/19.

I ran 19x10 ET25 275/35/19 595RS-RR in the front, and only experienced the rubbing on left hand turns.