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  • Pushing the E36 Tire Limits...

    A friend of mine has an E46 M3 with some wider wheels and tires, that I wanted to try to fit on the E36 for a little more grip.

    The rear will need a touch more fender rolling and a slight bumper trim, but even under ~2" of compression it wasn't rubbing on anything badly enough that I wouldn't have driven on it. The 265s are big in the back though, they may (or may not) be the practical limit for the rear. There's a possibility of squeezing a little more back there, but it would probably need stiffer springs to limit bump travel.

    For reference: 18x9.5" SSR Comp (ET 35), 265/35-18 Dunlop Star Spec. No spacer in the rear, 12mm spacer up front.

    Pics!

    Up on the ramp, to simulate some bump travel and check clearances:


    You can see that the bumper is, err, interfering here. Easy fix. The fender is also touching the tire, but it's only the last 2-3" of the fender that are touching... should be a pretty easy fix with the fender roller.


    Looking up into the rear fender - It's tight everywhere, but they fit. No problem.


    Checking front fit - These tuck in a bit more than the 275s did, thanks to the smaller diameter and width. As you can see, no fitment concerns at all up here. This was with a 12mm spacer up front - I think an 8 would probably be enough.


    Easy fit! No worries!
    Chris
    97 M3/4 - STU
    06 Evo - SM
    00 S2000 - STR

  • #2
    Re: Pushing the E36 Tire Limits...

    Next up: 275s?!

    We have a set of 18x9.5 ET22 wheels with 275/35-18 Dunlop Star Specs on them at the shop right now (thanks Dave!) and I decided I should probably test fit those on the front of my car. As it turns out, the 22 offset is just about perfect for the front of the car (not so much for the rear... didn't bother test fitting there.)

    As it turns out, I think with a little careful fender rolling and an increase in spring rate, I could fit these tires. As it is, the front ride height is a bit low and they would hit the fenders on compression. However, another .3-.5" higher, and upping to 625lb front springs, and I think it would be very do-able.

    Ideally, I would like to squeeze a set of 'narrow' (for their size) 285/30-18's on the car. This would get back to stock rolling diameter (275/25-18 is 21.5 mm larger than 285/30-18 rolling diameter), and add a LOT of clearance to the front while turning. As it is, I'm very confident I could run the 275s on the car up front... Not so sure about the rear, but I suspect I can make it work, somehow, with the right combo of wheels/tires/offset/rolling/hammering (ok, maybe not the last one)...

    On to the pics!

    Huuuuge rolling diameter:


    Snug on fender clearance (this is with the camber plates slammed all the way in, ~-3.7 to -4.0 camber)


    Slight rubbing on bumper and fender liner -


    You can see the rub mark on the tire here from moving them back and forth - They would 'clearance' the fender liners on the front side, but I don't see anything solid they would run into that would be a problem. Turning at full lock is most likely out of the question.


    Tires had around 36-38 psi in them - Obviously reduced contact path! Apparently -4 degrees of camber is a lot...


    Note that the fenders are totally stock and have not been rolled at all... Yeah, it's a slightly snug fit.
    Chris
    97 M3/4 - STU
    06 Evo - SM
    00 S2000 - STR

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    • #3
      Re: Pushing the E36 Tire Limits...

      Looks good! I considered trying 18x9 wheels and 265s, but wanted to wait it out and see how it works for others. I picked some of the TRMotorsport 17x9 wheels with 255/40-17, and they fit great.

      Comment


      • #4
        Re: Pushing the E36 Tire Limits...

        I'm pretty sure Fair ran 18x9.5 LTWs with 265s for a full auto season in STU. I'm sure there are tons of pictures of it all over this website.
        McCall

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        • #5
          Re: Pushing the E36 Tire Limits...

          Originally posted by McCall View Post
          I'm pretty sure Fair ran 18x9.5 LTWs with 265s for a full auto season in STU. I'm sure there are tons of pictures of it all over this website.
          We ran 265/35/18s with D-Force 18x10s (ET43) with a lot more backspace than that. Those 275s/wheels stick out... a lot. They wouldn't make it though one run without destroying a fender. Ask me how I know.


          This is with the 18x10s and 265/35/18 Bridgestones

          You can see that under full cornering load the tires just tuck under the fender lips (and in fact rub ever so slightly, inside and out). That was with 600# front, 750# rear spring rates and additional ride height out back to clear the tires. It fit, but not very well. This was after a lot of fender rolling (dolly + hammering, actually, as "rolling" would alter the magically unmeasurable "fender contour") in front and back to get it to work. Not streetable, but it worked for autocrossing. We had ~3mm from the inside of the wheel to the strut - there was no more room to go inboard.


          This is the event where we smashed a fender with the Yokohamas. You can see that it is still bent after a quick "pit repair"

          Before I had rolled the fronts we ran the 265 Yokohamas on these same wheels, first just on the rear at TMS (worked fine) then at a bumpy site (LaGrave Field). They didn't work so well at the bumpy site - one good bump pretty much destroyed a tire and fender. The tire caught the inside of the fender lip and, while turning, it curled it 180° outwards. The other side was also slightly smashed but it didn't snag and pull the lip outwards. The RF fender looked pretty bad and gashed the tire right at the shoulder, but I fixed it in the pits and finished the event.

          We tried them again after rolling the fenders and it was not going to work so we gave up on the wider 265mm Yokohama and had better luck fitting the 265mm Bridgestones. I couldn't see fitting any more width or especially height [such as 275/35/18] without major issues, in use. Sure, you are squeezing them a bit narrower with the 9.5" wheel, but the section width won't change radically.

          To fit 275s or 285s you would really have to start pushing the vague and contradictory fender rolling rules. I hope somebody tries it, of course, and if I had any inkling that out M3 could be competitive in STU again I'd do it to our car (as I've already borked the paint on the front fender lips) and try to see if it withstood protest. More than likely... it wouldn't be fast enough to warrant a protest.

          Don't let my pessimism detract you from racing and developing the E36 M3, of course!
          Terry Fair - www.vorshlag.com
          2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
          EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev

          Comment


          • #6
            Re: Pushing the E36 Tire Limits...

            Sounds great for E36 STX cars making the most of the current 9" and 265 tire rule. Thanks for the info.

            Comment


            • #7
              Re: Pushing the E36 Tire Limits...

              Originally posted by Fair! View Post
              I hope somebody tries it, of course, and if I had any inkling that out M3 could be competitive in STU again I'd do it to our car (as I've already borked the paint on the front fender lips) and try to see if it withstood protest. More than likely... it wouldn't be fast enough to warrant a protest.

              Don't let my pessimism detract you from racing and developing the E36 M3, of course!
              Considering Jon coned away a trophy at nats, and I coned away being .024 (or something like that) out of trophies, on 255s, and still having a lot of development work left to do... I think the car is definitely still capable of being 'competitive' in the SEB/STAC definition of the term. If I can fit the extra rubber under the car, I'm certainly going to try it out.

              Can't let all the boost buggies and E46's take all the attention.

              I'm really tempted to stuff 285's on 9.5s (yes, I know your opinion on this, Terry) and see if I can 'work' them into the fenders. The shorter rolling diameter would help some with fitting. With how those 275's fit, I think it's a plausible idea...

              ... Except that 285/30-18 Yoks are $369 each. That's a big problem.
              Chris
              97 M3/4 - STU
              06 Evo - SM
              00 S2000 - STR

              Comment


              • #8
                Re: Pushing the E36 Tire Limits...

                265s on 18x9's fit no problem. Not optimal, but it works and there are no additional clearance issues vs. the 17/255 combo other than a bit less room due to the larger rolling diameter.

                Rear spring rates are still a bit soft, as this picture illustrates.



                18x10's with 285 Yoko AD07s:



                Front is not all the way 'in' for camber here - Could probably get another 1/4" or more of the tire under the fender with the extra camber (was only at -3.5 in this pic)



                Didn't get a chance to drive around on the wheels/tires because I didn't have the right combo of spacers on hand to get the required clearance. The 15's are *almost* enough up front, and the 5's were not enough in the back with the -2.0 camber that I am currently running. I would really like to try running the car on this setup, as the shorter rolling diameter makes everything fit a lot easier and would help effective gearing quite a bit as well.
                Chris
                97 M3/4 - STU
                06 Evo - SM
                00 S2000 - STR

                Comment


                • #9
                  Re: Pushing the E36 Tire Limits...

                  18x10s and 285 Yokohamas on an E36????

                  Just the thought of that is making me feel.... funny....

                  Rollin rollin rollin.... fender rollin rollin rollin
                  Terry Fair - www.vorshlag.com
                  2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                  EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev

                  Comment


                  • #10
                    Re: Pushing the E36 Tire Limits...

                    Originally posted by Chris View Post
                    265s on 18x9's fit no problem. Not optimal, but it works and there are no additional clearance issues vs. the 17/255 combo other than a bit less room due to the larger rolling diameter.
                    I'll say... I got my damn hand stuck between the tire and the rear fender!

                    After Sunday's results, you think the 265s are worth it? Or push for 285s?

                    Comment


                    • #11
                      Re: Pushing the E36 Tire Limits...

                      The car *seems* faster on the 265s. I would shave them if I bought a new set, to minimize the additional rolling diameter (and gearing hit) as much as possible. I don't have any back-to-back comparison, other than running against you and Mark locally (and PAX..) but I think the 285s would be a HUGE step, vs. the small increase from the 265s.

                      I really don't think I will change much on the car to run the 285s. It will take a little "work" in the rear with manipulating camber/wheel spacers/toe-in but I don't think I will have to make any compromises. The shorter rolling diameter makes such a difference...

                      I bought a set of 700/800 springs this week as well. They may not be stiff enough, although I think 800's up front might be enough... Then 900/950/1000 rear?
                      Chris
                      97 M3/4 - STU
                      06 Evo - SM
                      00 S2000 - STR

                      Comment


                      • #12
                        Re: Pushing the E36 Tire Limits...

                        cool.

                        900 rear minimum. 1000 may push the 800 fronts to the point you can't tune out any undesirable traits with shocks and bars.

                        I'd say 950 and get the rest with shocks / bars.

                        Comment


                        • #13
                          Re: Pushing the E36 Tire Limits...

                          I am going to try 800F 900R in my STX car soon, will let you know how it works. I am running 650/750 now

                          Comment


                          • #14
                            Re: Pushing the E36 Tire Limits...

                            Originally posted by Chris View Post
                            The car *seems* faster on the 265s. I would shave them if I bought a new set, to minimize the additional rolling diameter (and gearing hit) as much as possible. I don't have any back-to-back comparison, other than running against you and Mark locally (and PAX..) but I think the 285s would be a HUGE step, vs. the small increase from the 265s.

                            I really don't think I will change much on the car to run the 285s. It will take a little "work" in the rear with manipulating camber/wheel spacers/toe-in but I don't think I will have to make any compromises. The shorter rolling diameter makes such a difference...
                            Yea, I keep meaning to try this. We have 18x10s and 285s mounted and an E36 M3 lying around... the 285 is radically shorter, but its still going to be down to 2mm clearances here and there, and full lock turning might be impossible.

                            The 265/35/18s barely worked before - it would rub pretty hard at full bump travel (600/750 springs) in the rear and I had to murder the paint on the front fenders to legally flatten the front fender lips. We likely needed to go to the stiffer springs that you and John mention and then optimize the entire setup for this "low travel" setup. Just don't see where we could have added that 20mm of tire....



                            And yes, the +10mm we gained over our previous 255mm tire on 17x9.5" setup (STU in 2006) was not enough to warrant all of that work and rubbing. And I absolutely SUCKED at Naitonals in 2007 on that 265mm setup (Scheier finished considerably better in the car but we were both way down the listing from the cars' previous bests of 6th and 2nd place finishes in 2005 and 2006). Going to 285s would probably have made it worthwhile, though.

                            Better enough to beat an AWD boost buggy? Me thinks not. Still... don't get discouraged from my pessimism!
                            Terry Fair - www.vorshlag.com
                            2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                            EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev

                            Comment


                            • #15
                              Re: Pushing the E36 Tire Limits...

                              18x10s ordered. 285 AD07s on hand. Let the games begin.
                              Chris
                              97 M3/4 - STU
                              06 Evo - SM
                              00 S2000 - STR

                              Comment

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