Got my new Apex EC-7s through the most recent group buy, and fitted them with BFG Rivals. Was dead-set on the Rivals after running them on my Roadstars for a full track / AX season last year. Great tire with massive grip and predictability. Went with 245/40/18 and 295/35/18 on 9" and 11.5" wheels.
Tried to measure and match overall diameter to my prior wheel set-up (19" HREs) to ensure no rubbing. No dice. The fronts are way too big. Heavy rubbing against the fender liners at L/R turn lock. The rears are millimeters away from rubbing, but seem okay. My intent was to eventually move to the EC-7s for both track and street use (I rarely drive the Coupe on the street, so regular wear / wet performance isn't a major issue for me). But now I'm stuck with Rivals that I need to return to Tire Rack, and not sure what direction I should go in for replacement tires.
I'm thinking I probably need to downsize to 225-235/30-35 up front to ensure clearance. Haven't done an exhaustive search, but there don't seem to be many comparable tires out there in that size range. Any impressions / ideas from experience? Nittos? Toyos? Hankook? Khumo?
Thanks.
Depending on the offsets if the wheels, you just need to drop a series. 245 40 is massive diameter. Rears can stuff almost anything. I'm running 305 30 19's now on 11.5's but is a bit bid, I like the 315 25's much more.
245 35 18, 295 30 18. One of the best setups. What offsets?
1999 M coupe, Black/Kyalami Orange, Sunroof Delete; GT4088R turbo, 610 WHP @ 22PSI Pump Gas; 2.79 Gearing; TCK D/A's; Forgelines 19x9 et38 w/265 30's; 19x11.5 et19 w/305 30's. Brembo GT Brakes; Race Logic Traction Control.
1971 Datsun 510: High Compression VG34e, CAI,Fuji Blue, GC C/O's; system, Penultimate Rear Crossmember R160 lsd 3.70, cv axels; CCW LM16's 16 x 7.5/8.5 w/215 40 and 245 35 T1R's.
Are you sure you have 11.5" rears. I've never seen that size in any cast wheel.
1999 M coupe, Black/Kyalami Orange, Sunroof Delete; GT4088R turbo, 610 WHP @ 22PSI Pump Gas; 2.79 Gearing; TCK D/A's; Forgelines 19x9 et38 w/265 30's; 19x11.5 et19 w/305 30's. Brembo GT Brakes; Race Logic Traction Control.
1971 Datsun 510: High Compression VG34e, CAI,Fuji Blue, GC C/O's; system, Penultimate Rear Crossmember R160 lsd 3.70, cv axels; CCW LM16's 16 x 7.5/8.5 w/215 40 and 245 35 T1R's.
Strong rule of thumb is anything over 25" diameter will cause rubbing up front where the tires moves around in the well and preferably less than 25". 255/40-17's marginally fit but will rub. When you go up 1" in diameter of the wheel, you need to drop an aspect -- ie. 35. I really have to wonder about the rears at 26.1" diameter unless you have some stiff springs.
Now in E92 M3 ZCP -- Absolute beast
255/35 & 315/30 f&r here with no rubbing. Like Greg said though, the offset is key (he should know as he sized mine).
-Todd
Overall diameter needs to be less than 25". Don't see any 18 inch tires that size in a Rival. Star Spec II 255/35 18 might work but you will probably need camber adjustments. Swapped hats or plates.
Agree with all previous. 25 inch diameter in front is about it. I squeeze on a 25.7 tire on but have to trim and mess with caster and camber to do it. dropping to a 18/35/xx should fix you right up. 18/30 as well but you start degrading ride quality on the street and increase your chance of bending a wheel lip greatly with 30 aspect ratios
Dan "PbFut" Rose
Really probably should've queried here before ordering . . . After comparing to my Roadstar setup, the under 25" rule of thumb makes perfect sense.
Offsets are ET31 and ET25, front and rear. The 11.5" was a typo. 11" in the rear, and it is at 26.1" with stiff H&R springs. Then again, I haven't actually driven it hard with that rear setup. Just eyeballing it, so under load, it may well rub in the rear. Once I realized the fronts weren't gonna work, I didn't drive it so that I could return the tires.
So, sounds like 25" max up front, with 245/35, 295/30 being an ideal setup?
Looks like the Khumo Ecsta XS comes in a 245/35, but only either 315/30 or 275/30 rear. Not seeing much else out there in the streetable / track variety in those sizes . . .
315 30 18 will fit nicely on the rear. Offset is really conservative. You could actually do a 5-6mm spacer on that rear wheel and still work with minimal rolling if any with a 315 30 18. You will need trim the plastic liner inside the rear wheel wells if anything.
The front is always more tricky. The 31 offset is not taking advantage completely of the space inward. A 255 35 18 is pretty ideal, but it may take some camber to get to work.
The apex wheels are an ok fit for our cars. In my opinion, they don't offer high enough offsets for the front, and they don't offer low enough offsets for the rears. The make a great product. To specify a cast wheel to perfectly fit the z3m makes it a not perfect fit for just about everything else.
1999 M coupe, Black/Kyalami Orange, Sunroof Delete; GT4088R turbo, 610 WHP @ 22PSI Pump Gas; 2.79 Gearing; TCK D/A's; Forgelines 19x9 et38 w/265 30's; 19x11.5 et19 w/305 30's. Brembo GT Brakes; Race Logic Traction Control.
1971 Datsun 510: High Compression VG34e, CAI,Fuji Blue, GC C/O's; system, Penultimate Rear Crossmember R160 lsd 3.70, cv axels; CCW LM16's 16 x 7.5/8.5 w/215 40 and 245 35 T1R's.
Many thanks for the valuable info. Guess it's just a matter of finding a tire I like in the relevant sizes. Not much out there, unfortunately . . .
So, really short on choices for tire sizes. Khumo Ecsta's are the only thing around with a 245/35, and it'll take 8 weeks to get them. Next best is Direzza IIs in 225/40 and 285/30. 25.1" diameter up front. That give anyone heartburn? No camber on my car. Stock plates and hats.
welcome to my world of limited sticky street tires. The most I can fit up front is an 285/30/18 which really limits tire selection. I have the Direzza ZII on now and really like them for autocross. I hoped to try them on track as well but have not had the chance to do that yet. Prior to that I used Yokohama ADO8, very capable tire for autox and track as well.
'99 M Coupe Supercharged autox/track toy* available for purchase, 2016 MX5 Miata daily driven, '11 Mazdaspeed 3 - dog hauler
*///Monster Coupe: FH/Race USA custom widebody front, 18 X 10.5 et 27 Apex EC-7 wheels 285/30/18
Active Autowerks Super Charger C30-94- 300 whp, SnowPerf Water Alcohol injection, AA Track Pipe, Supertrapp Exhaust, Ground Control double adj struts, Adj RD sway bars front and rear, Quaife 3.64 Torque Biasing LSD, Recaro Pole Position seats, HMS Harness Bar & Schroth 5pt & 4 pt Harness
285??? in front?? You sure about that?
Dan "PbFut" Rose
yep.
I run a square set up with 18" X 10.5" et 27 Apex EC-7 wheels with 285/30/18 tires
'99 M Coupe Supercharged autox/track toy* available for purchase, 2016 MX5 Miata daily driven, '11 Mazdaspeed 3 - dog hauler
*///Monster Coupe: FH/Race USA custom widebody front, 18 X 10.5 et 27 Apex EC-7 wheels 285/30/18
Active Autowerks Super Charger C30-94- 300 whp, SnowPerf Water Alcohol injection, AA Track Pipe, Supertrapp Exhaust, Ground Control double adj struts, Adj RD sway bars front and rear, Quaife 3.64 Torque Biasing LSD, Recaro Pole Position seats, HMS Harness Bar & Schroth 5pt & 4 pt Harness
Pimping the wide body front end.
I was on the EC7 group buy too. On my MCoupe with Coilovers, I have a 255/35/18 and 285/35/18 set-up with RS-3s. Wheels are 9" front, 10.5 rear. I originally ordered 11" rears, but when they arrived the fit was too snug with the Coilovers, so Apex replaced. Great guys to work with.
^ puts a smile on my face
I do not experience under steer very often ;-) and I do have some minor steering clearence issues. but those can and will be solved simply with a little (more) trimming.
'99 M Coupe Supercharged autox/track toy* available for purchase, 2016 MX5 Miata daily driven, '11 Mazdaspeed 3 - dog hauler
*///Monster Coupe: FH/Race USA custom widebody front, 18 X 10.5 et 27 Apex EC-7 wheels 285/30/18
Active Autowerks Super Charger C30-94- 300 whp, SnowPerf Water Alcohol injection, AA Track Pipe, Supertrapp Exhaust, Ground Control double adj struts, Adj RD sway bars front and rear, Quaife 3.64 Torque Biasing LSD, Recaro Pole Position seats, HMS Harness Bar & Schroth 5pt & 4 pt Harness
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