[IntegraR0064]

Hey guys,

I drive a SS 1LE and the main class I care about is SCCA time trials S2 class. So I have maxed out camber and 19x11 square wheels and otherwise totally stock. We're not allowed fender mods or camber plates. The wheels are the Apex ones with the perfect offset - ET11 front ET43 in rear. I've been running 305 square supercar 3 tires (200TW minimum tires for SCCA TT) and they've worked great even though it pokes out in the front a bit. Now we have a tire shortage and I'm thinking about my options since I can't get 305's. I noticed 325 supercar3 is in stock so I was considering that. I know some have run that in the rear, but have no idea if it'll work in the front.

I'm thinking I might need to run a small spacer in front for inner clearance, and on the outer clearance side even when I had tire poking out in the past it seemed to be fine.

Technically at the moment my alignment isn't totally maxed out yet, only close, so once I do that then I can try to take some measurements but was curious if anybody had thoughts or experience.

[kropscamaro16]

325 square is going to have alot of poke in the front and may not even fit especially if you have no camber mods

[DaveC113]

It's possible. One guy I know has run 335 square on 12s for autox. You may have some clearance issues up front but a little strut grind and/or spacer should work...

[VR Baron]

Originally Posted by DaveC113

It's possible. One guy I know has run 335 square on 12s for autox. You may have some clearance issues up front but a little strut grind and/or spacer should work...

Yeah clearance will be a issue. I have 19x 10.75” wheels with 15 offset, about same as your 11” with 11 offset . I run 305 re71s that don’t run quite as wide as Goodyear’s. I have the strut mod and run -2.5 front camber. With that combo I need to run a 3mm spacer just to get about 4-5 mm clearance. If you max out camber with strut mod, which will be about -2.7 depending, you will need a bigger spacer. Say about 15 mm. Another thing, 325s are most likely to big for a 11” rim. Tire people may not want to or be able to mount them, and when you squish a big tire on narrow wheel, the actual amount of tread on the ground maybe no more then a 305. Maybe.

[IntegraR0064]

Originally Posted by DaveC113

It's possible. One guy I know has run 335 square on 12s for autox. You may have some clearance issues up front but a little strut grind and/or spacer should work...

Thanks. And he didn't mod fenders or do camber plates?

Originally Posted by VR Baron

Yeah clearance will be a issue. I have 19x 10.75” wheels with 15 offset, about same as your 11” with 11 offset . I run 305 re71s that don’t run quite as wide as Goodyear’s. I have the strut mod and run -2.5 front camber. With that combo I need to run a 3mm spacer just to get about 4-5 mm clearance. If you max out camber with strut mod, which will be about -2.7 depending, you will need a bigger spacer. Say about 15 mm. Another thing, 325s are most likely to big for a 11” rim. Tire people may not want to or be able to mount them, and when you squish a big tire on narrow wheel, the actual amount of tread on the ground maybe no more then a 305. Maybe.

Thanks, when you say "strut mod" you mean grinding a notch in the strut for clearance, right?

I ran 335 hoosier A7 on my viper on the front 18x11, and grip was better than 315s, so it's not the end of the world pinch wise but those things were pretty pinched so you're right. That was an autocross car, not sure how I'd feel about that on track.

I think for now I'll keep running the tires I have, i used them a decent amount below freezing so they're probably a little hard but they have tread, hopefully the 305s become available again by the time the first actual time trial comes up.

[DaveC113]

I believe 325s are listed as acceptable for 11s, I have 315s on my 11s right now and it's about perfect. I think it'll be fine.

Right now I have 305/30/19 RE71s up front on 19x11 et 35, 26mm spacer, 2.5 camber, strut ground for about 5mm more clearance only because it takes 2 min with a grinder, lol... There's plenty of clearance. In fact one time I forgot the spacer, put a wheel on and it barely even touched the strut so I'd guess I have a bit over 20mm clearance which would allow 325s.

The guy running 335s does have camber plates but he runs 18x12 et 41 with 28mm spacers up front. Must be pretty tight but it works!

[VR Baron]

Originally Posted by DaveC113

I believe 325s are listed as acceptable for 11s, I have 315s on my 11s right now and it's about perfect. I think it'll be fine.

Right now I have 305/30/19 RE71s up front on 19x11 et 35, 26mm spacer, 2.5 camber, strut ground for about 5mm more clearance only because it takes 2 min with a grinder, lol... There's plenty of clearance. In fact one time I forgot the spacer, put a wheel on and it barely even touched the strut so I'd guess I have a bit over 20mm clearance which would allow 325s.

The guy running 335s does have camber plates but he runs 18x12 et 41 with 28mm spacers up front. Must be pretty tight but it works!

And there you go. Though what I posted up on my clearance is where the rim lip area was closer then the tire side near the top half of the tire sidewall. More clearance there. But got worn off paint at top of strut where you can’t grind anymore off. So interesting you got that much clearance.

[Mountain]

Originally Posted by IntegraR0064

Hey guys,

I drive a SS 1LE and the main class I care about is SCCA time trials S2 class. So I have maxed out camber and 19x11 square wheels and otherwise totally stock. We're not allowed fender mods or camber plates. The wheels are the Apex ones with the perfect offset - ET11 front ET43 in rear. I've been running 305 square supercar 3 tires (200TW minimum tires for SCCA TT) and they've worked great even though it pokes out in the front a bit. Now we have a tire shortage and I'm thinking about my options since I can't get 305's. I noticed 325 supercar3 is in stock so I was considering that. I know some have run that in the rear, but have no idea if it'll work in the front.

I'm thinking I might need to run a small spacer in front for inner clearance, and on the outer clearance side even when I had tire poking out in the past it seemed to be fine.

Technically at the moment my alignment isn't totally maxed out yet, only close, so once I do that then I can try to take some measurements but was curious if anybody had thoughts or experience.

You can’t run 325’s in S2. Limit is 315’s.
https://timetrials.scca.com/pages/sp...ory-full-rules

[Msquared]

A word of caution on comparing 325/30/19 tires to 335/30/18: the former is 0.8" taller than the latter, so any diameter-related interference is likely to be worse for the 325 even though it's nominally skinnier. I think you'd most likely find this at the top of the fender edge and where the corner of the sidewall/tread meets the strut.

To the OP, why not consider a 315/30/19? That size is available in both the Falken RT660 or the Conti EC Force. Of those, I would expect the Conti to be similar in performance and longevity to the Goodyear SC3 and the Falken would provide faster laps unless/until it overheated.

[IntegraR0064]

Originally Posted by Mountain

You can’t run 325’s in S2. Limit is 315’s.
https://timetrials.scca.com/pages/sp...ory-full-rules

Oh wow, i either totally missed that limit or it's a recent addition. Either way, that's the nail in the coffin for 325's. Thanks!

Originally Posted by Msquared

A word of caution on comparing 325/30/19 tires to 335/30/18: the former is 0.8" taller than the latter, so any diameter-related interference is likely to be worse for the 325 even though it's nominally skinnier. I think you'd most likely find this at the top of the fender edge and where the corner of the sidewall/tread meets the strut.

To the OP, why not consider a 315/30/19? That size is available in both the Falken RT660 or the Conti EC Force. Of those, I would expect the Conti to be similar in performance and longevity to the Goodyear SC3 and the Falken would provide faster laps unless/until it overheated.

My understanding is the Conti's are slower for sure. The Falkens are probably what I'll do if 305 SC3 isn't available in time. Really like the SC3 though.

So yeah my plan is clear now, try to hold off as long as possible for 305 SC3 and if that doesn't work get some Falkens. Thanks for all the input.

[DaveC113]

Originally Posted by VR Baron

And there you go. Though what I posted up on my clearance is where the rim lip area was closer then the tire side near the top half of the tire sidewall. More clearance there. But got worn off paint at top of strut where you can’t grind anymore off. So interesting you got that much clearance.

Ok, I double checked this yesterday and I have to admit I was off by a little bit, clearance with 2.5 deg camber + mild strut grind is closer to 10mm than 20 with my setup, but I could grind more off, maybe 5mm or a little more. I think 325s would work but camber plates would be ideal to get more clearance. For reference I have 19x11 et35 + 26mm spacers.

Also, my friend who ran 335 square on 12s did not have magride and did have camber plates. Magride has less clearance. 335s on 12s with magride might not work out that well!

[VR Baron]

Originally Posted by DaveC113

Ok, I double checked this yesterday and I have to admit I was off by a little bit, clearance with 2.5 deg camber + mild strut grind is closer to 10mm than 20 with my setup, but I could grind more off, maybe 5mm or a little more. I think 325s would work but camber plates would be ideal to get more clearance. For reference I have 19x11 et35 + 26mm spacers.

Also, my friend who ran 335 square on 12s did not have magride and did have camber plates. Magride has less clearance. 335s on 12s with magride might not work out that well!

Dave, good you got that much even. My 19x 10.75” wheels with 15 offset and 3 mm spacer is like a 11” with 9 mm offset if my math is right. It’s hard to measure back there, but All I can get near the ground off strut area is about 5mm. Stock wheels and tires is about 6-7mm, the 20” tire sidewall being closer vs the 19” wheel rim area.

[Sephx1]

Originally Posted by DaveC113

Ok, I double checked this yesterday and I have to admit I was off by a little bit, clearance with 2.5 deg camber + mild strut grind is closer to 10mm than 20 with my setup, but I could grind more off, maybe 5mm or a little more. I think 325s would work but camber plates would be ideal to get more clearance. For reference I have 19x11 et35 + 26mm spacers.

Also, my friend who ran 335 square on 12s did not have magride and did have camber plates. Magride has less clearance. 335s on 12s with magride might not work out that well!

I have the Apex 19x11/305 setup with negative 2 degrees camber up front and the car clearly needs more. Does yours have Magride? Mine does. Looking to find out how much more I can get without plates.

[Heartbreaker]

Originally Posted by IntegraR0064

Hey guys,

I drive a SS 1LE and the main class I care about is SCCA time trials S2 class. So I have maxed out camber and 19x11 square wheels and otherwise totally stock. We're not allowed fender mods or camber plates. The wheels are the Apex ones with the perfect offset - ET11 front ET43 in rear. I've been running 305 square supercar 3 tires (200TW minimum tires for SCCA TT) and they've worked great even though it pokes out in the front a bit. Now we have a tire shortage and I'm thinking about my options since I can't get 305's. I noticed 325 supercar3 is in stock so I was considering that. I know some have run that in the rear, but have no idea if it'll work in the front.

I'm thinking I might need to run a small spacer in front for inner clearance, and on the outer clearance side even when I had tire poking out in the past it seemed to be fine.

Technically at the moment my alignment isn't totally maxed out yet, only close, so once I do that then I can try to take some measurements but was curious if anybody had thoughts or experience.

I run 325/30/19 Apex Arc-8 (11 “) on the rear no problem