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Official Autocross/HPDE Thread.
- Thread starter Merkle
- Start date
RacingManiac
Drag Race Newbie
Wheel width vs Tire width is always the same debate. Anecdotally I've been having decent result running wider and I've not had reason to tell me to do otherwise. Celicas are running 225s on 6.5" now on street tires. In the past with R-Comps its even more extreme.
Its hard to get a cost effective way to test this though, since its unlikely you will have 2 new sets of tires that you can run back to back, at least for my wallet.
The way I see it, on stock suspension with basically no front camber, you are going to over use the shoulder, one way or another, bimmer635csi used to run 225 ZIIs on his stock width wheel, and his shoulders were wearing twice as fast as mine. Running 255s(or I think 245s will probably be enough) you are not using all the width, but at least you are not rolling onto the sidewall. Its also not as if my tire is not used on certain parts, since the wear is relatively even across, with bias on outside shoulder.
Its hard to get a cost effective way to test this though, since its unlikely you will have 2 new sets of tires that you can run back to back, at least for my wallet.
The way I see it, on stock suspension with basically no front camber, you are going to over use the shoulder, one way or another, bimmer635csi used to run 225 ZIIs on his stock width wheel, and his shoulders were wearing twice as fast as mine. Running 255s(or I think 245s will probably be enough) you are not using all the width, but at least you are not rolling onto the sidewall. Its also not as if my tire is not used on certain parts, since the wear is relatively even across, with bias on outside shoulder.
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troyguitar
Go Kart Champion
I'm not sure if it's as true in autox, but on big tracks more tire is basically always faster - but only if you optimize car setup for the extra tire.
RacingManiac
Drag Race Newbie
R-Comps is a different ball game since their sidewall typically are even stiffer. So they tolerate being mounted on narrow wheel better. I think people used to run like 275s on 7.5" before they moved to Street class.
Which is why I thought its interesting talking to my SRT-4 friend because he noted RS-3 running on narrow wheels don't work as well as Rival in that fitment. And Rivals are known to have that sidewall stiffening band.
Also I would not buy tires now. 200TW tire war is going to get heated next year with new Rivals coming out in the spring, plus now we have 200TW R1R. Bridgestone and Khumo might have new product next year also. This is on top of the existing players like ZIIS, RS-3 V2 and others...
Which is why I thought its interesting talking to my SRT-4 friend because he noted RS-3 running on narrow wheels don't work as well as Rival in that fitment. And Rivals are known to have that sidewall stiffening band.
Also I would not buy tires now. 200TW tire war is going to get heated next year with new Rivals coming out in the spring, plus now we have 200TW R1R. Bridgestone and Khumo might have new product next year also. This is on top of the existing players like ZIIS, RS-3 V2 and others...
troyguitar
Go Kart Champion
Yeah I have no idea what I would buy if I needed tires now, fortunately I have like 75% tread remaining on my RE-11's and don't care about national competitiveness so I can just wait it out.
I might just go 100 UTQG if the new R888R turns out to be good (my car is ssp technically but I want streetable tires).
I might just go 100 UTQG if the new R888R turns out to be good (my car is ssp technically but I want streetable tires).
RacingManiac
Drag Race Newbie
Does the new PS Cup 2 come in sizes for you Troy?
TW180 but its really still R-Comp...
TW180 but its really still R-Comp...
troyguitar
Go Kart Champion
Nah those are for 19/20/21" wheels and epic $$$ anyway.
I'm looking at 275/40/17 ideally and possibly one of the wide-running 255/40/17's in 100-200 UTQG. The trick is balancing between something that's not terrible when run cold (autox 30 second runs) and doesn't disintegrate when hot (track 20 minute runs).
I'm looking at 275/40/17 ideally and possibly one of the wide-running 255/40/17's in 100-200 UTQG. The trick is balancing between something that's not terrible when run cold (autox 30 second runs) and doesn't disintegrate when hot (track 20 minute runs).
troyguitar
Go Kart Champion
I finally ordered a new helmet tonight to be SA-rating compliant (lots of tracks require Snell SA rated helmets instead of just M-rating like autox/karting). HJC SI-12 on closeout for $380 from soloracer.com. Lightest helmet on the market, dat weight reduction doe :lol:
I would share the link but I bought the last one that they had and it was size small for small-brained people like me.
Comes with a cool looking case and stuff, kinda neat.
I'm thinking of getting one of these pink/purple shields to match my car:
I would share the link but I bought the last one that they had and it was size small for small-brained people like me.
Comes with a cool looking case and stuff, kinda neat.
I'm thinking of getting one of these pink/purple shields to match my car:
Grandturismo
Ready to race!
The HJC helmets are good value for money. It looks great. I ended up with the reflective chrome shield. I do like the purple one too.
Did you consider post clips?
Did you consider post clips?
troyguitar
Go Kart Champion
I'm not familiar with helmet accessories, what are post clips?
Grandturismo
Ready to race!
They basically allow you to have a HANS Device. If you track regularly and tend to push it, then probably the best investment you could make IMO.
There is also the Quick Click as another option.
There is also the Quick Click as another option.
troyguitar
Go Kart Champion
Oh, the helmet is pre-drilled for them but I didn't buy any yet.
I'll probably be getting something like that, just need to decide exactly which product to go with. I need to look at options that will work in both the car and the kart (if any exist).
I've gone "serious business" with an FIA seat, non-airbag steering wheel, and will be installing 5/6-pt harness once I figure out the best HANS-type device choice.
I'll probably be getting something like that, just need to decide exactly which product to go with. I need to look at options that will work in both the car and the kart (if any exist).
I've gone "serious business" with an FIA seat, non-airbag steering wheel, and will be installing 5/6-pt harness once I figure out the best HANS-type device choice.
Grandturismo
Ready to race!
I can see safety is fairly important to you having bought such a good helmet, I'd seriously think about them.
The basic entry level HANS device works perfectly well with the traditional post clips. How are you planning to attach your harnesses? It was this question that lead me to a half roll cage. There are other options though.
The basic entry level HANS device works perfectly well with the traditional post clips. How are you planning to attach your harnesses? It was this question that lead me to a half roll cage. There are other options though.
troyguitar
Go Kart Champion
The lap and sub belts just mount to the seat brackets and floor, but the shoulder belts will mount to an aftermarket crossbar which bolts in across the B-pillars. Fortunately the Corvette has a very strong "halo" section making it basically like having a big roll bar from the factory. The weak points are the A-pillars but I'm not really interested in going to a full cage on a street car.