Wheel Choice For Handling...

[teklein]

Hey,

I have a 98 RS with the following suspension mods:

Tein Flex Coilovers - cars ride height is set at the upper end of Tein's manual
Prothane kit
RM Sways
RRE front brace
DC2 strut tower bars

As for wheels/tires now:

17x7 Kosei K1 TS +42 wheels. I have 5mm spacers on them now.
Dunlop Direzza DZ101 225/45/R17

After putting the Prothane and RM sways in before the SO, it feels as though the car is hitting the tires limits with the *much* stiffer suspension. With the 250k bushings and stock sways the car would not start coming loose this fast it seems. Not that it matters, but the car also had brand new tie rods and ball joints at that time.

Now, I can only fit a 225 tire on the 7" rim. I am curious whether the car needs wider tires (235ish) now, or just better tires in the 225 size.

If I need something wider, should I sacrifice the 7lbs per wheel to go Evo wheels? Or would RX7 wheels be better at 16x8 and roughly the same weight as what I have now? The K1's are like 13.1lbs.

Thanks in advance, you guys rock!

Tim Klein

 

[crimsondragon]

Why can you only fit 225 on a 7" rim? I think you can go as high as 245.

 

[knochgoon24]

Eh, 225 is about all I'd stick on a 7" rim. 245 on the evo wheels (8") was pretty nice.

If you're looking for a good street tire, look at the Dunlop Direzza Z1 Star Specs.

 

[teklein]

Eh, 225 is about all I'd stick on a 7" rim. 245 on the evo wheels (8") was pretty nice.

If you're looking for a good street tire, look at the Dunlop Direzza Z1 Star Specs.

Yep, that is what I heard about the 7" wide wheel too.

So you think different tires could pickup the slack a bit?

 

[Calan]

So you think different tires could pickup the slack a bit?

No matter how awesome the suspension is, the car will only handle as good as the four contact patches allow it to.

 

[snowborder714]

I would go for a wider wheel for sure. I run the same setup as Wes (Evo 8 wheel with 245/40 Star Specs) and on my car with the Tein Flex and RM sway bars, the car handled really well. I could push it much harder than when I had my 18" wheels with a 225 tire.

I'm not a big fan at all of the weight of the Evo wheels, and have considered getting something lighter. However, the budget for a good, strong, lightweight racing wheel is out of the budget.

 

[jtmcinder]

Agreed with above. If you're stuck on 7"-wide wheels, 225 StarSpecs if it rains where you live, RS-3s if it doesn't. But moving to an 8" or 8.5" wheel would do wonders.

 

[teklein]

No matter how awesome the suspension is, the car will only handle as good as the four contact patches allow it to.

Sweet! Making sure I was along the correct line of thinking.

Agreed with above. If you're stuck on 7"-wide wheels, 225 StarSpecs if it rains where you live, RS-3s if it doesn't. But moving to an 8" or 8.5" wheel would do wonders.

Very cool - appreciate it!

I would go for a wider wheel for sure. I run the same setup as Wes (Evo 8 wheel with 245/40 Star Specs) and on my car with the Tein Flex and RM sway bars, the car handled really well. I could push it much harder than when I had my 18" wheels with a 225 tire.

I'm not a big fan at all of the weight of the Evo wheels, and have considered getting something lighter. However, the budget for a good, strong, lightweight racing wheel is out of the budget.

Awesome! Exactly what I was looking for. I love the 13lbs 17x7, but I do not like the width.

And 16" would be too small? I have found a set of 16x8 FD RX7 wheels with 245/45 tires and I can get 12mm hub-centric spacers to run them. I would be giving up no weight with these.

Like you - cant budget for larger lightweight wheels right now, but plan on autocrossing as much as I can. I know the 225's are going to give me issues though.

 

[snowborder714]

I haven't read of too many people racing on a 16" wheel, and I always default to recommending 17" wheels to people for that reason.

Another thing I don't like is the mention of 12mm spacers to run the RX7 wheels. That's thicker than I'd like to see, personally.

 

[teklein]

Makes sense - 12 does seem a tad excessive.

Ill start looking for a set of Evo's or a good deal on Star Specs

 

[jtmcinder]

I haven't read of too many people racing on a 16" wheel, and I always default to recommending 17" wheels to people for that reason.

Hm. My info is probably out-of-date, but here's what I've seen at autocrosses.

For street-tire classes (with soggy sidewalls), I agree. With AWDs limited to 245s (on any wheel), the default was and still appears to be 17x8.5. If I could get 17"s on my Evo, I would have them and I'd run in STU, for example, so this isn't just DSMs.

But for Rs, it's different. For example, who was arguably the most successful 2G autocrosser (in terms of average finishing place), never having lost to another DSM at any notable event, including the ShootOut? Sean Caron. What did he run on his car, even when it was in SM? 16" Kosei K1s.

Yes, the trend shifted a while ago to giant tires, which are always on 17" or 18" wheels, but for a long time 245/45/16 was pretty much the standard on 2Gs and I'm not sure that going larger (in any direction) is helpful, at least at the SP and duffer-in-SM level.

But, again, for street tires, I agree with 17s. I'm mostly being a troll at this point.

 

[teklein]

That gives me a good bit to think about!

The car will never be competitive. It has a built engine, EMS, etc. But at only 170whp and the fact that it has to go into SM it will get destroyed

Looking up Sean Caron's stuff now.

Found another slight issue - apparently they only make race slicks in the 245/45/16 size now.

 

[snowborder714]

More power doesn't always equal better. I ran a local autox with a guy running a 90 or 95hp AE86 who spanked us all, including an RX7 with racing slicks and an Evo. It's all about your talent as a driver and your car's setup.

 

[jtmcinder]

One final thought (but you're not going to like it): as long as you're on Teins, you won't be getting everything out of the tires, anyway. At some point, you'll need to shift to making the tires happier. For now, I'd get the cheapest and lightest 8"-wide wheel that you can, put some 245 StarSpecs or R-S3s on them (either 245/45/16 or 245/40/17, depending on wheel) and call it a day. Ramen twice a week. Konis in the summer of '13.

 

[teklein]

More power doesn't always equal better. I ran a local autox with a guy running a 90 or 95hp AE86 who spanked us all, including an RX7 with racing slicks and an Evo. It's all about your talent as a driver and your car's setup.

True - I just need seat time and see what I can do.

One final thought (but you're not going to like it): as long as you're on Teins, you won't be getting everything out of the tires, anyway. At some point, you'll need to shift to making the tires happier. For now, I'd get the cheapest and lightest 8"-wide wheel that you can, put some 245 StarSpecs or R-S3s on them (either 245/45/16 or 245/40/17, depending on wheel) and call it a day. Ramen twice a week. Konis in the summer of '13.

I completely understand about the Tein's. They were free off of a parts car I had.

I could trade them straight up for a set of 2000 mile Koni Yellow's with Eibach ProKits on them while I get the parts machined over the next year or so. Would you recommend that, or are the Tein's better than the Koni/Prokit but not better than the Koni Coilover from DG?

 

[jtmcinder]

Nope. Not because of the miles on the Konis but because ProKits stink.

 

[teklein]

Nope. Not because of the miles on the Konis but because ProKits stink.

Sweet - thought so! Just wanted to verify. I had Tokico Blue's plus Prokits before - it was bleh to say the least.

 

[ACM]

No matter how awesome the suspension is, the car will only handle as good as the four contact patches allow it to.

Actually, you kind of have that backwards - the suspension (geometry and damping) is what allows you to extract the maximum grip from your tyres. Bad suspension will leave the best tyre hamstrung.

You can fit 17x8 (42 offset iirc) and 245/40.17 with no spacers, just rolling the rear lips. 235s fit without rolling the lips. At least they did on my 98.

It's a fact of life that you have to sacrifice weight, there's no way around that - however there are a number of not-too-expensive rims out there that are lightweight. Kosei K1 & TS, Enkei RPF1 - check out Tire Rack's ad in SportsCar or GRM, they list the weights for the different wheels.

As an example, on my autocross car I went from a ~35lb package - 245/45.16 on 16x8.5 K1s - to a ~45lb package - 285/30.18 on CCW 18x10.5 wheels. Coming off the line the car felt like it was dragging a boat anchor behind it, you could really feel the additional mass. However, the car dropped over 1 second per run with no other changes, no pressure fiddling, no damping changes, nothing. But I soon learned to overdrive that package too