Any suggestions for a good alternatives to Hossier SO4's? I corded another set at WG this week and do not have time to wait for S05's due out in July. Supposedly the new SO5's have a rounder design that will avoid the current cording problems. I'm looking for similar adhesion and price. Tires are for a track prepped 968 with track suspension settings, plenty of negative camber. Sizes are 275/45 x 17 and 245/45 x 17.

Thanks!

Joe

 

do yourself a BIG favor, try the Toyo RA1. Used in speed vision and look at the times cup cars run, as well as the motorsport upgraded . they are ripp'in!!! trust me, its not all power either!!!!

ive done some pretty controlled testing, verifying the difference of the RA1 vs S03 and to other cars running S04s. probably on the order of only .3 to .5 seconds slower after 2-3 heat cycles. new vs new, maybe 1 second max.

half the price about! And in the sizes you need.

MK

 

In my expereince there is no alternative to the Hoosiers if lap times are important to you. If you don't mind giving up 1 to 1.5 seconds per lap, then the Toyo RA-1's are an excellent alternative. They're cheaper, and much longer lasting than the Hoosiers. On a 968 you can run 255/40/17 front and 275/40/17 rear. Get them shaved for best results in the dry, or leave them full tread if you need the flexibility to run them in the wet and don't mind sacrificing some dry performance.

 

MPSC

Or Kumho V710

 

Joe,
What alignment & tire pressures are you running?

I run 245/35/18 and 275/35/18s on my E car (1988 951S) and run them at approx 40 pounds hot (depends on the track). I just threw away a set of tires that I had used for DEs and practice sessions - they had 19 heat cycles. They had become very hard but had quite a bit of rubber left on them.

Cheers,

Rick

 

Joe,
That looks like a cool car. What are the specs on that baby ? Do you run it in PCA ?

 

Pressures cold are 35 at all corners except passenger front is 36. 42-44 when hot.

The alignment is -3.19 and -3.18 at the rear, - 2.33 at left front and -3.12 at drivers front. We use the Beissbarth Wheel Alignment to ensure accuracy.

The cording was very strange, 1" wide and about 17" long on drivers front outside of tire. I rotate all after 3-4 DE runs. The passenger front corded on the inside and had the same look. Both tires had about 4 track hours on them.
Both of thes tires looked like new earlier in the AM.

Thanks to all for the tire suggestions!

 

Carrera Cup21;

This is a true FireHawk prepped 968 with the IMSA stickers on the cage. It was originally a factory delete 968 w/o a/c and sunroof. It has a 6 point Nascar type cage, fire system. The engine had the head milled, crank lightened and special chip designed by Dave White, runs with 13.5 compression, 3" exhaust, Car has been completely rebuilt over the past 3 years, cosmetically and mechanically.

It's a blast to drive!

 

Correction on the rear camber, -3.05 left, -2.59 right. This was after I had all the rubber taken out and added solid camber plates.

 

13.5 !! What kind of hp does that give you with the chip and headers ? What was hp like when you got it stock ? What are the differences between the Firehawk and the regular 968 ?

I run S04's and have not had any problems. I am at -3 and -2.8 camber F/R and 0 toe at front and minimal toe in rear. 40 - 43 psi hot , doesn't seem to make much difference in that range. Car is 3000 lbs. with driver and 3/4 fuel. Some of the heavier cars (>3000 lbs. empty) have had some issues. I might consider MPSC's if I was that heavy as they last forever with mild performance loss. Some people have had some bad luck with Hoosiers. I don't know why, but some feel toe may be the culprit. Some may just be hard on tires. I don't drive like I am on rails, but I try not to get to crazy with slip angle unless I'm ready for new tires anyway.

 

Joe,
IIRC, there was a redesign to the S04's, whereby they changed the tire profile.

My first set of S04's corded as you described, but the latest set (with the newer profile) haven't corded after the same # of runs.

 

I purchased the car with all the engine work already done. The paperwork claims 260hp at the crank. About 20 more than stock! The cars interior was completely stripped for the FireHawk series and then re-installed to race PCA E-Class.

My cording may be less of a set-up issue and more of a defect problem with the original lots. Hoosier claims they've changed the newer SO4's and will allow me to exchange the other un-mounted set I have. New S05's supposedly are closer in design to the SO3's excpet they're steel belt.

 

Yeah, it will be interesting to see how the S05's perform. The S04's were supposedly slightly faster than the S03's, wonder if the S05's will be faster or slower with more durability.

 

And your car would be legal for E stock? I think you ought to edit your post if you want to pull that off! Lots of PCA scruits on these boards.

Edit on power: I got confused between crank and rear wheel hp. Sorry!

 

Uh Ohhhhh !!