CraigC

Fantastic job! I wish I had some of your mechanical talent.

garrett376

Hi Tom! It's the POC's Tribute to LeMans event at Willow Springs. I'll be running the Cup Races, not the endurance event. I don't want to beat the heck out of the car at its first event! Plus, Willow Springs is not a good track for a heavy car, but it will be a fun first outing!

Tom W

Garrett: Have fun. I'll be doing my first enduro in the HSR/PRC races that weekend. I had a ride in a 964 C4 this weekend (I was instructing a student) and was amazed at how well the front wheels pull the car through some of the turns. Your car should be a real hoot.

joey bagadonuts

Congrats, Garrett! Nice work!

You mean the 275/40 rear, correct? I used that combo on my C4 without issue.

Have you considered the Avon Tech R-A's ? I just ran them at Road Atlanta last weekend and the grip was amazing! Good price at Tire Rack, too. Under $600 and should be good for a half dozen weekends perhaps?

Drop me a line if you have questions. Regards,

ilko

Was the previous owner of the silver WB C4 Randy Ching by any chance?

kgorman

Who would have that been? ;-). Thx again Tom!

pete000

Nice Work. I can't even imagine taking on such a big job!

garrett376

Whoa! Joey, I am glad you posted! You made me realize I ordered the wrong sized front tires!!!!!! I ordered 235/40 17 fronts, and 275/40 rears.... I didn't even notice I should have ordered 235/45's... oops. Did you run 40's front and rear, or 45's on the front??

At least I have not mounted them yet, so hopefully they can be swapped. I was wondering why the rears seemed so much bigger than the fronts when sitting next to each other. I am looking forward to trying these new tires.

joey bagadonuts

I actually tried the 235/40's with the 275/40's and, yup, the difference in OD's set off all the sensors and made the car shimmy like crazy. The 235/45 is the right size but they ARE taller and wider than what you previously used so watch for clearance.

Also, you may experience a difference in handling. While the fitment is not a problem, I found that the wider fronts really created a tail-happy car. It made trail braking and exit throttling somewhat treacherous. Your results may vary but it's something to keep an eye on.

Finally, you may want to have them shaved. Aside from the reduction in squirm, it appeared to add to the tires' longevity. I used the Toyo's for maybe four weekends and then passed them on to a friend who then got another dozen, or so, track days out of them. Those things were good for some 55-60 heat cycles!

cobalt

Great job, but I still say that is too nice of a car to turn into a track rat.


What sensors are you talking about? I am running the 235/40's with 275/40's RA-1's. This was the tire size used in the cup series sponsored by Toyo way back when. I never heard of any issues.

joey bagadonuts

This is more of a C4 issue. The wheel speed sensors determine the variance in tire OD and if it exceeds a certain amount, the car will let you know.

IIRC, the Factory spec requires you to stay within 6% front and rear but in my experience the tolerance seems to be slightly tighter. The OD variance between the Toyo 235/40 and 275/40 (according to their specs) is only 5% but that still didn't work. The greatest OD differential I've run successfully on a C4 is 3% or 3/4" but you should do everything you can to keep them virtually the same.

cobalt

Duh!!

As soon as I read "it is a C4 issue" it came back to mind. I remember my friend having issues with his 95 c4 same type problem. So I should be OK with the ones I am running.

Thanks

Jeff Curtis

WOW Garrett, the FLASHBACKS!!

It's well worth it when everything comes together and WORKS - eh?

Did I miss something with regards to what happened to your other track toy?

Can anyone tell me a part# for the SACHS clutch disk and pressure plate associated with a lightweight flywheel setup on a 964? I want to get a new clutch disk and PP and thought I had saved that info. somewhere...somewhere...somewhere???

cobalt

I have the part numbers at home. If nobody posts by tonight I will.

Great upgrade.

garrett376

Hi Jeff! It's been converted back and is up for sale!!!