Tires - Thoughts on the BFG’s and More

First...contrary to what is published and known about the other Comp T/A tires, the Spec Racer version DOES NOT have an asymmetrical sidewall.  Many an hour was spent in the early parts of the 1998 Pro Season fooling around with the assumption that the tire had asymmetrical sidewalls.

Second...read the information BFG provides on the “Care and Feeding” of this tire.  This information was written by Jim Fogarty, the designer of the tire.  Believe what he says (ignoring the asymmetrical information) ...especially about the “scrubbing” of the tire.  The tires have dramatically different behavior between scrubbed and un-scrubbed.  Bluntly, there is no point in trying to race on new, unscrubbed tires.  You’ll be slow and the tires will be greasy.

Third...setup. Check out our setup info on this site. As you will see, the setup we ran is very similar to the Yokohama setup.  As an aside, in talking to Jim Fogarty, he told me that one of the design objectives on the tire was to make it as similar to the Yokohama as possible.  In general, this is what we found:
- Run the car softer than with the “Yok’s”.  We strongly preferred the Koni’s with the BFG tires.  Robert always really liked the Penske shocks with the Yokohama tires.  He said the car felt way more precise with the Penske’s.  And, truthfully, we wanted to keep running the Penske’s for that very reason.   Unfortunately, the car simply handled better with the Koni’s.  Our supposition is that the softer bump valving of the Koni’s is a better match with the BFG tires.   I’m sure that Penske could offer a softer valving on their shock...and I think that ultimately that would be the hot setup...but for now, we recommend Koni’s.  And since we won’t be running SRF anymore, you’ll have to decide if the Penske has been “fixed” at the time you read this.
- The tires get better as you get into the “under-tread”.  At some point, the tires start looking like slicks...i.e. no tread...and, unfortunately, no wear bars.   At this point you’re into the under-tread. I can’t tell you how deep the undertread is.  After 5 races, we were still running the first set of tires we bought at the beginning of the season...and they were working great.  Now, there’s a flip side to this.  If your rear tires are slicks and the front tires have tread, you’re going to push.  If the front tires are in the under-tread and the rears are brand new (scrubbed of course), you’re going to be loose. You want to keep the front and rear tread depth approximately matched.
- Wheels:  The BFG’s work well with either the Weld’s or the Alloys.  We liked running alloys in front and Weld’s in the rear.  The idea here was to get the lower rotational inertia of the Weld’s...and the wider rim width of the rear Weld’s.  In the front, we liked the better brake cooling of the alloys combined with the slightly more advantageous offset.  That being said, one successful Pro competitor ran the exact opposite wheel configuration...for the same reasons.  You decide.

Tire Softeners
Tire softeners aren’t legal in the Pro Series -- and I can’t remember on club.  You’ll have to check the rule book.   That being said, I’d like to share our findings on tire softeners.  We tried ’em all, and never found much lap time (if any).  I’ve been happiest with “Track Claw”, but we hardly ever ran it (maybe when trying to stretch the life span of some old tires).  We did however, frequently use VP Fuel’s “Tire Bite” softener when breaking in Yokohama tires.  We found that the first few sessions on “Yoks” weren’t as good as later cycles.  We found that we could get the tires to come in sooner by using Tire Bite on them when they were new (and then discontinuing after about the 2nd or 3rd cycle).  Our premise was that Tire Bite is a solvent which helped dry out the mold release oil Yokohama was using on the tire.  It seemed to help.  Note: We did not do this on the BFG and our experience is that you don’t need to.

Titanium Wheel Bolts
We used titanium wheel bolts (the 5/16" bolts which hold the rim to the wheel center) and jet nuts on our Weld wheels.  These nuts and bolts are about 1/2 the weight of the factory supplied steel parts.  Using these light weight parts further reduces the rotational inertia of the wheel -- as well as contributing to reduced unsprung weight.  The cost is about $75 per wheel.  If you choose to use titanium bolts, be sure to use plenty of anti-seize on them to prevent galling.

Other Weld Wheel Tips
Here a some things we found with the Weld wheels:
- Be sure nut seats are bottomed. We found that on new Weld’s we had to over-tighten the lug nuts the first time the wheel was mounted to ensure that the nut seats where fully bottomed in the wheel.  We tightened to 75 ft-lbs or so and then removed the wheel and remounted it at 55 ft-lbs.   Obviously, there should be no movement of the nut seat allowed.
- Torque the wheel bolts regularly. We tightened the 5/16" wheel bolts to 27 ft-lbs.  New wheels always required torquing.  We felt that the wheels worked much better with the bolts tight.
- Check valve stem washers and stem tightness.   Unfortunately, I’ve never received a Weld wheel which didn’t leak at the valve stem right out of the box.  I got in the habit of automatically replacing the rubber washers on the valve stem right away.  This also ensured that I checked the tightness of the stem (and while the stems can be overtightened relatively easily, I’ve had several loose ones cost me tires and/or laps).

Barry