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Posted: Sun Sep 10, 2006 7:37 pm
by jim sanders
:roll: i have been having electrical problems lately... the cute chick shows up with her insulated pliers, I run to the bedroom, hand her some cash, she writes out a reciept and leaves.... my stereo is still playing so i figure i'm GOOD TO GO at least till Tuesday ?

September 13th Test and Tune

Posted: Thu Sep 14, 2006 8:51 am
by Mike-Casella
We did a track rental on Wednesday for some test and tune. It turned out to be the most informative day we have had all year. We only got in two passes, but learned a great deal in the process. The first pass was a total waste of fuel and nitrous, as I just blistered the tires about 5' out of the hole and just motored down the track. It was amazing to find out just how many people are actually watching you make a pass, and then come over to us in the pits to offer suggestions and tell us exactly what they happened to see. One mentioned that it looked like the chassis was unloading causing the tires to break loose and not transferring the weight to the rear. After checking the rear shocks, we found out that both front and rear shocks needed an adjustment. This is where a full crew would have helped, one guy just can't see everything. You all remember the old saying "Everything happens for a reason". Well, that was the case on that first pass also. One of those little things happened where I forgot to turn on the NOS fuel pump. Now, had it actually hooked, and I was able to make a full pass, I would have burned up the motor due to no fuel being injected with the nitrous. Go figure.

Mikey made the adjustments to the shocks, and we were ready for the next run. We also dropped the tire pressure down to 9 lbs, for no particular reason. We made a decision to try a shorter burnout thinking that we may have been getting the tires too hot. I shortened the burnout as discussed, made sure everything was ready, bottle pressure was at a solid 1000 psi, and inched into the beams. The launch felt great for about 10', and then the tires went away again. This time I pedaled and got underway for the remainder of the run. I ended up with an 8.60.

Back in the pits, trying to figure out why we dusted the tires again. It was at that moment that my cell phone rings and it turned out to be a call from Wally Bell. We chatted about this and that, and possible reasons for what happened. During our conversation, one of the things we talked about was tire pressure. Then it hit me, the car was able to launch like it should when we had the old tires on it. Back then, we were unknowingly using a tire gauge that was incorrect. It turned out to be off by 2 1/2 lbs, so while we were setting the tires to what we thought was 10 lbs, we were actually setting them to 7 1/2 lbs. After putting on the new tires in Iowa and making those two passes on a track that was very hot and sticky, we thought we were all set. We were now putting in a known 10 lbs of air also. Back on our home track, we couldn't get the tires to bite at all. Could this be the reason? It makes sense to us.

I sure wish we had thought about that before, at least for the second pass anyway. Unfortunately it started raining and the day was brought to an end. The tire pressure deal will be tried on Saturday when we have our next race date. If this turns out to be the problem we have been chasing............................. LOOK OUT!!!

I can't thank you enough Wally, and all it took was a 15 minute phone call to turn on the light.

Mike

Posted: Thu Sep 14, 2006 9:11 am
by Rapid Randy Baker
Great report Mike! That tire pressure gauge is bitting us both this year for some reason. I have something new to try at Joliet. I will let you know if it works. 8)

Rapid

Posted: Thu Sep 14, 2006 9:15 am
by Mike-Casella
So simple, yet so far back in the brain. Wally brought up the 7 1/2 lb pressure. That must have been what triggered the memory banks.

Posted: Thu Sep 14, 2006 11:56 am
by Lippy
You'll get it Mike, sounds like your on the right track, Saturday will be interesting. 8)

Posted: Thu Sep 14, 2006 12:02 pm
by Mike-Casella
Thanks. One of our troubles is we can't just go over and ask one of the Mustang, or Camaro guys what they are running for tire pressure because our cars are worlds apart. We just have to run into these bumps and try and figure it out.

Posted: Thu Sep 14, 2006 12:08 pm
by Lippy
If you know any of them real well you could ask them if they would do a little testing for you, tell them you want to add 1500 lbs to their car and swap back tires with them for an afternoon just to prove or disprove a theory you have. :lol: :lol: :lol: Then watch them scratch their heads. :lol: :lol: I want video of their first run also. :lol: :lol:

Posted: Thu Sep 14, 2006 12:18 pm
by Mike-Casella
Yesterday there was a guy with a 70 Chevelle running the same engine and also the same chassis we have, and I thought Great we finally have something close to our set-up, maybe we can compare notes!! Then we peeked under at the rear tires. 34.5 X 17. Oh well.

Posted: Thu Sep 14, 2006 12:20 pm
by Lippy
Swap him wheels and tires for a pass. :wink:

Posted: Thu Sep 14, 2006 12:23 pm
by Mike-Casella
It will happen, it's only a matter of time.