CAT3

iTrader: (9)

Ok, ran my gas tank down and filled up using 114 race gas, full nitrous bottle, Iam not sure what my afr and timing were, but I had pulled out all timing and added all the fuel I could using the predator, jetted rich, and ran the 200 shot, after purge pass, and I sprayed it outta the hole but...no luck. I actually went slower, by 2/10's. So, pulled plugs, check everything said they were good, just rich. So, jetted down and ran again, picked up a tenth, and no mph. Didnt add timing, or reduce fuel, so can say for sure which it is, but figure it comes down to:
1) too little timing
2) too much fuel
3) too much leaded race gas octane

The timing and fuel ratio are the same I used for the 175 shot that pulled in a best of 11.01 @ 122, but I mixed 1gal of 114 with 2gal 92octane gas/ Would the pure 114 really slowit down that much? WIll check max timing later today and post up.

Charlie.

DERTY

What heat range are your plugs. Running that high of an octane on something like TR6's might be able to wash them out. What was your timing set to? I'm assuming you were watching your timing and knock retard? Anything going on there?

CAT3

iTrader: (9)

No KR, and timing was about 27.9* WOT, but I agree should have bumped timing up a little. TR6 plugs gapped short at .038".
All components are fine, but it just fell down..

Question on the race gas, will race lower the AF ratio, like if I am tuned for on bottle of 12.5:1 and then change to race gas, like the 114, would it lower the AF more so? Or is just so slow burning that timing should have been brought back up. I used to mix a little 100 with my 92 and nail the 150 shot, but then when i tried the 175, i got a little careful...overly so.

DERTY

A good way to check is to pull your plugs. I usually click the car off after the run and coast around the turn. I'll bring a spark plug socket with me and check one of the holes. I usually reload one of the drivers side with a fresh plug. Where was the timing mark on the strap? Towards the tip, the bend or the base? Since you are using NGK's is the coating still firmly attached, is it burned off or is it easy to flake off. If you've already driven back on the plugs, it's too late and you've washed them off. If it is running with the right amount of heat the coating will flake off. Burned off = too hot and vice versa for too cold. I'm thinking a TR6 may have just been too hot for that much juice on race gas.

Running nearly straight up race gas would have required more timing. However 27.9 is high for a 200 shot compared to mine. I'm only running 22 degrees for the most part on 117 octane, taking away some of the tuning I have in other RPM bands for the converter and such. I can't draw a fair comparison since I never sprayed my stock motor, so I don't know where they like to be as far as timing.

CAT3

iTrader: (9)

Whats a colder plug good for the bigger shots?
No i didnt check plugs at turn, just after i pitted. They looked good, with a burn around the begining of the bend on the strap. I know on the 150 with full timing and less added fuel, running pump gas, the burn would be towards the base for comparison.
When you mention coating you talking about on the porcelain, strap or facing of the plug?

DERTY

The gold coating on the NGK race plugs is designed to separate when the temperature is right. Too cold and it will remain gold. Too hot and it will burn it all off. The problem is that once you go back to the pits you will wash the plugs off and you won't be able to get an accurate read on them.

If you go to a store that has an NGK catalog there is a chart of all the heat ranges below a TR6. I think Thunder Racing sells them as well in a couple ranges colder. It's 1 range colder per 100 HP or so. The timing mark sounds about 1 to 2 degrees high, but it's still safe if that's truly where it is.

CAT3

iTrader: (9)

I love learning. Thanks for the great info. I will check on getting some new plugs for race nights. The timing marks your speaking of, as in where the flame point is on the strap right? May have been washed by driving to the pits, but from the tip of the strap to the very early part of the curve is where it was, not down towards the base. Thanks Steve.

Charlie.

Big Mike

iTrader: (4)

CAT, I'm using the NGK TR8's and they are awesome plugs for the big shot of steam (200+).

CAT3

iTrader: (9)

Cool thanks Big mike.

What kinda gap?