Turbo 400

[Dick Butler]

Bobby, Was the testing Back to Back same track and day? If the track will hold the 4.10 it should be quicker in 60 and et unless running out of RPM and running flat. The fact you quote a slower 60 worries me about the test ..... Tried a 2.75 versus a 2.48 trans back to back runs picked up et with MY way of driving. Picked up more by leaning on the convertor also after that... Shifting later to 2nd also helped to a point. I needed to retest the 2.48 with all the later facts too to be sure I couldnt make it better with convertor torque.

[bobby]

No, but the weather conditions were close (yea, I know, close only counts in horseshoes and handgrenades) They don't change a whole lot in south Texas. Kinda worries me to. But being a Pontiac powered Pontiac, seems to run out of torque. and horsepower. doesn't like 1/4 mile anymore.

[Dick Butler]

I was lucky I had my kids running at all the same tracks too. They didnt like to change stuff so they made an unchanged run and I made a change. If I gained I could also judge for others or the kids ets.
Good Luck. Sounds like the pontiac thing of low end torque may be the real answer..

[bobby]

I went from a 10" conv and 3.90 to a 9" and 4.10 within a couple of races (old parts break easy, LOL) and that's when it slowed down. Put a longer duration cam in it and picked most of it back up. Then the cool weather came and picked up way more. Those small intake runner Edelbrock heads I think are hurting the air coming in. don't think they like anything bigger than 400", and I have 468.

[Dick Butler]

Bobby, The 9 inch convertor needs maybe MORE cam yet. if it doesnt like it you know you have met the max flow for the heads with your set up. Have you shortened the headers primary yet? Or tried bigger tubes?

[bobby]

I did put bigger headers on it, don't remember right now how much bigger, maybe 1/8. But that did seem to help. Just need to save the $ and get me heads ported.


Actually the only reason for the header change was b/c my new Haulmark trailer ate the old ones, LOL. The ramp door is higher than the floor of the trailer and I hung the driver side header on it. That was $475 before I ever got the car out of the trailer.

[Dick Butler]

Bobby, As much interest as you have in massaging your combination to always improve, have you considered running CLASS. Maybe Stock where many expenses can be limited by the rules but you have others as a standard to shoot for as a goal?