How many RPM'S

[garrell.770]

A couple of months ago I told you about my let down landspeed racing on the Ohio Mile in Sept. Where with a new Comp Cam kit and an LSXrt I ran 5 to 6 MPH slower than I did in the spring without those two changes. The truck ran great, pulled hard and never missed or faltered in anyway but it did drop from 6200 RPM to 4000 on the 1to2 shift and never recovered consistently on four runs. All of you said torque Convertor. I had suspensioned that but I had never really research converters and realized how much HP is lost to the track through them.

I talked in length with Andre the owner of Edge Performance Convertors in California. He wanted the specs on the cam, intake, distance ran etc. He designed a custom Convertor for my truck and after reading review after review I turned him loose to build the Convertor which was wound of all carbon fiber material. I also talked with my transmission guy who owns a Corvette with over 600 rear wheel HP and is very performance oriented. The Convertor is in now plus he installed a shift kit, serviced the transmission and installed a synthetic fluid and said the internals of the truck looked great.

I have an appointment with my tuner next Tuesday to tweak the tuneup. I have made four passes on a stretch of county road that is flat and straight for over 1 1/2 miles and you can watch a hill beyond that and if no one drops down in it you no the road is yours. The truck is tuned to shift at 6200 RPM and on each pass it only dropped 200-300 RPM on each shift on each pass.

My truck only has 52,000 miles on it, has always been garaged and I have added some custom touches to it and it looks great. The question is should I leave the shift points at 6200 or would I stand a chance of hurting something in the engine if I bumped it to 6400-6500 RPM. Remember this is a standing me and reaction time and ET'S mean nothing, only top speed. If I run well and the winds aren't angry I can set three more landspeed records by resetting my own records giving me 9 or 10.

I would like to hear some expert opinions from you guys and girls if any.

Thanks

Garrell

[JC03SS]

Depending on size of the cam I would say you want your shift points to work with the cam. You want to stay in the cams power band as long as possible. But to me 6200 seems a little low unless it's as small cam. Mine likes it a lot higher.

[zippy]

The stock LQ9 will handle in the 7200-7400 rpm range without an issue as long as you have a good valvetrain to go with it. As for your converter, if you are only dropping 200-300rpm on a wide open shift that converter is way too loose and inefficient as all hell. As for what shift point to use it does depend on what parts you have chosen for your setup. On the same hand though that should be a decision made by your tuner based upon his data found with your chosen mods.