Dave2000GT
Active Member
Get a new fuel pump (155), skip the injectors. A GT40 setup is FINE with 19s. I make power to 6k rpm and the 19s go about 80% load.
What kind of a cam are you running?Get a new fuel pump (155), skip the injectors. A GT40 setup is FINE with 19s. I make power to 6k rpm and the 19s go about 80% load.
There is no power at 6500rpm with a stock cam and gt40 iron heads (power probably stops about about 5500rpm).I've got a couple stretches of open highway on my way too and from work that I can't seem to keep my foot off the gas on, with 3.73's I'm over 4000rpm a lot and have had it up close to 6500rpms. At high rpms the car has plenty of power, will spin the tires when I drop a gear and floor it at 50mph and then chirp them again shifting up to 3rd gear. I have owned the car since it was new and it never did that before with the stock 5.0, not even with a 10 inch torque convertor.
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You will spin the tires at a 50mph roll when your stock auto trans drops a gear?
Get a shift light, and don't guess.Just as a reference, I shift at 6500 on my stock tach. Verified on the dyno this is about 5500 RPM.
Just as a reference, I shift at 6500 on my stock tach. Verified on the dyno this is about 5500 RPM.
Get a shift light, and don't guess.
Stock HO Cam. The thing spins fine if you drop the lifter preload to 1/8 to 1/4 turn. After I did the heads I really noticed the dropoff at 4500-5k. Took down the preload and it made a world of difference up high AND down low.What kind of a cam are you running?
When I set mine They went just over the 1/2 turn to get the proper torque setting, that is with the TFS valve springs and about 1/2 of them needed shims per the instructions from TFS. So from what you are saying I should back it off a bit to get better low end?Stock HO Cam. The thing spins fine if you drop the lifter preload to 1/8 to 1/4 turn. After I did the heads I really noticed the dropoff at 4500-5k. Took down the preload and it made a world of difference up high AND down low.
When I set mine They went just over the 1/2 turn to get the proper torque setting, that is with the TFS valve springs and about 1/2 of them needed shims per the instructions from TFS. So from what you are saying I should back it off a bit to get better low end?
I have great mid to high rpm power and no noise, just not as much low end power, I assumed it was from the larger cc of the GT40 heads compared to the stock heads and only having a stock torque convertor in my AOD. I will be swapping out the stock TC for a higher stall which should get the low end back for taking off from a dead stop, if that doesn't help I'll try to take some preload off and see what that does.I would definitely try that if I were you. Myself I'm using the Crane 1.7 rockers, and I was getting poor low/top end power, as well as alot of rocker noise at 3/4 to 1 turn of preload. After setting them all down to ~1/4 turn preload there was a noticeable power improvement AND the noise quieted down, despite everything I have ever read to the contrary indicating that more preload = quieter.