trick flow heads... loss of low end torque?

[saniutza]

i used to have stock heads with a E cam with S-Trim(#14 pounds) edelbrock performer rpmII intrake and when i stept on the gas started moving.. i just installed trick flow o ringed heads, pushrods, 1.6 crane roller rockers, lifters... now when i do about 2000 rpms and i step on the gas car starts slowly moving.. i mean its not as fast at low rpms as it used to be with stock heads... did i lose low end torque ? i mean when i start makin boost pulls hard ... is it because heads cam intake flow good so i lost low end torque?

fuel pressure its like 38... i have 42 punds injectors with an 80 mm proM mass air... power pipe... 70mm TB, shorties and high flow cats...timing its set to stock i guess 10*... just because i have a PMS and i was going to hook it up soon....

 

[gork1rogues]

Those heads burn more efficiently and will require a different tune than what was on there with the stock heads. Go get it tuned and then see how it goes.

 

[saniutza]

Those heads burn more efficiently and will require a different tune than what was on there with the stock heads. Go get it tuned and then see how it goes.

i see... like i've said got a PMS for it....

 

[tjm73]

You lost some port velocity when you went to the bigger valved heads. BUT you gained a lot of flow capability.

Are you still making 14 psi of boost? Bigger heads often reduce boost slightly.

3.55 gears (listed in sig) are small for a Vortech blower car.

I suspect more than one factor is at work causing what you describe.

I'm guessing that your stock heads carried you through the low rpms with good throttle response getting you into the boost where the blower took over and powered you on past where the stock heads woudl normally fall off in power.

Now that you have heavy breathing heads, you don't have that low speed port velocity that the stock heads offer and the 3.55 gears are not enough to overcome the loss of that port velocity.

Make sure you still have 14 psi of boost, get 3.73 gears and get a tune. I'm sure it'll dramatically change the car's behavior.

 

[saniutza]

You lost some port velocity when you went to the bigger valved heads. BUT you gained a lot of flow capability.

Are you still making 14 psi of boost? Bigger heads often reduce boost slightly.

3.55 gears (listed in sig) are small for a Vortech blower car.

I suspect more than one factor is at work causing what you describe.

I'm guessing that your stock heads carried you through the low rpms with good throttle response getting you into the boost where the blower took over and powered you on past where the stock heads woudl normally fall off in power.

Now that you have heavy breathing heads, you don't have that low speed port velocity that the stock heads offer and the 3.55 gears are not enough to overcome the loss of that port velocity.

Make sure you still have 14 psi of boost, get 3.73 gears and get a tune. I'm sure it'll dramatically change the car's behavior.

i thought 355 were good for s/c cars.. and 373 for n/a... yes i've seen 12-13 pounds ... i never went past 5800 rpms.... well i'm glad its nothing wrong with the car... yes i will take it to a dyno and O2 wideband as soon as i hook the PMS up to it...

 

[5spd GT]

You very well could have experienced the loss of torque...that is common. You will get a harder pull up top.

Keep your 3:55's...those are a great gear