I documented this in my '1.7RR install' thread, but wanted to start one just to get feedback on these dyno results.

Only engine mods I have (besides the ones in my sig) are TB bypass, K&N filter, and a hacked factory airbox to let more air in.

How do these numbers look? Are these typical for an LT-1, or did the 1.7s really help out? Keep in mind, I don't have headers and am running a stock tune. Looks like with headers and a good tune, to lean it out, I should be over the 300hp mark.

I ran 3 times, and opened the cutout on the 2nd run.

Environmental conditions were: 91'F | 29.0-0.49inHg. | CF=1.04

Cutout Closed:


Cutout Open:


I was surprised to see 6hp and 2ft-lbs gain with the cutout open. I wonder if this would hold true after I have headers?

Thoughts??

Thomas.

 

FWIW, i have bbk shorties into a y pipe with the cutout where the converter used to be with a flowmaster american thunder cat back. I have no dyno numbers but i run within .05 with it open or closed, so 6 hp sounds about right. Hope this contributes, Prorac1

 

Those numbers seem right on... a pair of headers and a mail-order tune and you should hit 300 at the wheels.

 

I picked up 14rwhp with the cutout open on my 383. It was running through a flowmaster when closed.

 

Thanks guys. I agree, headers and a tune are definitely next on my list.
I was hoping to be closer to the 300hp mark, but I guess the manifolds are really restricting the efficiency of the motor.

Should I wait until after the headers to get a tune, or would the tune be the same regardless if I had headers or not?

Thomas.

 

Are you doing mail order tune? Just tell them you already have headers and then you only have to send the ECM out once. It will run fine on a header tune.