Flow #'s are in!
Thread Starter
Burning Brakes
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Flow #'s are in!
I just got my heads back. Here are the #'s
STOCK
INTAKE EXHAUST
LIFT L/D CFM LIFT L/D CFM
.200 .112 140 .200 .138 109
.300 .169 179 .300 .207 135
.400 .225 201 .400 .276 158
.500 .281 224 .500 .345 158
.600 .337 215 .600 .414 165
PORTED
INTAKE EXHAUST
Lift L/D CFM LIFT L/D CFM
.200 .112 156 .200 .138 121
.300 .169 210 .300 .207 150
.400 .225 240 .400 .276 175
.500 .281 265 .500 .345 193
.600 .337 257 .600 .414 196
What do ya think?
STOCK
INTAKE EXHAUST
LIFT L/D CFM LIFT L/D CFM
.200 .112 140 .200 .138 109
.300 .169 179 .300 .207 135
.400 .225 201 .400 .276 158
.500 .281 224 .500 .345 158
.600 .337 215 .600 .414 165
PORTED
INTAKE EXHAUST
Lift L/D CFM LIFT L/D CFM
.200 .112 156 .200 .138 121
.300 .169 210 .300 .207 150
.400 .225 240 .400 .276 175
.500 .281 265 .500 .345 193
.600 .337 257 .600 .414 196
What do ya think?
Drifting
Joined: Mar 2001
Posts: 1,351
Likes: 1
From: Kingwood TX
Re: Flow #'s are in! (1MoorTym)
I have a question that is perhaps too general to answer accurately...is 1 cfm improvement about +1hp. Or is it less/more than that. I am sure it varies but is their a normal range on street cars?
Thread Starter
Burning Brakes
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Re: Flow #'s are in! (Vette9d1)
I am not sure what the exact number is myself. I am sure someone can give the right answer. I think it still depends on the rest of your setup too.
Melting Slicks
Joined: Aug 2001
Posts: 2,047
Likes: 0
Re: Flow #'s are in! (UB2 SLOW)
Are the heads that you ported the LT1 heads?
How's about valves? 2.00" intake and 1.56" exhaust valves?
It's interesting to see that the point of diminishing returns occurs at .600" lift... that's the same phenomena that occurred with my LT-1 ported heads. Of course, to get flow over .600" lift, more cubes are required, so it's no big deal..
My .500" lift numbers are damn near identical to yours. I'm running a different cam and shorty headers and the car achieves 360rwhp. You should be right on that mark or a little more. It really pays to have someone that knows what the heck they're doing with the programming of the ECM to work on you car while on the dyno. "Seat of the pants" tuning is no good. I picked up 35hp in a dyno session by tweaking the programming. Air/Fuel ratio is gonna be a big issue.. there's no way it can programmed by mail order.. trust me!
Let us know how it works out!
How's about valves? 2.00" intake and 1.56" exhaust valves?
It's interesting to see that the point of diminishing returns occurs at .600" lift... that's the same phenomena that occurred with my LT-1 ported heads. Of course, to get flow over .600" lift, more cubes are required, so it's no big deal..
My .500" lift numbers are damn near identical to yours. I'm running a different cam and shorty headers and the car achieves 360rwhp. You should be right on that mark or a little more. It really pays to have someone that knows what the heck they're doing with the programming of the ECM to work on you car while on the dyno. "Seat of the pants" tuning is no good. I picked up 35hp in a dyno session by tweaking the programming. Air/Fuel ratio is gonna be a big issue.. there's no way it can programmed by mail order.. trust me!
Let us know how it works out!
Thread Starter
Burning Brakes
Joined: Jul 2002
Posts: 822
Likes: 0
From: I could tell but then I would have to kill you
Re: Flow #'s are in! (EricVonHa)
EricVonHa, They are LT4 heads. The Dyno that is in my area does not have allot of experience with LT engines. He does not have the software to really tune. The only thing I can really do is change fuel pressure.
