AFR LT4 H/C dyno results.
Thread Starter
Registered User
Joined: Feb 2004
Posts: 180
From: MI
AFR LT4 H/C dyno results.
379.2rwhp @ 6400rpm & 334.9rwtq @ 5300rpm on the Mustang Dyno at AP Engineering. I have 300 ft/lbs above 2700rpm and the torque "curve" is more like a flat line.
Stock shortblock, and here are the mods:
Race ported AFR LT4 heads, 280cfm @ .6; port matched intake; 58mm TB.
233/239 .569/.577 XER Comp Cam.
Hooker longtube headers; "catless" y-pipe; Corsa catback.
K&N filter & airbox.
A while back, I was having some valve-float issues. I got some new springs put in and went back to AP to make sure the problem was corrected. The motor pulled strong to 7000rpm.
Chris at AP Engineering said he's never had a stock-cube LT1 car put down 400rwhp on their dyno. I think I could get pretty close. For one - I have a Ford 9" - I'm thinking that sucks up a little more power than a 10 bolt. For two, I could swap over to 1.7 ratio rocker arms from the 1.6's on there now. For three, I have some KOOKS 1 7/8 stainless headers waiting to go on. I could also throw on some underdrive pulleys and an electric water pump. Anyone else think 400 at the wheels is attainable?
Stock shortblock, and here are the mods:
Race ported AFR LT4 heads, 280cfm @ .6; port matched intake; 58mm TB.
233/239 .569/.577 XER Comp Cam.
Hooker longtube headers; "catless" y-pipe; Corsa catback.
K&N filter & airbox.
A while back, I was having some valve-float issues. I got some new springs put in and went back to AP to make sure the problem was corrected. The motor pulled strong to 7000rpm.
Chris at AP Engineering said he's never had a stock-cube LT1 car put down 400rwhp on their dyno. I think I could get pretty close. For one - I have a Ford 9" - I'm thinking that sucks up a little more power than a 10 bolt. For two, I could swap over to 1.7 ratio rocker arms from the 1.6's on there now. For three, I have some KOOKS 1 7/8 stainless headers waiting to go on. I could also throw on some underdrive pulleys and an electric water pump. Anyone else think 400 at the wheels is attainable?
Whats the size of the AFRs on there?
Thread Starter
Registered User
Joined: Feb 2004
Posts: 180
From: MI
Re: AFR LT4 H/C dyno results.
Richard Cummings did the heads. Hand port job. I've heard pulleys are a waste. As far as electric water pumps, what kind of number might I pick up?
As far as going to the track - I don't think I'd put down what I would call "respectable" times. I've never raced it. It's strictly a street driven car. Not to say that I won't try . . . quite honestly I'd be thrilled if I could break into the 11's for the 1/4 mile. That would require some much stickier tires - cause 1st and 2nd gear go up in smoke whenever you floor it. I thought I solved that problem with ZR1 17X11's with 315's out back . . . apparently not.
As far as going to the track - I don't think I'd put down what I would call "respectable" times. I've never raced it. It's strictly a street driven car. Not to say that I won't try . . . quite honestly I'd be thrilled if I could break into the 11's for the 1/4 mile. That would require some much stickier tires - cause 1st and 2nd gear go up in smoke whenever you floor it. I thought I solved that problem with ZR1 17X11's with 315's out back . . . apparently not.
Registered User
Joined: May 1999
Posts: 537
From: Watertown, Mass
Re: AFR LT4 H/C dyno results.
I have those same rims in the rear. They dont do anything for straight line traction but they are really awsome for handeling. The electric waterpump will give you 7 rwhp. An exaust cut out will give you 15 to 25 rwhp. Did you use stock injectors? If you did not get bigger ones. Plus a fuel pressure regulator to make sure you get the right amount of fuel. Was the ski jump in the intake ported? If not thats another 10 rwhp.
Under drive pulleys are a waste. After the over drive pulley needed for the altenator all it does is spin the power sterring slower. And that makes steering pretty hard with 275's up front.
Under drive pulleys are a waste. After the over drive pulley needed for the altenator all it does is spin the power sterring slower. And that makes steering pretty hard with 275's up front.
Registered User
Joined: Dec 2002
Posts: 690
From: Denton, TX
Re: AFR LT4 H/C dyno results.
i was told that on a stock LT1 shortblock to leave the intake alone. there are cars making 425rwhp SAE with stock intakes. just look at AIs site. 15-25rwhp for a cutout, only if you have a 12:1 396 and a stock exhaust.