Iron Block 370 W/ L92 Heads, L76 Intake
05-14-2010, 01:24 PM
#1
Iron Block 370 W/ L92 Heads, L76 Intake I just recently assembled a forged 370 for the black car (1997 Z28). This car is mostly a drag car so I don't really care about drivability etc... Eventually I'll be switching the intake manifold to a single plane Vic Jr w/ 4bbl style tb. Here's a rundown on the setup and numbers it put down last night after some tuning. This was done on a Mustang dyno also.
-LQ4 Iron Block
-Mahle -2cc Forged Pistons
-Compstar H-beams
-242/250 .611/.619 114+4 (Old Speed Inc Grind)
-GM MLS Head Gaskets
-Self Ported L92 Heads (exhaust flows very well) Milled .028"
-Self Ported L76 Manifold
-36lb SVO Blue Top Injectors
-NW90
-Custom 4" Intake w/K&N Cone
-1-3/4" Grotyohan Headers
-Custom 3" True Dual Exhaust w/ Summit Bullet Mufflers
-T56 w/ Monster Level 3 / Billet Steel Flywheel
-9" Rearend w/ 35sp Axles and 4.30 Gears
-28-10.50 MT ET Drag Slicks
Baselined the setup with my old tune file from the 387 and it put down 474rwhp with a few degrees of kr up top and was pretty lean. Added some fuel to the tables and she jumped to 482, did the same thing and jumped to 486. Took out 2 degrees of timing up top (my suggestion to the tuner), added some more fuel and she got:
490rwhp @ 6600
437rwtq @ 5300
We stopped the dyno session because on that last run we hooked up a fuel pressure gauge and saw the fuel pressure dropping after 4600rpm. It was only 33psi at 6700rpm.
Time for a new fuel pump lol.... 
http://www.youtube.com/watch?v=Ti0zoMlMonI
I'll try to post up the graph here in a bit..... Overall I'm pretty happy with the numbers for such a small cubed engine.
Mike
-LQ4 Iron Block
-Mahle -2cc Forged Pistons
-Compstar H-beams
-242/250 .611/.619 114+4 (Old Speed Inc Grind)
-GM MLS Head Gaskets
-Self Ported L92 Heads (exhaust flows very well) Milled .028"
-Self Ported L76 Manifold
-36lb SVO Blue Top Injectors
-NW90
-Custom 4" Intake w/K&N Cone
-1-3/4" Grotyohan Headers
-Custom 3" True Dual Exhaust w/ Summit Bullet Mufflers
-T56 w/ Monster Level 3 / Billet Steel Flywheel
-9" Rearend w/ 35sp Axles and 4.30 Gears
-28-10.50 MT ET Drag Slicks
Baselined the setup with my old tune file from the 387 and it put down 474rwhp with a few degrees of kr up top and was pretty lean. Added some fuel to the tables and she jumped to 482, did the same thing and jumped to 486. Took out 2 degrees of timing up top (my suggestion to the tuner), added some more fuel and she got:
490rwhp @ 6600
437rwtq @ 5300
We stopped the dyno session because on that last run we hooked up a fuel pressure gauge and saw the fuel pressure dropping after 4600rpm. It was only 33psi at 6700rpm.
Time for a new fuel pump lol.... http://www.youtube.com/watch?v=Ti0zoMlMonI
I'll try to post up the graph here in a bit..... Overall I'm pretty happy with the numbers for such a small cubed engine.
Mike
Last edited by Mikey 97Z M6; 05-14-2010 at 01:51 PM.
05-14-2010, 01:31 PM
#3
I just recently assembled a forged 370 for the black car (1997 Z28). This car is mostly a drag car so I don't really care about drivability etc... Eventually I'll be switching the intake manifold to a single plane Vic Jr w/ 4bbl style tb. Here's a rundown on the setup and numbers it put down last night after some tuning. This was done on a Mustang dyno also.
-LQ4 Iron Block
-Mahle -2cc Forged Pistons
-Compstar H-beams
-242/250 .611/.619 114+4 (Old Speed Inc Grind)
-GM MLS Head Gaskets
-Self Ported L92 Heads (exhaust flows very well) Milled .028"
-Self Ported L76 Manifold
-36lb SVO Blue Top Injectors
-NW90
-Custom 4" Intake w/K&N Cone
-1-3/4" Grotyohan Headers
-Custom 3" True Dual Exhaust w/ Summit Bullet Mufflers
-T56 w/ Monster Level 3 / Billet Steel Flywheel
-9" Rearend w/ 35sp Axles and 4.30 Gears
-28-10.50 MT ET Drag Slicks
Baselined the setup with my old tune file from the 387 and it put down 474rwhp with a few degrees of kr up top and was pretty lean. Added some fuel to the tables and she jumped to 482, did the same thing and jumped to 486. Took out 2 degrees of timing up top (my suggestion to the tuner), added some more fuel and she got:
490rwhp @ 6600
437rwtq @ 5300
We stopped the dyno session because on that last run we hooked up a fuel pressure gauge and saw the fuel pressure dropping after 4600rpm. It was only 33psi at 6700rpm. Time for a new fuel pump lol....
I'll try to post up the graph here in a bit..... Overall I'm pretty happy with the numbers for such a small cubed engine.
Mike
-LQ4 Iron Block
-Mahle -2cc Forged Pistons
-Compstar H-beams
-242/250 .611/.619 114+4 (Old Speed Inc Grind)
-GM MLS Head Gaskets
-Self Ported L92 Heads (exhaust flows very well) Milled .028"
-Self Ported L76 Manifold
-36lb SVO Blue Top Injectors
-NW90
-Custom 4" Intake w/K&N Cone
-1-3/4" Grotyohan Headers
-Custom 3" True Dual Exhaust w/ Summit Bullet Mufflers
-T56 w/ Monster Level 3 / Billet Steel Flywheel
-9" Rearend w/ 35sp Axles and 4.30 Gears
-28-10.50 MT ET Drag Slicks
Baselined the setup with my old tune file from the 387 and it put down 474rwhp with a few degrees of kr up top and was pretty lean. Added some fuel to the tables and she jumped to 482, did the same thing and jumped to 486. Took out 2 degrees of timing up top (my suggestion to the tuner), added some more fuel and she got:
490rwhp @ 6600
437rwtq @ 5300
We stopped the dyno session because on that last run we hooked up a fuel pressure gauge and saw the fuel pressure dropping after 4600rpm. It was only 33psi at 6700rpm.
Time for a new fuel pump lol.... I'll try to post up the graph here in a bit..... Overall I'm pretty happy with the numbers for such a small cubed engine.
Mike
05-16-2010, 02:33 PM
#5
TECH Regular
Join Date: Dec 2003
Location: Cherry Hill, New Jersey State
Posts: 486
Received 0 Likes
on
0 Posts
nice set up.
from what I see from the other threads, you will be hitting the 530rwhp wit the following:
-cam of 228/235
-1 7/8 headers
-Fast and TB
from what I see from the other threads, you will be hitting the 530rwhp wit the following:
-cam of 228/235
-1 7/8 headers
-Fast and TB
Trending Topics
06-09-2010, 11:46 AM
#13
Here's the custom intake setup I made for it,,,, there used to be an LT1 in there. The stock LT1 elbow off the the TB fits the NW90 perfectly so I re-used it. Also, the ABS delete eliminates clearance issues with the larger 4" piping.
Mike
Mike
The tuner kept adding fuel and adding fuel and finally I was like; 
"Maybe we should check the fuel pressure?" LOL.... 
06-10-2010, 03:30 PM
#18
Nice results, but I believe you have an easy 10-20 rwhp left on the table with your intake setup. 90 degree elbows have been known to kill power, especially on the GTO's and yours is similar. If you can come up with an over the radiator type intake setup you would gain a bit. Good luck at the track, this Washington weather is making me go insane!
06-10-2010, 05:42 PM
#19
Nice results, but I believe you have an easy 10-20 rwhp left on the table with your intake setup. 90 degree elbows have been known to kill power, especially on the GTO's and yours is similar. If you can come up with an over the radiator type intake setup you would gain a bit. Good luck at the track, this Washington weather is making me go insane!
And you're right, this weather here is sucking....
Mike
