Dyno help, c5z bolt-ons
I just helped my friend install a H/C/I/E in his 04 z06, need some opinions on this build, we think it should be making more power with the current list of mods.. So does the tuner. Dyno sheet attached. Numbers are 439whp/ 393wtq, stock bottom end with 70k miles.
List of mods:
-Vararam with PD
-STOCK 85 maf
-Ported ls2 throttle body
-Fast 102 with velocity ring
-FIC Bosch 3 inj 42lbs at stock pressure
-Ls2 fuel rail
-Dart 225 heads with psi springs: 120lbs seat-1.800, 360lbs-1.175, coil bind 1.100, .625 max lift
-STOCK rockers currently, Harland sharps will go on soon
-Ls7 lifters and comp hi-tech pushrods
-Mike Jones cam: 231/236 @.050, .612/.600 lift
-Melrose exhaust: 1 3/4 headers, no cat, x-pipe, corsa xtreme axle-back
Mike Norris did the tune on a 248x dynojet, power delivery is smooth and strong. I am curious by the power curve flatlining for 700 rpm, Mike Norris thinks the numbers are low and not sure why. I got with Mike Jones and he looked at it and doesn't see signs of valve float.
What do you guys think? No leaks, engine operates quietly and smoothly and no codes.
Did anyone do the math on compression?
Was the MAF clean when it was tuned?
Is there a baffle loose in the stock muffler?
Was the air filter clean? They get dirty QUICK with a VR
That curve on the sheet is quite ugly, jus sayin.
Last edited by FASTFATBOY; Jul 15, 2017 at 09:20 AM.
Did anyone do the math on compression?
Was the MAF clean when it was tuned?
Is there a baffle loose in the stock muffler?
Was the air filter clean? They get dirty QUICK with a VR
That curve on the sheet is quite ugly, jus sayin.
Last edited by cypher85; Jul 15, 2017 at 12:42 PM.
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Can you turn the key on and confirm 100% throttle blade opening while the MAF is off?
Clean the MAF with Q-Tips and alcohol, that spray stuff won't get it done.
Is this a SBE car?
How far is the piston out of the hole?
Full flat top piston?
Did you actually CC the head or take their word for it(before and after if they were milled)?
What gasket compressed thickness?
Last edited by FASTFATBOY; Jul 15, 2017 at 01:22 PM.
Clean the MAF with Q-Tips and alcohol, that spray stuff won't get it done.
Is this a SBE car?
How far is the piston out of the hole?
Full flat top piston?
Did you actually CC the head or take their word for it(before and after if they were milled)?
What gasket compressed thickness?
Heads brand new when we put them on, they were not milled.
Last edited by cypher85; Jul 15, 2017 at 04:51 PM.
Heads brand new when we put them on, they were not milled.
My LS6 243's were 65 CC's AFTER they were milled for a clean up and the valve job done. So I could guess they were 66 ish cc prior.
My piston was 8 out of the hole(block was square decked), Mahle piston had 4cc reliefs, .051 gasket. I had to mill to 59CC to get 10.95 to 1.
I would not surprise me if you were down on compression. How much wot timing does it have?
What length push rod is in it? The LS7 has a taller cup in it over the stock lifter if memory serves, so it'll take a shorter pushrod.
What is the cams LSA?
Last edited by FASTFATBOY; Jul 15, 2017 at 06:53 PM.
Cam is 114 LSA, pistons do not have valve reliefs. Dart claims this head is cast at 62cc, my AFRs in my vette were much smaller than advertised. I do not think we are down on compression.
I do not have timing information, Mike Norris did the tuning and we have not datalogged the car yet.
I just helped my friend install a H/C/I/E in his 04 z06, need some opinions on this build, we think it should be making more power with the current list of mods.. So does the tuner. Dyno sheet attached. Numbers are 439whp/ 393wtq, stock bottom end with 70k miles.
List of mods:
-Vararam with PD
-STOCK 85 maf
-Ported ls2 throttle body
-Fast 102 with velocity ring
-FIC Bosch 3 inj 42lbs at stock pressure
-Ls2 fuel rail
-Dart 225 heads with psi springs: 120lbs seat-1.800, 360lbs-1.175, coil bind 1.100, .625 max lift
-STOCK rockers currently, Harland sharps will go on soon
-Ls7 lifters and comp hi-tech pushrods
-Mike Jones cam: 231/236 @.050, .612/.600 lift
-Melrose exhaust: 1 3/4 headers, no cat, x-pipe, corsa xtreme axle-back
Mike Norris did the tune on a 248x dynojet, power delivery is smooth and strong. I am curious by the power curve flatlining for 700 rpm, Mike Norris thinks the numbers are low and not sure why. I got with Mike Jones and he looked at it and doesn't see signs of valve float.
What do you guys think? No leaks, engine operates quietly and smoothly and no codes.
If all looks well get a mph at the track as you said
Nothing wrong with Dart heads they just approach things a little differently; you know Mike Jones grinds one hell of a good cam
Go from there...see how your C4 stacks up against it.
Last edited by cv67; Jul 16, 2017 at 10:34 AM.
If all looks well get a mph at the track as you said
Nothing wrong with Dart heads they just approach things a little differently; you know Mike Jones grinds one hell of a good cam
Go from there...see how your C4 stacks up against it.

Then we will datalog and see how it does at the track. One day I will get back my intake and will see how it does against the Z. I bested him when his car was stock, so we will see if the older brother c4 can keep the same with a bigger cam and some intake and head work! Thanks for the advice.
Last edited by cypher85; Jul 16, 2017 at 10:29 PM.
















