Vinnie's dyno results

[Fbomb]

Well, on my last pull (the best one) I only made 380hp and 368 lb. ft. of torque. I definitely think something is up because it's about 50 less than I was shooting for.

I think I'm going to do a compression test tomorrow. Remember in the spring when I was doing my build it seemed like the pushrods were just a hair too long. Maybe I'm not getting enough compression? May have to go 7.4" from 7.425"

[ThreeHonks]

WTF? you released your dyno numbers? ya know, the new craze is for everyone to pretend they're one of the grudge racers over on Motown...

[Fbomb]

I don't race it so there's no point.

Oh yeah and mods:
cam-230/230 .612/.591 111+2
heads-LS6 unported, PAC dual springs
Intake-LS6 manifold, SLP lid
Exhaust-1.75" primary longtubes into 3" Y with cutout open

380 to the wheels does NOT seem normal to me for this build. I don't think it's the tune but I might look at spark timing later. Phil told me that the WOT AFR is about 12.2:1. I'm thinking maybe it's not building enough compression because the valves are staying open just a bit.

[ThreeHonks]

I don't race it so there's no point.

Oh yeah and mods:
cam-230/230 .612/.591 111+2
heads-LS6 unported, PAC dual springs
Intake-LS6 manifold, SLP lid
Exhaust-1.75" primary longtubes into 3" Y with cutout open

380 to the wheels does NOT seem normal to me for this build. I don't think it's the tune but I might look at spark timing later. Phil told me that the WOT AFR is about 12.2:1. I'm thinking maybe it's not building enough compression because the valves are staying open just a bit.

I was being sarcastic. But yes, it sounds like it could just be something as simple as a pushrod issue

[Fbomb]

Yeah I know Ryan, I'm just not in a very funny kinda mood right now ya know?

Anyways, with a pushrod issue wouldn't it cause it to run like complete dog ?

It's not like it's backfiring out the intake or anything.

[Fbomb]

Any idea on what kind of cranking pressure I should be seeing?

[ThreeHonks]

not sure on that. i would start with a compression check.

[DETROITMUSCLE]

check compression first, those pushrods are gonna be damn close if you ask me and no the car wouldn't run like crap just make a bit less power and drop off up top. Post the graph.

[Fbomb]

Well I got 180psi cranking pressure so no problems there. Maybe the valve not seating properly would make more of a difference at higher rpm? Doesn't seem like it though because there would be less time for pressure to bleed off. Of course, during the combustion cycle it may make a huge difference. Although my intake ports looked very clean.

[DETROITMUSCLE]

how do the plugs look?

[Fbomb]

Looked fine. Not black, not white. I'm looking at my spark tables right now though, spark advance looks a little retarded. At cylinder airmass of .08 to .24 it's at 3* BUT, .52-1 it's only 26* I'm not sure how to relate cylinder airmass into the equation but you'd think under more throttle there'd be more cylinder airmass.

[Fbomb]

Ok well after looking into it, it seems like I only have 26* of advance at WOT from 2200rpm to redline. Should be more like 36* shouldn't it? Not that I think it would cost me 50hp to the wheels but it's something.

[DETROITMUSCLE]

36* is a lot IMO 26* sounds more correct. Why don't you call Phil and pick his brain a bit.

[prorac1]

IIRC LS1s like around 26 to 28 degrees of timing at WOT. LT1s are a little higher at around higher thirties depending on the setup.

[Fbomb]

Well I did some more reading and apparently LS1's don't need as much timing as the older engines because the heads are more efficient (HAHA!). Guess I've been doing too much tuning on the 67...

Other than that I have no idea why I'm not making as much power as I should. Maybe the pushrods being just a bit too long wouldn't affect cranking pressure that much? I PM'd Phil for some ideas.