weird dyno session... stumped and gunshy

[IDRIVEAG8GT]

IMHO I would up to a TR6 over the 7 with a .0028 gap. Being that the belt shit on you too leads me to believe you could've had belt slip in the first place combined with what I previously read about about the TB sucking shut.

To be honest I'd pick up the Kenne Bell version of the LS3 throttle body with that badass motor on it to prevent that from happening. If your still not in the high 700's after all that then I'm lead to believe something is mechanically wrong with engine, or choice of cam is FUBAR.

[edcmat-l1]

Get it on a dynojet. As much as some of youse guys hate them, they are notoriously consistant from machine to machine.

[DSteck]

Cam specs are reasonable for this setup. I couldn't say anything about the engine, and it just seems odd it had low numbers on the 434/2300 combo as well.

Why run a hotter plug? I don't doubt the belt was causing low numbers, considering it picked up almost three pounds of boost with a fresh belt.

For getting a consistent number, we usually do try using a DynoJet just because they do come up consistent. This guy wants a drivable car but wants a number too (and I don't blame him one bit). I don't hate them. I am not even getting into that though.



The throttle body is the least of my concerns right now.

[PGA2B]

What I think he is saying about the belt is that it was slipping or misaligned and that is why it shred. Was there any signs of belt slip or a misaligned belt? Also can he do a continuity check on the injector wiring harness to check for a break in the wire? Being an ex-car audio guy (13 years) I have torn my hair out chasing down wiring issues.

[DSteck]

No dust from a slipping belt, although I noticed belt squeal all morning and the belt looked like it may have been rubbing something. It only had 600 miles. We will see what the new belt does. No witness marks on it thus far.

[PGA2B]

Nevermind. I read the last sentance again......

How about holding the idle higher and have someone play with the injector and coil harnes to see if it stumbles or changes? If it is intermittent the flex of the motor on the dyno could have caused it to short.

[edcmat-l1]

I'm not saying run it in a DJ for a number, but the sake of simplicity. No issues with calibrations, etc. Strap it down, hit the button, make the pull.

[DSteck]

That's on the to do list, just to rule out a heartbreaker dyno.

[edcmat-l1]

That's on the to do list, just to rule out a heartbreaker dyno.

Yep. I like the least amount of variables. Another reason for a DJ over other brands. But that's for another thread.

[DSteck]

Needs a stronger throttle first. Reported blade position would only get up to 92% or so with the pedal to the floor, then the ETC position would start to waver and then just crap out and close.

[IDRIVEAG8GT]

I run a hotter plug just because they seem to burn more efficiently, but that's here at 3,500 ft in elevation.

[DSteck]

I guess changing coils side to side may have inadvertently fixed it. No more misfiring and with the older LS2 throttle body, I can sustain WOT. The owner is elated. Lol. Thanks guys, I'm going to keep an eye out next time I'm with this car.

[Mike@G-Force]

valve float will also show a similar effect

YYUUUUPPPPP!

[Mike@G-Force]

FYI Ive done a 700 RWHP 2009 V with a NW102m tb with no issues.


And a BIG 3.6L Kenne Bell on a 2011 Camaro that made 22 psi and the 102 tb didnt shut on that one either.

[DSteck]

This 102 definitely didn't want to play ball.

[realcanuk]

I guess changing coils side to side may have inadvertently fixed it. No more misfiring and with the older LS2 throttle body, I can sustain WOT. The owner is elated. Lol. Thanks guys, I'm going to keep an eye out next time I'm with this car.

Just a thought since moving the coils fixed things. I had some strange and similar issues and after many hours trying to figure it out it turned out that the wiring harness to the coils on one side had gotten crushed under the bracket and was causing crazy, hard to trace missing. A new harness fixed things after hours and hours of swapping coils, plugs, wires, etc. If its that, then its possible by moving the coils you fixed the issue temporarily.

[DSteck]

Yea, I'm still hesitant to call it fixed. I hate intermittent problems.

[PGA2B]

I had some strange and similar issues and after many hours trying to figure it out it turned out that the wiring harness to the coils on one and was causing crazy, hard to trace missing. A new harness fixed things after hours and hours of swapping coils, plugs, wires, etc. If its that, then its possible by moving the coils you fixed the issue temporarily.

Just like what I said in post 24 and 26. I have spent several hours of my life I will never get back chasing down wiring issues.

[realcanuk]

Yea, I'm still hesitant to call it fixed. I hate intermittent problems.

Yes. They are the worst. I am not even sure that on that car the coil setup is the same but if it is, this is a problem that pops up fairly often with LS2's and LS3's. If not carefull it is easy to crush those wires under the bracket that holds them.

[DSteck]

These coils have been slightly relocated due to the Mast heads.