PT88 turbo 347 wont pull past 5k w/dyno graph

[Eagle]

waiting on my tuner to ship it over to me...

[JoeyJoeJoe]

Put stock wires on it, and retest. If you get misfires at idle, you are most likely getting them at higher cyl pressures as well. It is electricitly it will always take the path of least resitance. At higher RPM you might not even feel the miss, it will just be a lack of power.

If you have MSD coils toss stock ones on as well. The stock stuff works great. I have seen turbo cars putting 750 to the wheels with stock ignition.

[Eagle]

Coils are all stock. I've tried 2 diff sets of stock coils, same issue exists with both sets.

I've tried 2 sets of MSD wires too. Same prob.

[Google]

I could see the plugs being the issue but doubt it. I would think maybe the lifters are bleading down under the pressure, but if they are new then I doubt it. How many miles/hrs are on the lifters. Still would like to see a good log with airflow, afr, retard, timing, and what codes are set in the pcm. I do see that some tables are not adjusted in relation to calculated max map under the diagnostic tab but if no code I don't think it would make a differance. I am still leaning on the mechanical side.

Just a thought you could try taking your stock file and start over. Applying the custom 3 bar and save it then open and make all of your changes and save to a new file name, then write entire and make a pass and see what happens. I have seen two times that for what ever reason the file did not take correctly and when it flashed it did wierd things. The threads are around here on hpt though. It took a bit to figure it out and still may not be your issue but worth 10min to try.


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[Eagle]

What do you guys suggest for dwell tables on a turbo car? Another site is suggesting I set everything thats <5msec to 5msec across the entire table...

Thoughts?

Searched and found this... looks like its "understood" not to adjust dwell tables...

[JoeyJoeJoe]

Try STOCK spark plug wires. The MSD ones are junk for LS motors.

[LS4 Delta-V]

Why are we looking at ignition? Are you logging miss-fires?

My opinion is you are out of camshaft.

I have included a dyno graph from a 2000 WS6 that shows the change before and after a custom grind cam.

The specs are ;227/233 on a 112

You can clearly see the difference. The stock cam hits the 5000 RPM wall. While the custom grind continues to pull nicely to 6400 Rpm.

This dyno graph is from mustang dyno.

[LS4 Delta-V]

Here is yet another WS6 stock cam that hits the 5000 Rpm wall.

[LS4 Delta-V]

If I was you, my first step would be to beg, borrow or steal a set of high ratio rockers and re-dyno the car. This should give you the heads up you are moving in the right direction.

[JoeyJoeJoe]

He mentioned in an earlier post that he had some random misfires at idle. Wires are a lot easier and cheaper to try as a test.

[JoeyJoeJoe]

LS4-The last two dyno graphs you posted, are just a normal torque curve. The HP in both continues to climb past 5k.

[LS4 Delta-V]

LS4-The last two dyno graphs you posted, are just a normal torque curve. The HP in both continues to climb past 5k.

You do realize they are double run overlays? In both cases where the stock cam is implemented power stops at 5000 Rpm.

[JoeyJoeJoe]

I do realize that. And in all 4 runs the HP keeps climbing well after 5k. The torque curve drops off, but that is normal. You might want to scale your HP and Torque the same, IMO it make reading them a lot easier.

[SweetS10V8]

May be too much spring. Those are good to .675+ lift, and your running around .500? This would mean the springs are about .200-.250 from coil bind. You need to do some serious shimming or put on a spring that is a better fit.

I also missed what rockers your running.

[2xLS1]

I'm going to suggest that it may not be a problem with the car at all and just may be the Dynojet. I've seen some occasional strange things with turbos when on a Dynojet that aren't there when driving on the street. I would suggest that before you kill yourself trying to sort out a problem that may not be real that you put it on a loaded dyno like a Mustang Dyno and see if it the problem is real under a real load.

[smithers]

I'm going to suggest that it may not be a problem with the car at all and just may be the Dynojet. I've seen some occasional strange things with turbos when on a Dynojet that aren't there when driving on the street. I would suggest that before you kill yourself trying to sort out a problem that may not be real that you put it on a loaded dyno like a Mustang Dyno and see if it the problem is real under a real load.

that all depends on which dynojet. Newer ones and certain models are loaded (same as a Mustang dyno ) (eddy current) and can do constant speed as well.
Check out their site.

[2xLS1]

I'm aware of that option on Dynojets. You can't just say newer ones automatically have it because it is a newer one.

[ns158sl]

My bet is its misfiring and probably spark related too...

[LSxpwrdZ]

I'd stick a camshaft in it... stock cam's suck anyway!

[Hped]

I seeing this on a friends 08 Z06 everything was good to 5200, but there was to much valve float from not closing valves. VALVE FLOAT at 5200 rpms like it would kill the motor felt like a misfire just got new valves and got heads done right everything look much better. Valves where to heavy and not enought seat pressure. Its was fun to figure that out may have something to do with that cam just expierence I had with a friend I personally thing it has to do with ValveTrain. Hope I help out a little bit. Sorry forgot to mension this was at F1-R 18 psi on a 441 LSX.