losing power with load, tuning question.

[OinkAodeOink]

This cars really odd..

For anyone who doesnt know the car/motor it consists of a 342ci stroker, 57mm turbo, Edel heads/intake, stock cam (1.6rr's)373 gears, stock AODE.

Now for tuning with the tweecer, i havent messed with a whole lot. Ive bumped the CID to 342ci, 42lb injectors, 42ProM maf, and raised th low end timing a tad ( 4*)


The car is a complete animal until you hit 3rd gear, with some load on the motor. I mean it pulls nice, but you can defintaly feel it drop off in power.
Boost stays around 9-10psi all through the gears. I do have some serious boost leaks, but it manages to stay around 10psi.

So basically, without alot of load on the motor, the thing pulls like a train.. when it catches traction, and some load.. it drops off in power. It also breaks up real bad past 5500rpms..Im almost certain thats ignition, or spark blow out, by the sound of it.

Oh yea: datalogging has shown 199% load figures under boost. 80% cruise. with the CID set to 342ci. Whats up with that?

 

[wytstang]

Sound like under a load there isn't enough spark being made. How do the plugs look?

 

[OinkAodeOink]

I havent even checked the plugs in months.. They are Autolite 23's gapped at .32 i believe

 

[wytstang]

I would pull the plugs out and see what they say if you don't have proper ignition they are probably starting to build some heavy carbon oxidation on them. I'm not to sure/know about proper gaping but .32 seems too small of an opening to give off a proper or strong enough spark.

 

[89 blue lx]

I would pull the plugs out and see what they say if you don't have proper ignition they are probably starting to build some heavy carbon oxidation on them. I'm not to sure/know about proper gaping but .32 seems too small of an opening to give off a proper or strong enough spark.

yeah but a bigger gap on a blown application would be more likely to blow out dont you think

 

[OinkAodeOink]

that is true, thats why i run a pretty tight gap at .32 I could go down to 30, but its probably more so a need of better ignition, then plug gap.

 

[VibrantRedGT]

Mike are you running any ignition upgrades?

 

[final5-0]

Oink

On the high load thing it is normal with a power adder. I don't read a lot of power adder threads but I've seen enough of them to know that those guys sometimes change, I think, the scaling to report lower loads.

Lots of threads about it on the two Tweecer sites.

Your high end miss does sound like spark blow out. I've seen the power adder guys move the plug gaps down to 25 to 35 thou and or go with an ignition that will pump out more spark.

Do you have a wide band to let you see whats goin on under boost?

Later
Grady

 

[OinkAodeOink]

as for ignition the only thing i have is an MSD coil.

As for the a/r under boost.. Last time i had the car on a dyno i was making 15psi, 19* total timing, running in the 8 range on the a/f..
Now im running 10psi, and have bumped the timing 5* more, and the car seems faster on 10psi then it did on 15.. I still get the black clouds, as i did when i had it dynoed.