I went to the Dyno and did some runs to find out what kind of power I am making and to get the S-AFC tuned on the '91 TII. My numbers are rather disappointing. Anybody with experience reading dyno plots mind seeing what they think?

The tuner thinks the stock turbo is maxing out because of the street porting. I really don't know what to think. I am going to try new spark plugs. But I really doubt that will do jack. Any ideas?

James

 

looks like the boost started droping off around 5700rpm which is pretty normal for a stock turbo since it's too small.

what boost were you running? what gear?

I didn't see any intake in your sig. a cone filter and 3" TID would help alot.

 

Oh yeah...what boost am I running. Starts off at 13psi and then it drops to about 7-9 as it gets to redline. They were 3rd gear runs. We were spraying ice water on the intercooler during runs and after runs. She also has the stock intake with a K&N filtercharger.

I am considering upgrading the stock turbocharger. Like the SR - Motorsports page has.

James

 

get a cone filter and a TID. it will give alot more power and stop the boost from droping as much. but beware of more creep!

a 4th gear run would net some more power too.

 

Just a few comment or 2..

You really want to try and stay at about 12:1 air/fuel ratio to stay safe.. from the dyno you seem to be running pretty lean even past the point of your secondaries kicking in, in 3rd gear, you should hit full boost at aprox 3500rpm, and at that point you are showing well above 13:1,much too lean.. then past 5500 rpm you're power starts to take a bit of a dive, but you are also running quite rich starting at that point..

I could suggest you lok into leaning out the top end out a bit with the s-afc , while richening things up below 5000 rpm ..

Just out of curiousity, what are you urrent s-afc correction settings at right now?

 

Yeah, I have to agree with Chris here,(and not just because he gave me a killer deal on my TII)..You are lean under lower rpm's on boost, thats where detonation is most likely to happen, and its getting way rich on the top end, pull back the top end fuel a tad, and you should see the torque drop off a little farther up the rpm band...
What exhaust is on your car? That drop at 6000 is pretty dissapointing , the TID, and other flow tricks should move that up a bit, being that's the better of the TII turbo's and manifold, you would think it would be higher than that, any exhaust leaks around the turbo? The power band ending at the high 5's does not take any advantage at all of the rev range of the rotary.. in fact right now your car would probably be faster on the road if you shifted at 6 and no higher.. The fuel curve looks totally rpm dependent, If memory serves me corrrectly, Chris has his s-afc wired to the boost signal, he will probably add to that..
It looks like you have the famous "secondary hesitation" too, but you may be able to lessen that low rpm power drop off with more fuel down low, just watch your pulse width...Max

 

HAha. Wow. I am making alot more horsepower 8 1/2 PSI. Somethign is definetly wrong.

 

make sure you dont' have an ignition problem

 

[Vosko] How do I know if I have an ignition problem? I have replaced the spark plugs and there are new wires. The timing is on.

James

 

its rare but you could have a bad coil or even the new spark plug wires might be bad. only way to test is swap them out and see what happens ..... have you done a compression test?

 

hmmm my 91 TII hit 173-177 (last run-first run) all stock...somethings up...

 

1) You're running too rich.

2) You've got nasty ignition break-up.&nbsp Have you changed the spark plugs and spark plugs wires recently???




-Ted

 

is that because the lines are so unstraight? I noticed that but didn't know what would cause it. the lines should be "straight"