A disappointing day at the dyno.
Power and torque are low for my 383 TPI.

What is wrong with this graph? I've never seen a graph where the tq and hp are parallel.

What can I do to bring my levels to where they should be?

The car is the 92 in my sig.

 

And where should the levels be?

I think that camshaft is way too big for that engine.

 

Way too lean then goes rich, you've got a tuning prob for one.

 

I would've thought about 40hp more.

Camshaft too big?
Really?
That cam was actually custom ground through thunderracing.com's suggestion for my 350. I just through it in my 383 since it was still 400 miles new.

What would you suggest for a cam?

Did you also notice that the hp and tq curves were parallel? I've never seen that before.

 

The graph is pure full throttle. We tuned for 12.9:1.
Couldn't seem to get rid of the jiggle around 4600rpm.

 

Exactly which heads are on the engine?

 

cam is not huge for that setup, i think it should work pretty good with TPI on a 383.

Your way to lean at first in your lower rpm bands where torque will be greatest. I see your near 17 to 1. You will pick up 30-40 lbft torque just by getting that down to near 12.8-13.0 to 1. Richen that up. I gained 30lbft going from mid 15's to 1 air fuel down to mid 13's.

Whats your timing curve look like at WOT? give it a 30-32 degrees at 2800 to 3000 then hit it with full 34-35 degrees from 3000 to redline. AFR's dont need alot of timing to run good. My setup ran best at 34 and I tried 34-39 degrees both on dyno and track.

Do a better job on the tune to get air fuel in the 13.0 to 1 range and it should pick up. Richen up the bottom end, lean out the top end

Was the converter locked up on this run or did it stay open? Locked up will show more power

BUT overall your graph looks funky. Torque should NOT be peaking in the 5200+ rpm range on that setup. It should NOT follow the hp curve like that. HP = torque*RPM/5252. Your curve does not follow this, so verify that they had a good tach/rpm signal and that the dyno was calibrated correctly.
Its good to see hp peaking up in the 5500 rpm range with TPI and 383, and it holds flat to near 6k. Just should be much more than what is shown on the chart but like i said, something is wrong with the dyno readings because the torque curve should not look like that.

 

Maybe I'm missing something, but it looks to me like everyone is looking at the first graph and not the second one which looks pretty funky to me. It peaks then drops off and goes flat. The AFR actually looks pretty good on it. Did you let off the gas a little at 46-4700 or something?

 

Looks like the infamous TPI wall to me.

The second run is for a very short RPM range, not surprised it looks 'weird'. The first portion is most likely the converter settling in, the rest is all TPI. The only odd thing I see is the thing going lean after the AFR hits about the right spot. Either it needs more tuning or something is amiss with the fuel delivery. Checked your plugs?

 

AFR 195 Eliminators

 

I'm running a sligthly massaged s_aujp_v3 spark table. Changing the table at 4K+ either plus or minus even 2 degrees netted me lower numbers.
I'm going to have to say that the converter did lock. I did not disable it when going into the dyno shop.

 

Good point.
The first graph is my first run.
The second graph is my final run.

I was not allowed to press the go pedal. One of the shop guys was doing that. The jiggle around 4600 rpm was there on every run. We did manage to make it flatten just a bit.

 

The reason the second (and concurrent 10 runs) is so short is because "This thing shifts so fast and gets up into the rpm's so fast that we can't get anything useful below this rpm" said the dyno shop guys.
Crap I say but they're the closest dyno shop around and I had virtually unlimited time to dyno for $90 bucks.

The TPI wall? Shouldn't it have been raised higher than 4800 with the addition of an entire enlargement of the intake system?

My plugs have a very nice tan to them.

 

When it was a 350 with all of these mods except what made it a 383 it felt so much more powerful.
This thing was pulling like a raped ape even to 6800 in second and well into third gear. I missed a shift twice during the 6800 rpm run causing the meltdown of a piston
Still feels good with the 383 just weaker. I know the SOTP dyno isn't accurate but that aside, I was a bit disappointed with these 383 results.
I see 350's on here with better numbers than these.