This information is from my Corvette but it is still usefull for the thirdgen cars.

I was able to dyno my 406 with the SR intake, ported trick flow heads and ZZX cam today (other mods are in my sig). I was hoping for 400 RWHP and 450 RWTQ numbers and I was close.

The final numbers were 405 RWHP at 5400 RPM and 436 RWTQ at 4000 RPM with a very flat torque curve. The car had more then 400 RWTQ from 3400 RPM to 5300 RPM and more then 350 RWHP from 4200 RPM to 6400 RPM. These numbers were generated with a locked torque convertor so I could see what the engine was doing without the effects of the torque convertor.

When I unlocked the torque convertor the RWTQ numbers jumped to 490 RWTQ at 3600 RPM and then steady dropped as the RPM increased and the HP still occured around 5500 RPM but was down to 379 RWHP. The multiplication effect of the convertor actually boosted my low RPM HP but it dropped off the max HP readings by 25 HP over the locked set-up. Up to 4800 RPM the unlocked convertor set-up made more power then the locked convertor but after 4800 the locked set-up pulled away. In other words the multiplication effect of the convertor did its job up to 4800 RPM, after that the slipping of the convertor cost me 25 RWHP. It would be nice to lock the convertor after 4800 RPM and get the best of both worlds but my current combination cannot do that.

All in all I was pleased but there is still some power on the table that I am going to attempt to find.
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1986 Coupe, auto, 3.45 gears, 1973 406, 11.5 to 1 compression, SLP cold air, gutted MAS, 58 MM throttle body, ported plenium, Superram intake, TPIS BASE, 23 degree Trick Flow Heads, ZZX cam, TPIS headers, TCI 3000 stall, 3" duel exhaust, Cheap and easy free mods, custom chip, daily driver
RWHP 405 @ 5400 RWTQ 436 FTLBS @ 4000
Best ET 11.81
Best MPH 114.78
Best 60 FT 1.554

 

Good report and numbers. I was particularly interested in the torque converter numbers. I have changed my torque converter from an SLP 2400 to a Yank SS3600. I suspect my HP and Torque curve will also change some on my next dyno session. Anyways it won't be an apple to apple comparison.

 

Awesome numbers, particularly with the SR and MAF. Why can't you lock the converter with your current combo? Typically you can force lock-up by jumpering the ALDL connector or by using the forced lock-up MPH threshold that is defined in some PROM masks. Would either method be an option for you?

 

I can use either option to force lock-up of the convertor but the convertor is not designed for that abuse and it will eventually be destroyed. I could change to a three disk convertor that can handle forced lock-up at WOT but they are expensive.

 

I do not have numbers to back up but locking my converter in 2nd gear at 5000 rpm definately gives the sensation of a much harder pull from the motor. I upgraded my vigilante to a multi-disc for that very reason.

I'm curious as to what my 406 will do on the dyno?

Good numbers!

www.geocities.com/dzperf

 

Understand. My single disc Vigilante isn't made for that either but I'm not pushing anywhere near as much power. I'm thinking about bringing two PROMs to my next track outing. They'd be identical except one locks the converter at a MPH that corresponds to an engine RPM past the HP peak and the other keeps the converter unlocked through the whole quarter. Know this isn't conducive to converter clutch life but it would provide data to see if a multi-disc is a worthwhile upgrade.

 

Excellent numbers!

Thank you for sharing!

 

Thank you for sharing. Sounds like a very strong running combo.

I did some math on that torque converter loss..... 25HP at the 400HP level is 6%.

So, it appears that the old rule of thumb about a 20% drivetrain loss through an automatic vs. 15% through a manual is probably pretty close to the truth.

It's also interesting to see a 3000 stall converter still multiplying torque more than 1500 RPMs beyond it's stll speed! If you see the torque curve on a high stall combo it's often a straight downward-sloping line from stall speed to redline. I've often felt in my bones that the converter was still affecting things well beyond it's stall speed (I had always guessed it was about 1000 RPMs beyond stall) but it's nice to have some real-world data that is consistent with that theory.

 

i guess 400rwhp isnt a bad number for that combo, although i figured it would be abit more than that.

i'm shootin for a 375-400rwhp 383 stealth ram idea

 

The slope when it is not locked up is a downward slide but if you compare the locked up run to the non-locked up run the slope is higher on the non-locked up run until arounf 4800 RPM. (My combination, others will be different)

 

400 RWHP with a superram is hard to do. A miniram may have produced higher numbers but the superram is the combination I own so I worked with it.

By the way I ran the car at the strip this weekend and it ran a 11.18 at 121 MPH at 3400 LB race weight. (400 RWHP is a-lot of power)

 

bjankuski - What car did you run that ET with? Nice Times!

 

The 1986 corvette that is listed under my first post.