this was on a mustang dyno

the better one is with the exhaust dump opened.. right infront of cat.. the other is with the full exhaust in use..

 

anyone know if these are good figures.. according to edelbrock with these mods it should do 270hp.. I imagine that's at the crank.. someone told me you loose 20% in the driveline/tranny

 

The peak torque you are seeing (328 or 315 ftlbs, depending on the run) looks like the bump caused from the converter torque multiplication. So the actual engine torque peak is happening around 2600 rpm (the other peak in the torque curve), at approx 310 ftlbs.

The hp peaks (222, 207) look accurate but it also looks like the power may have climbed at bit further had the test gone to a higher speed. Why did the test quit at 4700 rpm?

207 hp at the rw is just slightly less than what a 5.7 liter stock Bcar LT1 (Impala SS, Caprice) measures, and those are rated at 260 fwhp. They usually measure 215 to 220 rwhp at a similar rpm. You are also getting more torque than they measured at (LT1 Bcars run 280 to 290 rw ftlbs typically bone stock, but 300+ with minor exh mods). So I'd say you have approx 250 fwhp and 360+ fw ftlbs. The fact that your torque is so good, suggests that the power is a bit lower than what you should have, and I'd attribute that to not enough fuel at higher rpms.

Also, the curves are nice and smooth (no holes, no erratic ignition issues) and that's also good.

I think I posted a note to you a few weeks ago concerning this (fuel starvation at high rpms, a chip won't solve this problem... you need bigger injectors, more fuel pressure, or both). I think you also said you were running in the 15s in the quarter mile, a time that's about where you should run with 4500+ lb vehicle and the torq/power numbers you've posted. HTH. - Ken

 

i would be interested in seeing how more of the curve woudl have looked. in both cases it looks like the hp has reached a peak, but what happens after the little flat spot? we can't really see if it falls on it's face or carries a little bit.

later
tim

 

Im curious as to what the curve looks like after 4700, too. The curve is very smooth going up.

What are the specs on your cam again?

*edit*
Just re-read the original post and saw that it was a Mustang dyno. Gotta remember those read lower hp/tq numbers. I guess that would be the difference with the Edelbrock numbers.

 

yes.. a friend of mine that dynoed his modded dodge neon was very disappointed with his numbers and did some research and found out that mustang dyno's always show underpower..

THE OTHER THING>>> the guy couldn't use the pickup for the tach because the msd apparently interfere's with it.. so he had to calibrate the dyno but running my truck at 3000 rpm or something like that and he told me depending how accurate my tach is will make a diff as well.

the reason he didn't keep going is because he said that he didn't figure it would make anymore power..

now I'm using stock torque converter that was on the truck which apparently has a very low stall .. like 1500 or something like that..

anyone see any advantage to putting a higher stall? some people told me not to waste my time/money on that..

ALSO I think edelbrock's dyno numbers are at the crank..
here's the link to the dyno results

http://www.edelbrock.com/automotive/3704pp.html


they say they were running 36degrees at 3000 rpm for timing..

how would I acuratly set mine to obtain that? I'm running 8 degrees base..btdc how do you know how much the esc adds?

 

putting in a higher stall? ive driven a modded 350 with a 2500 stall in it, it was hard to tell if it was lag from going rich/lean or if it was the stall. tough to tune for me.

did it get up and go like all get out after the stall locked, um, YES!

 

I'd go back there and bitch about the guy not running it past 4700. You just dont drop off when you hit peak, how would people figure out where to shift?

The 1500 is a towing stall, whats worse is my 1200. A good stall will cut at least .4 off your ET assuming you have good traction.

Keep us updated on whatever ya do!