rmata

iTrader: (34)

We had a local dyno day and I decided to put my car on there for ***** and giggles, especially since it would give me chance to do a little more fine tuning on the new motor. I figured with a th400, nitrous stall, and 9" rear my drivetrain was going to eat up a lot of power. I was still hoping for 425-450hp though, and only put down 337 n/a. Dyno was done with 28" et streets at 15lbs. I was in race mode and the dyno was just a last minute decision.

I know n/a numbers don't really matter if in the end it's going to have the bottle on it, but I was just wondering if any of you other th400 guys have ever dynoed your cars and seen numbers as low as mine. 100 horsepower seems like a lot to be leaving on the table. First pull was 322, so I guess on the positive side I did pick up 15hp.

Jimmy P

iTrader: (177)

Sounds way too low IMHO, even for a car with lots of drivetrain loss.

rmata

iTrader: (34)

That's exactly what I was thinking. The pulls were made in third gear and it did seem like it was taking forever to climb up in the rpms like a lower hp car would. It rips hard on the streets though so I guess it is what it is.

got-a-ls1

iTrader: (12)

was it an eddy current mustang dyno? Heres what happened with my car... stock stall and tr220 cam i put down 383 on the chart. Changed the cam to a eps 226 234 with the 3800 stall and put down 360 rwhp... gained 5 mph in the 1/8th on the best runs on each setup.. dynos do not like stalled cars. The bigger the stall the worse it shows. Luckily however we dont race on dynos and at the track they shine!

What i think happens on these load dynos is that they push the converter way out of its efficiency range. I know when i was on the dyno it took far longer to wind out third gear then it would have on the street.

Another example same day there was a 68 camaro with a 468 (not really all that built) put down only 344 rwhp and ran 7.30 at 94 in the 1/8th, he had a 4400 stall.

briancb1

Your low pressure slicks probably accounted for a decent loss. I've seen a drag car lose 80rwhp from low pressure steam roller type slicks on the dyno. Dyno are for tuning like the guy said.

Carter01

iTrader: (11)

What does it run NA? Read through an old thread of mine, maybe it will help especailly since I have a Nitrous Speced converter as well.

https://ls1tech.com/forums/drag-raci...g-outcome.html

rmata

iTrader: (34)

I wish I would have known to air up my tires and see How much of a difference that would have made. It's a dynomite dynometer so I've always been kind of weary of it.

I did run an 11.5@118 two weeks ago when the tune was still half ***. I would think now it's a few tenths quicker, but I won't be able to know for sure for at least another month or so when I get time to make another trip to the track. Plus I'm curious to see How much the car will pick up on spray

rmata

iTrader: (34)

Here's a video of it
http://s223.photobucket.com/albums/d...t=693eadcd.mp4

minytrker

iTrader: (13)

I put down 380rwhp with a stock ls2 through th400 and 9in on drag radials. I had a single plane and no accessories with 2in headers.