The dyno results at best were 307.3 rwhp at about 5250rpm and 315.0 rwtq at about 4-4.5k rpm. From what I have been reading this seems pretty average for a stock C-5, what I was wondering is if hp usually drops significantly at about 5250-6000 rpm range. Oh yeah, I just had to pick up a B&M shifter while I was there. I love the short shifter but, I see what everyone was talking about with being able to hear the synchros. Not a big deal to me though.

 

:cheers:

 

IM interested in your results. For some erason I was under the impression that the LS1 motor made peak HP at 5750 or there abouts. W/ that in mind I was shifting at the track at 6000rpm. MY car was only trapping 109.6 best. I figured w/ a Hard top being 100#s lighter(then a coupe) I should see 110 easy and 111mph on a good run. Can anyone else help out ?

 

HP & TQ drop off pretty fast above their peaks. My max HP 337 is at 5700 and falls off to 329 by 6000. TQ is 347 @ 4200 and falls off to 316 by 6000.

On the other side my TQ is 319 @ 2200 but HP is only 141 at 2200. The TQ range is pretty flat, my LS1 needs to get up to ~ 4600 to produce 300+ HP.

All these numbers are RWHP/TQ w/ 3.42 rear.

:cheers:

 

I think most drag racers will recommend you shift at red line for your best times BUT, unless you're using a shift light, you need to figure out what your tach lag is, especially in 1st. I'm assuming you have a MN6 or 12 trans.

With a little experiementing you'll find the tach is indicating ~300 - 400 rpms less then what the motors turning. IMHO the ideal shift points will keep you at the top of the TQ curve in a fairly flat area, maximum area under the TQ curve. If you do have a 300 rpm lag, shifting at 6K indicated means the motor is turning ~6300, way beyond the 5700 rpm you're looking for.

It's tough to get a handle on how much lag your tach has. What I did to get a feel for it was, wind it up to several different points 5500, 5700, 6000 indicated, shift to 2nd and note where the tach settles before it starts climbing again. Aim to have your 1 - 2 shift hit near 4200, max TQ. If you find it landing on 4400, 4500, you've probably run beyond 5700 on the motor, not tach, in 1st.

Do the same for 2 - 3. 3rd doesn't wind up as fast so the tach lag is minimal on the 3 - 4 shift.

I find I turn pretty fair times with lots of top end shifting at ~ 5700 indicated. I figure the motor is pretty close to 6000. Beyond that and I can tell by SOTP and ear that I'm losing power.

:cheers:


[Modified by scool93535, 8:15 PM 1/21/2003]