H-I-J '76 Nova re-fit.

[Mark Yacavone]

Originally Posted by FED 387

Todd-- look at the video --the launch RPM appears to be about 62-6300----- is that low ?? 1-2 shift was 72-7300 did she nose over or over rev the engine???-----2-3 shift is about 66-6700 is this too low???--------3-4 shift is again low in the 6600 range--- do you agree ??? Not sure what racepak is showing but the shift points are all over the place that might be what is giving you goofy ET's.---you have a fairly heavy car with a low HP engine and once you run out of gear going into high gear it just does not have enough power to recover and produce a real good ET.----Not being overly critical but the driver must aim for consistent shift points ---are your RPM shift points in the correct range not too high or not too low???---what is your finish line RPM it seems to be fairly low shouldn't it be in a higher range looks like low 6200-6300 range???--just my observations from the video----FED 387

It's because the clutch is slipping..It's not climbing and dropping in the gears.Probably toast by now. Also the wing, wing, wing and dump on the up throttle is hard on the clutch. Need to have enough clutch for 3rd gear burnout, without going to 7000 grand! ...and hold it there for a second, then drive out as the tires dry. IMO

[Rich Biebel]

Just going off the online Wallace calculators.

Your ET / MPH computed from your vehicle weight of 3400 pounds and HP of 390 is 11.99 seconds and MPH of 112.73 MPH. That's optimistic IMHO....The car did go 12.0 something so its not far off.....Don't know the MPH on that 12.0 run......MPH indicates HP better than ET....


11.99 x 112.73 =1351 and that is very high of a factor number for a limited cyl head type stocker...…..They are usually weak on MPH with fast ET's due to gearing. Your biggest ET gain is in the first part of the run with a Stocker...


Just yesterday at Maple Grove some H/SA cars were running 11.0's......at about 116 we'll say......11.09 x 116.7 I think I saw....do the math...thats1294...…..Very fast ET......not a lot of MPH....not sure if that was flat down on it......maybe off one or two MPH's at most...…. A Low compression 350...


I did not think the run sounded like the clutch was slipping badly at all....
RPM did not flair.....engine was weak and rpm did not climb....


Its been way to many years since I had a stick shift car. We had no rev limiters, just picked an RPM and held it there......


Most stick racers I watch put it to the mat on the first or second amber and on a chip...…


She's doing a pretty good job and just needs more laps......and some tuning to get the most out of what's there....It's Way harder than driving an automatic.....

[Nmbr1GMfan]

Originally Posted by Rich Biebel

I did not think the run sounded like the clutch was slipping badly at all....
RPM did not flair.....engine was weak and rpm did not climb....

This is exactly right, the clutch only seems a little light at the hit, which, as you mentioned the lower starting line rpm will have a hand in slippage running a counter weighted setup.


Here's the Waller 1/8 mile calculation, remember we only ran it just past the 1/8th.

[Rich Biebel]

Originally Posted by Nmbr1GMfan

This is exactly right, the clutch only seems a little light at the hit, which, as you mentioned the lower starting line rpm will have a hand in slippage running a counter weighted setup.


Here's the Waller 1/8 mile calculation, remember we only ran it just past the 1/8th.

If you ran those numbers in a 1/4 mile run You’d have to be real happy. I would be.

I wired the stock horn button to work the line lock on our ‘68 Nova back in 1969.

That car had a built in rev limiter. It would just go flat at 6000 or less with what we had to work with back then...Some cams pulled up a little higher at 6200.....Hydraulic lifters, stock springs, stock rockers. 12.20’s at 114+ was best numbers back in 1970 on 7” tires ! 10-1 compression 350...


The clutch was low tech. Schiefer RevLoc diaphragm clutch, 10-1/2” GM disc 11” 30lb wheel.

[Nmbr1GMfan]

Originally Posted by Rich Biebel

If you ran those numbers in a 1/4 mile run You’d have to be real happy. I would be.

I wired the stock horn button to work the line lock on our ‘68 Nova back in 1969.

That car had a built in rev limiter. It would just go flat at 6000 or less with what we had to work with back then...Some cams pulled up a little higher at 6200.....Hydraulic lifters, stock springs, stock rockers. 12.20’s at 114+ was best numbers back in 1970 on 7” tires ! 10-1 compression 350...


The clutch was low tech. Schiefer RevLoc diaphragm clutch, 10-1/2” GM disc 11” 30lb wheel.

I'm honestly amazed after the dyno runs and where the power was, how far this thing will rev, in lower gears it will hit 7500 no problem.

[Rich Biebel]

Originally Posted by Nmbr1GMfan

I'm honestly amazed after the dyno runs and where the power was, how far this thing will rev, in lower gears it will hit 7500 no problem.

A stock Z/28 302 would rev to 8000 if you let it back in 1969-1970

I drove one and that’s with stamped rockers and springs that had about 100lbs on the seat IIRC..

The difference from a hydraulic cam engine to a solid cam was like night and day.

[Rich Biebel]

My friend Joe Demarzo making a real nice pass this past Sunday at MG



https://www.facebook.com/larry.guest...4756815921752/

[Nmbr1GMfan]

Originally Posted by Rich Biebel

The difference from a hydraulic cam engine to a solid cam was like night and day.

Absolutely

[Casey Miles]

Originally Posted by Rich Biebel

A stock Z/28 302 would rev to 8000 if you let it back in 1969-1970

I drove one and that’s with stamped rockers and springs that had about 100lbs on the seat IIRC..

The difference from a hydraulic cam engine to a solid cam was like night and day.

Please tell that to NHRA, the solid lifter engines were penalized with HP from the factory and now that all the hydraulic engines can use solid lifters they didn't get HP. But the solid lifter engines didn't get a reprieve of HP.
Casey Miles
Stock

[Nmbr1GMfan]

Originally Posted by Mark Yacavone

It's because the clutch is slipping..It's not climbing and dropping in the gears.Probably toast by now. Also the wing, wing, wing and dump on the up throttle is hard on the clutch. Need to have enough clutch for 3rd gear burnout, without going to 7000 grand! ...and hold it there for a second, then drive out as the tires dry. IMO

Mark, by an outsiders obsevation it seems you're quite a revered member of this site, with that being said, maybe you shouldn't comment about things that may derate your classracer social status. In other words, everything you said is wrong.