[Skip Fix]

Lighter flywheels can cushion the hit and rev a little quicker also.

[AdamIsAdam]

Thanks everyone. Good info for sure. I should have posted this while at the track! lol Like I said, I did find that a soft/steady clutch release was my best run, but barely. However I was concerned about burning the clutch. I hot-lapped it about half a dozen times. (Temps stayed right at 180, car ran great and the top end MPH barely varied.)

I would like to get a different tranny some day. I hate that M21 with 2.20 1st. At idle I'm rolling at 9MPH!

What street-friendly clutch do you suggest that can live and last with the above launch technique of slipping? I've got a McLeod Racing Clutch 75221-Super Street Pro

[tom s]

Unless you get a slipper clutch you have a really good on.Tom

[Tom Vaught]

Very Nice 11" clutch system.

Tom V.

[AdamIsAdam]

Originally Posted by ry57pont

1970 gto (4spd) 462 500 hp
11.940@114.21 / 1.843 60'/ 3980 lbs

ry57pont,
In comparing your times to mine, I have two observations that I'd love to hear feedback/comments about:

You: 1970 gto (4spd) 462 500 hp, 11.940@114.21 / 1.843 60'/ 3980 lbs

Me: 64 M21 (4spd), 3.42, 26" tire, 469 360rwhp (very flat curve), 12.80@108 / 1.90 60' / 3600 lbs race weight.

But you are pulling the wheels off the ground but have about the same 60' time, yet are a full second faster in the quarter! You have about 100hp more but weigh about 400lbs more.

Q: how are you pulling the wheels yet "only" at a 1.843 60'?
Q: how the hell are you a full second faster? wow

Just curious. I'm back to bench racing now that I've been to the track with this car finally!

[JSPONT]

Adam my 60 was a 2.4 and got the tires off. Front suspension works well.
Hey I know a guy with an Aluminum flywheel with a Mcleod RXT dual disc and a real strong Toploader!

[rtanner]

Originally Posted by AdamIsAdam

Thanks everyone. Good info for sure. I should have posted this while at the track! lol Like I said, I did find that a soft/steady clutch release was my best run, but barely. However I was concerned about burning the clutch. I hot-lapped it about half a dozen times. (Temps stayed right at 180, car ran great and the top end MPH barely varied.)

I would like to get a different tranny some day. I hate that M21 with 2.20 1st. At idle I'm rolling at 9MPH!

What street-friendly clutch do you suggest that can live and last with the above launch technique of slipping? I've got a McLeod Racing Clutch 75221-Super Street Pro

just go back to the track keep practicing with higher rpm launches and that smooth clutch release, you have already seen all the answers to all the pertinent questions, I would not change any parts on car, you need SEAT time at the track, the more you get the faster the car will go, the only area that needs improvement before changing parts, is you getting track time!!!!

[Silver Judge]

Originally Posted by AdamIsAdam

Thanks everyone. Good info for sure. I should have posted this while at the track! lol Like I said, I did find that a soft/steady clutch release was my best run, but barely. However I was concerned about burning the clutch. I hot-lapped it about half a dozen times. (Temps stayed right at 180, car ran great and the top end MPH barely varied.)

I would like to get a different tranny some day. I hate that M21 with 2.20 1st. At idle I'm rolling at 9MPH!

What street-friendly clutch do you suggest that can live and last with the above launch technique of slipping? I've got a McLeod Racing Clutch 75221-Super Street Pro

I have the same clutch and agree with Tom S and Tom V that it's a good one.
I had to do a lot of experimenting with launch and shift techniques at the track and found my best 60 foot times & ETs came from side stepping the clutch and shifting like ry57Pont does in the youtube video link he posted.

My best 60 foot time ever was a 1.74 and this was with a launch RPM of 3,400. I keep this info in an excel spreadsheet and on this run, I managed a 12.17 at 113.56 MPH, my notes also indicate I didn't have the best 2-3 shift and I was on the rev limiter on 3rd.

This kind of driving along with loads of spirited street driving ultimately broke my M-22, I completely wasted 2nd gear and bent the tailshaft. I have since upgraded to a supercase M-22 with all of the goodies plus the 2.52 first gear ratio that's optional when putting these together.

[AdamIsAdam]

Originally Posted by Silver Judge

My best 60 foot time ever was a 1.74 and this was with a launch RPM of 3,400. I keep this info in an excel spreadsheet and on this run, I managed a 12.17 at 113.56 MPH, my notes also indicate I didn't have the best 2-3 shift and I was on the rev limiter on 3rd.

I'm curious as to what ET and MPH you posted when your 60' time was around 1.90-2.0?

[Silver Judge]

I have info on 18 passes I took on this spreadsheet, here's some info on 5 that were in the 1.9-0-2.0 range on the 60 foot times. All my other 60 footers were low 1.80's and on those 1.8xx 60 footers, I ran low 12's on my ETs.

I'll add that 18 PSI in my Mickey Thompson drag radials was my sweet spot with testing.

60' ET
2.10 12.95
2.07 12.64
1.97 12.99
2.18 12.96
1.89 12.47

[AdamIsAdam]

I'm guessing you MPH is higher than mine. You seemed to have done something to drop from high to low 12's with similar 60' times.

[Silver Judge]

Another dynamic at play for good 60-footers of course is tire spin.

With a stout driveline and good axles I would be inclined to film launches and analyze wheelspin with your rear tire marked with a big white grease pencil line, as many other PY'ers have done. Some have said that somewhere around 1 revolution of tire spin or less may be optimal for us 4-speed guys, but I don't know for sure. A dead hook is hard to pull off but not impossible !

And those fast shifts like the ones Ry57Pont demonstrates in his cool video and we see of old schoolers like Ronnie Sox & Grumpy Jenkins doing in the old videos are obviously pretty important for improved ETs

I used to practice these super-fast shifts at low RPMs with street tires on good stretches of deserted roads, it's also a fun way to string together scratch marks on the road for 1, 2, and 3rd gears without beating on it too much

The best stick driving Pontiac guy I've seen in person is Richard Guido, aka Guidos in his 65 GTO. I've seen his runs at the track and (before he had the 1,000 hp supercharger set up he has now). With a very high end twin disc adjustable clutch set up, he would simply side step the clutch at about 5,000 RPMs, pulling the wheels and GONE !