[Chris-Austria]

Hi,

once a year there is a 1/8 mile race where I live and I go racing with my 66 GTO.
Since I still have some traction problems I wonder, what mods would help me to improve my ET.

I'm thinking about other springs, drag shock, traction bars and so on.
How would these parts help me and is the car still streetable?

Car is a 66 GTO with a 462 with a mild HR cam, Sniper EFI, 4 Speed Muncie and 3.55 rear gear. I use MT Street SS tires (275/50/15) with 16psi.
Anti hop bars are already installed. I think everything else is stock.

At what rpm should I start with my manual transmission? I start at 800rpm since I have wheel spin even at that rpm in 1st gear. I think it would be best to start with some more rpm, if I can get it to hook better. I shift at about 6000rpm and best time was a 8.5 @ 86 mph.

I want to beat a Corvette C6 with about 700hp next year. I won't reach the horsepower level, but I can get more traction I guess (my friends Corvette comes with street tires.. this year I easily beat a 640hp Camaro with street tires)
Maybe I'll have the E heads ported to 300cfm and get a 236/242 cam from Butler.. this should result in about 550hp I guess.
I'm also not sure, if I get better times with my full exhaust or open cutouts.. when I had the car on the dyno with the old engine it produced 15hp less with open cutouts.

Thank you very much!
Chris

[Half-Inch Stud]

I would Spectate because the Muncie 4-Spd is a scatterbox when a 455 Pontiac is front and traction occurs in back.

When you get the traction you want for 1.7 60foots, then my Post will make sense. That 2-3 upshift can be a real Grocery cart getter.

[Chris-Austria]

60ft time is 2.11-2.12 at the moment.. I think it should be less than 2sec. at least
is there a way to improve the Muncie as well? at what point is it likely to break?

[leeklm]

I loved my 66/4spd GTO but sold it a few years back, mainly because I wanted to be at least somewhat competitive at the track, which for most of us requires an Auto.

Before I took mine to the track, I was told a fully prepped track with full traction "eats muncie's for lunch ". The A body is a fairly heavy car, which compounds the stress on the drive line.

When rebuilding the Trans, I did so with an aftermarket case and few other goodies. In addition, I had a GM 12 bolt 3.31 with aftermarket axles. Engine was a 455 with KRE heads and Stump Puller cam from SD Performance.

I was still worried about the trans, so never side-dumped the clutch, nor did I power shift. I think I ran low 12 sec around 110mph.

For traction, make sure rear end floats freely. I used poly bushings on lower arms and adjustable top arms with roto joints. With a heavy car and 500hp, you may be fine with street shocks. I did have a set of air bags and would run about 10lbs in right rear and 0 in left side.

If you are semi serious about drag racing, drop in an auto, beef up the rear, and have fun!

With all that said, some people can be successful bracket racing with a manual, but I am not one of them and, we have not even started talking about clutch upgrades!

Sent from my SM-G965U using Tapatalk

[242177P]

With an auto, my No-Hop bars didn't need any persuasion to induce body separation, it was there if I even looked at the throttle. That lifting action is what plants the tires, and that's how they give you traction. But with a clutch they're, umm, let's call them inactive? Tire spin also doesn't let the suspension work. While it might seem counter intuitive, I fully expect that harder launches are where you're going to find traction?

[ponyakr]

All things considered, you should probably just live with spinning off the line.

If you are serious about running quick, with a 4-speed, you'll need to buy one that will not break. Will also need a clutch set-up which is adequate for strip duty.

A street/strip 4-speed set-up would have to be a compromise.

https://midwestmuncie.com/product/su...ncie-case-m22/

[grandam1979]

Don’t take this the wrong way but your 60 ft times are slow for your setup. Are you doing a good burnout with your drag radials? Launching at 800 will not help at all 2500+ will help after a good burn out. My buddy has a pure stock car on red lines and he leaves around 1000 and will pull 2.0 60 ft times but it took some seat time to be good at it. We converted the car from a auto to stick a couple years back and it was a lot of seat time to get good. I think on a good launch you should easily get 1.7-1.9 60 ft times.

[ta man]

Originally Posted by grandam1979

Don’t take this the wrong way but your 60 ft times are slow for your setup. Are you doing a good burnout with your drag radials? Launching at 800 will not help at all 2500+ will help after a good burn out. My buddy has a pure stock car on red lines and he leaves around 1000 and will pull 2.0 60 ft times but it took some seat time to be good at it. We converted the car from a auto to stick a couple years back and it was a lot of seat time to get good. I think on a good launch you should easily get 1.7-1.9 60 ft times.

The biggest mod you can do is "seat time" you need to dial yourself and the car in.
Work on the launch,tuneup and shiftpoints. I think 6000 rpm is a little high to shift ..what is your engine combo..it most likely will like a 5500 rpm shiftpoint.

[Chris-Austria]

I also think that my 60ft times are too slow. I believed that a harder launch will result in less traction, but if the suspension will bring the weight to the rear by doing so, it may actually help. Thats some good information and worth to try.
The Street SS tires don't need much burnout I think.. maybe I shouldn't drive through the wet box at all and launch with about 2000-2500rpm. If I'm able to reach a 1.8sec 60ft time instead of 2.1sec, will the 1/8 mile time also be 0.3sec quicker? Or even more?
What do you think about drag shocks and these traction bars with a damper? I'm not sure if I need it and if it will make it ride worse on the street.

I don't want to break the transmission, maybe it's safer to add some power and only improve the launch with the existing suspension components and tires.

Thats the result from Engine Analyzer.. the lower numbers are with the combo at the moment, the other would be a more radical camshaft:


462cui, e-heads, CR 10.3:1, full roller valvetrain with a 224/230/110 cam, Holley Sniper with Hyperspark and RPM intake, headers and 2.5" dual exhaust

What do you think about NOS? That would only add some power maybe at 2nd gear when I got traction.. pistons are custom made by ROSS, stroker kit from Butler.

[AG]

As mentioned earlier, the more traction you get, the higher probability you will grenade your trans. I used to run a Muncie in my '65 until I blew it up at the line launching at 4000 rpm with slicks. I don't know why you are spinning those tires, either you are not heating them enough or the air pressure is not optimum. Working with those two variables should get you hooked up enough to get a 1.8-1.9 60' time. As said earlier, seat time is important. Good luck.

[Goatracer1]

If your 60 ft time drops by .3 sec you 1/8 mile might drop by as much as .45 to .5 sec's.

[Goatracer1]

As stated above YOU need more time at the track. Practice makes perfect is not just an expression. You really have to learn you car's combo responds. A good set of up lift shocks on the front will help. One thing you can do for FREE is remove your front sway bar before you go to the track.

[Half-Inch Stud]

Some ideas tally'd for you to consider;

air bag in right rear spring at 0-10 psi.
Electric fuel pump
Battery in trunk for weight distro.
1000-1300 rpm launch for practicing.
i'd keep upshift rpm below 5300 rpm until all other stuff sorted to satisfaction.

As for me i chose TH400 in my Teens, and recently went to a manually-shifted 4L80 behind the 469 Pontiac 4-Speed Floor shifter, clutch pedal for locking converter.

[pokey1]

I have found that if there are any groves in the tires they will hold some water from the water box even after a burnout and lose traction. I started going around the water box and backing up to do the burnout. Helped me.

[Chris-Austria]

Don't you think that 5300rpm is too early? I will have to spend more time in higher gears and the multiplicator for the wheel torque will be less. Maybe I should make a calculation and see how the wheel torque will be at some different shift points.
In the past I always shifted at 5500rpm and ran 8.7, but the better times from this year may not result from that since I added the Holley Sniper (with electric pump) and the rpm intake. Funny thing is, that last year it was 8.7 @90mph, now it was 8.5 @86mph. Did I lose speed because of the different shift point?

And I totally agree.. I don't have much practice.. that's a good point to start improving ET's.
What do drag Shocks do? And do I need them in front and rear, if I use them?
The air bags will be used next year!

[steve25]

Shifting a 6k is out of the best rpm range where the motor is making its most average Tq and Hp going by your graft.

Even super stockers with far more Cam then your running and about the same cid still don't shift above 6k rpm!

The 2 to 1 or better torque multiplication of a converter when it flashes at launch in a Auto set up more then compensates for the added weight of a Auto trans for the 1/8 mile type of racing your doing. In fact with the right converter they will reflash again at the shift points.

I think your 4 speed set up needs to , first so that you don't blow it and second for quicker track times!

[slowbird]

Originally Posted by steve25

Even super stockers with far more Cam then your running and about the same cid still don't shift above 6k rpm!

That's completely false! The guys running Super Stock currently shift 7000-7500 maybe more

[ponyakr]

Originally Posted by pokey1

I have found that if there are any groves in the tires they will hold some water from the water box even after a burnout and lose traction. I started going around the water box and backing up to do the burnout. Helped me.

We did this, even with slicks. Most seem to love gettin the tires wet, then grinding them down, & makin lots of smoke.

We just did a couple of short, dry burnouts, mostly just to clean the tires off.

But, at some tracks, there was no way to drive around the water. Had to go thru it. Had no choice then but to get the water off. Tires last a lot longer, if you only do the minimum necessary burnout, each time.

[J.C.you]

Save tranny and your gear rowing for the cruise nights. Another fan of a turbo 400 swap if you are a once per year racer.

[Skip Fix]

Originally Posted by slowbird

That's completely false! The guys running Super Stock currently shift 7000-7500 maybe more

I think Lynn is shifting closer to 8000 with his SD SS car.