Loudmouth LS1

iTrader: (10)

**** no, I haven't measured anything with me in the car, it's hard to find someone that's 270 to sit in it for me, hehe!

It was 1 - 1.5 w no one, so it would probably be less, so the third hole might be the best then, huh?

Terry'sToy

kevredz,
pretty much, or you'll just burn up U-joints.

Terry'sToy

Loudmouth,
Ok, maybe get someone in the front and rear seat of the drivers side.
I would think that the lower hole may work better for you. But I would get someone with a very small head to get under the car while you sit in it. Also measure your pinion angle with yourself in the car, as this changes too.
Have fun.

Loudmouth LS1

iTrader: (10)

Aight cool, i'll try that, or i'll go out and buy 270 lbs worth of concrete or something and throw the bags in the drivers seat, hehe!

MADMAN

iTrader: (4)

The pinion angle is set to lift the car upon launch and load the tires. The driveshaft angle is irrelevant.

When the car is launched the rearend is pushed down out of the car. The rearend also tries to pivot around the ring gear. The pinion tries to raise up. This in turn lifts weight from the front. This weight is moved to the rear to plant the tire harder.

Terry'sToy

thanks Madman, this is all making way more sense. I drew some pictures and now I understand how the driveshaft angle is irrelevant. For the longest time I thought it was somewhat important. Cool I feel way smarter now.

Terry'sToy

I guess this also means that we are going to chew up U-joints faster than normal?
That of course is relative to how much you drive the car with the pinion set at the angle required for drag racing. Not a biggie for me. The car goes cruising and racing. That's it.
Again thanks Madman, I realize you are running a business and this takes time away from that.

kevredz

iTrader: (2)

So having excess negative pinion angle (more than what you need to obtain 0 degrees under hard acceleration) would tend to lift the car more upon launch?

12secSS

iTrader: (30)

Nope! The small negative pinion angle is required to keep the relationship of the pinion/driveshaft/yoke in alignment under acceleration. It get's to a point where the increased negative pinion angle gives diminished results vs. excessive wear on the drivetrain. To lift the front of the car more would require changing the torque arm length IIRC.

onfire

iTrader: (17)

Coilovers for the rear would be the ultimate in height adjustment.

Any comments on the rear V6 springs vs V8 springs for launching?

Terry'sToy

Ok, I said I would post up my results.
First off I don't have any weather data, so this is not completely valid info, however, I have been racing this car for 5 years and you kinda get to know how it feels.
So, It hooked real good on two passes, the rest of time was kinda shitty as it was a street car night.
With me in the car I re-measured everything at the track one more time, and I had a tiny bit of rake towards the front by approx. 0.5* LCA's at 2.5* and pinion -2.5*
So my normal 60's are around 1.68-1.66, once in awhile if everything was perfect it would do a 1.62.
Last night it did 1.599 and 1.60
There is more in the car as it was a little rich and I was running the ET Streets. The ET Drags are going on today and I'm racing at another track tomorrow. I need a more consistant tire to get better at suspension tuning (like shock adjustments). The car did a tiny bounce when the front tires came back down, so I will try and sort that out tomorrow. As well, there is still more to be had with tuning. I have HPtuners and I'm still learning. Also the car has no headers YET. Come on Santa, hurry up.

onfire

iTrader: (17)

Looks like the leveling theory sorta works. Are you totally stock height in the rear with stock springs,rubber spacer,etc?

V6 Bird

iTrader: (15)

Its not matter of degrees as its more of a matter where it moves your instant center point in relation to where the front of your torque arm is mounted.

.

SlickVert

iTrader: (5)

I would like to know also, what is your recommendations for rear springs?

MADMAN

iTrader: (4)

I either run the V-6 springs or I run a 150lbs per inch 2.5" diameter spring.

SlickVert

iTrader: (5)

Thanks for the reply MADMAN

onfire

iTrader: (17)

Yep, we appreciate all of the advice!

1dirtyZ

iTrader: (1)

gret thread, subscribing too!
what benifit do the v6 springs give over the v8 ones?

Carbed4thGen

iTrader: (2)

Is that for full weight cars or just for most f-bodies u do? Wat about a car that weighs in about 3000-3100 with a driver? And wat brands do I look for? wat length also?

MADMAN

iTrader: (4)

I have the springs in stock. They run $125.00 a pair