SLP IROC-Z

iTrader: (14)

got the car to hook now with my new ET radials and some suspension, but car falls on its face after moving 20-30 feet out, launching at 5k, 5.2k, 5.5k rpms slowly come down and drop to 3500rpm and the car falls on its face leaving me with 1.8x 60fts, best the cars seen is 3 1.78s. the car has very little mods, makes just over 300rwhp best pass with it is 12.708 @ 109.05 (1.828 60') i need to figure out a plan of attack to get this thing to 60'. im still running a stock clutch but its pretty strong. i dont know weather to go to a stronger clutch to hit the tires harder and get them to turn over a bit off the line or if a stronger clutch is just going to bring the rpms down quicker and bog it even worse. ive tried slipping the clutch but it seems to not work so well, probably glazes it. any advice anyone has would be great. i know its not a powerful car but i feel that even with what i have i should atleast be getting mid 1.7s out of it.

3660 lbs w/ driver
QP 9" with 4.11s, pinion angle set to -2.5
poly torque arm bushing
stock LCAs with energy suspension bushings
Spohn LCA relocs, LCAs are in middle hole
stock 19mm rear bar with spohn brackets, no front bar
275 50 15 MT ET Radials on 15x10 Racestars, i run 18psi in them.

nmass399

even with a set of bias ply's it will bog down with the m6 but i bet it will 60 ft better, and get a new clutch, the stocker probably won't last too long but if you want to try some higher rpm clutch dumps regardless of what clutch you have then go ahead but beware it could come apart on you, so you might want to invest in a stout bellhousing too.

O.N.

how big are the burnouts you are doing it sounds like it might be not be 100% hooking up, try a big 2nd gear burnout and see how it launches off the line.

gregrob

iTrader: (8)

Uhhh, no thats pretty much the opposite of what it sounds like. It's hooking so well it's bogging the car.

There is one simple thing here with an M6, launch higher. Launch as high as the tires will hold, and gear it so that it doesn't bog.

A set of 4.30's will make it roll out a little easier.

gregrob

iTrader: (8)

Also, ditch the drag radials... Fast manual cars dont use them.

You need to be able to keep some driveshaft rotation / slip out of the hole to keep from bogging so bad. Slicks can be slipping yet still cut an awesome 60.

Once a drag radial breaks loose it's not going to recover very well.

O.N.

but if he says its falling in revs after already traveling 20-30ft as he said wouldn't that indicate he is spinning slightly as the revs stay elevated, then when his wheels hook up at the 20-30ft mark his revs drop.

WheelsUp84z

iTrader: (14)

Yes. Either that or his clutch is slipping off the line from the initial hit and catching. a M6 car does need a little bit of spin to keep the RPM's up, just not a whole lot. A slick style tire is much more forgiving for this.

here's a spin/bog on DR's 1.8x 60 ft

http://www.youtube.com/watch?v=YrZWn...eature=related

and here's a spin with no bog on Bias ply's, 1.5x 60 ft. (left lane)

http://www.youtube.com/watch?v=U9RQnt6MRBE

SLP IROC-Z

iTrader: (14)

no spin, rpms slowly come down from the initial launch and end up dropping to 3500rpm a ways out, thats where it falls on its face.

SLP IROC-Z

iTrader: (14)

i go around the water, back into it, turn them over, pull up set the line lock and hold the rpms 5-k in 2nd.

SLP IROC-Z

iTrader: (14)

you hit the nail right on the head, clutch slips at first than catchs, rpms drop to 3500 and game over.

60ft aside, how much did the bias plys effect ET and mph vs the drag radials?

SLP IROC-Z

iTrader: (14)

one thing i forgot to mention is how much more my left rear tire is wearing than the right rear. my friends 01 with a moser 9 and detroit locker does the same thing. i get a lot more rubber on the bumper on the left side than the right. the axle is torquing real bad lifting that right rear and planting the left rear, what will cure this?

SLP IROC-Z

iTrader: (14)

thinkin about starting with doing the clutch, just unsure what to go with. im thinking a ceramic puck disc is probably to much? should i stay with something organic/dual friction like a monster 2 or a mcleod super street pro?

nmass399

Puck style, and figure out how much power you plan on puttin down in the future, that should help you decide on how much holding power you need.

SLP IROC-Z

iTrader: (14)

heres a video of one of my slower runs last night, spun to a 1.883 60'

http://youtu.be/oLfJipqLlsI

SLP IROC-Z

iTrader: (14)

probably will never be more than a bolt on car. i thought with a puck style they are on or off, wont that drag my rpms down in a hurry? not questioning you, just trying to understand.

LSxPwrDZ

iTrader: (4)

You have a few issues going on. I ran a stock bolt on car for a few years and the stock clutch no matter what kind of shape will not grab on a clutch drop with a sticky tire. You need to datalog the engine RPM and vehicle speed to see this. When you launch the vehicle speed will slowly increase but the clutch is slipping which is indicated by the higher rpm when you launch. The engine rpm slowly catches the actual speed and catches causing it to bog. The cure is a few different things, more gear, better clutch with a stock or maybe even slightly heavier than stock flywheel and a better tire like a slick or bias ply to take a higher RPM hit.

You were complaining about the rearend twist which is caused by the engine torqueing the rear counter clockwise if viewing from behind which is wasted energy. The cure for this is a drag bar! Here is a video of my 403 launching on a 150 shot with a 3.89 gear 28x10.5 slick and a drag bar. Notice the rearend doesnt twist on the launch. This is a 1.39 60'

http://www.youtube.com/watch?v=VODpzrTZafg

gregrob

iTrader: (8)

You need a drag bar as mentioned. And IMHO do NOT run a Puck style clutch. Especially if you have any hope of the tires grabbing on the street. I would invest in a McLeod street twin. It will last a lot time at your power level.

SLP IROC-Z

iTrader: (14)

yup you guys are definitly right about the drag bar, never thought id need one this soon, check out that vid i posted, hangin the left front.

i would really like to keep running drag radials, im afraid bias plys are going to slow me down at the top end of the track. going from 18psi down to 16psi will slow the car down a mph/tenth. that is a concern for me. im a big fan of hoosier quick time pros and will run them if i absolutely have to but im willing to spend more time and money to make the radials work.
going to ditch the 4.11s and step up to 4.30s.
anyone have any experience with the ram vds and a solid sintered disc?

SLP IROC-Z

iTrader: (14)

i appreciate the advice. oh and your car is nasty btw!

LSxPwrDZ

iTrader: (4)

You wont see as big of a drop as you think! If anything you may pick up. The radial's you are running are ALOT heavier than a slick is. At your power level the lighter rotational mass will help you. I've tried both and have ran faster ET and trap with slicks over any radial tire. Radials are for auto's, you need sidewall flex to get off the line and bite. When mine was headers, lid, 9" and tune only I was launching it off the rev limiter to run good times. Full weight with AC and all it went 12.2@111 and that was with a 1.6 60'. I also didn't have enough gear for motor... 3.89 and still ran those times without bogging. As far as clutch I was running a Textralia OZ700 Z-grip. It cut multiple 1.5 60's on a 100-150 shot with the stock motor as well and went a few 11.0@123 passes as well.