coolraptor

Still a drag racing NOOB here. Tried it off and on for years but usually destroy parts and only get to run a few times a year, so not much experience.

Car is 95 Z28, 383lt1 A/I trickflow heads, hyd. roller cam, ported stock intake, etc probably ~440-480hp range (never had it dynoed) Engine also has a lightweight aluminum flywheel that was stuck on there before I started getting into drag racing so much. Clutch is a clutchnet 2x racing 5puck design that is a bear to drive.
Car has no emisions, AC, heater but still has full interior with working stock radio. No cage or race seats. No idea what it weighs. Battery also relocated to trunk.

Tube LCA's(non adjustable), Tunnel mounted torque arm, tube panhard bar (non adjustable), SFCs, Moser 9inch 4:11gears w/ detroit locker diff. & LCA relocation brackets.
Stock new Monroe Sensatrac struts/springs in back.
Tires are Mickey Thompson drag radials 325/50?/15's(i know, waaay too big) on Race Star wheels. Tire pressures tried from 24psi down to 15psi. Short burnouts without much smoke to huge-people cheering burnouts have been tried.

Front is stock except 1le swaybar(coming off ASAP), KYB adjustable struts (set to stiffest setting, only one adjustment) ls1 brakes, skinnies but cant remember the tire size right now.

Best time is 12.0x with a 1.75 60foot at 114mph with engine builder driving and not powershifting.

My best is 12.1x with a 1.8x 60foot at 115mph. I have also ran a 12.3x at 118mph spinning badly at start. Dont remember 60foot on that run. Powershifting every run.

Have tried using the 2step set anywhere from 3000rpm all the way to 3800rpm and it either spins enough to where I have to feather it or bogs. Regardless of the rpm setting. Also I accidently let off the button and RPM's spiked to 7k right at launch once this weekend and it spun the tires but also pulled fairly hard?? Missed 3rd, so i forgot and blocked out the time on that run.

Have tried the LCA's in both holes on the relocation brackets, the lower holes seem to be the better choice but not by much. Pinion angle is -2.0.


Any recomendations from some of you gear slammers out there? Thanks for any tips!

TedH

First, there are many people here with more detailed knowledge than myself.

That said, one item left out of your description is the rear gearing? That can make a huge difference in 60 foot times.

What I do know is that losing the front sway bar, loosening the front shocks, stiffening the rear, having the correct tire pressure, and being on a track with a decently prepped surface are all important to a good launch.

Keep things simple. I installed taller Et Streets to slow down my 60 foot times to stay just above 12.0 in street class. With the smaller tires I was dipping significantly into the 11s and 60 foot times were in the low to mid 1.5s...

Post your gearing when you have a chance.

coolraptor

Wow iam so sorry, I cant believe I forgot to put that in the description, I have 4:11 gearing.

I bought the rear tires also before I knew very much on drag racing. I figured the bigger they were, the better chance I'd have of hookin' up lol.

I will remove front swaybar, turn adjustment to soft setting on struts before I head out again.

Thanks for the reply TedH!

96m6lt1

The only problem I see with your combination is the tire you are using.... The M/T dragradial was not designed for stick cars! You would be better off moving on to the ET street or Hoosier QTPs as you know clutch cars shock the tire a ton more than an automatic......

coolraptor

Makes sense. Once I can afford to, I will start shopping around for new rear tires. Thanks

slomarao

ET Streets and problems are solved.

what rear end are you on?

us91bravo

i had the mt drag radials on my and never had a problem hooking up with my
m6.

3DFORMULA

Bias ply tire for the m6 and it should be a good improvement.

coolraptor

I have a Moser 9inch w/ 4:11gear set & detroit locker diff. Lower Control Arms set to lower holes, cant remember pinion angle at the moment but I think it was -2.

(will be racing this coming weekend)
So far ive removed my 1le swaybar, and turned my front struts to the softest settings. Seems to lift front end up a bit quicker just trying it out on the road with my drag radials on it. Curious to see what/if any improvement at the track!

coolraptor

Got down to 1.61 sixty foot time, and 11.90etc at 115. The trap speed was down but the time was better, funny how that works.
Had ~15psi of air in tires and a long burnout

Still spinning, but not as much. Cant afford slicks at the moment, so that was on my MT Radials.

coolraptor

Just about got the $$ to buy slicks. What size would you folks recommend? My radials are 325/50/15's. I cant go any taller or wider if i wanted to.

Ive been told i need a slightly shorter tire, and not as wide since it will be a slick but iam not trying to stay in a certain class or anything (just run test and tune usually) so i dont care if its over 10.5 wide or whatever the rules say.

My rims are 15X10.

Dunno what the car weighs, its not gutted except for AC & Heater stuff is gone. 9inch probably makes up that plus some weight. Also removed front swaybar, EGR, etc little stuff.

Bob Cosby

With the M/Ts, at what rpm are you crossing thru the traps? For drag racing, you ideally want to be several hundred rpm above peak HP in the traps. I know you haven't put the car on a dyno, but we can take a pretty good stab at it.

Anyway, once that is known, it will make the proper slick size (height) easier to pick. For width, a 9" or 10" should do the job.

I have no doubt removing the swaybar and setting the struts to full soft helped - very common thing to do!

coolraptor

I should have paid more attention, i dont know exactly. I want to say between 5k and 5500rpm
I should know this. I have watched before, but i cant remember what it was. Iam usually so focused on keeping it straight and driving i dont look down once I get that far down the track. (shift w/ shiftlight)


The swaybar and softening the struts did wonders lol

Bob Cosby

Ok. Your 325/50/15s should be ~27.8" tall. With a 4.11 gear in 4th gear, that calculates to ~5715 rpm. Given that you don't know where your HP peaks, it makes a tire recommendation kind of hard. For optimum ET, I'd want my finish line rpm to be ~600 rpm above peak HP in 4th gear. I don't suppose you know where that cam is supposed to make peak power? A stock LT1 peaks at 5k, but I would guess your motor peaks somewhat higher. Anyway, here are some numbers...

26" slick, 4th gear, 115 mph = 6110 rpm
27" slick, 4th gear, 115 mph = 5880 rpm
28" slick, 4th gear, 115 mph = 5675 rpm

My first inclination is to recommend a 26x10 slick, but if your peak HP really is close to 5000 rpm, that would be a bit short, and would necessitate a little less gear. I think 28" would be too tall, though it would provide the most absolute bite (even with the same width, a taller slick puts more rubber on the ground due to is larger circumference, plus it has more sidewall).

Really need to know the engine's peak HP....if it is 5500 rpm or above, I'd go 26x10".

Good luck!

coolraptor

Wow thanks for the usefull info!! A dyno run would deff. be helpfull at this point I suppose.
If I remember right, the cam was supposed to be good untill 6500 or a tad higher.

If I cannot get a tune/dyno run in I will spring for the 26'' or 27'' inch slick.

Again, thanks!!!