99TransAmLS16Spd

iTrader: (8)

I'm a little frustrated as I was hoping the launch controller did more for my launch, but I only went from a 1.55 to a 1.52 60'. The engine was built with the 6 speed in mind, making plenty of torque. Its right at 500rwtq @ 4800rpm on the Mustang dyno.

The important info is:
RPM stage 5 T56, Textralia oz700, MWC 9" 4.11 spool
strange 12 way singles rear, BMR rear springs, BMR drag sway bar, Rod end LCAs
MWC tq arm, QA1 "R" single adjustable up front on 275 springs

For the 1.52, the launch controller was set at 5,700 rpm, front shocks at 2, rear at 6, pinion angle at -3, and LCAs in the second from the bottom hole in the relocation brackets.

Tires are M/T ET drags 28x10.5" tubed and screwed. Pressure at 17psi warm. They spun a little after the fronts came back down after launch, may have been due to a weak burnout.

Any thoughts or experience on this? I am hoping to achieve consistent 1.45 60's

01SS99red

iTrader: (6)

You need more gear , M6 cars need 4.56 or better. With a 9in. gear swap is easy.

studderin

iTrader: (28)

how many passes you have. i get the vibe not many.

have any videos.

what did the motor do after you were moving in 1st. did the front tires come off the gound, did the rear end sqwat or lift, did that happen when they spun.

17 is alot, i only go over 15 if the car was dead hooking and pulling the motor down, and not spining, with the spention doing the right stuff. and i want them to spin.

411s with thouse tires is probally not ideal, unless you can't rev the motor over 6k or trap over 140

AChotrod

iTrader: (17)

I would say your doing pretty good for a M6 car. I also agree with the above post.

Seit

skinnies?
Sway bar front delete?
Reduction weight front?
more Tune?
more octan?
remove a pulley?
14.x volts continuous?

All seven?

Mikey 97Z M6

iTrader: (37)

I agree with Studderin about running a lower tire pressure. I'd also raise the 2-step rpm to 6200+ and then start tuning the suspension. Sounds like you might be:

Hooking>bogging>front end drops>rear suspension unloads>then spinning. In this scenario you'll want/need more wheel speed to prevent the bog, that's why I suggest raising the launch rpm, especially if you lower the tire pressure.

Hard to analyze without video though...?

Mike

nmass399

m12, launch at 6500, et drags at around 13 psi, i would work my way down from 15psi and see what works the best. It would be a good idea to data log and see how low the rpm's are dropping during your launch.

Get someone to record a close up of the rear tire from the side and see how much the tires are spinning and how far, and how the car is acting like squatting or not and make shock adjustments from what you see.

Hope this helps some, i see you got your stocker built so you won't be going to a m12 but the m12 helped me keep my rpm's up a pretty good versus the m6 on virtually the same setup(just a different clutch).

nmass399

Just looked at my logs and with the m6 launching at any rpm which was up to 6000 it rpm always dropped to around 3000, but with the m12 launching over 5000 rpm's the lowest it would drop to was 4400 rpm's. Went from a 1.64 best with the m6 to a 1.57 m12 and got a new best. Launching it at 6400. Severe traction issues in first now with the m12 at the track, hooked way to good with the m6.

Magnet

iTrader: (36)

Improved et as well? I've heard mixed reviews about the m12 bc apparently 2nd gear is terrible, but again thats jut what I hear...

nmass399

2nd is not bad at all, i only picked up a .10 that day but my car was overheating compared to last time so i lost a little power goin down the track. Honestly i am still trying to debate if this transmission is worth it or not. So far i think its better, but i wanna go back to the track and get some more results with it.

just looked at my log file and the drop going from 2nd to 3rd is 6000 rpm's to 4400, with the m6 it was 6000 rpm's to 4800. Same with 3rd to 4th.

Nitroused383

iTrader: (10)

Look at your rpm drop from 1st to 2nd, it only drops around 800 rpm. Than 3-4 is a dog as it drops way too much. 1st gear is an advantage though, and drag racing is all about the 1st 60' anyways.

Watch this video at the 2:50 second mark and listen to the 2nd to 3rd shift. He wasn't in 2nd gear long and that was a 6600 rpm shift.

http://www.youtube.com/watch?v=ztWKVR_0DQI

99TransAmLS16Spd

iTrader: (8)

Thank you for the ideas everybody. I had a chance to analyze the video my buddy took of the car launching. Its pretty poor quality (camera video) and not worth posting. However, the rear end is not squatting.

The tires broke loose on the 1.52 run after the front tires came back down and hit the pavement. So the rear end did unload, most likely because of bog, but also possibly due to a weak burnout. I doesn't feel like it's bogging, but I'm sure the drop in RPM at launch is hurting it.

I'm pretty sure I have the right parts - beyond what is listed in the 1st post, I have a tubular k member and a-arms, sfc's, HVAC delete, lightweight carpet, and a few other goodies. I was also 40lbs lighter up front this last time at the track, installing a PC680 and moroso DS-2s.

The 4.11 gear I have is probably to tall - it's the nitrous gear, i just haven't sprayed yet. However, I may consider a second center section with a 4.56 locker.

I haven't had a lot of seat time this year - I'll be sure to get better video footage next time out and try bumping the launch controller up to 6-6.2k. Any more ideas would be appreciated

nmass399

yeah i am out of 1st really quick, and the drop from first to 2nd is about 800 rpm's, i am runnin again today might get some video.

Nitroused383

iTrader: (10)

Set your front shocks to 1, if it pulls the tires too much tighten one click at a time until it launches with out dropping the front end too fast. Drop your tire pressure down to 11-14 psi and launch the thing off the rev limiter. Start your burnout in 2nd gear and spin them until they start to smoke, roll out while spinning. A 1.52 60' with a 6 speed is nothing to complain about but you have a ton of potential for some better 60' times. If it feels like it is squatting too much tighten up your rear shocks.

Old Geezer

iTrader: (3)

Remember what Madman says: "Girls squat, race cars don't."

BADD SS

iTrader: (4)

^ This Need more info..... And definately want the tires to spin a lil bit....

SlickVert

iTrader: (5)

I agree with two important points 4:56 gears and drop the pressure to 13psi cold.
I hope that is a S tire they work much better in a stick of heavy car.
Not sure what your engine build is or where peak power is but the higher you shift it the faster it will go.
I had a cam only car that peaked right a 6,200 and the higher I shifted it the better ET/MPH, I end up shifting it at 7,200rpm with the only upgraded to the bottom end was rod bolts.

mike c.

iTrader: (1)

Just my thoughts here. People seem to think you need a 28'' tire to 60 foot or to use n.o.s. You do not. I have a m6 trans am with 4.11's and a 26x11.5x15 M&H Racemaster cheeter slick. I run 15psi at come out on a 2 step at 6,500rpm's. I cut n/a 1.42 60's and 1.3's on the nos. I make it down the 1/4mi easy and my rev is at 7,300 rpm's. A 4.11 gear with a 28'' tire is like having stock gears back in your car. So,you can add more gear and turn higher rpm's when street driving or swap to a 26'' tire and watch your 60's drop either way you go. On the n.o.s,i shift short at 5,500 rpm's 1st and 2nd.in 3rd i shift at 6,800 and cross in 4th. I ran 10.2's on the nos with a 26'' tire.

99TransAmLS16Spd

iTrader: (8)

Thank you for everybody's help. I made it to the track tonight, and managed a 1.46 and 1.48 60'. Because my truck is down for the count right now and I drove the car to the track, the runs were on my ET streets and sportman front runners instead of the ET drag with the DS-2s

What seemed to work for me was setting the launch controller to 6,000 - 6,200 rpm, front shocks set to 2, rear at 7. Tire PSI was 16 warm. They did spin a little which kept the car from bogging.

I am happy with the 60's, especially considering these are N/A runs with a nitrous gear.

BTW, my best run was a 10.58 (with the 1.48 60'), short shifted little on that run. Best MPH was 130.79. Missed a gear on the 1.46 60'

BADD SS

iTrader: (4)

Congrats!....

Always want a little spin, it helped you...trust me.