How to 60 a car and keep it together?

[slowgsr]

Hi,

I have a shep stage 4 trans w/REM ISF, welded diff and evo III 1st gear. DSS aluminum driveshaft, 4 bolt rear end.. stock axles, stock Tcase. I use a MT ET Street tire, there about 26" tall, 8ish" wide, on 15" wheels, QM twin disc.

The car is making about 350hp, (128-130mph) full weight 1g dsm. Im launching at about 5400 building about 15-17lbs on the s258.

The car 60's OK, I ran some low 11's with bad 60's but I don't have safety equipment to run faster than 11.5 so they threatned to ban me so I have just been running 1/8 mile to work on the 60s. 60s got better than on my 11.2 pass.

Heres my problem. Whats easier on the car.
1) Launching 5400 building 15-17lbs
2) Launching 6800 building 4-6lbs

I poped the Tcase today, made it home.. wasn't a far drive.. only did 50kmh or so, trans has a welded center diff so i figured it wouldn't be hard on it. T case is still there, but the insides are broken.

Anyways, What do you guys think is 'less stressful' option 1 or 2.

Track prep was good today, there were some 10.5" outlaw guys running.. I was doing some T&T. I am not complaining I broke my car, just wondering if I could reduce the stress for the future.

I got about 80-100 passes on this Tcase, roughly the last 30-40 were on these tires, previous on the stock 98 17" wheels with some all season tires.

Thanks,

Eric.

 

[Hubbell91Tsi]

studder box at 5500 on ecmlink is pretty much the best or something close. really depends on weight and tire though.

 

[Spdfreak]

there is alot of other variables to consider but i like option 1 while slipping the clutch a little to reduce the shock to the drivetrain less broken parts

 

[Andrew Conrady]

properly slipping the clutch can help alot, also get all the slack out of drive line before you launch can really help for starters.

 

[SonySlave]

Use the e-brake to preload the drivetrain when you launch.

- Go to the line
- Pull e-brake, hit the 2-step, and begin to let out the clutch slowly
- When you feel the car start to squat and want to move, hold it there
- When it's time to leave, keep the gas down, let the clutch out the rest of the way and drop the e-brake.

It takes some practice, but you'll get the hang of it over time. It really does help though. I cut a 1.64 60' on street tires using this method, then I missed a gear... HA!

 

[91tizzy]

go auto! ftw! haha jk....yeah the preloading of the drivetrain really does help in my opinion....

 

[Phil1320]

Like the above guys' have said, loading the drivetrain is key. For instance if you roll through the beams and have to back up to stage, back through the beams, engage 1st gear again, and pull forward to stage. A slip of the clutch is the way to go. Our cars can 60' very well with an easy less abusive slip of the clutch as throttle is applied. Shattering a transfer case is not that common, just a bit too aggresive I'd guess. Good luck!

 

[nikkeebabee]

What suspension is in the car??? What are the current settings???

What are your current 60's???

 

[Demon33]

I don't know which scenario has less stress on the driveline, but preloading the transmission using the e-brake like someone mentioned is a step in the right direction. Also, slipping the clutch vs just dumping it off the line is a good strategy to prevent broken parts. And one more thing, an aluminum driveshaft dampens alot of the driveline shock during lauanching because it twists a little under hard acceleration, unlike the stock steel shaft. Another bonus to using an aluminum driveshaft is the weight savings.

 

[viperlp01]

It seems like it would be harder to launch at a higher rpm because of the extra rpms your going to have to slip to.. I launch a 5250 via dsmlink with antilag set to 6 BTC and +1 fuel and i launch at 18psi and pulled a 1.76.. That was my first and only time launching w/ antilag at the track.. I had a hell of a time learning how to properly slip the clutch.. But once i got it man does it rip.. When you slip the clutch its starts to load the engine so its constantly building more and more power..

 

[slowgsr]

What suspension is in the car??? What are the current settings???

What are your current 60's???

Im using K sports.. off the shelf front springrates, and the rears are different springs from Ksport but double of the 'off the shelf' springrate. The rears are fairly stiff.

They are on hard settings all the way around. I have no idea how I should have my suspention adjusted.

Currenty 60's were 1.6 - 1.8. Usually I hit a 1.7. I do however, slip the clutch when I launch, when It broke I was getting too agressive. However, I NEVER preload using the Ebrake, but I do not go past the beams and back up and than not roll foward again.

I tried using the Ebrake once, and I yanked it instead of shifting into 2nd, . I know this is the best way and will practice this method once the car is together/

I got a new Tcase today in great shape, for just $120 CAD picked up.. (remember the dollar difference)

Thanks for the advice. Im going to take the 'clicker' out of my Ebrake, and it would be nice to set up some sort of hydraulic handbrake I could use or a 'staging brake'.