After the holidays I’ll be sending my 3rd member with 4.11s for a refresh and gear swap to MWC. Right now they don’t hook for s**t. 2nd spins even from low rpm rolling into throttle..as soon as boost starts to come it blows the tires, the car is honestly faster from a roll right from 3rd from 40-90 mph than a 2-3 run up to 90 because it doesn’t spin and I don’t need to make a shift. I’ve searched and had a trouble finding similar setups. Mostly A4s or stockish cars making 500whp.

I can’t imagine 4.11s to 3.70s is a large enough of a change to help with my traction is it? Should I just jump right to 3.50s? Anyone out there have experience with both gear setups or been in my shoes with a similar build? I’m sure 3.70s would be close to perfect at the strip with a mid 130s top end, but on a mostly street car how do they do? I’d hate to spend the money and have a gear that still can’t hook for sht.

car is f body, ls1, heads/custom Smallwood cam, D1SC making 12-13lbs at 6500rpm with a T56. Running stock 17s with drag radials(have a new set of MT streets I’m dying to try which are the most aggressive DR I’ve ran so far) I have no plans to run a 28” tire etc. currently I’m leaning to trying the 3.70s as that’s what bob always recommends but I figured I’d ask everyone else here what they think..thanks guys. Happy holidays.

 

It still won't hook for ****. Likely going to 2.73's will not stop 2nd from spinning.

Things that worked well for me. Try and get the LCA landing point on the rear to go lower. I run ~5 deg and the car is not a deathtrap under heavy braking.

Alternatively, run a traction control system. I run a RaceTCS and it instantly solved all of my traction issues. I run the car at 10% slip on the street and the traction control system dials the engine into just enough power for 10% slip within a fraction of a second. https://ls1tech.com/forums/forced-in...quivalent.html. Possibly best mod I've done on the car.

 

Noooo. Reading this made me want to just post it for sale lmao.
I have a MWC fab 9 rear and I think they are already lower than typical. Car is on stranos so it doesn’t help. Long arm frame mount torque arm etc. I will check out that system. is it a standalone? I haven’t even thought into trying to tune the factory traction control..wonder if that can be done. I’ve retained 4 channel when I put my 9” together so everything still works as factory
EDIT: just checked out the raceTCS. How did you wire it in? Would it play nice with my lingenfelter 2 stage rpm box I wonder? I’d rather it cut spark than the injectors for obvious reasons

 

I played with the factory TCS a lot probably 15 years ago. I was playing with the torque reduction calculations. Probably a better way to do it, but it worked. The issue I ran into is that it was just too long of a delay to bring the car back up to power. So, it works well for keeping me out of the woods, but doesn't dial in the power like the aftermarket stuff.

The RaceTCS is a standalone. I put mine next to the ABS module and just ran about 12" of wire to the box from the ABS sensors. You run the injectors over to the box and the 4 wheel ABS sensors to the box (along with power/ground). I put off putting it in for a while because I just didn't want to mess with the wiring, but it has been a game-changer with the car.

I prefer an injector cut over an ignition cut when chipping off a couple hundred horsepower. Folks prefer the timing cut, but you have to pull so much timing that it puts a ton a heat on the exhaust valve and it takes a sec for the motor to clean up with the fuel still going in. I've worked on both types and much prefer the injector cut - I put on the RaceTCS specifically because of the injector cut.

The system is able to pull an RPM signal from an injector rather than the reluctor signal - so likely works just fine in tandem with the lingenfelter box.

 

Been checking these out. So, what is the difference between the v2 and v3? V3 is already harnessed or something? Also, I’d assume you’d want to disable the factory trac control or does this kick in so fast you don’t even have to mess with it? Definitely want to check this out. After further playing around with the speed calc, 3.70s look to be the better option for me not considering traction issues.

 

V3 has spark and fuel and you configure to use which one you want or a mix. It is also a little more robust box. I run the V2 because I don't need/want the spark control.

For normal driving around I keep the factory TCS on. The RaceTCS runs in the background at ~5% and dials the power in fast enough where the factory TCS doesn't come in. If I want to go quicker, I click of the factory TCS via the button and turn the RaceTCS up to 10 to 12% via a **** right next to the factory TCS. It picks the car up from about 15 mph/sec up to ~17 mph/sec for roll stuff.

 

You are fighting a number of things here. You don't want to dead hook a stick car. Something has to slip a little. Since a slipper clutch isn't an option, then you have to get that slippage somewhere else, which would be from running the right tire pressure.

Do you run a two step and a line lock? Without those it would be extremely difficult to have any consistency at the track, imo. If your car is lowered at all, that's another negative. What shocks and springs are you running? Stick cars typically need a lot of front end travel, so an adjustable shock and front springs with lots of stored energy are used. Just running an adjustable shock on the front end and removing the sway bar while still running a stock front spring or a lowered spring won't make much difference for front end travel, in my experience, but it's easy enough to measure it before and after and see.

Would prefer a 15" wheel, too, for the sidewall, and a stiff sidewall slick is usually used with a stick car.

A 3.50 gear would be good for over 150 mph with a final 1:1 transmission ratio, and you'll be able to do about 200 mph in overdrive, lol.

There is a reason why you don't see many stick cars at the drag strip, especially with solid power like yours. They are just very hard to setup and get traction with without ruining their driveability for the street. I raced a 69 Chevelle with a Muncie M20 for years, and it is quite a challenge. I had like 8 or 10 inches of front end travel on that car, iirc. Nice for the track but terrible for the street.

What you are doing is an interesting challenge, and so I am not trying to be negative, just realistic about what it takes to make a decently powered stick car work at the track. Modern clutches hit really hard and slip very little, and that instant power simply makes it way more difficult to hook up than it would be for an auto car.

 

I had a toggle switch for my two step and had it wired in with my line lock, so I could use the line lock for my burnout, and then I'd flip the toggle for the 2 step and my line lock and 2 step were on the same switch so as soon as I released the button on my shifter they both were de-activited at the same time.

 

Nothing wrong with dead hooking a diaphragm clutch stick car, the key to success is in softening the clutch hit without giving up torque capacity. Lots of drag-n-drive guys ditching adjustable slipper clutches in favor of a non-adjustable diaphragm paired with an external hit controller.

Grant

 

My car is an '01 6M Trans Am, SBE, HCI, Procharged D1SC @ 9/10lbs making 660/590 at the wheels. I have a MWC Fabricated 9" with 3.50 gears.

From a dig it will blow the tires off but from a 40 roll in 2nd it hooks and goes.

The previous owner had 4.10 in the car and said it was worthless. just knocked the tires off 1st, 2nd, 3rd, chirping in 4th.

If you a looking for consistent launches I would look in to your wheel tire setup along with ditching the strano springs. Not that strano springs are bad. I had them on a z28 and they are great but not for 1/4mile.

Like someone said above, look in to 15" wheel with some serious sidewall for your racing applications.

(Id love to see the car though....)

 

Optimizing how fast the clutch engages against WOT is critical to bringing the engine/chassis together for a good 60'. Sadly, it's usually one of the last areas that gets addressed.

Grant