ian1320

I just bought an 88 IROC for daily driving so my 86 IROC project has changed directions. Its now going to be a drag car only concerned about going in a straight line as fast as possible. The entire driveline is out of the car currently so now is the time to make changes and im looking for some input.

I have a 96 28 spline 10 bolt with posi carrier that is getting new 3:73's soon (I know its going to break eventually but its what i have in the garage ATM) and a SLP adjustable torque arm. I plan on welding in the LCA brackets and getting some good non-adjustable tubular LCA's.

I plan on eliminating the rear disk brakes and rear sway bar as i dont think they are needed for my application.... crazy right? Shave those pounds where i can.

What springs and shocks would be the best for hooking hard with a 10 inch tire? Also should i be concerned about changing ride height to allow more rear suspension travel? The car should weigh somewhere in the 2600-2800 lbs with fuel and driver.

built91Z28

You plan on eliminating the rear brakes all together? And the rear sway bar?

Normally in a drag only setup your running skinny front tires. This means you cant hit the brakes too hard. I would definetly keep the rear brakes. 5 pounds or so is absolutely not worth even possibly risking your life or someone elses. And the rear sway bar is one of the most important parts of the suspension for a drag car. Its the front you do away with.

ian1320

I am running the stock gen1 IROC wheels so the 245 fronts should give me sufficient stopping power dont you think?

As for the rear sway bar... thats why i figured i would post and let someone catch my slip up before i did something stupid. If i run without a rear sway bar what would happen? Violent body twist on the launch? School me please.

built91Z28

Yeah the sway bar is so that the car doesnt lean on take off. If you run without one and the passenger rear will squat hard and the car will not take off straight at all.

I still say when it comes to brakes, I will take absolutely no short cuts. My life is not worth it. The brake calipers and rotors weigh what, a few pounds? If your that worried about 5 pounds, go on a diet.

ian1320

For a street car i see your point but on a drag strip with a pretty lengthy run off eliminating the rear brakes makes sense to me. 245 front tires with good front disks should be enough to stop the car right? Its not like i will ever drive it to the track, it will be trailered and will only ever see life 1320ft at a time. In that scenario the fronts should be sufficient right?

By the way when i say eliminating the rear brakes i dont just mean the 5lb calipers.... its gotta be closer to 30lbs when you add up the backing plates, caliper mounts, rotors, calipers, pads, and lines all the way to the master cylinder.

Edit, cause i forgot something: Also its a stick car so downshifting will help slow it after the run.

built91Z28

Your life, your choice. You know where I stand.

Primetime91

iTrader: (15)

You'll never pass tech without rear brakes, they'll never even let you run. And personally I think you're going about this the wrong way...

Why not keep the brakes in all 4 corners, and run skinny tires up front to balance the weight back out? That's a much better idea

leftyblitz

Im with prime and built on this youll never pass safety inspection and brakes in all four corners is a great thing trust me ive had a close call cause of brake failure(on the track) if your concerned with weight get brakes that are light weight.

ian1320

Although the weight is a nice byproduct the main motivation for losing the brakes is i don't have all the parts to put them on (rear caliper mounts) so if i didn't need them why not save the money?

Didn't think about tech inspection though, guess i have to get the mounts after all.

Anyone have a suggestion about spring/shock combos?

Primetime91

iTrader: (15)

Stock springs and 50/50 drag shocks should be all you really need, adjustable shocks are good but 50/50's should be fine for you.

AlkyIROC

All vehicles need 4 wheel brakes except lightweight vehicles such as altereds and dragsters but even then, many altereds still have front brakes. Depends what kind of front end they use. These vehicles with rear only brakes also use parachutes to slow down so the rear only brakes are not doing as much of the braking. With front only brakes, it's too easy to lock up the brakes which will cause you to lose control of the vehicle.

Unless you're doing a 1/4 mile run on a 2+ mile long track, you're going to need 4 wheel brakes to slow down safely and quickly. You typically only have 1/4 mile to slow down. Braking force is reverse HP. If you have 500 HP to get you up to speed, you need 500 braking HP to slow you back down in the same distance.

As for the rear sway bar, keep it. It will help to keep the car from twisting on launch and help keep the right rear tire on the ground. As the driveshaft turns the pinion, the pinion is walking up the ring gear. This torque is trying to spin the differential the same direction as the driveshaft is turning. That's why when you see a one wheel burnout, it's always the right rear tire spinning. With less downforce on that wheel, it will spin easier. With a rear sway bar, the force acting on the sway bar will help keep that tire on the ground.

When I first installed my 4-link, the car was always violently launching towards the right. Adding preload to the 4-link bar helped a bit but adding too much preload changed how the car traveled down the track. I installed an aftermarket anti-roll bar and the car launches so straight now that I can almost take my hands off the steering.

ian1320

thanks all for helping me steer clear of headaches early. Ill be putting the rear brakes and sway bar on...... btw anyone have a set of disk brake caliper mounts for a 96 camaro rear end? I guess that's another thread....

Primetime91

iTrader: (15)

Those backing plates shouldn't be hard to find in a junkyard

And Alky knows what he's talking about, definitely keep your rear bar. If you ever really get serious with it, upgrading from the anti-sway to a true anti-roll bar will be a real upgrade, you'll launch much better (if you have the power to need it)

And you never mentioned anything about them, but weld-in subframe connectors & a torque arm with adjustable pinion angle are good ideas too. SFC's are one of the first things you should do in my opinion

ian1320

I have the backing plates, i just need the mounts for the calipers. I have been to the local junk yard 3 times in the past month and i cant even find a rear disk brake f-body there, let alone on with good salvageable parts. That's why i was considering just leaving them off.

I did mention in the original post that i have an SLP adjustable torque arm. The SFC's are there. I just assumed they were a given so i didn't mention them but to be sure the chassis is good and stiff i have a 6 point cage welded in already. The engine is capable of 525hp and 500lbs on paper, we will see what it does at the track soon enough.

cannan5

will a stock sway bar work or do you need to go with a thicker diameter bar??

cannan5

will a stock sway bar work for the rear or go with a bigger diameter??