Upgrading brakes for 1/4 mile-Opinions??

[TurboBird]

Working on a 93 Pontiac Formula..Looking for loads of brake pressure so I can build up boost on the line.. Was wondering what everyone is running?? Has 625 hp at the wheels.. Also looking for recommendations for alum. driveshafts as well..Thanks in advance.. 7004r trans..

[ConElite]

Your best bet is a Trans Brake b/c if your going to try and build up a lot of boost the car is going to be pushed forward. If you just want to go with brakes then some Bear brake system or Wilwood. With a proportion valve you should be set.

[TurboBird]

Thats fine.. Someone else suggested bypassing the proportioning valve with a hard line and switch.. What kind of switch??

[ConElite]

Hardline and Switch.

[lsdengines]

You are talking about the type setup a pro stick car uses to load the driveline. The hardline and switch is to load the car against the brake pressure you set, and then use a linelock to hold it. I haven't seen it done very often if at all on an automatic car. Turbo cars a different animal altogether to get them to spool hard on the line. The 3.08 first gear in the 700/4l60 doesn't do much to help that. I would do away with the stock booster, mc, abs block. Change to a manual brake setup, I'll look at my notes to tell you the best bore size to go with, and run 2 adjustable proportioning valves to allow you to adjust the brake pressure front and rear until you can fully load the car against the convertor to start building decent boost. You can also research the anti-lag methods from the ricer world. Nitrous out of the hole also does wonders for a hard launch and instant spool.

[TurboBird]

Interesting.. Sounds like something I can do.. Pics would be great or illustrations..Dont want to change off the ABS or mc as this is a driver as well..And need to pass Del. inspection next month..Anyone know what specs are for a 350 LT1 are?? Need to get as close as possible beforehand, then punch it back up for the next 2 years.. Great answers so far.. Thanks..

[lsdengines]

what specs are you wanting, emissions? I have an lt1 edit file that I used to pass when I lived in NC, but I was na. The problem with the stock abs, mc, and proportioning valve is that it biases the front brakes for safety and stopping performance. This is great for driving, and average circuit racing, but you need full pressure to the rear brakes to properly hold the car on the line. Have you tried slicks, and setting up the suspension? If the tires are sticky and the suspension loading properly, you should be able load the car up against the convertor pretty good with the stock brakes. For street/strip duty however, I run aerospace components brakes all the way around, do away with the abs, and run manual brakes. But my idea of a street car is a little extreme for a lot of people.

[Injuneer]

With the correct stall on the converter, your brakes will not be fully loaded. Why not use that approach? Stall + a T-brake is all you need.

[Red93TA]

as long as your brakes are functional in the stopping test they do for inspection it normally doesn't matter what kind of brake setup it is whether it be manual or power. The ebrake has to remain functional as well as the regular brakes and if you make it so you can load them like that it will definately be functional enough to pass an inspection. As far as smog tests go I would dare to say (not 100% on this) but as long as everything is tuned properly you won't have a problem. I have a friend that runs an inspection station and just for fun we hooked my carb'd car up and it passed. No egr, no smog, no cat, no crap just a holley 650dp on a built motor with headers and alot of mods. But I had it tuned properly on the dyno.

[TurboBird]

Yes am needing emission numbers..Have a Buick Grand National motor in car and with a different setup 2 years ago[DFI], still had to pay someone off to get it thru.. Am now the newer XFI Fast system and just wanted stock numbers to give engine builder specs to see if he can get the numbers down..Tags run out next month..But back to the brakes and am ordering rear drag Wilwoods today from either local parts house or Summit ..Summit wants 615.00 for the setup..Got a source for them cheaper??? Local dragging their heels on just getting me a price..Called monday..Since last months tragedy on old torque convertor[ shreared off torque conv. bolts putting shifter into overdrive at 128mph] have new TCS conv. rated at 4000 rpms installed and to try out first chance I get, will see if its better, then install Wilwoods and adjustable prop. valve..Not ready to jerk out trans for trans brake , just got it done at Deltrans last year but will consider it it all else fails..Got a bunch of money out on this and its been down for 19 months.. Just want to hit some lows 10s , maybe high 9s before it sets on the rack again.. Before new conv. , best time is 2.0 60ft,11.19 @ 128mph bouncing off rev limiter in third[think this is set at 6500]..Thats why I shifted into overdrive even tho told not to..Sh!t happens.. Thanks for the info guys.. Appreciate the responses for the new guy to the board..Just as friendly as the Buick boards..