Tom 400 CFI

You may not believe this, but here is what I did;

I drilled a 3/8" hole in my torque arm where it mounts in the braket at the trans. I then used a 3/8" die grinder to oblong the hole length wise in the arm. Then I drilled a 3/8" hole all the way through the mounting bracket and rubber. Both sides. I re-assembled the whole thing with a grade 8 3/8" x 2 1/2" bolt running through the braket and arm, thus totally eliminating any vertical flex in the mount itself. Now the only flex in the torque arm system is in the arm itself. This mod DID NOT increase NVH in the car in anyway. It DID, however drop my 60' time! My previouos BEST ever 60' was a 2.08. Last night I made only two passes, and I nailed a 1.97 60'!! This is on WELL worn Yokahama AVS tires, Eibach Pro Kit springs, and all other suspention is stock. I am very happy w/that. A few more passes and I can get that number lower I'm sure.

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'83 Trans Am: 400 CID oil burning junkyard long block, 224/234 crane cam, Summit aluminum roller rockers, hand ported intake, home bored 2.09" (53mm) throttle bodies, MSD 454 injectors(75 lb/hr), Holley 255LPH fuel pump, custum modded FPR, Edelbrock TES headers, SLP 3" stainless steel cat back, stock ECM & chip. Borg/Warner T-5 World Class, 12" Corvette rotors and clipers, GTA 16" wheels, South Side Machine subframe connectors, 1LE sway bars, 3.45 ring and pinion, Alpine sound.
Best E.T. 13.532
Best MPH 102.24

[This message has been edited by Tom 400 CFI (edited September 27, 2001).]

chevyguy1969

iTrader: (7)

Hey Tom, could you post pic of what it looks like? Cool Mod.

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Poor college student(donations welcome)
1988 5.7L TPI IROC-Z Hardtop, 700R-4, White ext. w/Gold/Black accents (soon to be silver), Black Custom Deluxe int., 4-wheel discs & G92 pkg. Car is all stock and original.
Best run: 1/4 14.90 @ 92.7 MPH

#3 Gone but shall never be forgotten. Long live the legacy of the man in black. RIP Dale Earnhardt "The Intimidator"

Matt87GTA

You are creating a lot of bind in the suspension by doing that. The idea behind the way the torque arm moves forward and back inside the rubber mount is due to the sweep of the suspension and lengthening and shortening of the distance the torque arm becomes during suspension travel. Since the torque arm is static mounted to the rear axle housing and that rear axle moves up and down with the control arms maintaining a static length, the axle is actually moving forward and backward, with respect to a side view of the car's wheel well, during it's movement. This sweeping movement of the rear axle housing forward and back dictates that the torque arm be able to increase and decrease in length to accomodate this motion freely. If the torque arm cannot slide in that mount, it is going to bind the rear suspension. This may stiffen the rear suspension during hard compression and solve some traction issues at the drag strip, but will wreak havoc on street manners and road course tuning.

I am not surprised that this increased your 60' performance, but it is a quick fix and will ruin all of your bushings and mounts much quicker due to the binding. The correct way to increase your 60' times would be to get your suspension moving as freely as possible (ie spherical bearings) and use the springs and shocks for tuning.

I also know that most of us are on a tight budget so I think it is awesome that you have found a cheap way to gain traction . I would remove that bolt if you ever go road racing though, as you definately don't want any binding in the suspension for the twisties.....

Laterzzzzzzzz

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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

[This message has been edited by Matt87GTA (edited September 27, 2001).]

Tom 400 CFI

Matt, my jaw nearly hit the floor when I read your post. PLEASE thoroughly read a post before posting an incorrect reply.

There is NO BINDING in this system with my mod. The slot I cut in the torque are isabout 1.5" x 3/8". The 3/8" acommodates the 3/8" bolt, and the 1.5" lenth ENSURES there is more than enough longitudinal travel. There is no binding in this system. I picked up a better 60' time because I removed the "jello" from my torque arm system (somewhat -the arm itself leaves much to be desired). I also have an Energy Suspentions trans mount, but I've had that for years.

Again, untill Wednesday, most of the time I pull 2.1x 60' times, with a BEST of 2.08. Wednesday, my first run netted me a 2.06. I thought that was pretty good, but then on my second run I laid down a sweet 1.97 -with no binding! lol.

I will take pics this weekend, and post them on this thread at the begining of next week. Sorry for the delay, I need to borrow a digital camera. Later.

clemsparks

iTrader: (1)

I was about to second to Matt's post until I read your re-qoute. The "lengthwise" part slipped through the cracks of the somewhat hazy details. So in Matt's defense, I would've posted the same thing (however incorrectly).

That does sound like a good low-tech solution to a traction problem. It's easily reversible too, if you've got any problems with it on the street, you should be able to bolt it up and unbolt it at the track, no problem.

I like it,
Clem

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Clem
SCCA TransAm Series Race Mechanic/CrewChief
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1983 Z28 with LG4, 5 speed, and (unfortunately) T-tops
1983 Z28, NO T-tops, (unfortunately) Auto Transmission (hopefully not for long)

[This message has been edited by clemsparks (edited September 28, 2001).]

Tom 400 CFI

Clem, yea I hear you about the hazy description. As I was typing it I knew it was going to be tough to articulate what I had done clearly. Anyway, pics coming this weekend.

Good point about the ease of putting it back to stock, although I never would now. I do Auto x the car regularly, and have done so since the mod. Any comparisons on the autox course are fairly worthless b/c since every event has a different course, it leaves the judgement to subjectivity. Subjectively it did feel like I could exit corners with more throttle. It seemed like I didn't have to be as "dainty" on the gas(my car has historically been a$$-happy). But that could be in my head. The drag strip gave me the only useful, hard numbers.

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'83 Trans Am: 400 CID oil burning junkyard long block, 224/234 crane cam, Summit aluminum roller rockers, hand ported intake, home bored 2.09" (53mm) throttle bodies, MSD 454 injectors(75 lb/hr), Holley 255LPH fuel pump, custum modded FPR, Edelbrock TES headers, SLP 3" stainless steel cat back, stock ECM & chip. Borg/Warner T-5 World Class, 12" Corvette rotors and clipers, GTA 16" wheels, South Side Machine subframe connectors, 1LE sway bars, 3.45 ring and pinion, Alpine sound.
Best E.T. 13.532
Best MPH 102.24

michta

New to site and so far there is good and home depot mods. I own a 84 ta with tubular torque arm and cross member(SPOHN) and square lower rear control arms and tubular panhard bar(LAKEWOOD) and I have no wheel hop or even when cornering hard rear tires are planted well. No front mods yet but they are in process. Have to do more side jobs for extra cash.

BigWhiteGTP

Pics!!!!