Warped ???
 

Hey,

I'm a new member. I have been a car enthusiast for many years but just recently started taking a serious interest in classics. Currently I have a 1978 trans am being restored. The original engine has 220hp/ 320 torque. This engine has been slightly modified and produces 375 hp/ 475 torque.

So my question is, would the increased power warp the chassis?

If so, what would be an economic fix that would not effect the originality of the car. I know, I already messed it up with the engine.

Thanks

subframes to start

Does that mean it will warp the chassis?

Sub frame connectors on just about any uni body car (stock or modified) are a good investment. They will help prevent twisting from the engines torque and sagging that gravity alone will cause. Also a good set of body mounts will help a bunch.

What type of investment are we looking at?

Sub frame connectors range from 150-250 + install depending on which style you go with
Body mounts range from 75-150 + install depending on type..

what's the different in the sub-frame of a 3rd gen f-body to a 4th. meaning are they both uni body

They are both uni-body but different designs..

Pricy, but the hotchkis ones probably meet the "not effect the originality of the car" part best. Problem is they only give you new rear bushings (stupid asses), so you still need a whole set. Global West solid body bushings are very good.

The other SFCs I know will require too much drilling and/or welding to "not effect the originality of the car"

We can also fabricate a set that will tuck up nicely and not be as easy to see from the side as some of the bolt in ones available..

Custom FTW!

Deff pick up a set of solid frame bushings, along with a set of subframe connectors.
Scott, i have a set of PTFB's sfc's, doesnt look like a lot of moddification is needed to make work?

to bolt them in he has to drill both through the frame and the frame rails. I think with the hotchkiss it's just the frame, and that is easier to fix if need be.

yeah, dave's will work too, they are basically the same. i was thinking maybe josh could get the GWs for him

Thanks for the knowledge. Trying to absorb it and apply it.

Contact #'s would be great to order the part.

The web address is in my signature or just click the link on the right
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With the engine already being leaned on, I'd worry less about the SFC effecting the originality of the car, but focus more on the functionality they provide. That said a custom made set is probably the way to go. On my 70 Nova I made a set out of .120 wall 2x3 and sectioned the floor so from the side you can barely see them. Granted, section them through the floor is kind of a one way deal, but it is also very strong and kinda stealthy. The bolt in Comp Engineering ones are ugly. They hang down too far and I'm not sure they are all that effective. The Comp Eng weld in versions can get pretty involved on the install and might require other mods. For bolt in, look at the Global West offering. For pre made weld in go Detroit Speed if you otherwise go custom.

Global West (nice bolt in):
http://www.globalwest.net/1970-81_Ca...obal_West..htm

Comp Engineering (these look like pooh):
http://www.competitionengineering.co...?CatCode=10054

http://www.competitionengineering.co...?CatCode=11001

Detroit Spreed Engineering (nice stuff, but weld in)
http://www.detroitspeed.com/productp...b_con_prod.htm

I vote for weld in, either DSE or custom....
Chris

OK. So I will take your advice but the car is being retored in North Carilina. Is there some kind of template for the 1978 trans am so I can send him the part and he could do the installation?

Who's advice are you referring to? I'd call Detroit Speed Engineering. Follow the link provided. They are designed for your 2nd gen and come complete with all kinds of templates, destructions, DVD etc. Don't think you could ask for more than that?

Good Luck

Chris

Just to add a bit to what was already said:

3rd gens are pretty notirious for flexing/twisting. T-top cars seem to have the most problems. You can see in 3rd gens that the paint on the roof where the rain gutter ends/back upper corner of the door windows is where they start to crack the paint first. Over time it will get worst. I twisted my 84Z - (none T-tops with bolt in SFCs) so badly it cracked the seams in the door jams!

With 375HP I would strongly suggest getting subframe connectors that weld in. They do a better job.

While all pertinent anyway, a 78 is a 2nd gen. :)

Thanks 1qwikbird. I'm just trying to get the resto done right.

I'd seriously consider the DSEs too, except that comment about originality. That is a hard mod to reverse. That is the only reason I listed the hotchkis ones.

Well that's a decision only you can make. If the originality is high on the list, a set of weld in SFC's is gonna kill that. Only you know your car's history, its uniqueness and how important all this is and in what order it stacks up for you.

IMO, a set of well executed, properly installed weld in SFC's wouldn't be the end of the world. They might even be a help in keeping the car straight if you have enough power to hurt things down the road.

But a set of SFC's (bolt in or weld in) poorly executed would be a shame.

Do your homework.

Chris

Thanks Guys,

I'll keep you up to date with the progress of the car.