Exhaust system differences between hot air and intercooled cars?

[TR Custom Parts]

Got a question from a customer about exhaust systems for a hot air car. Don't know a lot about the hot air cars, do they have the same setup from the cat back as the intercooled 86-7 TR's? Same exhaust hanger and four bolt flange?

 

[hesermon]

Mark, I can't say with 100% certainty but when I converted my 85 to I/C I had to change nothing from the cat back and from looking at pics of the underside of 86/87 cars I believe they are the same. Now did they use the same exact muffler, I don't know but I do believe all the pipes, bends, hangers, etc. are the same. Hope this helps some,
Hugh

 

[Boost231]

yes they do, everything is the same. this start getting different fron the front of the cat forward

 

[Boost231]

if you need someone to put your exhaust on their hotair i will i have a atr unit still and i love it. however if i was going to change it would be yours for sure

 

[turbonut85]

x2. I'm with Brent on this....however....
I'm ready for a different exhaust for my hot air.....just sold mine.....if a guinea pig is needed...I'm your man for sure....

 

[TR Custom Parts]

Waiting for your order. So do the hot air cars use the same hanger off the crossmember? That is the only place I think things could be different. Hell, I haven't run that hanger for years now. I have hangers right after the mufflers and the system is fairly light.

 

[forcefed3.8's]

Hot airs don't have the 4bolt flange. There is a square 4 bolt flange at the down pipe to cat then a ball flange from the cat to the exhaust system.

 

[TR Custom Parts]

Aha! So you would have to use one of our test pipes along with the exhaust and then adapt it to the existing downpipe.

 

[turbonut85]

Hot airs don't have the 4bolt flange. There is a square 4 bolt flange at the down pipe to cat then a ball flange from the cat to the exhaust system.

Not true. They are the same from the cat back. Square flange on the dp side of the cat...but they have the same oval type flange as the ic cars behind the cat....at least mine, and every other hot air I have seen have been this way....

...and they use the same cat hanger as the ic cars....again....every one I have seen does anyway...

 

[forcefed3.8's]

Well, mine must have been an odd ball. It had an original cat with a ball flange on the end.

 

[O SO LO]

My original exhaust had cat with a ball flange on the end...

 

[Boost231]

Hot airs don't have the 4bolt flange. There is a square 4 bolt flange at the down pipe to cat then a ball flange from the cat to the exhaust system.

you sir are correct. i forgot i bought a test pipe when i got mine. its a 2 bolt flange. the hanger is the same. Damn im losing it.

 

[turbonut85]

My original exhaust had cat with a ball flange on the end...

you sir are correct. i forgot i bought a test pipe when i got mine. its a 2 bolt flange. the hanger is the same. Damn im losing it.

Hmmmm......I guess mine had been replaced or something....as rusty as it was, I guess I figured it to be original. the cat had the square and oval flanges on it though....weird.

 

[standupjskiguy]

The wife's 85 also had a ball flange at the back of the cat. To put a hooker system on, they had to weld a four bolt flange onto the ball end.
That was a palce called ANS in Illinois, they had a bunch of flanges CNC'd for that purpose waiting to be welded on.

 

[novaderrik]

my 84 has the ball flange on it..
maybe they got away from the ball flange and went to the 4 bolt flange towards the end of the 85 model year- maybe right around the time they switched from the hydraboost to the PM brake booster?

 

[Jerryl]

I am pretty sure the HA cars had a ball-end connection after the cat.
The cars that did not have this were more than likely modified.
With the ball end, the cat hanger would have to be different since the bolt pattern would be different.
The bolting location of the cat hanger to the cross member would however be in the same place.

 

[charlief1]

Don't know if this helps but my 83 T had a square flange on the cat to the back.

 

[Casey Jensen]

My 84 GN has the ball end on the inlet and square 4 bolt flange on the outlet of the cat. When I put on my hooker exhaust, I had to make a new rectangular flange to bolt to my hooker cat back when I bought it. As far as the hangers go, I can't remember unless I look under my car.