Oldsmobile 350 Dual Exhausts in a 80 G Body El Cam!no

[WanaBa442]

That would be "Mr Horsepower" of Clay Smith cams.

 

[ssn696]

http://www.heartthrobexhaust.com/
http://www.heartthrobexhaust.com/2008488p.html
http://www.heartthrobexhaust.com/2008488.PDF

I suspect that this kit will fit a wide range of G-bodies. El Caminos and wagons may need customization. For behind-the-wheels exits, perhaps cutting and adding straight pipe out would also work. Contact them...I had a nice chat with the sales manager.

http://www.heartthrobexhaust.com/aboutus.htm

 

[Oldscarnut]

http://www.heartthrobexhaust.com/
http://www.heartthrobexhaust.com/2008488p.html
http://www.heartthrobexhaust.com/2008488.PDF

I suspect that this kit will fit a wide range of G-bodies. El Caminos and wagons may need customization. For behind-the-wheels exits, perhaps cutting and adding straight pipe out would also work. Contact them...I had a nice chat with the sales manager.

http://www.heartthrobexhaust.com/aboutus.htm

THANK YOU 😳!

 

[olds307 and 403]

Try the 2.25" W31 downpipes that Inline Tube or Yearone sells. Go 2.25", 2" is too small, not sure, except for sound control, why Olds shrunk the tail pipes. My custom 2" setup fit my G body, was tight near the A arms but fit. The main reason with manifolds that 2.5" isn't suggested is because the smaller pipe will fit the manifold flange better. I was surprised the shorty headers and 2.5" system helped the 260 a noticeable amount. In theory the 2" system with manifolds and straight through glass pack mufflers should flow plenty for a 260.

 

[Oldscarnut]

That is good info, thanks! My Oldsmobile source said precisely what you did about diameters. No more than 2.25" and 2" at the exit.

 

[olds307 and 403]

I disagree with the outlet but he may have dyno experience with those cars.

 

[xcookpac]

2 1/4" dual exhaust pipes (smallest section of exhaust) should be good to about 375HP. Whereas 2" dual pipes are good to about 290HP. See https://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

 

[olds307 and 403]

I have seen different charts with slightly different numbers. Huge jump from 2" to 2.25" and then 2.5". Also depends on if it is inside OD or not. Also manderal vs compression bends. I think the main reason the 2.5" exhaust doesn't kill bottom end on my 260 is the smaller 1 5/8" primary tubes. Also my 2" exhaust has 2" OD mufflers so the pipe is more like 1 7/8" and the regular SBO 260 manifolds suck as do all factory manifolds. The Thornton "High Performance" manifolds as cast are only a small improvement. I know DoubleV cleaned up the casting and said they needed a lot of work to flow worth a dam.