Engine/Transmission (1994 - 1998) HP ratings for 3" exhaust.

[Gray 5.9]

I know this has been run over a few times,Oo. ... What is the max Hp rating for a 3" exhaust... . Thank You

 

[Shrimpy]

I stand to be corrected, but I seem to remember about 2 to 3 years ago Joe Donnelly (sp) hitting 550+ with a 3 inch.



As stated, I stand to be corrected by someone with a better memory than mine

 

[Gray 5.9]

550+!! DANGIT MAN:--) , I thoght it might have been around 250 or 300HP. A friend of mine has a 96' was wondering. Thanks

 

[Joseph Donnelly]

The most I ever got with 3" was 416 hp. FWIW, that was with 3", Walker 21468 muffler, custom torque plate (similar to my #10 that TST markets), HX35 with 16 or 18. 5 cm2 housing, and 300 marine injectors. Got 408. 8 with stock 215 hp injectors. EGTs were crispy. I found that with the HX35, I gained only 7 hp (from 380 to 387) in testing a 4" system with no muffler.



After working with Piers of BD (at that time) to find an HX40 (courtesy of Carl Gross, then at Holset Aftermarket), I went to 4" for that turbo with the Walker 21471 muffler. Since this turbo helps significantly with egts when over 330-350 hp range, I think 4" with the HX40 is a good idea at that point.



I got a best of 613 hp with 4" exhaust, and a best of 774. 8 hp with 5". Maybe changed a few other parts too, along the way It seems that 5" helps a bit beginning at around 570 hp.



Hope this helps Oo.

 

[Shrimpy]

Thanks Joe. Looks like I was a little to optimistic on the 3" .



Thanks for clarifying.



Jim

 

[Gray 5.9]

Thank You Joe'

Where these figures based off of using a 160hp pump, sounds very interesting. I'm still running the stock WH1C turbo, and 160 injectors, with a #5 tst plate slide all the way back. How much HP would you guestamate I'm making? Thank You for the reply.