Looking for after market exhaust system recommendations. I am running a 455 with headers and motor dyno’d at 500 hp. I had a stock dual exhaust system on my 68 Cutlass from Gardner with their turbo mufflers. Nice system but now that I rebuilt my motor and added headers does not fit my needs anymore. The Gardner system is currently just hooked up to the headers and I am not happy with the sound. Looking for something that sounds aggressive but not crazy loud either.

Any recommendations and what is everybody running?

 

FWIW my preference is Pypes 2.5” w/ X Pipe and long case Dynomax Super Turbos. Muscle car sound, relatively quiet, no drone. Note on the X pipe - it tends to eliminate the blub, blub, blub that is somewhat a trademark of Olds V8.

 

Get the pipes 2.5” stock style with no crossover. They even have tips for 2.5” and connection pipes to bolt on to stock manifolds.

 

I know a crossover of H or X pipe helps performance. Does not having one and having true duals **** off the engine any? I wouldn't think so.

 

I am working on installing my PYPES system with x-pipe crossover. I'm using the PYPES Streetpro mufflers. Installation is not complete so I don't have any useful firsthand info regarding how it sounds, runs, etc. I've seen several threads with high regard for this system, including statements that the X-pipe adds some small amount of horsepower. Mine is an OE 400 of unknown heritage. What I do know about the engine is that I've replaced the timing set and the rubber seals on the front and rear of the intake manifold that were trashed and leaking. Someone had been inside my engine before I bought it, but at this time I've no idea what may have been done. It ran well enough with the OEM 2.25" dual exhaust. I'm anxious to see how it runs after the addition of the 2.5" pipes, X-Pipe, and headers.

 

My advice for an x-pipe: use band or v clamps to allow easy removal.

 

If you are after max power then a crossover is the way to go and X pipes tend to be better than H pipes as they both help balance the exhaust pulses and increase the savaging effect, especially with the long tube headers. But that crossover tube will balance off the exhaust pulses as well as change the sound and lope some, depending on the cam.

 

Thank you. I should have rephrased, a normal car on the street is not harmed from not having a crossover, correct?

 

No it is not harmed, maybe just hampered. Dr. Oldsmobile built many of them this way at the plant sans headers.

 

I have the Pypes 2.5” system on my 69 without an x pipe through stock manifolds and with their violator mufflers. Used their trumpet tips and band clamps. Fit pretty darn good. Stock 400 engine except for a BTR spec’d cam. Mild cam but lots of chop spec’d in the design. It is pretty darn loud from the back but very little drone. Almost like glasspacks. If you want a sound clip let me know and I’ll see if I can upload one.

 

Thanks for all of the reply’s and keep them coming. I see that the Pypes system seems to be popular. I have been looking at and leaning towards the 2.5” regular or x pipe Pypes system but less sold on a muffler choice at this point.

 

Good luck with your choice, but remember. what's music to one person's ears is like nails on a chalkboard to another person.

 

2 1/2" Pypes with h pipe and Violator mufflers

 

3" Pypes Race Pros and shortened tail pipes

 

I'm partial to the Flowmaster American Thunder system. No comment on mufflers - way too deep a subject - but the exhaust system can be purchased in 409 stainless. I prefer an H-pipe rather than X and this system fits and functions great. I do run Pypes stainless downpipes to connect the manifolds to the Flowmaster system (header back) and Pypes 2.5" stainless trumpet tips. Everything fits great and works well together.

 

I put a stainless 2 1/2 flowmaster American thunder with h pipe on my 66 .. love the sound of it

 

The difference between the H and X pipe is where on the power band the extra torque comes in. H pipes generally produce the increase at lower RPMs and the X at the upper. I'm not a fan of the X as it results in a more raspy sounding exhaust.

 

Pypes 2.5 X pipe with Dynomax mufflers here, sounds awesome.

 

considering this same combination. Which Dynomax muffler did you go with?

 

Ultra Flow Welded.

 

I prefer Walker 17749 Super Turbo long case mufflers.

They have the perfect muscle cars sound.