1990dtgL98

I'm looking to redo my exhaust. I'm going to be running about a 400CHP motor into Hooker long tube headers, then some Random Tech (or the Magnaflow cheapie off brand ones) cats. I plan on doing this to reduce emmissions, but also to take off that raspy upper end the car has now without cats. I'll be running true duals into an X-pipe or H-pipe into these mufflers.

Most likely 2.5" to 2.75" to 3" piping, mandrel bent, all the way back. (not sure on the best size yet)

But going with dual high flow cats, I want to get a little louder mufflers to counter-act this. I currently have Flowmaster 40's, but figured I'd try to get louder.

First off, is there any preference to the sound quality/power benefits of an X vs H pipe? I figure the X would be more common as it seems easier to fit.

Secondly, with at most...420CHP, what size exhaust would you recommend?

Secondly, and the main reason for the thread...does anyone have "bullet" or "race" type mufflers on their car? If so how do they sound? Any preference to brand, or if I'll notice much difference between brands (in terms of build quality and flow)?

I'm looking right now into Flowmaster "outlaw" series, Dynomax bullet muffer, Magnaflow round race series, or the Gibson race series.

And no, I can't go straight pipes....won't pass a visual for inspection.

Any help?

1990dtgL98

Anyone?!?!

aboatguy

420 chp dual 2.5" should be fine.

Here's the blurb from magnaflow
Engine size HP single dual
150-200 CID 100 to 150 2" to 2-1/4" 2"
200-250 CID 100 to 200 2-1/4" to 2-1/2" 2" to 2-1/4"
250-300 CID 150 to 250 2-1/2" to 3" 2" to 2-1/2"
300-350 CID 200 to 350 2-1/2" to 3" 2-1/4" to 2-1/2"
350-400 CID 250 to 550 3" to 4" 2-1/2" to 3"

kingcato

Dynomax racing bullets

Aardwolf

I have some Hooker aero chambers waiting to go on. They are a bit heavy. Here is a picture looking through:



The price is pretty decent for the universal fit. These are 2.5" dual outlet.

1990dtgL98

How do you like those dynomax bullets?

They seem to be what I'm after. Little muffler, but unlike the glasspacks, they don't bottle down too much.

1990dtgL98

Also, any idea how much the cats will take off in sound?

I want to keep the deep rumble I have now, and get a good lump from the cam by possibly lowering the idle speed down a bit, but will cats affect loudness on idle? Or will they mainly take off the raspyness up top?

1990dtgL98

1990dtgL98

Figured I'd bump this up for another question:

What are your opinions on running chambered pipes? With or without cats.

jsup

Hey man, here's a reminder.....same car.

1990dtgL98

Yeah, I'm pretty sure I'm going to go the same Pypes cats into an X-pipe route as you, however I don't need/want a 500+ dollar sets of Corsa/Borla/etc. mufflers. I personally don't care about the hype that goes with them. It's not a DD, so I don't really care about loudness, so long as it passes visual.

Though I do think the adjustability of the Power Effects is pretty slick

jsup

Gotcha. The little bit of driving I did with the exhaust, about 10 miles, this setup seems to have zero resonance, and the sound all comes from the back of the car, behind you.

As for the mufflers, I guess you're looking for an inexpensive cat back type system. Is that right?

Deakins

I'm currently running a set of Borla XR1's and love them; I used to run the dynomax magnum race mufflers and for a race car they are ok but for a street car they are getting a little load all the time....

Hotred94

Man that's a tight fit. Makes it difficult to do much of anything.

Z51L9889

I ran Dynomax 3" bullets and Hooker dual outlet tips with built in resonators on a 3" catback with a single 3" high flow cat. It had a great sound -- none of the raspiness that I used to get with my 3" flowmasters. There was quite a bit of resonance, although it wasn't nearly as severe as the flowmasters.

I would recommend 2 1/2" pipes all the way back. At your HP level, 3" won't do anything except drive you crazy with the resonance. If I had it to do all over again (actually, I do ), I would not have put the 3" stuff on at all.

I'm in the process of building a 500+ horse 383, and I will be running no larger than 2 1/2" after the cats. I'm getting too old for all the resonance ....

1990dtgL98

Interesting. On your dynomax bullets, how was the idle sound compared to the flowmasters? Similar, or a higher tone? What flowmasters did you have?

And jsup: Not necessarily. I have access to a mandrel bender at a friend's shop (ours doesn't have one). So I was going to build my own

1990dtgL98

Interesting. On your dynomax bullets, how was the idle sound compared to the flowmasters? Similar, or a higher tone? What flowmasters did you have?

And jsup: Not necessarily. I have access to a mandrel bender at a friend's shop (ours doesn't have one). So I was going to build my own system. I just needed ideas on cats and mufflers.

I'm still not sure if the bullets will have too much resonance that I'll need 2 per side (4 total). Also, I was thinking chambered pipes...any opinions on those?

Finally...would it be stupid to run 2 chambered pipes into 2 bullets? I mean if I have 18-24" behind a X-pipe it would almost be the same price to get extra piping vs. putting in 2 chambered pipes.

Would mufflers after chambered pipes defeat the whole purpose of getting them?

jsup

Depends, what's your purpose? Do you want a loud car? Or a fast car?

In my setup I have little resonance. I will know more when I get the car back from the shop. I'll let you know.

Curveit

Chambered pipes are disruptive to the flow, and the pipe is only as big as it's smallest diameter at best. If you run them I would keep it as far to the rear as possible. They were originally designed to replace mufflers altogether, but were still too loud.

1990dtgL98

Both

HAHA.

But in all honesty, what I meant was will a muffler, even straight through like the Dynomax bullets, screw up the chambered pipes unique sound? IE- Would I be able to run mufflers after the chambered pipes if it's too loud for local laws?

I doubt I could fit chambered pipes where the stock mufflers go, so the bullets would go there.