5 replies to this topic

[D-Train]

G'day guys.

My new setup has a 2.5" collector at the headers and my exhaust system is 2". My local exhaust shop want me to start my car to put it on there Ramps and I said it needs to be tuned and can't properly until it's got a system on it. They had a cry about pushing and hard work. So I sled if I give them my 2" system could they replicate it and I'll take responsibility for it if it doesn't fit correctly, but no dice so I'll give it a bash.

Here's my setup.
Black 202, 30 thou over,
Stg 1 cam dur 208@50, lift 448 lift travel - hyd lifters,
56cc yella terra alloy head, 7cc dish pistons, I imagine about 8.5:1 comp, pulleys running about 10ish psi, 42lb 440cc injectors, surge tank, Bosch 044 pump, w2a intercooler. Wolf Ecu

What should I do? Original has one muffler, but I'm not fussed, I just want to know what I need for correct back pressure etc, as I have no idea. Just can't be a monster noise maker that wakes every cop up around the neighbourhood. I was planning on copying the old one as a 2.5" but any other ideas welcome.

Cheers, D.

[grumpy xu1]

I would be trying a hooker aerochamber muffler. They come right up to 3.5", as a boosted engine, i don't think it will be really loud anyway. They'll flow heaps & they're reasonably priced at tuff car parts, about $180 ish for 1 of 2.5", if it's to loud, you could add a hi flow resonator in there somewhere. I have them on my ss & with 100 cell very open cat's it's around 79 decibels at idle, but it's aspirated & as i said the cats are 100 cell, if they weren't basically new & I'd go 200 cell magna flows, a lot quieter. But you'll probably have to put the hooker up the back, as they're a large muffler. Never loose their original sound, sound deep ect. Gary.

[warrenm]

G'day guys.

My new setup has a 2.5" collector at the headers and my exhaust system is 2". My local exhaust shop want me to start my car to put it on there Ramps and I said it needs to be tuned and can't properly until it's got a system on it. They had a cry about pushing and hard work. So I sled if I give them my 2" system could they replicate it and I'll take responsibility for it if it doesn't fit correctly, but no dice so I'll give it a bash.

Here's my setup.
Black 202, 30 thou over,
Stg 1 cam dur 208@50, lift 448 lift travel - hyd lifters,
56cc yella terra alloy head, 7cc dish pistons, I imagine about 8.5:1 comp, pulleys running about 10ish psi, 42lb 440cc injectors, surge tank, Bosch 044 pump, w2a intercooler. Wolf Ecu

What should I do? Original has one muffler, but I'm not fussed, I just want to know what I need for correct back pressure etc, as I have no idea. Just can't be a monster noise maker that wakes every cop up around the neighbourhood. I was planning on copying the old one as a 2.5" but any other ideas welcome.

Cheers, D.

Don't worry about the correct "back pressure" it's a bit of a myth, particularly on a forced induction engine. Like Gary said, Aerochambers are a good choice, 2.5" isn't too big, I run twin 2.5" of my n/a 202.

[D-Train]

Thanks guys, grumpy xu1, that helps in more ways then one. I'm trying to sort a good exhaust for my stinger.
Warrenm, I unbolted the exhaust from the turbos on a dyno on my daily and lost 70hp, but that is extreme going from full to nothing. I appreciate the help, that answers my questions. Legends.

[grumpy xu1]

You'll be chasing flow, on a forced induction vehicle though, so you shouldn't really compare it to a n/a car, 70 hp seems like a massive amount of power to loose. On something with cat's i would not go finer than 200 cell, factory 1's are probably 700, not sure about a stinger though, but 200 are the legal cut off number in qld. I have twin 2.5" on my ss & my clubsport (which is my daily) the clubsport has MagnaFlow 200 cells, those & the hookers are aluminized outside & inside & have all the plates in stainless welded in not spotted the cat's are steel core rectangular shape for better ground clearance, with the hookers underneath, let's just say, it's rather low, but you can get them to fit, with some massaging. I know a few guy's who've put them on ve & vf ls engines, they sound really good. Don't be worried when you see they're almost straight through. They'll flow about 97%, so should be great on the boosted engine. Gary.

Oops, just saw it was turbo'd that seems surprising.

[I'm a Red Motor fiend]

I run a Hooker Aero and a small resi, 2.5" on an n/a 202.
Really nice sound.