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N/A 2.5" Exhaust Setup Suggestions

drunkmonkey

drunkmonkey

George James @DrunkMonkeyCustoms
Joined
Jun 1, 2020
Location
Sacramento
Does anyone have any suggestions on a 2.5" NA setup?

The car is a 88' 245 running LH 2.2 with EZK and a A Cam and adjustable cam gear.

I cut the exhaust off right where the primaries merge on the header and welded a 2-2.5" adapter.
From there I ran 2.5" pipe to the muffler (turbo style).

The car pulls harder and seems to breath better but its as loud as a Prius with a missing cat.

I thought about welding the factory cat back on (was replaced a couple years ago and seems to be 2.5") but am worried about restricting flow.

Will a high flow cat quiet down the exhaust?
Will a cherry bomb in place of the cat help?
Will a resonator work?

I don't want to spend a bunch of money on things that may not work.

This is also a temporary setup until the car is boosted.

I will probably use this setup on my drift car eventually.

https://flic.kr/p/2oAQh5G
https://flic.kr/p/2oAR75Y
https://flic.kr/p/2oAMmdd
https://flic.kr/p/2oAR752
https://flic.kr/p/2oAR76e
 
My take-away is if you add a decent sized volume shortly after the downpipe, you can get lower noise and almost no power loss...
Of course you can get into the weeds with calculating tuned length and flow volume, yadayada.
 
for me a high flow spun-style catalyst didn't quiet the exhaust down a worthwhile amount
 
Put in a resonator close to the stock resonator location, should help with the high pitch tones
 
I did a full 3” exhaust from the downpipe back with nothing but a bullet muffler… loud as hell. The turbo eventually made a noise level reduction difference but not near as much as you’d think. What are you after? If you want a quiet but powerful system, buy large mufflers and put them as far back as possible. I ended up using a pair of borla xr mufflers with a 3” cat and the sound was pleasing but not intrusive.
 
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740atl said:
I did a full 3” exhaust from the downpipe back with nothing but a bullet muffler… loud as hell. The turbo eventually made a noise level reduction difference but not near as much as you’d think. What are you after? If you want a quiet but powerful system, buy large mufflers and put them as far back as possible. I ended up using a pair of borla xr mufflers with a 3” cat and the sound was pleasing but not intrusive.
Click to expand...
I'm just after a good sounding exhaust with minimal flow restriction.
The setup before this had the same muffler but with the stock pipe and cat. It had no drone and was quiet until you got on it.
I didn't realize how much a cat muffles sound.
I might just add another cheap muffler and call it a day.
 
Jack said:
right let me clarify
dont approach an orange 244, 122 with whitewalls, black or blue 850 in sac
Click to expand...
You'll hear him with enough time to run:rofl:

Related to the original topic, might get a muffler out back that you want for the turbo setup so when you do swap everything you've only bought one muffler. Bigger = more quite for sure, I had a 12589 magnaflow for a while and It was a touch too quite with a cat and no resonator.
 
Are you doing 2.5" because you're planning ahead for +T? These engines only make about 100whp on the best day of the week, if you're going to keep it N/A you might consider a smaller tube size more appropriate to the power output. I had a 11:1 compression B23 in my old 242 that put down 121whp with K-cam, fairly aggressive timing, and 91oct gas. All through a 4-2-1 header with 2.25" tubing size and Dynomax Super Turbo muffler. Same configuration as yours with a turndown at the rear axle position. The muffler on your car currently looks to be a straight-thru style muffler not a turbo-style. Turbo style will be quieter by far. I also had a resonator where the converter was originally, it was fairly tame with a bit of raspiness at the 5k+ RPM range.
 
I have a 2.5" system from the collector back. I went into a Magnaflow Hi-flow cat into a 12" cherry bomb, then over the axle and into a 24" cherry bomb and it exits close to the stock location. 2.5" all the way.

My car is rowdy sounding but isn't terribly loud OUTSIDE the car, but it drones like crazy inside the car. Someday I'll get around to solving the drone, but for now I wear bluetooth earbuds and ignore it.

I've thought about moving the 24" cherry bomb to the middle of the car and getting some kind of real muffler at the end. Maybe a magnaflow in the rear.
 
James M said:
You'll hear him with enough time to run:rofl:

Related to the original topic, might get a muffler out back that you want for the turbo setup so when you do swap everything you've only bought one muffler. Bigger = more quite for sure, I had a 12589 magnaflow for a while and It was a touch too quiet with a cat and no resonator.
Click to expand...
I plan on doing a full stainless 3” for the turbo setup. I figured I’d experiment and learn while doing N/A stuff. This current setup will eventually be swapped into my 264.
 
stevE85 said:
Are you doing 2.5" because you're planning ahead for +T? These engines only make about 100whp on the best day of the week, if you're going to keep it N/A you might consider a smaller tube size more appropriate to the power output. I had a 11:1 compression B23 in my old 242 that put down 121whp with K-cam, fairly aggressive timing, and 91oct gas. All through a 4-2-1 header with 2.25" tubing size and Dynomax Super Turbo muffler. Same configuration as yours with a turndown at the rear axle position. The muffler on your car currently looks to be a straight-thru style muffler not a turbo-style. Turbo style will be quieter by far. I also had a resonator where the converter was originally, it was fairly tame with a bit of raspiness at the 5k+ RPM range.
Click to expand...
I chose 2.5” based off a couple threads on here.
I definitely feel a difference in power but im not sure if it’s because I deleted the cat or went up in size, or both.
At the end of the day, this motor and exhaust setup will be on my track car so whatever makes it sound better without sacrificing power works for me.
 
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