LT1powered89

I will be doing my LT1 swap in about a month and a half and after the swap I was going to run new exhaust. I search around knowing that it is just about impossible to run duals on a third gen and found the 4 inch single exhaust system from mufflex performance. Has anyone used this sytem? If you have, how does it sound?

www.mufflex-performance.com

firebirdjosh

iTrader: (1)

True duals is possible, I'm putting it on next week!

1989GTATransAm

iTrader: (3)

The 3.50 Mufflex should do you just fine. Allen

vejatabul

i have a mufflex 4inch on my stock long block l98 gta. it made 378wtq at 2200rpm and 271whp at 4900rpm. with a 3 inch flowmaster it made 352wtq at 2600rpm and 260whp at 5000rpm. the mufflex made a big differance. i get 28mpg on the freeway with a th350 and 2800 converter with stock 3.27 gears. i am very happy with sound. i have edelbrock headers and no cat.

406TPI

iTrader: (1)

28mpg with a turbo 350 and 3.27 gears....now that's impressive.

BulliTooth

that is a big diffrence between 3 and 4 inch...wow

Matt87GTA

I have the 4" Mufflex system and EVERYONE loves the way my car sounds. I mean even Mustang guys feel the need to tell me they wish their cars sounded like mine. I'm by no means bragging - I didn't design it or anything. I like the sound a lot as well but it really is wierd how many people come up to me and comment on the exhaust note of my GTA.

As for flow, well I made the numbers in my sig with it.... I think it works alright .

CraZ-28

I have it too and love it. It has a nice healthy sound to it and I to get compliments on it. Plus people FREAK when they look and see that there is 4 inches of sewer tube stuffed up in there. Plus I now don't have to worry about having enough flow for my new engine.

83 Crossfire TA

iTrader: (2)

Which mufflex setup do you have (flowmaster, spintech or spintech with dual outlets)?

I can’t tell you that I’m really surprised at the results, the 80 series flowmaster doesn’t really flow enough not to be a restriction for more then somewhere in the mid 200 hp range, and you’re way in excess of that if you’re putting down 270 to the wheels. Really, that 80 series doesn’t even flow as well as the stock 4th gen mufflers

BulliTooth

love the way it sounds matt87 u have a good pic of the 4 inch ?

FASTR

Hey Matt.. yer everywhere

I have the 4" mufflex system as well. With the way I want my car to be, I do not like it at all. I couldnt stand the tinny obnoxious sound of the flowmaster it came with, so I bought a 4" edelbrock victor series muffler. Its a slightly more mellow, much deeper sound. But still just loud all the time. I like to be a little more incognito.

I have the eibach sportlines, so the exhaust scrapes Everything. The system really wasnt bolt on either.. took alot of grinding here and there. At full throttle it sounds great.. but the part throttle sound is real garbled. Just my 2 cents =)

Im going to switch to a single 3 " exhaust for cruising and use a cutout for the track. I bought that SLP tc from Zimrandy.. so Im going to see how that works to increase driveability as well.

Nixon1

What all do you have done on that L98? Those numbers are up there...

Matt87GTA

Not really... I'll work on it though...

People do tend to really freak out when they see the size of that tubing....lol.

I get around!!! lol...

Yeah it is hella loud. But I like it.... I like that signature Flowmaster sound too so it works for me. My car is pretty low too but I have yet to scrape any part of the catback. The crossmember for the Torque Arm and the headers (collectors) scrape long before any part of the catback would.

I think if I ever want mine to be a little more tame sounding I would try a Borla muffler or possibly a Dynomax UltraFlow Welded. I know Traxion really liked the sound of his DUW and it is basically straight through so you know it flows well.

vejatabul

crossfire,
it is one of the old systems, from like 1999 or 2000. it is a flowmaster.

nixon,
its pretty much bolt ons only, and last time it was dynoed, it had 92,000+ miles on it. it made 229whp and 330wtq. msd 6al(zero hp on the dyno) with blaster coil and msd wires,coated edelbrock headers(8whp and 6wtq, kinda low), no cat, no ac, no smog,it has an electric vacume pump(worth 6whp and 3wtq),production lt4 cam with stamped steel non roller 1.6 rockers on the exhaust and 1.5 on intake, self ported base/runnes/plenum,smothed tb with molded air foil,afpr,12* initial timing, self made cold air intake(5whp and 6wtq), march underdrive crank pulley(9whp and 4wtq), self made grounding system, (just a few 2 gauge grounds running to the motor and ps pump and from ps to frame, but it made 2hp and 3wtq). with all this it made 260.2whp and 352wtq, with the muflex it made 271whp and 378wtq. these hp increases are not from one part alone, because somethings were done at the same time and then dynoed with 3 or 4 of the items installed.

83 Crossfire TA

iTrader: (2)

A lot of choices there… the spintech mufflers are mellower sounding. Dynomax ultraflow welded and the hooker max flows are both quiet at idle but get louder with some throttle, especially the maxflow. The 4” hooker Aerochamber would probably be your best choice, they tend to be slightly louder at idle then the dynomax or maxflow, but they don’t get much louder with throttle, just low and mean sounding.

If you split that single 4” tip into twin 3” you’ll kill some of the noise also.

1FastZ

For those of you who are running the mufflex system, what headers are you running and are you running the flowmaster or spintech dual or single out.
The reason I asked, is because I run shorty headers and the guy at mufflex said they don't make a y-pipe to work with shorty headers.

1FastZ

TTTTTT

FASTR

The ypipe they make is only for the Hooker Super Comp full length headers. Any other headers and youd have to have a shop custom weld you a y-pipe. Mine originally came with the flowmaster single out. I then bought an Edelbrock 4" muffler for it, it sounds better but still not what I want.

REALPOWER

Ya know whats funny, I have a complete mufflex system with Y pipe and 4" cat I was trying to blow off for 300 bucks AND NOBODY WANTED IT

I still have it....ANYONE WANT IT?

crazy3rdgen

iTrader: (1)

sound clips of the mufflex please?

Marc 85Z28

iTrader: (3)

I'm running SLP's shorty headers and the Mufflex system (an original LS1 system no less) fit right up to my current piping after the cat.

And the 4" single in/out Flowmaster is MUCH more aggressive sounding than the 4" in Spintech dual 3" out I originally had. If you want a tamer sound, get the Spintech.

unknown_host

iTrader: (1)

Yeah just like the header adapter plates you ripped me off on

firebirdjones

Well Realpower, I was interested in it until Mr. Unknownhost posted and scared me off. Oh well, guess you never can tell with people nowadays,,,,especially these dag nabbit computer transactions Larry.

REALPOWER

Call the whaambulance. I havn't gotten them out for the second time yet. I work 7 days a week and go to school, and the US post office doesnt exactly work late. Go on ebay and buy a set for 5 bucks. Thats where these came from. I gave you a hell of a deal on those headers and I am not gonna rip you off. But if you wanna badmouth me maybe I'll just keep them...

unknown_host

iTrader: (1)

Hm that's funny, this is what you told me last time I asked about them via PM:

And the cheapest I have found Hooker adapter plates is $90. I have been EXTREMELY patient with you, that PM was 3 weeks ago!!!

firebirdjones

Hey Realpower, I would consider just driving up to you and check out that exhaust if you are within a couple hours driving distance of Cincinnati. Any chance of that? Larry.

REALPOWER

I am somewhat near philly. Its a drive from Ohio. Unknown heres your tracking number. The rest of thirdgen.org can now track it too. Ups # MMYJKHOD1KXNN

REALPOWER

.

unknown_host

iTrader: (1)

I would really appreciate if that is the tracking number, but I tried it on UPS, Fedex and USPS and none of them worked. You sure that is the right number?

REALPOWER

Go here. www.mbe.com and track it. Im just shipped it so its not on yet.

unknown_host

iTrader: (1)

Tracking number still isn't working for me.

soulbounder

Just an observation: If you change the tracking # to

MMYJKH0D1KXNN

it comes up with something at the mailboxes etc site. (O changed to 0)

Also lists the UPS tracking # as 1Z9WX1470329045885.

Don't know if that's for you or not though.

unknown_host

iTrader: (1)

Thanks man!

Matt87GTA

Well I have a friend that is definately looking to put that exhaust setup on his car... I PM'd ya about it but it appears that PMs don't work very well with you. If you send me a phone number or Email address that will work to get a hold of you I will forward it to my friend.

REALPOWER

adnoh400@hotmail.com

power6

Any of you 4" boys have any ground clearance issues? How about on lowered cars? I know the ls1 crowd is always b*tching about smushing pipes on speed bumps and such.
thanks!

Marc 85Z28

iTrader: (3)

I've never had any scraping issues, even with my car lowered just over 1" from stock. Never had more than 2 passengers with the 4", so a loaded car might cause problems. My air dam is the only thing that scrapes on speed bumps, and that's going diagonally over them when possible.

vejatabul

i have mac sfc's( i call them subframe protectors) and they scrape before anything else gets a chance to touch. my car is lowered almost 3 inchs. my exhaust does not scrape on my gta, but the mufflex that was on my camaro did on occasion.

DanTheMan_smlk

does the mufflex fit on the car without hitting the rear axle? i cant believe there is enough room for that

stage20

iTrader: (3)

too impressive.

Matt87GTA

Yes, there is. Plenty in fact.

Matt87GTA

Well I turn and run if I see a speed bump because of my headers and subframe/torque arm setup, but I also have never had problems with the catback scraping.

flyitlikustolit

I ressurrected this thread because I'm building a 400hp 383. it's going to be N/A, but i was looking at exhaust options. I'm definitely going to get the hooker 2210's, but as far as exhaust, i've been burned twice already by custom exhaut shops that screwed it up. I'm running an Eibach pro-kit, Spohn SFC's, and a Spohn Torque arm/X-member. I'm also running spohn tubular LCA's and Panhard bar. now: will the mufflex 4" system fit on my car? I've heard the spohn X-member prevents this. also, which is the best flowing muffler? I'm leaning towards teh spintech or the dynomax (if dynomax is available) and while i want it to sound good, I NEED it to flow well.... sound is a by-product. any options? if the 4" mufflex won;t work, I'm just gonna dig up some bullet mufflers and run lake pipes next to the SFC's.

bigdavesiroc

i am going to need an exhaust setup also. with my 406 and hedman headers i'll need something a little different then most. where are you guys locating or getting the mufflex 4 inch setup from? i've done searches before for this on yahoo, etc. no such luck. the headers i have have a 3 inch collector and i'll need a y-pipe. do they have those also? thanks

stage20

iTrader: (3)

a mufflex y pipe wont work too well with a torque arm. ive seen some people modify them, but i wouldnt.

a 4" catback will work with the spohn torque arm, you may just need to cut it back several inches and add your own y collector on the front of it, so a custom y pipe can be made.

currently there is no dynomax(oval) muffler in a 4". you can get bullets all day long, but they arent as quiet.

83 Crossfire TA

iTrader: (2)

a 4" exhaust is not _really_ needed for 400hp

flyitlikustolit

hmmmm. so how quiet ARE the bullets? and are the spintech mufflers high-flowing? or do they suck? if they flow decently, i'll get them. (if they flow significantly better than flowmasters, that is.)

83 Crossfire TA

iTrader: (2)

EVERYTHING flows significantly better then flowmasters (look around for some flow numbers, or get your own, you'll be suprised). Bullets are a straight through design Which both flow well and barely muffle the exhaust

flyitlikustolit

is it obnoxiously loud or just LOUD? in other words, does it sound good? or just red neck?

firebirdjones

Just depends on the person. Some people like the sound and some don't. You really have to hear a car with them and judge for yourself. Or do what I do and buy different mufflers and test them and hope for the best. I have not found that much of a performance difference between all the good oval mufflers regardless of all the bad talk about flowmaster and some others, bullet mufflers are in a catagory all their own. Keep in mind the pipe sizing, X-pipe, H-pipe, configuration of tailpipes etc...all play a roll in how the muffler or mufflers will sound. So if you hear a few take the time to see how the rest of the system is configured. Hope this helps. Larry.