I've had this exhaust on my car for a couple years now, but I just got arround to taking some pictures of it. Enjoy!

Here's a couple more....

wOw! That looks really great. I don't think i've ever seen such a clean underbody. Whazzit sound like?

It sounds pretty damn mean!

You definitely know it's got a decent cam in it...

.503/.510 w/1.5's
224/230 @ .050
112 LSA
108 ICA

On a side note, the muffler is a Spintech 3.5 inch single in / single out..

I'll try a take an audio/video clip sometime early next week.

Nice! No sound clips?

Not yet, I just got a pretty nice camera (Sony Cybershot 12.1). It does videos too, so I'll make an exhaust video soon....

Oh yea, and the X-member is a custom double-hump x-member so I could tuck the pipes higher in the tranny tunnel.

very nice, i'm gonna be building a mufflex like setup myself..but a 4inch system. yours gives me a good idea of the clearances under there. I think i will be ok

I think the 4in. maybe overkill..... You may lose too much velocity.

on a 383 with a big hydraulic roller cam, AFr 195's and 11 to 1? i think its about right for the hp this motor should be making. I'm sure i can get away with a single 3.5 but i also plan on more power down the road with nitrous and maybe a different cam/heads package if i dont like how it goes so far. Maybe even a blower? who knows

Here in Houston, MTI (Motor Sport Technologies) which is a pretty well known speed shop, usually used a dual 3in. Y with a 3in. corsa catback on most of there big HP 422 - 455 cubic inch LS-X motors. That setup made more power than the cars with the 4in. systems on the dyno.

Just something to think about....

i was gonna do true dual 3inch but i dont wanna go thru that aggrevation to get all that piping to fit under my car i wont be making 420+ ci LSx power n/a, but could match that on the bottle. i think 4inch will be enough for my setup

3.5 seems to work well for 355's. 1989GTATransAM has a 3.5 and is making 370whp at over 6000 rpms so its up to the task of making power.

what model spintech muffler is that, my spintech muffler is blown out and it raddles like crazy!

I don't know what model it is. It came with the mufflex kit.....

Man nice car back in 1997 a ran 12.4s at 115miles on pump gas with a setup similar to yours in my 91 z28 350 fully ported tpi with slp runners and 58 mm tb, tremec TKO 5 spd ,9 in ford rear with 4.11 and same exhaust has your but i used the 4" cat back.Congratulations for a nice car.
I sold my 98 ss and i lloking to go back in time to buy 91 or 91 z28 to play with it again.

I took a sound clip, I'll try to post it up soon.....

Really looks good. Nice job.

IMHO if your are running two 2 1/2 inch collector pipes you should have a 3 1/2 inch tail pipe. IMHO if you are running two 3" collector pipes you should have a 4" tail pipe. The key to exhaust gas velocity is the collector pipes and headers. The tail pipes insures that there are no restrictions. I know that there are a ton of cars out there with 2 1/2 inch collectors with 3" tail pipes that run good but I don't think that is the optimum setup.

So what your saying is since my Y-pipe is 3 in. per side that I should have went with a 4 in. intermediate pipe and muffler instead the 3 1/2 ?

Man that looks sweet! I wanna hear this thing!

I second that I want to hear it. Look great waht cross member you running

1bad91Z, yes if you do the math. Two 3' diameter pipes is roughly equivelant to a single 4" pipe in cross sectional area. Actually a 4" pipe is a little smaller.

Two 2 1/2 inch pipes is close to a single 3.5" pipe in cross sectional area. So you are necking down your capacity at the wye. Depending on your horsepower level it may or may not hurt anything.

Motor is roughly ~400 at the flywheel. I figured what I put on there exhaust wise was probably slight overkill, but I originally built my current motor back in 2001-2002 with intentions of using a 7 PSI procharger once funds permitted... funds still haven't permitted!@

Maybe one day


I had the crossmember custom fabricated.

You are fine at that horsepower level. That is the location of where I'm going to put my custom made transmission mount for my 4L60E. It will give me clearance to run an exhuast pipe through there on the passenger side like you did so that I can fit in my exhaust termination box.

Damn Mike, i had no idea your under side was so clean man!

What trans crossmember are you using? I have the Spohn with my T56 and I don't think I could squeeze those pipes through there like you have it.

Dawn nice setup BTW.

Thanks! I had cleaned it up a bit when I did the new sending unit and holley pump along with rebuilding the rear end.

Must be the Spintech becuase I have the flowmaster Mufflex and you can't hear the cam, which is a tad smaller than yours 219/219 .560/.560.

To answer a couple of questions that I've been getting:

The crossmember is a T-56 conversion double-hump x-member. It was fabricated specifically for my car. I've tried a few times to get in touch with the guy who built it for me several years back (2000 or 2001) I think is when I did the 6-speed swap, but I haven't been able to get ahold of him since.

It is powdercoated black, the steel is pretty thick (I don't know what guage though).

I was able to tuck the pipes quite a bit higher in the tranny tunnel due to the extra clearance that the double-humps provided.

The torque-arm is a Random Technology adjustable "transmission mounted" TQ arm.

You can hear the cam loud and clear on my setup because the cam is bigger and I may have higher compression and a lower idle speed (rpm), not because I'm using a Spintech muffler.

My old exhaust setup was still using the same dual 3in. Y-pipe, but I used my old Flowmaster 3in. catback (cross-flow style) with dual 2 1/2 inch outlets. Even with the old, more restrictive exhaust, you could still hear the cam clearly (it's pretty choppy at idle).....

The cam is pretty decent, it was a challenge to tune the PROM for it. It's the reason I got into PROM tuning, because the custom Ed Wright chip I bought for my setup still ran like crap... (wouldn't idle and ran so rich it made your eyes water). So, I learned to tune PROM's back in '01, but thats another story. Anyway, my cam is actually small in today's standards!

Hope the above info helps a bit!

Here's the video/exhaust clip..... The exhaust almost blew the camera off of the bucket.

Crank up the volume!

http://www.youtube.com/watch?v=kfLWpAy0c1o

Pretty sweet.

wow that thing sounds mean as hell!

Believe it or not, this system is actually less noisy inside the car than the old flowmaster cross-flow system I had on there (at cruising speeds).

But at WOT, holy crap!

i bet, that thing sounds meaner than my ultraflow 4inch on my 383 haha. nice sound

Bump - that way a buddy of mine can easily find the link to the video clip......

http://www.youtube.com/watch?v=kfLWpAy0c1o

Oh, and click "watch in high quality".......the video has decent resolution.

your car sounds great!! Do you have any port work done to the SLP and TPI setup? also does it pass emmissions...or should i say could it pass? How does it drive in town with that cam? im lookin to do a bigger cam and heads but need to pass the sniffer test

I ported the runners/plenum, and port matched base to ported vortec heads. It should pass if I install the 2 random-tech bullet cats.

Runs just fine in town and the highway, very streetable! 17 mpg city, I haven't used a full tank on highway only, so I don't know highway mileage.

I've put in a bunch of hours tuning the PROM for the cam though to get it right.

PROM tuning is the key to streetabilty, especially with a larger cam.

where can i get that exsaust i'm having problems with mine not enough flow its really holding my car back

You can get the cat back from Mufflex, the headers from hooker or summit, but the Y-pipe is custom made and you'll need a custom tranny crossmember and a six-speed for ground clearance of the y-pipe.

I went 2 the mufflex web site its more of a directory can you be a lil more specifec on where to go

never mind I found the right web site thanks

Oh, sorry about that...

their website is: http://www.mufflex-performance.com/

Why do you say your exhaust is holding you back? What are your motor specs?

I like how clean the mufflex installs.I think mine is overkill though. I went with the 4" cause i see turbo setup or big cubes in the near future

There was still a bit of work to make it clean though. I didn't use any of their clamps (I welded everything). Then I ground down the welds and painted them with high-temp aluminum exhaust paint. Then I cut the intermediate pipe right as it bends up to go over the axle and I flanged it there so I could unbolt the whole Y-pipe if I ever have to remove tranny or other stuff under there while maintaining not having to take off the muffler and over the axle pipe..........

Long story short, it was still quite a bit of work for a cat-back. The Y-pipe was a bigger challenge and harder to make than the cat-back though.

To the top for a friend to locate...

Hey 1bad91z nice car. I had the same set up on my car as well. Sounded awesome, but man did it kill my performance. My old combo was similar to yours. 355ci, 11.1 comp, AFR 190 out the box, Holley stealthram out the box, same cam but w/1.6 rockers, 700r4 3500 stall, 4.11 w/ drag radials. Street trim a/c, power windows, ect. Car always ran 12.3-12.5 @106. One night at the track 1st round I ran 12.3 @106. 2nd round when I launched about the 60' my clamp came loose the muffler fell off. It felt like I hit the nitrous the car went 11.7 @ 118 that round on motor. I threw the muffler away.

Too funny!

Did you have the 3 1/2" muffler or 3" ?

What are you running now for exhaust?

Nice ride yourself, by the way!

Very nice setup! Love the car! Just as I was about to say that me and 1bad91z have similar setups, I see me and you also have similar setups. Not often do you see Teal Green cars out there! I can vouch for the Spintech muffler being crap as well. Although I didn't see as much gain as you did, I did see about a 12rwhp gain by swapping over to a Hooker muffler.

There are a ton of things that I would like to do to the car if $$$ ever permitted. But, working 2 part time jobs and going back to college part time (career change), has prevented me from dumping money into the toys. And, I wouldn't have time to work on it if I had the extra cash.

I was at one time thinking about running dual electric cutouts right after the header collectors. That would eliminate ANY power loss due to muffler choice.

But, I'm not in my 20's anymore and speed isn't that big of a concern anymore. I just enjoy taking the car to the car shows a few times a year. That's about all the free time I have to drive it. Most of the time it's a garage ornament.....

I'm jealous how your car looks underneath though. You still have the stock rear?? I want to clean up under mine and maybe paint the ole stock rusty rear.
Here is a pic of my custom made y-pipe going into flow collector then to 3.5" exhaust. The rear pic shows when I had the spintech muffler, I now use a Hooker Aerochamber.

I had the 3 1/2" muffler. I sold that system and went with dual 3" with bullet mufflers. I just got my car back together after 2yr. I yanked the 355 out and put in a 427 sb. I was using the hooker super comp on the new motor its killing me at top end. Still managed 10.15 @ 133 on motor. My friends are custom building me some header . Going with 1 7/8 step up 2" into 3 1/2 Borla XR-1 mufflers.

I know what you mean! I haven't really tinkered with the car either in the last few years. Heck the last time I brought it to the track was Nov 06! Got to fix my clutch and now I'm having some fuel pressure issues so it's not even running. Getting back on this board though is helping me want to get off my butt and start on it!