I'm confused on 3" exhaust

[SchoolBoy]

Ok quick run down of my DD svo, its an early 85 with a nice manderal bent 2.5" exhaust that has a cat and a hooker muffler. Also if it matters I have the E-6 exhaust manifold. And I am sure it helps over stock, but I am curious about trading it out for a 3" from stinger after reading the MM&FF artical. Now I started searching the forum and got really confused about 3" in general.

When someone up grades the exhaust on their car, does the 3" kit start from the elbow that houses the wastgate or is the elbow part of the kit. If the elbow is not part of the kit, what good is 3" piping from that point on? Does the turbo simply not care on a low hp car "less than 300hp" because the elbow is so close to the t-3 it could be part of the turbo?

Next I keep reading about 3" down pipes, is this used to go from the turbo elbow to the stock exhaust? I take it this is like a longtube header on a v-8 before it goes into the mid pipe.

I was looking at getting: stingers Item # S3MS Mustang 2.3 Turbo 3" Single Exhaust for the drivers side. I belive that it looks like this..... http://www.stinger-performance.com/P...stSingleD1.jpg Is this the kit I would need to replace the stock location exhaust I have now, while deleting the cat? What am I going to need to hook all of this together? What is a quite muffler you would recomend? Is this mod worth the almost 300 bucks over what I have now?

Also how do I keep from over boosting the car like MM&FF did after they put the 3" exhaust on there 85.5?........Nelson

[chalkys_explorer]

I will leave the explanation about exhaust theory to the experts, but to solve the overboost problem, start with the adjustable boost valve at a low setting and build up from there. Practise on mine if you like, I showed Neil how to do it.

the problem with the MM&FF article is they bolted it on and ran the crap out of it without any other tests. The thing I hated about the article was the "we blew it up so we're done" attitude.

[indiana dave]

The 3" downpipe allows the turbulent exhsaust to straighten out before entering the 2-1/2" stock system.
A 3" elbow just allows the exhaust a cleaner exit, for less turbulence overall.
A full 3" exhaust includes the above and the tailpipe, and just decreases backpressure overall.
You can do this in steps, in the above order, or all at once.
Either way, You'll notice a difference in the seat of the pants.
FWIW, I started with the downpipe years ago... then added the MAC 3" single tailpipe, then ported the E6 manifold, and added a 3" elbow.
Sounds great, and made a huge difference in spoolup and overall power.

[Alex L]

the stinger kit does not include an elbow. it bolts to the stocker. it does include the downpipe for that part number.

the only thing not bolt on about the stinger setup is that it does not include hanger provisions. clamp on work fine for the tailpipe and muffler hangers, you will need to fabricate up a transmission mount hanger. if you're going to go 3" on the exhaust, might as well get a 3" elbow and do it right. 40 bob makes a nice one, but requires a core exchange. chop off the 2 bolt flange, and reduced section, and replace it with a 3" flex pipe. its quite a tight squeeze, but can be done.

its also a very tight squeeze over the rear axle and around the fuel tank.

if you dont want to throw down the cash on everything, get the 3" elbow, downpipe, flexpipe and replace the cat with a 3" -> 2.5" reducer. upgrade the rest of it later.

[freakos]

i bought the 3" exhaust from stinger, excelent product!! I asked if he could not weld on the stock DP flange and make the elbow/dp to be used with a v-band flange, of course he didnt mind and at no extra cost !! If i was to redo it again, i would go the same route

[dagenham]

I'm confused on 3" exhaust

I think I'm still confused. Can I get a 3" pipe to basically replace the original factory exhaust on my '84. I just put a 21/2" Dynomax ultraflo muffler and tailpipe on and want to replace the rest of the exhaust from the turbo to the muffler while eliminating the cat. I was going to get it all bent in 21/2" , but everybody keeps telling me to put 3" on back to the muffler.
Like I said I'm confused.
P.S. My engine is bone stock.

[svono50]

I think I'm still confused. Can I get a 3" pipe to basically replace the original factory exhaust on my '84. I just put a 21/2" Dynomax ultraflo muffler and tailpipe on and want to replace the rest of the exhaust from the turbo to the muffler while eliminating the cat. I was going to get it all bent in 21/2" , but everybody keeps telling me to put 3" on back to the muffler.
Like I said I'm confused.
P.S. My engine is bone stock.

I would suggest going with a "xxx" (name your favorite vendor/muffler shop) brand 3" down pipe from the turbo elbow to the inlet pipe of the muffler, don't bother with the 2.5" piping. I put a locally made 3" DP w/o cat on my 86 back when it was stock and felt a very noticeable improvement in spool up earlier in the rpm band as well as ~1 psi of boost increase.

Remember that your exhaust gasses will cool considerably between your turbo and muffler and therefore take up less volume. You can reduce your exhaust piping as you travel along, which will keep your flow velocity up to help with some slight scavenging and not create a restriction. Just my general understanding of gas flow.

[at8tc]

does anyone have a picture of the MAC 3inch single exit??? and also where can i get one??

[Xpeditious]

The stinger down pipe hangs to low.. All it took was one speed bump and there went the down pipe, I don't recommend it.

[SVO-Roy]

when I did mine I added the 6" flexpipe into the down pipe and trimmed it to a good clearance height . works great for me

[indiana dave]

"does anyone have a picture of the MAC 3inch single exit??? and also where can i get one??"
It looks like any 3" LX style tailpipe. I got mine from online-racer.com