What size exhaust?

[Bogue]

Hi this is my first post here and i'm new to the whole turbo scene. I have a completely stock 87 daytona shelby z and i'd like to open up the exhaust system some. I am wondering if i should go with a 2.5" system or a 3". Also what kind of muffler is best on these cars?
Thanks, Seth

[BUCKWHEAT]

I love my 3'' with big glasspack you can hear the turbo nice and clear and its not too loud when iam in town.

[Bogue]

Does the glasspack give it an aggresive sound? I don't want to make my car loud i just want a better flowing exhaust and an aggresive sound.

[1983Rampage]

No matter which you upgrade to, you will have to upgrade the swingvalve (aka SV), which the exhaust pipe hooks up to on the turbo. What I would do is get a 3" SV and run 3" all of the way out the back, or atleast get a 2.5" SV and get it ported for better flow. But either way, the 3" will help it out alot, and if you want that "aggresive" sound, then run a straight exhaust. Sounds great when running, not to mention the idle.

[detobias]

well ya dont really "have to" upgrade the SV ; your current 87 will have a 2.25" SV; the 89 only TIIs had a 2.5" - kinda rare, altho they are available new also from our vendors

what you do, kinda depends on your $$ and wrenching ability; and also what future plans you have for the motor

finding a 2.5" downpipe from any 89+ TI (or 89 TII) and adding a mandrel bent 2.5" system from one of our vendors with a hi-flow cat (if required where youre at) OR a hi flow muff will give you a good combination of $$, ease of bolt on, and performance

if you really plan to continue to mod the motor and are looking for big power, then save your pennies for a full 3" system from SV to DP to exhaust

this is one of the most debated and discussed questions here on the exhaust forum... read some of hte past threads for more opinions

[Bogue]

Thanks guys! what i think i'm gonna do is get a 3" swing valve and run a full 3" system all the way back cuz i really wanna make this daytona run nice with some power so i can have decent fuel economy with decent power. I have a plymouth duster at home with a built 340 so i can have alot of fun with that while i get decent fuel economy out of the daytona with a lil performance and fun on the side.

[impuresoul2k3]

I run a full 3" exhaust, muffler, downpipe, swingvalve and its really not too bad with my 3" straight through dynomax muffler. Noticeable but not annoying.

[The Pope]

Quote:

Originally Posted by Bogue Thanks guys! what i think i'm gonna do is get a 3" swing valve and run a full 3" system all the way back cuz i really wanna make this daytona run nice with some power so i can have decent fuel economy with decent power. I have a plymouth duster at home with a built 340 so i can have alot of fun with that while i get decent fuel economy out of the daytona with a lil performance and fun on the side.

Being an old muscle car guy I love the 3". The sound is very deap, not high pitch at all. Then you add the rope of the batch fire FI and the little 8v sound like a nice V8 to many blue haired guys. If you go to a full 3" with straight through muffler and SV your done. You may never change the exhaust ever again, no matter how much power you go after. Otherwise 3" makes for great spool up and big torque, nothing better on the street. TU has the exhaust system, SS mesh muffler, and 3" SV. Consider a stage 3 computer from FWD or a stage 5 to work with the exhaust (moving a lot more air). You need to remove the slider cam to get mileage, the slider lowers your engine vac and makes the engine run more rich. A nice roller, TBI or turbo from an 88' will make the car use less fuel and run smoother.

[Hemi417]

I just wanted to make mention because your new to the forum ,Those swing valve bolts can be a (PAIN) , I normally take a small torch and heat up the housing a little before i get started (no broken bolts that way),dont go over board on the heat but it helps , on my lebaron i used the 2.25 sv on the garret went to a 2.5 pipe through a high flow cat for a 360cub engine straight from there, sounded great ,cruses nice, will put u to sleep though, u can here the turbo spool in the pipe , The only complaint i have is even with the high flow cat and straight before the cat i would get 2-3psi of back pressure under full boost14psi , but i'm running a g-head with port work, and gasket matched exhaust mani ,

[Bogue]

Thanks for the great info guys!