couple exhaust questions. - Third Generation F-Body Message Boards

87_TA_GTA · 09-20-2009, 01:35 PM

so right now my car has the Flowmaster 43083 mufler. it has a 3" in and a 2.5" out. does this mean my cat back is a 3"? does that also make my cat a 3"? i also am thinking about installing the hooker 2055 and 3" y pipe. i read a little on the 2055 sticky and they were talking about getting new spark plugs and 90* boots. are these a must for these headers? also what is a 90* boot?
thanks for your help.

87_TA_GTA · 09-20-2009, 08:21 PM

bump.

im also thinking about putting a cutout in the y pipe, but im worried about ground clearance. can i mount it so that it wont be the lowest thing, maybe pointed closer to the bottom of the car than the ground or is it small enough that it wont make that big of a difference?

//<86TA>\\ · 09-20-2009, 10:27 PM

what the muffler is doenst mean anything relating to the rest of the setup. A reducer could have been installed in the fuller inlet so they the stock catback piping could be used. You have to get under the car and see what you really have.

Only way to make a cutout practically on a stock style exhaust is to use an electric one. Put the cutout in the tunnel under the rear seat area. IF the cut out is not electric, you wont be able to upen/close it without jacking up the car.

87_TA_GTA · 09-20-2009, 10:56 PM

yeah i was planning on getting an electric cutout. so if the pipe is the same all the way through the exhaust that means its a 3". but because the car has the stock exhaust manifolds is the y pipe smaller than a 3? this would mean i also would need a new cat

JamesC · 09-21-2009, 07:52 AM

Quote:

Originally Posted by 87_TA_GTA

yeah i was planning on getting an electric cutout. so if the pipe is the same all the way through the exhaust that means its a 3". but because the car has the stock exhaust manifolds is the y pipe smaller than a 3? this would mean i also would need a new cat

Post #4 of the following link for sizes:

http://www.thirdgen.org/techboard/ex...-question.html (85 Z28 Exhaust Question)

JamesC

87_TA_GTA · 09-21-2009, 07:17 PM

maybe im just not looking at it right, but it doesnt have my year engine. mines an 87

2" outlet manifolds with single 2 1/4" y-pipe
82-87 305 LG4 (VIN H)
88-92 305 L03 (VIN E)
82-83 305 Crossfire
90-92 305 LB9 w/o G92 axle (VIN F)

2 1/4" outlet manifolds with single 3" y-pipe
83-86 305 L69 (VIN G)
85-89 305 LB9 (VIN F)
88 350 L98 (VIN 8)
89 350 L98 w/o G92 axle (VIN 8)

2 1/4" outlet manifolds with dual 2 1/4" cats
89 350 L98 w/G92 axle (VIN 8)
90-92 350 L98 (VIN 8)
89 305 LB9 w/G92 Axle (VIN F)
90-92 305 LB9 w/G92 (Vin F)

im guessing mine is the closest to that, and i know my car doesnt have dual cats and it looks like the only 350's are a 3" y. Am i correct in thinking this also means my cat is a 3", at least at the y pipe side?