I'm working on the exhaust for my 87 4.9/4t60e (auto). Trying to run 2.5 inch like the stock fiero.
I have a Y pipe (like the stock v6 setup), highflow cat, flowmaster 80 series, a bunch of 2.5 mandrel bends.

The pipe under the engine, that goes from the muffler to the cat is tricky. How far below the engine cradle can I go with this pipe? How close to the oil pan and engine mount is too close? Should I wrap this pipe with something because it is close to the engine?

I'm thinking about having a shop do this pipe, but I still have to have a good idea of where it goes in order to position the muffler and cat.
Thanks!
-john

Whats a cat?

I would be wrapping it in some insulator if its getting close to anything that burns or melts. I'm unfamiliar with the 4.9 swap. Got any pics of the underside that you are talking about?

If you dont mind me asking, why are you running it all the way around like the stock exhaust? Why not just cap off the manifold nearest to the firewall, use the stock Y-pipe, and then run the exhaust out of the manifold closest to the trunk? makes alot of a cleaner setup, and leaves so much room in the back where the cat used to be, and you can still run a cat doing the setup like this.

All 4.9 exhaust links with pics and some sound links too---Have fun
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20050818-2-060501.html
http://www.fieroaddiction.com/caddy49f.html
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20060811-2-071733.html
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20060206-2-063183.html
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20040710-2-048722.html
https://www.fiero.nl/forum/Archives/Archive-000001/HTML/20060811-2-070117.html

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Proud Member of the North Florida Fiero club

4T60E Parks harness/ Rockcrawl chip-- more to come--

maybe help (or not)




Been running like this for the last 3 years as mostly a daily driver with no problem (yes it needs to be washed). Also of note, my system is a bit different: no cat, y-pipe right rear side of motor (no exhaust pipe going over the tranny).

[This message has been edited by Mickey_Moose (edited 09-27-2006).]

cat = catalytic converter, which I need to pass emissions in my fairfax county, virginia.

KeithGT - I do not want to cut the trunk. cat and muffler wont fit that way without removing half the trunk.
jeffndebrus - thanks for the links.
Mickey_Moose - That helps a lot!
It looks as though having the bottom of the pipes level with the bottom of the cradle will be a good rule to follow.
I may have to use a different engine mount to get a little more room.
Do you know which mount you used?

Thanks for the responses.
-john

quote Originally posted by twodogjohnny: cat = catalytic converter, which I need to pass emissions in my fairfax county, virginia. KeithGT - I do not want to cut the trunk. cat and muffler wont fit that way without removing half the trunk. jeffndebrus - thanks for the links. Mickey_Moose - That helps a lot! It looks as though having the bottom of the pipes level with the bottom of the cradle will be a good rule to follow. I may have to use a different engine mount to get a little more room. Do you know which mount you used? Thanks for the responses. -john

I used the Bubba Joe system - his brackets and poly GM TH400 transmission mounts.
http://members.fortunecity.com/bubbajoexx/id14.htm

[This message has been edited by Mickey_Moose (edited 09-29-2006).]