Hi there! I'm a newbie to the 4th Gens so I gots some questions about my decision to put shorty headers (Speed_Daddy from Ebay) on a stock 94Z that also has a new Magnaflow Y-pipe and cat.
Questions:
1) What are the extra tubes attached to the orig exhaust manifolds for? One connects to the lower pass side exh manifold and goes back across the top of the transmission.

2) Are they critical to performance? Can they be blocked off? (I live in an area that does not require emissions testing).

3) How difficult is it to get an O2 sensor bung welded and tapped into the new shorty headers?

4) Is it possible to put the shorty headers in without lifting the body off? And if so, do they get installed from the top or from underneath?

Sorry for all the questions. I am used to a '69 Camaro with loads of underhood space to work with.

Thanks,
Greg (Yenkohead)

 

1)

photo credits: shbox.com
2)
No. Read up on what the EGR/AIR systems do and determine if you want to delete them.
3)
Not too hard. Talk to an exhaust shop and get a quote. I'm not a welder so I don't know what goes into it.
4) Yes

 

6SpdLT1Z:

Wow! I didn't expect such a quick and useful response. I just tried test fitting the shorty headers and its going to fun..........

I have the utmost respect for you guys who work on these 4th Gens.

The reason I went with shorty headers was because I managed to twist off 5 of the 6 exhaust manifold bolts that connect to the y-pipe. I tried drilling out the bolts and using an easy-out without success.

Those pics you sent were definitely worth a 1000 words.

Thanks!!!!

Greg

 

Why didn't you just get headers with O2 and emissions connections? You need two O2 sensor bungs.

With regard to welding the O2 bungs on, are your headers cera-metallic coated? Is the Y-pipe cera-metallic coated? If you weld coated surfaces, you damage the coating. IF you didn't get coated headers, you're going to have problems with high under hood temperatures, and header rust.

Here's a writeup on installing a set of shorty headers in an LT1. Its for JBA's with emissions, but it should provide some guidance.

http://www.injuneer.com/JBAHeadr.html

 

I purchased the car for my daughter. It is not necessarily for performance. I had suspected that it had a clogged cat so I started by replacing the cat with a Magnaflow cat and Y-pipe. Upon removal of the exhaust manifold bolts I managed to twist off 5 of 6 bolts. I attempted to drill and easy-out the twisted off bolts without success. I then decided to replace the exhaust manifolds with stainless shorty headers. The Y-pipe has one O2 sensor bung (driver's side). The passenger side has no O2 sensor bung on neither the Y-pipe nor the shorty header.

Any thoughts on the possibility of welding a bung onto a short "intermediate" pipe (between the shorty header and the Y-pipe)? Or is this just crazy?

I now see why it is preferable to go with the more expensive "complete" setup with bungs already in place. I could still go that route since the shorty headers were only $85 plus $30 shipping.

Thanks for your input.

Greg

 

Any exhaust shop can weld an O2 bung on the headers. You want it in the passenger side of the Y-pipe. That's where the stock bung is located. The "intermediate" pipe is the pipe that connects the cat to the muffler.