3400 in a Fiero (headers)

[Bridgetown]

I am putting a 2002 3400 into my '86 fiero that came with a 2.8. I want to run a set of headers that are designed for the 2.8 to make exhaust routing easier and gain a little performance. My plan is to buy the headers and cut off the flanges and weld on some 3400 flanges so they will bolt to the heads. The primaries are 1 1/4" I.D. so they shouldn't hurt performance from size, and gain a little from better routing then the manifolds would have. My questions is this: The 2.8 headers are designed to have the exhaust mounted vaccuum style 2.8 EGR, with my swap I will be using a digital EGR(top mount style). Could I just mount the EGR in place of the 2.8 (mabey need an adapter) and run the flex tube into the intake (side mount EGR style intake)? OR would it be easeir to use an adapter (side mount to top mount) on my intake and run the flex tube into the header and weld a fitting onto it and eliminate the 2.8 mount on the header? There are pics of my swap on the fiero thread.

http://www.fiero.nl/forum/Forum1/HTML/071783.html

I know this is kind of confuseing, sorry, but using three different engines to make one working car gets that way. If more info or pics are needed let me know.

[IsaacHayes]

should be able to just enlarge the bolt holes for the headers and bolt them on I think. Merlot would know.

[Alxsmt]

i believe you can enlarge the holes too. i was looking into it at one point for mine but i never got the 3400 in and i cant rember for sure

[Bridgetown]

Yeah, I'm confident the headers will work. The real question is in regard to the EGR, and what the best setup would be. Mount to the cross-over pipe, or onto the 3400 manifold?

[merlot566jka]

just use truleo headers. and u have to slot out the holes. thats what i did. they worked, cut to fit headers would be much better idea tho

[Bridgetown]

Yeah, I was planning on using the truleo's, the heasers aren't the problem. It is where to put the EGR. What didi you do on yours? Pics?

[Alxsmt]

who needs egr? my car passed emissions with out it... if you have inspections just rig it up so it looks like its there

[ForcedFirebird]

No too long ago, I made a set of turbo headers for a 3400. The easy thing to do is to weld a bung within reach of the stock 3400 EGR tube and thread it into the fitting. I don't remember the thread size, but I *think* it was 1/2"-13 NPT. It doesn't matter where in the exhaust stream the gasses are pulled from, but typically the closer to the head is better.

There is no real reason to remove the EGR. It lowers combustion temps and does help with the environment.

[fudge]

killerbv6 makes some headers and not that expensive either.

got better pictures of your low mount alternator bracket that you bought?

[merlot566jka]

no egr needed

i didnt have one.

[Bridgetown]

I'm pretty sure I have to run the EGR, no? I am not using the 7730 I'm using the ecm from a 95 firebird. I baught the harness and computer from another fiero owner who was running a 3400 in his car. The difference was his 3400 used the early style EGR and mine uses the late side-mount style EGR. The connections are different. So I have to figure out how to use the older style EGR on my newer 3400. I thaught that mabey I could mount the EGR to the Crossover pipe like the fiero's vaccuum EGR does.

[Bridgetown]

killerbv6 makes some headers and not that expensive either.

got better pictures of your low mount alternator bracket that you bought?

I have some pics on my build thread here.

http://www.fiero.nl/forum/Forum1/HTML/071783.html

I'm pretty sure it is off of a 3.1L from a RWD car. I had to cut it up a bit to make it work for my application. I think it is going to do the job though.