3500 manis

zofo61 · 11-11-2008, 06:38 PM

If I decide to use the 3500 exhaust manifolds........it seems that everyone wants to use two fronts. The only problem i see with the rear is that it needs a block off plate for the egr. My main question is that the 3400 uses one O2 and the 3500 uses 2. The 3400 has a second one but its behind the CAT and useless for fuel calculations. Would you somehow combine the 2 3500 O2s or eliminate 1 and block off 1 and if so would you use the rear bank for the true O2 as the 3400 set up does for fuel calculations......just a thought

Thanks

montess408 · 11-11-2008, 07:07 PM

i had the same idea about using 2 3500 front mani's and that's what i was gonna do use the back one for the O2

zofo61 · 11-11-2008, 08:02 PM

Is the only reason to use two fronts is so you dont have to block off the EGR hole or is the a configuaration issue with the downpipe............just trying to get it all figured out.....i know that there are a lot of front manis out there but if i dont need it then i will just block off the EGR hole.

RedBird · 11-11-2008, 08:05 PM

i dunno about in a newer monte but in my sunbird, the rear manifold points directly into the firewall, and makes contact with the steering rack. the front mani's point almost straight down, hence the reason for using a pair of them.

johnnymossville · 11-11-2008, 08:18 PM

^^^^ Same on the Beretta/Corsica.

zofo61 · 11-12-2008, 06:21 AM

Well then...who has a front 3500 mani they would sell....cheap, cheap, cheap?

>plan on sandblasting porting and having them coated as well.
Thanks for all your input
Chris

3400-95-Modified · 11-12-2008, 10:49 AM

I have one. 20+ shipping?

zofo61 · 11-12-2008, 11:14 AM

anyone cheaper...shipping is gonna be a bitch from CT............any FLA boys out there?

RedBird · 11-12-2008, 11:22 AM

shipping won't be that bad. i paid less than 50 total for one of mine shipped. just put it in a flat rate USPS box, i think they are small enough to fit, $10.95 anywhere in the world

I'm not kidding

IsaacHayes · 11-12-2008, 07:15 PM

In a new gen W body you might be able to use the rear. The newer cars like GA's and the W bodies like Impalas have the down pipe coming more straight back than straight down like the older cars (thus the reason front on the rear). Plus the newer cars have the steering rack mounted on the subframe not on the firewall high up like the older ones.

On the older cars the front hits the AC compressor or something too. But on the newer cars once again it might work.

I'd see how the front and rears work, might be perfect. Forced_Firebird has flanges for them to weld pipe to.

Then just run the front pipe however, if you can do it under, or make it curve back up and through the stock cross over location, then have the 2 pipes merge into a Y under the car. Put the O2 in just the rear, or after the Y. Closer to the motor is better as it's hotter, but having just one isn't a true reading of all cylinders.