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1gn Exhaust Manifold on 2gn and powerband vs tube length

Posted: Wed Jun 05, 2013 6:22 pm
by D-Railed_Neon
Hey guys, doing some thinking out loud and debating on solving one problem or killing two birds with one stone. Here is what I am currently running into. My car has a mag head with a mild PnP, a comp 400, and obx tti longtube. My exhaust leaks...and badly, at the swivel joint on my longtube. spring bolts don't work all that well and seem to come loose or break and the leak coupled with the creaking noise of the manifold moving up and down at idle due to the lope of the cam are becoming more and more annoying. I have considered removing the OBX provided swivel completely and just flanging a flex pipe at both ends and at the beginning of the cat pipe and just bolting that into place. Now, I think that would solve my leaking and creaking problems however as the great Billy Mays would say "wait there's more!"

This setup (03 sxt stock bottom btw) put 184 down to the wheels with the mag intake on a MSD switch, an AEM cai, and underdrive pulley and has dyno slips to prove it. Anywhere above 4K rpm the car is a blast but at the low end its kinda lame. I have advanced the cam forward on a adjustable cam gear to bring the power band back about as far as the stock ECU will allow before coding or limping and I still don't have the power as soon as I would like. I know that tube length has some effect on powerband and with that I can come back to the question of the thread. What I would like to do is actually switch manifolds altogether to a decent mid length style and bring the cam back towards reccomend position. The manifold I had an interest in is actually for a 1gn sohc this one to be exact- ... headersEGR

Now, I know that the end of the header is probably gonna line up straight exactly to the stock exhaust but as I am already running an aftermarket manifold I am aware some new pipe and welding may have to happen and am OK with this. My worries are i the sohc mid length will clear the firewall and fit into the exhaust tunnel. Does anyone know? Also, if it will does anyone have any experience with the header I am looking at or one similar and have any info or opinions to share on it. Ultimately I just want a nice sounding, good looking exhaust that brings me some low end kick but doesn't completely neuter the car up top.

This is my current exhaust manifold- ... st_headers

Sorry about the rant and thanks for any feedback :thumbup:

Posted: Thu Jun 06, 2013 9:44 am
by timk225
I have a Pacesetter header on my 5 SXT ATX, and it's about the same size and shape as that header you linked to. My Pacesetter clears everything by a mile, no problem at all.

When I first put it on, I noticed the ball flange end of the header was a bit dinged, and it did leak a lot a first, but after a month it carboned up and sealed for the most part.

I'm putting a Magnum head on soon, and when I do, I'm going to coat the ball flange end of the header with RTV Copper 700 degree sealer, for a better seal. I don't believe it will move around enough to tear it up and even if it does it'll probably still carbon up and seal.

A 2.0 is a weenie little short stroke chainsaw engine. Short of a turbo, or dropping in a 2.4 short block, or both, there's not much you can do to help the bottom end power. You've got to rev the piss out of it and enjoy it at over 4000 rpm when you want to go fast. My 5 SXT ATX needs more bottom end and mid range too.

Posted: Thu Jun 06, 2013 2:54 pm
by INVUJerry
You will lose power throughout the power band with the short tube vs the long tube. Get a standard 3 bolt 2.5" flange and get it mated to your exhaust with a flex pipe, that's what I did. Do you already have a 2.5" catback?

Posted: Thu Jun 06, 2013 10:09 pm
by D-Railed_Neon
Thats what I thought. Thanks guys. Jerry, gonna take your advice and stick to the original plan which was to get some 3 bolt flanges and just weld up a flex and remove the stock OBX swivel pipe. Thanks again guys. Also, no its stock pipe from the header to the thermal R&D rear end.