supermo26

I am helping a friend with a motor conversion. We are putting a 98 LS1 into his 87 S-10 Blazer. We got the short tube headers from Sanderson. We worked out all the clearance issues by grinding some of the cross brace as required. We are now looking into the design of the exhaust system from the headers back. We are looking for so good info that will help us decide how to set this up.
The motor is stock for now but we don't want to limit ourself for any modd that will come in the near future. Stroker or SC or Turbo will never happen so this will be an NA motor only.
I seam to have trouble finding information on True Duals verses single pipe set up. I would like to know what the advantage of duals would be with an X pipe set up verses a single pipe set up. Can a single pipe flow as good as duals if the pipe is sized accordingly?
Do mandel bends help gain HP/TQ?
Does placement of the X pipe matter ( to far forward or rear of truck)?
What size pipe would we be looking to use? Dual or Single?
Would we want to step it up or down after the muffler?
What muffler would flow good for this setup while producing a nice truck rumble that won't be excessivly loud?

I can't seam to find the post that explains the pipe size vers flow vers ect. Please help.

OldSStroker

Mufflers can be the biggest restriction. Look at Dynomax Ultraflow SS or welded, or the very similar Magnaflow. The 2-1/2 in. Welded "Sport"versions flow a lot of air. A pair of these should be able to mount vertically side by side or horizontally staggered about where the stock muffler was and, depending on the length, give you the sound you want.

Yes, by all means use mandrel bends. 2-1/2 inch should be adequate and fit in the stock V6 area. If you want to do a little more fabrication, and the headers have 3 inch outlets, use 3 inch and then a long 3 to 2-1/2 transition (8-12 inches long) just prior to the mufflers. Don't do any short step down on pipe size.

You could put in a crossover where the left pipe meets the right pipe. Location isn't all that critical.

As for tail pipes (after mufflers), don't step up, stay the same as the muffler outlet. Remember the gasses are cooling rapidly as they travel thru the system and therefore flow is less, so same or smaller pipes are ok. That's the reason for stepping just in front of the mufflers.

You could use one 3 inch tail pipe over the axle if you joined the pipes after the mufflers, or do twin tailpipes on one side.

If you want to use just one muffler, use a tapered 2 into one transition just before the muffler. One 3 inch Ultraflow wouldn't be as good as two 2-1/2 inchers, but the higher flow rated ones would be ok.

Are you using the conversion info from www.jagsthatrun.com ?
Their stuff isn't for LS1 conversions, but a lot of it helps.

My $.02

Camaro_Guru16NY

Hey man sounds like a interesting Conversion Hope you guys post pics when your done. Why not just dump the exhaust after the headers aor the at the most infront of the back tires to give you a enough room for an X pipe.


Later,
-JOhn

supermo26

we have used some info from Jags that run along with a few other message boards to track down people who have been doing their own conversion. We are waiting to spray the eng bay and then stuff the motor and tranny for the last time. Of course then we will need a DS built. It would be nice to get a 12 bolt rear end in the near future as well.

So if we go dual all the way back it should be 2 1/2? I thought it would of been 3in. Im curious about something I read earlier. It said that after the muffler you could decreas the size of the pipe to help keep the cooling gasses at higher velosicity?

Where is the best place to buy mandrel bends?

Thanks for the info.

supermo26

we have been running ideals about single or dual, and where to have the tips located and if they are to be seen or not. We came to the conclusion that performance and sound take place over most of the look's.

Any one know about the Hooker Aero Chamber mufflers?

OldSStroker

supermo26

Right ON! I am die hard against Flow buster's. I never jumped on that sound wagon. Thanks for the info. James