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Posted by: 3d914 Feb 13 2012, 09:52 PM

Seen a couple different approaches for exhaust on V6 & V8 teeners. Gettin ready to fab a Y-pipe for the SHO motor going into the 914. Want to run single exhaust down the right side, muffler in stock position, and single tail pipe out the back-left.

Curious to see different approaches there are for routing exhaust above or below the axles. Post pics!

Here's a picture of the 3.2L SHO motor.


TIA

Posted by: pdlightning Feb 13 2012, 10:38 PM

I am also interested in the exhaust, but what are you going to do for the intake and filter?

Posted by: matthepcat Feb 13 2012, 11:25 PM

My 350 used to have one side cross under the oil pan meet up with the other side. This went through a 3" cat and a flow master in the stock location.

This configuration was great because no drone! Should have kept it.

Oh and it went under the axles (holds axles off the ground if your cv blows out!)

Posted by: jimkelly Feb 14 2012, 10:21 AM

drone - not sure i will ever grow accustomed to it

an upside to dual exhaust is that when hooked to a sniffer - you can see if one bank of 4 cylinders is buring different than the other.


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Posted by: andys Feb 14 2012, 11:06 AM

Over the axles.

Andys



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Posted by: slothness Feb 14 2012, 11:58 AM

I went over the axles too for maximum lower-ability
Just beware if using block huggers...don't use em. The collector dumps right out on the shift rod on the drivers side, angling the bend is a true bitch. I wanted to go y-pipe also but I bought all my parts long ago before I discovered all my mistakes and couldn't return them. I ended up building a custom straight shift rod linkage per the Jwest design and now there is more room down there. Beware you might have to unexpectedly fabricate some items.

Ignore the poor welds, they dont leak

Posted by: Andyrew Feb 14 2012, 12:06 PM

Above the axles is the only way to fly.

Posted by: slothness Feb 14 2012, 12:13 PM

Oh and the heat shields in Andys first pic is a recommended idea for going over the axles. I can probably roast a pig in my trunk on a 30 minute drive. mmmmm

You'll probably have less of a problem with that being a single side muffler, but its something to think about.

Posted by: bulitt Feb 14 2012, 01:07 PM

Did you just weld up a bunch of pipes, have them bent, or is it the ass end of an available kit (like an axle back section of a mustang as an example)?
Thanks

Posted by: andys Feb 14 2012, 01:20 PM

I bought stainless mandrel bends from Summit and TIG welded them together. Mufflers are FlowMaster 3 chambered for reduced interior noise.
A note on heat shielding: don't forget to shield the shocks in the event your muffler or pipe is close; no need to heat up the shocks un-necessarily. Can't see it in the photo, but there's a shield between the shock and the muffler.

Andys

Posted by: Andyrew Feb 14 2012, 01:22 PM

Muffler shop. 5 years ago they did mine for 300 including 2 magnaflows and resonated tips.

Posted by: computers4kids Feb 14 2012, 10:28 PM

No drone, over the axles and a crossover pipe with SBC

Posted by: 3d914 Feb 18 2012, 09:37 AM

Great feedback guys, thanks. Above the axles it is. I wanted to keep the exhaust as close to the trunk as reasonable and was concerned about heat. I'll plan for some kind of shielding - similar to the stock muffler shield welded to the underside. That keeps it off the exhaust.

pd, The intake will use the stock manifold as shown, fed by straight tubing from the rear of the trunk where a naca duct will draw intake air in. The MAF sensor will sit between the filter box, under the naca duct, and the throttle body. I'll also have to fab a metal or FG riser to the forward part of the trunk/engine lid to cover the exposed throttle body.

Posted by: 914.SBC Feb 18 2012, 11:21 AM

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Posted by: TC 914-8 Feb 18 2012, 06:52 PM

My car now, SBC goes over the axles, never thought about the heat in the rear trunk I'll have to check it out. this does give better clearance and more roome for mufflers.
My first 914 had a Capri V-6, I went under the axles and used a bursch exhaust, dual in, single out left side. It sounded just like a Porsche 6. Hot and loud once it aged and blew out the FG glass packs.
The single chrome 2-1/4 outlet was very 6ish. yes, I was a poser in the 80's, and still can't afford the real deal 6
Your Ford SHO is the bomb

Posted by: 3d914 Feb 18 2012, 07:49 PM

Thanks for the encouragement. TC - got some pics?

914.sbc - nice test stand for the engine. I think I overdid it with mine. I wanted it to be able to stand up on end for storage. Found a design on the net and modified it.

Posted by: 3d914 Feb 18 2012, 08:01 PM

Here's the mockup pics for the down pipes from the two headers that will merge into a single 2.5" exhaust. Fortunately it merges on the right side, away from the shift bar. PVC is 2in ID - same as mandrels.

Left side. Piece of 1.5" square steel represents the engine bar. Don't want to weld it until I test fit in the engine bay.


Front. Could have come straight down with the right pipe, but need an extra inch of clearance when its on the engine cradle during testing.


Right - well already see something I'll need to fix. Mockup's doing its job.

Posted by: matthepcat Feb 18 2012, 08:03 PM

Good idea using PVC pipe. Also great choice merging into a single pipe, as it is one of the easiest ways to have NO drone.

Posted by: 3d914 Feb 18 2012, 10:12 PM

matt, can you elaborate on the "drone"?

Posted by: matthepcat Feb 19 2012, 12:41 AM

Drone is when your exhaust creates a harmonic vibration often changing depending on RPM and engine load. Conversions with "true dual" exhaust routing seem to suffer from an aggressive version of this problem.

Ever ride in a hotrod with no carpet, and 2chamber flow masters that dump at the rear axle?

Drives you crazy on a longer drives.

Posted by: 3d914 Feb 19 2012, 05:36 PM

Wouldn't a cross-over tube help eliminate that?

From following the SHO sites, it seems they can suffer from raspy exhaust if a resonator (or glass pak) is not fitted. Not sure I'm gonna have room for one.

Posted by: matthepcat Feb 20 2012, 12:30 AM

Sure, but the crossover needs to be close to the manifold/header to be effective.

Crossing under the oil pan is your best bet like you are planning.

I wouldn't think the raspy SHO problem will crossover to the short length 914. There is however probably enough room to run your resonator & muffler if creative.