X pipe location
 

Kinda is where it is now but wondering where or if the X pipe location is all that critical. Put on the oversized ram air manifolds and the 3" head pipes. Bought a 3" pypes X pipe universal kit and made it fit. Used Flowmaster 3 to 2.5" reducer cones to fit in my existing 2.5" mufflers and tailpipes . The X pipe ended up about 10" back from universal joint. I'm about to weld most of it up. I could cut the head pipes and slide the whole thing forward a few inches but would require additional pipe now by the mufflers. It's tucked up decently for being 3".

Looks like my Pypes kit

Do you already have a driveshaft loop? If you don’t and will be adding one leave room to make sure it won’t interfere

Location isn't super critical Scott. I put them where they fit the best and that usually differs slightly from car to car.

Scott, really nice looking car and here's a couple pics of mine w driveshaft loop. 3" headpipes to 2.5" mufflers

Sorry to be off topic. Your wheel ramps, they do not appear to have a brace on either side to prevent them from spreading apart.

I had a set just like those when I was 18, but they had the brace. One day while I had my 72 Lemans on them one collapsed. I had just got out from under the car to go get a different tool, and I am sure I would have been dead had I been under it.

Not trying to be a PITA but wanted to point this out.

I put mine just far enough back to drop the transmission-and flange them front and rear to just drop the X if needed.

While the subject is side tracked, here's another faulty designed piece of garage equipment that has not been made for ages, but is still hanging around in some peoples garages.

I had a pair of these under a stripped out 69 GP (actually it was my stock car pictured in my signature photos). The car was gutted awaiting me to start on the roll cage. I had a pair of these under the rear frame rails. I left one night after working on the car in the evening after I had closed the garage. The next morning I came in to work to find a collapsed jack stand, and the car lying on the ground. If you have these stands, destroy them so no one can use them, and throw them away:

https://i.ibb.co/NmJGwKz/dangerous-jack-stand.jpg

They weren't even supporting 1000 lbs, and they failed. I know I'm not strong enough to lift a car off of myself, so I never get under one that isn't well supported, and rocked side to side after it's resting on the support system.

:focus:

On the original question about crossovers, and i'll include H pipes too. I've put them in different positions depending upon layout of the chassis. Every time I've employed one, it has toned the exhaust noise down, as well as picked up power each time. Usually most noticable at low, to mid range RPM. I really don't think the position is critical either. You might gain a few HP by moving it, but with undercar room at a premium, especially with 3 inch pipes, You're pretty much limited by available real estate.

The 2004-2006 GTOs have a resonator behind the transmission that feeds both banks into one resonator, similar to a crossover. It is very well packaged for the room that was available. My guess is that Holden/GM must have done some testing to prove it's value, or they wouldn't have gone to the trouble of putting it on those cars.

I've also noticed that the exhaust tone changes when combing both banks, it seems to get less throaty, and has a different sound. Like 180 header systems have. A little higher pitched note, some people don't like the different exhaust sound, although I have never had a problem with it myself.

:2cents:

Only reason I would bother to bring the X-pipe forward is if the driveshaft hit the X with the rear axle down against the extended shocks.

Here's some pics of mine, I put it in the best location to fit the car. 3-1/2" mandrel bent pipes.

I did have enough material to move the X pipe forward another 1.5" from whats in the picture. Yes the ramps arent the best,,,been meaning to get better ones. I keep a jack under the front crossmember for a little insurance. Still havent got around to welding it up...soon. I will make sure at full rear droop that the driveshaft clears the X.

Very clean install,,,I like the Oval.

On my 79 Camaro IA the 3.5 X I have to drop it to get the driveshaft in and out of the rear end.And the muffler shop forgot to put rear flanges on it so I have to let it hang after unhooking the headers.

If you want to tuck the X up a pinch higher, it doesn't hurt to have it touching the driveshaft with the rear at full droop. You'll never see that condition in real world driving unless you're Bo Duking rail road tracks.
Lol
Generally if I can I have the X forward as much as I can anyway and ends up closer to the u- joint if I have the room

Any note change using oval head pipes over round

Hard to say, I've had a LOT of different configurations over the years. It is still louder than I'd like it to be.

For what it’s worth…,
I was told that either the X or H should be placed at the closest junction to where the pipes come the closest.
Don’t know if it is true or not, but that’s what I did.

On my ‘65 with 2 1/2” pipes and 2 chamber Flowmasters, the H was louder with a more throaty tone.
The X seemed more toned down but with a little more of a “tinny” sound.



Mike