Hi,

I remember seeing some information about this several months ago.

What is the best location to install an H-pipe? Or does it not really matter?

Place close to the headers, meaning 15-18 inches from the collectors or would further back provide more benefit?

I have location about 15 inches after the collectors and then I got another 8 inches or so to work with further back right after the cross member.
Basically I can install before the crossmember or right after.
Thanks,

 

Mine is right after the crossmember.....just out of sight with this pick:

 

IIRC the way to determine the best location for a h-pipe is to spray paint along the exhaust pipe and look for the area where the paint burns off. On a Vette it's more of a 'where you can fit it' issue. Usually a H-pipe or X-pipe is placed near the rear of the transmission. Here is where the X-pipe is located on my car.



Rick B.

 

Here's mine, the above advice about the paint is what I've heard several times also. I've heard a crayon works too. I didn't do that as I picked where I could fit it. It put it as far forward without getting in the way of the trans pan so I could still drop it when needed.

 

Magnaflow chose the location for my x-pipe (after) but I'm not sure puting an H pipe in front of the crossmember is a good idea with a big block. I think it's going to have to hang pretty low up there, not to mention heating up the transmission. Maybe it's OK with a manual or an automatic with a shallow pan.

 

Good tips, thanks.. You guys all have some nice looking exhaust there... Dang....
I am thinking of putting if after the cross member, ie. further away from the Trans.
Bob, also good point about the trans heating up. I guess the further back away from the headers the cooler they get.
I will post some pics early next week if and when I get it completed.

 

Personally, I prefer the "H" to the "X." I don't know that there is really any hp difference one way or the other, but the "X" appears "co-mingle" the gasses and to me, this looks like this would create turbulance as the gases ram into each other at the point of contact. Also you'll note that the "X" pipes have more bends to accomplish this task, and bends are never a good thing.

 

I'm no 'expert' on this, but it seems to me that the "H" pipe setup would be simpler and [possibly] better, as mentioned above. (Where the "H" pipe simply minimizes differential pressure between the pipes.) A single junction pipe installed where the two pipes are near to each other (and after the crossmember & tranny) would seem to be best.

But, once the exhaust flow is cooled that much, I'm not sure how much real benefit there is for either arrangement.

I have heard that the sound of an "H" pipe setup is a bit different from that of an "X" pipe arrangement...but I don't know what that difference is.

 

Yes, I do not think one is really any better than the other. I just know either is better than nothing at all.
Good point about all the bends with an x. Looks like some of the guys have mandrel bent tubing which looks great but cost some big $$$. I am installing 3 inch exhaust and the regular bend method is tuff in those tight areas espcially coming up around the rear spring to the mufflers.

 

I just went into a local, reputable muffler/radiator shop that regularly works on muscle cars, with my headers on the car and said, I want a 2-1/2" mandral bent system with 2-1/2" tips and an H pipe and stainless Ultra Flo mufflers" and let them do what they do.

When I priced it out, this was cheaper than buying/putting together a commercially available system and I knew that everything would match up and align.

 

Sounds nice, post some pics if ya can. California .. did they make ya slap cats on there?

 

as close to the collectors as you can is how i always do them, which is usually just past the transmission where the pipes come together

 

Just a quick question on the above pics.............the bolt-in trans crossmembers look aftermarket. Where did you get them?

 

Mine is from BTO and is for the 2004r trans swap.

 

See post #7 above. Also, note how nicely the 2-1/2" tips fill the bezels.


No, it's on a '64 so there are no smog requirements/inspections. CA exempts pre-'66 from smog requirements entirely and no inspections for smog for vehicles earlier than '76.

 

Sound is a subjective topic... but I will say there is a very noticeable difference to the "sound" of a Chev V8 fitted with an X-pipe compared to an H-pipe mounted in a twin exhaust system.

I initially fitted a twin 2.5" stainless system with an X-pipe and with some very free flowing straight through style mufflers. I could notice a performance improvement. But there was a drone created with that system... with a resonating vibration from 1000 to 2500 rpm which was completely intolerable.
And with the X-pipe, my 68 C3 sounded like a late model LS1 with a single pipe system. I didn't like it at all.

Off came the X-pipe and free flowing mufflers, and on went a 2.5" system with reverse flow Turbo mufflers without any balance pipe.

A slight decrease in performance (noticed by the butt-ometer) but drone was minimised almost completely, with only some resonance between 1200~1300 rpm.
BUT the vette sounded like a mean 60's muscle car again.

I then fitted an 2.5" H-pipe just after the trans crossmember, and the intensity of the resonance reduced more, and now is just noticeable between 1250~1300 rpm. It's narrow enough and low enough in the rpm band that it is no longer an issue.
The H-pipe subdues the significant burble from each pipe slightly, but it still sounds like a 60's muscle car.

Like I said.... sound is a subjective topic.

Have a listen to a few cars with the type of system you are considering before parting with your cash.