H pipe placement question

[Dino]

I would like to install an H pipe kit on my car so not knowing for sure what size the pipes were I crawled under the car with some calipers and came back up more confused than before.  That's usually not a good sign!

So the pipe is supposed to be 2 1/4" right?  It measures like that in most places such as the short straight piece right before the mufflers.  The angled pipes going from collector to that point though are flattened.  I don't know why or how but they'r both the same so it measures 2 1/2" on the wide part and 2" on the narrow.  Roughly.  Is that normal?

Now, where exactly do I need to place this H pipe anyway?  It seems I have plenty room but if it needs to go on the slanted part of the pipes I will have to massage those slip over things to fit.  

Since the pipe is (or should be) 2 1/4" I assume that is the kit size I want?  

[resq302]

H pipes are 2 1/2" and tapers down to 2 1/4 where the muffler slides on.

[lukedukem]

just curious, which kit (if any) are you going with.

[Dino]

I'm not sure where my exhaust came from but it did not have any crossover pipe.  It was a sb car originally so that exhaust is long gone.  The pipe also does not measure 2 1/2" except where it's flat.  Strange....

Any idea where the crossover should be placed?  That way I know where to measure again.

These kits seem to have a step up to slide over the pipes.  I guess where ever I make the cut, that's the size I want.

just curious, which kit (if any) are you going with.

http://www.jegs.com/i/JEGS-Performance-Products/555/30650/10002/-1?parentProductId=751638

Seems the same as the Summit kit, but free shipping at Jegs.

[bakerhillpins]

Isn't there some sort of trick where you draw down the side of the pipe from the header with a crayon and watch it heat up. Where the crayon first starts to melt is where it goes?? Or sompin like that?? 

[Dino]

Isn't there some sort of trick where you draw down the side of the pipe from the header with a crayon and watch it heat up. Where the crayon first starts to melt is where it goes?? Or sompin like that?? 

I did hear about that trick with crayon or paint and it's worth a try.  I have crayons at work (don't ask) but it's a 20 minute drive home so by then I think all of it will be gone.   
I'll try it tonight though and see what happens.

Since I want to bolt the kit in instead of welding, I guess I'm stuck with doing so somewhere on the straights where both pipes run parallel before going into the mufflers. 

[bakerhillpins]

Culled from the web: (which means it's true  )

This is exactly what we did on our circle track cars. Run the engine long enough to get the exhaust good and hot ,spray the pipes with cheap rattle can paint (we found white worked best for us) starting at the headers working toward the back of the car. The spot where the paint quit bubbling and burning off is where we put the X cross over (never used a H pipe). We did do some experimenting on location and according to our driver at the time this worked best . He said that he could tell a difference in power (seat of the pants dyno!) with the pipe installed this way.

[Dino]

Culled from the web: (which means it's true  )

This is exactly what we did on our circle track cars. Run the engine long enough to get the exhaust good and hot ,spray the pipes with cheap rattle can paint (we found white worked best for us) starting at the headers working toward the back of the car. The spot where the paint quit bubbling and burning off is where we put the X cross over (never used a H pipe). We did do some experimenting on location and according to our driver at the time this worked best . He said that he could tell a difference in power (seat of the pants dyno!) with the pipe installed this way.

So it's not the first spot that burns but the last?  I've got white paint so I'll give it a shot!

[flyinlow]

I think the burnt paint or crayon trick is used to suggest a header extension length for use without an exhaust system at the track.

[firefighter3931]

I think the burnt paint or crayon trick is used to suggest a header extension length for use without an exhaust system at the track.

Craig is correct ; the crayon trick is for an open header exhaust system using collector extensions. 

Dino, just install the crossover near the back of the transmission....that is where the factory installed them 


Ron

[flyinlow]

Consider any future trans upgrade plans. A518 works with H or X pipe behind the trans. Gearvenders , H pipe behind unit. Don't think an X Pipe would work.  Keisler or Tremec not sure.

Just a thought.

[Dino]

Thanks guys.  I'll get the kit and will snap some pics when I'm ready to go.

It won't be any time soon but either a used ViperT-56 goes in or one of the new ones on ebay.  I want that 6 speed!  If I can do that I can also buy a better exhaust system but for the time being the H-pipe will make the current one more efficient and stabilize and support it.  Both pipes are sagging badly, creating leaks at the collectors.

[Mopar Nut]

Here's a good picture I borrowed from another thread.

[Dino]

Thanks for the pic!   

I don't think the bolt on thing is going to work here, unless the pipes are perfectly parallel this cannot work.  Oh well, I'll just have to cut it a bit to make it fit and then take the whole thing to a shop to weld it all up.  If that's what has to happen then so be it.  I'd buy an entire H-pipe setup if it wasn't $200 +.  I'm sure I'd still have to modify it to make it fit the headers.