I'm going to make my own X pipe because I want the X right after the headers as early in the exhaust to be most effective.

I really like the design of the Bassani which looks like a true X pipe to me.

Anyone know the size I will need to buy or can recommend a brand?
On the auction site when typing in x-pipe they have them for cheap but Im not sure which design and size to get. Some look very nice of stainless steel others not so much.

 

I had a Bassani X-pipe with my old set up, when I went with the LG/LT Street set up, I used their X-pipe. I thought Bassani was excellent. Check the parts section, and see if anyone has one for sale, or, put a WTB for one.

 

I dont believe theres much of a difference beyween them..

 

I had a WCC one. Good quality and fit.

 

Interesting. I installed a WCC one this past summer. Quality seemed good, but the fit was not so. I ended up bringing it to a shop to have the female pipe ends expanded some. There was NO way it could be installed right out of the box.

 

I'd use the x-pipe designed for my exhaust system.

 

Dang, I hate it when that happens,,,,poser!

 

Unfortunately it takes one to know one!

 

If you are going to fab it in yourself,,I'd just check out the individual X section in the hot rod catalogs like Jeg's or Summit and weld it in They have a variety of pieces at a more affordable cost than full X prices!!

 

had mine custom made by a shop - here is what they look like

installed between headers and high flow cats

 

This doesn't answer your question, but thought you may find it interesting as you are planning on installing the X-pipe close to the headers. I found a post I had some time ago on an article on X-pipes contained in the June, 2001, issue of Hot Rod Magazine. Basically, here is a synopsis of the article:
They discussed how an X-pipe works, then ran a car on a dyno, and the strip, with:
1) open headers
2) mufflers & pipes w/o a crossover
3) mufflers and pipes with an H-pipe
4) mufflers and pipes with an X-pipe.
These are the results:
a) Test Vehicle / 1970 Olds 4-4-2 w/350 block and modified
b) Where first seen / NASCAR guys began using X-pipes
c) X-pipe design theory - "By running the two exhaust pipes together in this fashion, the alternating pulses in each bank can work to create the same type of scavenging action in the other."
d) Works best on a V8 engine running 300-500 hp because the volumetric efficiency is not as great as on a 700-800 hp V8 engine.
e) Dyno pulls:
1) Open header
430 hp @6850 rpm, 384 lb-ft @5600 rpm
2) 3" exhaust pipes w/Straightline mufflers and no crossover
412 hp @6650 rpm, 371 lb-ft @5600 rpm
3) Same setup as #2 except with an H-pipe
419 hp @6600 rpm, 378 lb-ft @5600 rpm
4) Same setup as #2 except with an X-pipe
428 hp @6600 rpm, 391 lb-ft @5600 rpm
Strip tests:
1) Open header
1.65 sec 60', 10.885 sec @123.89 mph
2) No run with the exhaust system w/o a crossover
3) Exhaust system w/Straightlines and full pipes and an H-pipe
1.55 sec 60', 11.007 sec @121.33 mph
4) Exhaust system w/Straightlines and full pipes and an X-pipe
1.62 sec 60', 10.897 sec @124.13 mph
This car, which used to run open headers at the strip, now runs with a dual exhaust system with an X-pipe. More details in the magazine, naturally, but very interesting, I thought.
And yes, the article discussed mounting the X-pipe far forward in the car, just after the headers, to maximize scavenging. Just thought you may find validation numbers of interest.
Ed

 

Ed thanks a lot, I already have an X pipe just dont like the design of it and want to move it more forward right after the LTs, thanks for confirming everything now Im really ready to rock. The car will have about 650rwhp, hopefully this will make it easier to get to that goal.

Basically I was asking what size of the just x pipe portion I should buy from jegs or summit or ebay if anyone knows 2.25 2.5 or 2.75 3 2.25?

 

I would stay at the same size piping the remaining portions of your Mid Pipes are going to be... 3" I hope for your power goals. The "X" style and "merge" style isn't much of a debate I don't believe, A X or "merge" type like this;



Crossectionaly has more area then the bassani "X" type and is less restrictive as well. This isn't my opinion it's been flow tested...

 

There have been a few other tests that have shown the longer the LT, Collector 4 into 2 in one and placing the X pipe as far BACK as possible, right before the over the axle. More low end torque was provided.

ie off the line or out of corners grunt.

Placing the X closer to the headers provided more high rpm HP. but low end or off the line tq suffered a bit.

LT design along with x-pipe design does make a difference in performance.

as with every part of your car, each componet is designed for your intended need.

ie What do you want your car to do?

Then design the modification around your cars purpose.

 

Hmm never thought of it like that so maybe mine was placed back in the exhaust on purpose?

It's a forged supercharged low compression engine with heads/cam
Sounds like I'd need to low end power as my power comes in the high rpms

 

You did not mention what exhaust you are running right now,,or WHAT kind of driving is going to be the main usage. Stock is 2.5",,and this size can support quite a bit of HP as is providing it is free flowing,,mandrel bent tubing and high flow mufflers (which most systems are). Lots of guys automatically go to 3" which again brings up the top end/bottom end point. 3" will gain a bit on top end,,BUT again you loose a little on the bottom end. IMO unless you are going to lower rear gears,spending a lot of time at the strip,,I'd stick with 2.5",,to me,a more streetable package,,and still have LOTS of power!! Also you did not mention what type of S/C,,as there is also a difference. Screw type(ie Magna charger) or centrifugal (ie Pro Charger),,as they develop their power in slightly different ways. Screw type a little more bottom end,, centrifugal more towards top end. Now these are not huge differences,,but again things to consider!! Happy New Year!!

 

centrifugal, just a weekend car little of street fun drag and road coarse maybe

 

My opinion,,I'd stick with the 2.5". You'll STILL make plenty of power,,more that most of what you may encounter. Enough to get you in trouble for sure!!

 

you don't need to make one. Magnaflow makes a small version that could easily be mounted in the position you describe:

 

oh theres a ton of places that make one thats what I was trying to decide what brand and style