C7GS. I have a Speed Engineering catless X pipe. Quality seems great, Fitment seems great, but with one question

The muffler side fit perfectly, but the 'header' side appeared to be very slightly off?

Pipe diameter is perfect, oem gaskets fit perfectly, but the X pipe ends seem to be just a tad closer together vs the oem pipes they connect to. Not much at all...maybe 3/8ths - 1/2 inch off on both sides. The difference is symmetrical. to make them line up, the oem pipes would've had to have moved slightly inward toward each other to line up with the new X pipe. I didn't have 1:1 reference points between the OEM x pipe and the new one, but as best as I could tell, the dimensions were the same.

I got everything fitted loosely and tightened each bolt slowly and progressively until it was finished. (aka i didnt fully tighten 1 connection at a time)

When I did this, I never felt like I was forcing anything and the bolts were straight (not at an angle between the 2 flange holes as if misaligned), and no leaks

so everything seems fine, but i'm still wondering if i'm putting any undue torque/force on the collectors or header joints, or if this sounds normal/ or acceptable. or - am i going to get a leak or cracked header eventually and should i swap the x pipe back out for one that fits perfectly

first corvette. thanks.

 

Mine had somewhat the same issue, but it was maybe 1/4" off. I used a small clamp to pull the head pipes together so they lined up before tightening the screws. With the small amount of force I applied with the clamp I'm not concerned about over-stressing the head pipes. If it bothers you you could always cut the tie-bar on the x-pipe. FWIW I noticed some x-pipes have a tie-bar and some don't.

 

was yours a speed engineering pipe as well?

mine could've been closer to 1/4 inch off, i'm trying to recall from a few months ago - it definitely wasn't much. i didnt put any more than normal torque tightening the bolts so i think i'm going to call it OK for now.

 

Yes, it was a Speed Engineering unit. I was looking for that issue specifically because I read someone else experienced it on an install.

 

Unless its grossly off you will be fine , usually you have everything loose like manifold to head bolts , then you start to bolt everything up , tighten the x pipe , then tighten the manifold to head bolts .

This is what I did when I installed headers on my C6 and then my C7 X pipe install and now my C7 header install

Dave

 

Did you purchase the single piece X-pipe? Speed engineering also makes an X-pipe in 3 pieces. This would help with alignment, but a little harder to install. I purchased a two piece X-pipe. When I put it together I matched it to the OEM pipe I removed. Both in length and side to side.

 

The two piece pipe was made to make shipping easier and much cheaper as it was a bit expensive to ship a single long x pipe
The disadvantage of a two piece pipe is one more joint that can leak and aligning it perfectly in the tunnel .

 

My "two-piece" x-pipe was a snap to install and have yet to have issues with leaks.

The benefit of the two sections was that it actually allowed for perfect fitment at the two ends because of the additional flexibility at the center connection. At least that was the case for me.

Having a one piece aftermarket x-pipe requires that the manufacturer fabricates the assembly perfectly. Even with a jig there are chances that they can be off slightly as is apparent with the OPs comments. Which by the way, I don't think he should have any issues with his as described.

One-piece or two piece shouldn't make a difference as long as you take the time to make the proper connections. After all they are just a simple section of piping. They all basically do the same thing.

 

Agreed. I can see the benefits of both designs. But I would like to see SE remove the tie-bar from the one-piece unit and allow the X-pipe some flexibility to match up with the head pipes. If I need to remove my X-pipe again for whatever reason I'll take the tie-bar off.

 

The main thing to watch for when installing the X-piece. The pipe will have two slots that allow the fat end to be squeezed around the smaller ends, just make sure the slots are covered by the smaller end. This is important even for the single piece X-pipe. The connection at the rear has the same slots. I also used some exhaust pipe sealant. Again, when putting the two or three piece pipe together, stand it up next to the original pipe that you removed and make sure they match in length and twist.

 

Have AWE and it fits like a glove. Match up to the head pipe flanges perfectly. Guy at my local performance shop had it on in 30 minutes.

 

Does AWE still make this? It's not on their website, or I'm blind. LOL

 

No. Only available on the used market now. I found one on FB marketplace in like new condition. It's a great addition and USA made. Fit perfectly. Good luck in your search.

 

Yes the EPA cracked down on them and others. I bought one from a CF vendor who bought the last of them. They are out there. Billy Boat has new ones but are double what I paid for my AWE a couple years ago.

 

https://extremeonlinestore.com/produ...-pipe-mid-pipe

 

Actually BB is $799, and EOS is $260. So, 3 times higher price!