TheCorvetteKid

Hey guys,

I need a bit of advice here. I'm in the process of installing a set of TPiS long-tube headers on my '89 and I'm running into a few issues.

The headers themselves are installed and all the EGR/AIR piping is attached. However, I have noticed that the header on the passenger side is touching the frame (very slightly). Does anyone else have this issue or has anyone else experienced this? If so, how did you overcome it?

Also, I've fit the Y-pipe onto the headers but: a) the outlet isn't centerd, and b) I need the Y-pipe to move a bit further forward in order to get the center exhaust hanger to work. I have tried to pull the Y-pipe off in order to 're-center' it but it's not coming off. Are there any tricks to getting a slip-fit Y-pipe off? These parts are all brand new so you'd think everything would just go on and off with ease… so far, that hasn't been the case.

Any help at all would be greatly appreciated. I haven't driven my car in over two years, and I don't want to miss another year.

Square

I have TPIS long tubes on my 86', with the emissions plumbing. If I recall correctly, I had to dent one of the passenger side primaries to get the clearance I wanted. I also had to have the passenger side header flange cut to clear an item. I also had to have the Y-pipe bent as when I did the test fit, the muffler end was clearly 2 inches too low to make the connection. I used a block of wood and a hammer as an "encouragement tool" to separate the Y-pipe from the headers during the test fittings.

Like you, I was expecting more of a "bolt up and go" experience. However, the Headers have made the largest "seat of the pants" improvement of the mods that I have done.

HTH!

TheCorvetteKid

Hi Square, thanks for your response.

I've actually just read through the install instructions for the headers (probably should have done that before I started) and it seems I may have found the source of my headaches.

As mentioned, I have already installed the headers themselves (everything is in place and all the bolts are torqued down) but according to the instructions I need to leave all the fasteners loose until the Y-pipe is fitted and centered. Once that's done then I can torque all the bolts to spec.

Also, it seems that on '87 and later cars there is a potential (and known) interference issue with the support brace on the passenger side. The instructions say that the bracket should be loosened during installation and if there is indeed any interference, then the bracket should be trimmed accordingly.

I'll loosen everything tomorrow morning and try re-fitting the Y-pipe. With luck the rest of the install will go smoothly.

Thanks again!

vinniemc

I had the same issues on my '92. The headers just barely hit the frame on the pass side. I didn't do anything about it and just sort of ignore it, it doesn't seem to mind being autocrossed every weekend.

You'll love the power gain from the headers, I gained about 15rwhp according to the dyno. Also, if you remove the cats and leave the stock mufflers, the car will be quiet until you get on it then it'll roar!

TheCorvetteKid

Thanks for your response vinniemc.

The interference condition I have it extremely minor as well. The header is just barely touching the frame cross member. But as per the TPiS instructions I am going to loosen the cross member itself and grind where the interference is happening. Given how small the contact is, I normally wouldn't worry about it, but I figure since I'm doing the work I might as well do it right.

And I can't wait to feel the difference in power. I've actually had these headers for several years, but I've only just now gotten around to installing them. I still have some other work I'm doing to the car so it won't be on the ground for a little while yet, but once it is I'm hoping the gains will be something I'll feel.