Sorry this is so long, but I just can't figure out how to say it any shorter. Anyway, here's my predicament:
I have an 88 mostly stock with about 110k miles and my catalytic converter started to rattle like dice in a yahtzee cup. Cool, I always wanted a "high flow" cat. While I'm at it, my front Y-pipe appears to have a small leak at the header connection. While I'm at it, I hate the resonance of the stock exhaust. So I whine to my wife that I just have to bite the bullet and replace the entire exhaust system, darn the bad luck! I tried to find a source that sold the front y-pipe without precats, the cat, and the corsa cat-back system. I'm sure such a source exists, but I couldn't find them. And of course I want the best price I can get. I ended up buying the front y-pipe and cat from Ecklers (around $300) and the Corsa cat back from lmperformance (around $800). I won't go into what a pain it was to remove the rusted/crusted/broken bolts and studs from the old system, but suffice it to say it definitely set the mood for what came next. I put the y-pipe and cat on the car then happily grabbed the rear Corsa y-pipe and slithered back under the car. The cat and the y-pipe opening are the same exact size meaning there isn't any overlap in the joint to get a good seal. I took a bunch of pictures, measurements, and even a drawing to illustrate what I mean.
photobucket pics

I sent e-mails to both Ecklers and Corsa and received replies as follows:
(Ecklers)
From: Corvette Tech
Sent: Monday, November 26, 2007 5:27 AM
To: Hawkins Family
Subject: RE: Order # 10394470-00001

The Converter system we supplied should fit the factory pipes that originally came on the vehicle. It appears that the Corsa pipe is too small. I would contact Corsa or have an exhaust shop make a new flange for the Corsa pipe that will fit to the converter. This can easily be done at a minimal cost as it can be easily done and is the quickest and best solution to the problem. Thank you.

________________________________________
From: Hawkins Family
Sent: Wednesday, November 21, 2007 8:44 PM
To: Corvette Tech
Subject: Order # 10394470-00001

I received my order consisting of part number 34198, Front Y-pipe and catalytic converter for 1986-1991 Corvette. The output tube of the catalytic converter is larger than the stock converter by approximately 8mm. The input side on the cat-back system I bought from Corsa is approximately 4 mm smaller than the stock Y-pipe. Together I cannot connect the two because the inside diameter of the catalytic converter and the outside diameter of the Y-pipe are exactly the same size which doesn’t allow a seal to be obtained. Please see the attached photos and receipts for further details. I would like to exchange the catalytic convertor for one with the correct size output pipe. The rest of the cat is perfect and mates to the front Y-pipe and A.I.R. pipe perfectly. Unfortunately, I now have over $1100 in exhaust system I can’t finish installing.

How can you help?

Ron Hawkins
CorvetteForum member

---------------------------
(Corsa)
From: Paul Santiago
Sent: Tuesday, November 27, 2007 7:17 AM
To: Hawkins Family
Subject: RE: (lmperformance.com)

Hello and good morning.
I do understand your original message and follow up Ron, yet thank you once again for elaborating.
One thing not mentioned prior; have you by chance checked the consistency against the factory convertor? Does our y-pipe fit the stock piece? All CORSA items are developed to work with OEM pieces and there may very well be some inconsistency with the aftermarket cat that Ecklers has produced for them.
So you are aware, the connecting flair that we produce for the y-pipe with these systems is manufactured within a forming collar that will only allow expansion to a certain inlet diameter having 15 thousandths as max tolerance, no more and no less.
Again, based off the original images provided, the flair itself may very well seal when tightened due to drawing the materials together between the flanges. Has this been done to verify?
If you do still feel there is an issue with the part itself, LM Performance is the selling party that was selected to obtain our kit and they would need to be contacted per our warranty policy if you want to initiate a replacement part. LM Performance is technically not an authorized CORSA dealer, but can arrange through their purchasing distributor to pursue this if necessary. Please check into the suggestions provided and verify.

Thank you once again.

PAUL SANTIAGO


From: Hawkins Family
Sent: Monday, November 26, 2007 8:18 PM
To: 'Paul Santiago'
Subject: RE: (lmperformance.com)

Paul, thank you for responding. The reason I attached the pictures is so you could see the difference in sizes and understand what I’m saying. I obviously need to do a better job so I also attached some drawings this time. I realize one pipe will not fit within the other, but there should be some overlap of the ball/knuckle connection in order to compress around the flair. As it is currently the y-pipe barely touches the cat with no overlap. Ecklers also responded and said the y-pipe is too small and I can “easily” have a new flange created for the y-pipe. This no doubt would void my warranty.

Please review the drawings and tell me if I’m crazy.

Ron Hawkins

From: Paul Santiago
Sent: Monday, November 26, 2007 12:26 PM
To: hawkins
Subject: (lmperformance.com)

Hello Ron and thank you for the purchase of our product.
According to the images provided, it appears that CORSA has produced the exhaust as it should be.
You see, the flange connection of the pieces is called a “ball/knuckle” connection. This is an OE design and not a direct slip-joint connection. The components according to this design will not fit within one another, rather, will but- up to one another and compress around the flair.
By tightening the flange bolts evenly, this will distribute the clamping force and will seat the flair around the knuckle from the exit side of the convertor- as long as the convertor was produced with the correct diameter on the exit side as well.
We trust that this proves to be of added assistance, however please feel free to let us know if you have any further questions.


PAUL SANTIAGO
Automotive Technical Sales
CORSA PERFORMANCE EXHAUSTS


From: Hawkins Family
Sent: Wednesday, November 21, 2007 8:54 PM
To: Jim Browning Jr
Subject: FW: Order # 209684 (lmperformance.com)

I received my order consisting of part number 14115, Exhaust system for 1986-1991 L98 Corvette from LMPerformance.com. The input side on the Y-pipe is approximately 4 mm smaller than the stock Y-pipe. The output tube of the catalytic converter I bought from Ecklers is larger than the stock converter by approximately 8mm. Together I cannot connect the two because the inside diameter of the catalytic converter and the outside diameter of the Y-pipe are exactly the same size which doesn’t allow a seal to be obtained. Please see the attached photos and receipts for further details. I would like to exchange the Y-pipe (intermediate pipe # 16CX4027) for one with the correct size input pipe. Unfortunately, I now have over $1100 in exhaust system I can’t finish installing.

How can you help?

Ron Hawkins
CorvetteForum member
---------------------------

If you've made it this far, thank you. So, both Corsa and Ecklers are saying "it's not our fault" and technically they are correct since each does mate up to the original exhaust. What do you recommend? I'll probably take the parts to an exhaust shop and see what they can do with them. I just feel I shouldn't have to do all that after laying out so much ca$h.

Thanks in advance,
Ron

 

Ron:

Welcome to the world of modification. I did read your entire post and unfortunately, I think both companies are correct because as you stated, their parts would have worked had you installed their products on OEM parts. I think you have the correct solution though. Take all the parts to a reputable muffler shop, explain what you need/want them to do and I'm sure they can make it all work to your satisfaction. They should be able to bend and/or fabricate any flanges or seals you may need. If they can't do the work there, in-house, you're in the wrong place and get out of there quickly.

 

Sounds like something that would happen to me...

If you didn't toss the old parts, probably the easiest thing to do would be to cut the end off the old oem cat, then cut the end off the new cat in the same location, and weld in the old one. Either that or do the same but with the end of the y-pipe. Piece of cake for a muffler shop.

Both parties are correct in that the parts would fit oem pieces, but it sucks that both parts are apparently not built to oem specs. Bit of a difference there that causes headaches like this.

 

I didn't look at the pics, but I can tell you that I don't like Ecklers after the way I was treated and I would never do business with them again. Ever.

 

I would just have the rear piece expanded to fit over the ball connection on the cat. Nobody is going to get out the calipers and know it was messed with so I wouldn't worry about them voiding any warranty. And it'll still fit the stock cat if you decide to sell it later. (What is all that black junk on the pieces? Should be a dry fit.)

You're getting nowhere with these guys. I understand you want them to make it right, but all they'll do is type you some words or exchange your parts for more parts that don't fit, and ultimately waste your time.

"Bolt on" exhaust parts are the most ridiculous waste of money IMO, when you consider the cost of materials vs. the profit margin. If you're lucky the rear pipe will fit without being cockeyed. Many of the aftermarket rear Ys I've seen are crooked on one side and have to be rebent or welded to the mufflers for the tips to match up. Everytime I buy aftermarket I feel like I'm the first person to try the parts, because it's baffling that they can continue to mass produce sh*t that don't fit.

 

Ecklers lost my business a long time ago.

Personally, I would return it and get my money back. But then again you'll lose out on shipping. You could have had a custom exhaust built for a lot less and it would actually fit your car.

The y pipe should fit about half way over the converter joint by hand. Tightening the bolts just snugs it. Should look like so:



Yours should be to about where the red line is:

 

"88 vert " Back in the spring I bought the Corsa from LM (free shipping) it bolted right up to the stock Cat with absolutely NO problems. I would hazard a guess that the cat from Ecklers is not an EXACT repro. I'm in the same boat now as I want to put on a high flow cat without the precats so I won't be looking at Ecklers for parts.

Don't want to hijack the thread but - does anyone know of a source for the front Y pipe without precats and a direct fit (replacement/OEM) high flow cat?

 

How does the Ecklers cat compare to your old cat's flange?

 

Very few pieces are truly "bolt-on" as advertised. One piece that doesnt fit quite right and.....

Went through that piecing together a lot on system for another Vette system I bought. Still needed welding and a little "work". Just take it to the muffler shop and have them work their maginc and be done withthe headache. Youll stress yourself out and add many weeks to your project messing with these bozos who are playing games.
Its worth the $100 or so to be done with it and move on to thenext thing.

You just learned a lesson in hot roding...Do it twice

 

I would send all of it back and either purchase a complete system from corsa or Magnaflow . Or take it to a shop and have them do it. Any time you try and match one system to another you will have problems or know how to weld and fabricate....get the complete system from someone, suck up the shipping charges and start over....G

 

I live 20 minutes away from ecklers and I only go there when no one else has the part I need. I would rather pay for shipping than deal with Ecklers...if someone lives that close to Ecklers and would rather pay for shipping and wait a couple of days that should tell you something....G

 

I would return the cat and purchase a magna flow cat, which from my experience is a good product. It fits well with any cat back system.

Some after market products just don't fit right. I had many issues with the no name aftermarket exhaust parts from mid america. The high flow cat just did not fit right. Connection from the front of the y pipe was sloppy big and the rear connection leaked like a sieve

They also make the front y pipe with both pre-cats or without in stainless. I purchased mine through summit racing, had it shipped to my home. Also I would clean up all that black goo, not needed if all pipes fit right.

 

Thanks everybody for the replies. I'll find a local muffler shop and see what they can do.

By the way, the black goo is exhaust sealant.

Thanks,
Ron