OBX Cat Bypass Pipe

[Roger 911]

I thought I'd do a little public service here. I bought a OBX cat bypass for the 3.2 I'm stuffing into my '72. If you're not familiar with these, they are polished SS pipes available on Ebay for $99 plus $20 shipping. Given that more reputable manufacturers such as M&K and FabSpeed sell their pipes for around $300, I wasn't expecting perfection.

Well, I can confirm that I did not receive perfection. It's a decent looking pipe. And for the price, I'm satisfied. However, if I was building a high performance motor where I was taking great pains to maximize air/exhaust flow, this pipe would not be my choice. As you can see from the pictures, the port sizes are noticeably smaller than those on the stock cat. And they aren't real pretty. I'm not going to lose any sleep over it. However, when the time comes for me to start modifying this motor, I'll probably get an M&K pipe.

Roger

[DRACO A5OG]

Wow, sorry to read that Brother.


All that glitters is not gold :-(

[oh snap]

Thanks for being the guinea pig, I've always assumed the OBX stuff was cutting corners but it's nice to know where and how.

[rnln]

almost 1/2" on one side, wow. Well, it's cost low and it looks nice

[James Brown]

if your using this pipe i guess you still have the stock exhaust now and will go with a backdate or headers in the future?

[naples911]

After studying your photos it's clear to me that your measurements aren't too precise. This is fuzzy Al Gore math at it's finest. You've measured an 'indent' that is apparent in BOTH photos, but have chosen to exploit that in the OBX photo (right side). And, on the left side of the photos, you've been generous with your Fabspeed measurement. I've owned both and the OBX is made extremely well, fits snug to the same pelican gaskets as shown. And not built with the shoddy measurements as you claim. If you're going to engineer a nice OBX piece such as this, why build something so far out of spec? Didn't happen...

[JAR0023]

Originally Posted by naples911

After studying your photos it's clear to me that your measurements aren't too precise. This is fuzzy Al Gore math at it's finest. You've measured an 'indent' that is apparent in BOTH photos, but have chosen to exploit that in the OBX photo (right side). And, on the left side of the photos, you've been generous with your Fabspeed measurement. I've owned both and the OBX is made extremely well, fits snug to the same pelican gaskets as shown. And not built with the shoddy measurements as you claim. If you're going to engineer a nice OBX piece such as this, why build something so far out of spec? Didn't happen...

Thanks. You put into words what I thought I was looking at. I have the OBX on my car. It's a nice piece for under a C-note. Not perfect but nice, none the less. I had to elongate one of the bolt holes on the collector (five minutes with a file) and spent a little time cleaning up the inside of the flanges. Bolted up nicely, no leaks, nice sound.

Oh and in before the s*&t storm all the other OBX threads turn into.

-J


ETA that 'indentation' is inside the weld. If you don't like grind it away.

[Roger 911]

Originally Posted by naples911

After studying your photos it's clear to me that your measurements aren't too precise. This is fuzzy Al Gore math at it's finest. You've measured an 'indent' that is apparent in BOTH photos, but have chosen to exploit that in the OBX photo (right side). And, on the left side of the photos, you've been generous with your Fabspeed measurement. I've owned both and the OBX is made extremely well, fits snug to the same pelican gaskets as shown. And not built with the shoddy measurements as you claim. If you're going to engineer a nice OBX piece such as this, why build something so far out of spec? Didn't happen...

I was waiting for someone to mention this when I saw the pictures. I even went back and looked again to make sure I hadn't missed that. What you are assuming is an indent on the stock cat is not. It is an aberration from the angle and the flash. That is actually the side wall of the port extending down about an inch from the flange.

I guess since you've owned one OBX pipe, you are now an authority on EVERY cat bypass pipe produced by OBX? Do they send every pipe to you for inspection before they are sold? Should we assume some sort of affiliation here?

Listen, I'm happy for you. I'm glad you're satisfied with yours. Either it was manufactured better than mine, or you simply don't know the difference. I don't really care either way. As I said in my original post, I'm actually happy with this purchase. But the pipe I HAVE, has an undersized and poorly shaped port. That's a fact.

It happened.

Roger

[Porchcar guy]

Roger, why didn't you send it back as defective and see if the second one was different...??

[Roger 911]

Originally Posted by Porchcar guy

Roger, why didn't you send it back as defective and see if the second one was different...??

In my application, i.e., a stock motor, I don't think it will have a material impact. Or maybe you can look at it like this, a cat bypass pipe with a slightly reduced port size will still probably flow better than a system with a stock cat in it. And, it's only $100. I just don't have the desire to go back and forth on this (paying $20 shipping each way). I just wanted to share my experience/observation. Again I will reiterate, it's not a bad looking piece for the money. But mine wasn't perfect.

Roger

[naples911]

Originally Posted by Roger 911

I was waiting for someone to mention this when I saw the pictures. I even went back and looked again to make sure I hadn't missed that. What you are assuming is an indent on the stock cat is not. It is an aberration from the angle and the flash. That is actually the side wall of the port extending down about an inch from the flange.

I guess since you've owned one OBX pipe, you are now an authority on EVERY cat bypass pipe produced by OBX? Do they send every pipe to you for inspection before they are sold? Should we assume some sort of affiliation here?

Listen, I'm happy for you. I'm glad you're satisfied with yours. Either it was manufactured better than mine, or you simply don't know the difference. I don't really care either way. As I said in my original post, I'm actually happy with this purchase. But the pipe I HAVE, has an undersized and poorly shaped port. That's a fact.

It happened.

Roger

I have a difficult time reaching the level of passion you do when it comes to bypass pipes so i will take your word for it. You're probably right..

[Roger 911]

Originally Posted by naples911

I have a difficult time reaching the level of passion you do when it comes to bypass pipes so i will take your word for it. You're probably right..

Honestly, if your original reply simply said, "From the pictures, I don't see any difference. I bought one and it was fine.", there would not have been a "passionate" response. But you took a few extra shots. That will ignite some passion.

Roger

[rnln]

umm.... his comment has pictures. The pics are clear to me that the ID of his new cat by pass looks "kind of messy" and smaller compare the the pic on the bottom.
Your OBX is perfect doesn't mean his has to be, and doesn't mean he is wrong on his comment regarding his new cat by pass... ???...

"If you're going to engineer a nice OBX piece such as this, why build something so far out of spec?"
knock knock... hello?
Are you with the design team or the marketing team?

Originally Posted by naples911

After studying your photos it's clear to me that your measurements aren't too precise. This is fuzzy Al Gore math at it's finest. You've measured an 'indent' that is apparent in BOTH photos, but have chosen to exploit that in the OBX photo (right side). And, on the left side of the photos, you've been generous with your Fabspeed measurement. I've owned both and the OBX is made extremely well, fits snug to the same pelican gaskets as shown. And not built with the shoddy measurements as you claim. If you're going to engineer a nice OBX piece such as this, why build something so far out of spec? Didn't happen...

[kkkarpuk]

This type of imperfection and the issues involved made my decision to purchase an M&K unit easy for me. I knew I was going to get a quality piece that fit and worked as it should. The whole transaction and installation was a good experience. Getting parts in Canada is hard enough I didn't want any hassle,returns or modifying to get this job done. I put real value in the "alte spruch" buy cheap, buy twice.
My $.02

Ken

[naples911]

The entire premise of this argument is flawed in the mere fact that your comparison of pipes is in comparsion to a GASKET, and NOT the pipe it is connected to! How do you know the gasket is perfect???

This is too easy..

[cdrik915]

No miracle.


You get what you pay for.

[uwanna]

I opted for the Dansk stainless cat bypass that looks almost exactly like the Euro bypass that came stock on Euro cars and I love it. Fantastic quality!
My motto when weighing the pros and cons on an item I'm looking to purchase is one an old businessman in Texas gave me on a slip of paper some 40 years ago. I have carried a laminated copy in my wallet ever since, and always refer to it before making any purchase decision!

"THE BITTERNESS OF POOR QUALITY LINGERS LONG AFTER THE SWEETNESS OF LOW PRICE IS FORGOTTEN"

Has never done me wrong!

[Roger 911]

Originally Posted by naples911

The entire premise of this argument is flawed in the mere fact that your comparison of pipes is in comparsion to a GASKET, and NOT the pipe it is connected to! How do you know the gasket is perfect???

This is too easy..

The gasket is simply an aide for the comparison. You can see how the factory cat port matches the gasket perfectly. Therefore, if the OBX port doesn't match the gasket perfectly, one can surmise that the two ports don't match. Very simple. This is actually a pretty common way of quickly evaluating cylinder head ports as well, using the gasket as a template.

Roger

[naples911]

Look again, do you really think the factory cat port matches the gasket perfectly, after you put a bolt in that hole??? yes or no..

[cjannelli]

Originally Posted by rnln

umm.... his comment has pictures. The pics are clear to me that the ID of his new cat by pass looks "kind of messy" and smaller compare the the pic on the bottom.
Your OBX is perfect doesn't mean his has to be, and doesn't mean he is wrong on his comment regarding his new cat by pass... ???...

"If you're going to engineer a nice OBX piece such as this, why build something so far out of spec?"
knock knock... hello?
Are you with the design team or the marketing team?

I'm guessing both
chris j