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Discussion Starter #1
Anybody know where I can acquire a cat bypass pipe for an '88 (US-spec) Esprit?

The vast majority of muffler shops around here (Seattle) won't make a custom cat bypass pipe for you out of concern around violating environmental laws and getting their business in trouble with the State. I don't have a proper pipe bender and good stainless welding resources so that really leaves me with no other option than to buy one from a known vendor....which is fine.

I've seen cat bypass pipes sold in the UK for Esprits but these look to be of a different design. Perhaps the UK/European exhaust is different than US-spec. So, basically, I'm looking for a US-spec bypass pipe. It should be a fairly short pipe, around 18 inches in length, with a 90 bend on one end going into the muffler. That's just my rough estimation.

Any help is appreciated.
 

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I hope this applies to an 89 turbo as well.
 

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I wouldn't even bother doing this, I did it a year ago and made my own out of 3 inch exhaust stock, as im a pretty good welder/fabricator, made no difference at all. The only difference was the car back fired slightly more. I first thought it did make a difference, however I think in was all in my head. I took the cat off for about 8 months, only to reinstall it for state inspection, no difference in power (loss or gain) in my opinion upon reinstalling. I have had cars (Mustang GT) where it did make I think a noticeable difference. I also owned a Shebly CSX, you know the old Dodge Shadow with the Shelby Turbo, another fast car in its day. I did the same thing to it years ago, again no difference. It did feel good to feel like I was "opening up" and removing that government crap, but like the Esprit, no difference, just a back fire.

3 words: Green Dot Pulleys
 

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I wouldn't even bother doing this, [snip]made my own out of 3 inch exhaust stock,[snip] made no difference at all. The only difference was the car back fired slightly more. I first thought it did make a difference, however I think in was all in my head. [snip]
At the risk of overgeneralizing, it's like tweaking any part of a system - old school thinking says that 'opening' the pipe is 'good'.

But with the air flow governed/monitored by a bunch of mechanic and minor electrical devices, impacting the standard air flow can result in fuel flow errors (accounting for the backfiring). If you got the time and money to tune the behavior, it might be worth it, but for most folks, you're better off staying with a standard cat (except for the price).
 

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An option is to get a high flow cat. I did that on my '89. I can't say for sure what performance consequences there were - I never put the car on any kind of dyno or tried to rigorously assess the change. I also put on the Al B header at the same time so I wouldn't have known whether any change was the header, the cat, or both.

For the last few weeks I have been working on Artie B's old car, which has a very big downpipe with no cat and a tiny-ass muffler and it sure puts out the fumes! When I did my rebuild I also wanted to get rid of the original cat because of its size, weight, and crummy attachments. I had a local shop weld in a Magnaflow high-flow cat and then make the exiting section of the pipe an expansion/slip fitting so I got rid of all the EBPV stuff and had a much easier time with fitting once the old awkward flare-and-coupling attachments were removed.
 

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Discussion Starter #7
Thanks gents, I do understand the mechanics of exhaust flow and back pressure pretty well. I do agree that less back pressure is not always good. Engines do need back pressure to operate properly and efficiently. But, in many cases, less back pressure IS a good thing, particularly where an engine (and engine management) was designed at a time and place when the gov't mandated equipment DID cause some poor running....as was often the case in the 80's, more often than not.

The esprit does need some back pressure, so a completely free flowing exhaust is not going to be helpful to clean and efficient operation. A muffler provides some good back pressure.

The cat installed in my Esprit is not the stock cat...it's a cat that someone hacked in there and the pipe and size is much smaller than stock. So, it needs to be dealt with anyway, in some way.

The cat puts a lot of heat into the engine bay and the back pressure provided by the cat is not helpful, so I'd like to get it out of there, hence the original question of "does anyone know of an available US-spec cat bypass pipe." Does anyone have a cat bypass pipe on their 4 banger Esprit?
 

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[snip]
The cat installed in my Esprit is not the stock cat...it's a cat that someone hacked in there and the pipe and size is much smaller than stock.[snip]"does anyone know of an available US-spec cat bypass pipe." Does anyone have a cat bypass pipe on their 4 banger Esprit?
For US you may want to try JAE. I know this Germany site has some pipe choic, but the prices would give you incentive to find a cooperative local welder:

PUK Esprit Racing

There was someone on eBay a few month back selling a gutted Esprit cat - it failed to get a bid if I recall so you may want to set up an eBay auto search in case it comes back. That should have plenty of flow closer to stock.
 

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Thanks gents, I do understand the mechanics of exhaust flow and back pressure pretty well. I do agree that less back pressure is not always good. Engines do need back pressure to operate properly and efficiently. But, in many cases, less back pressure IS a good thing, particularly where an engine (and engine management) was designed at a time and place when the gov't mandated equipment DID cause some poor running....as was often the case in the 80's, more often than not.

The esprit does need some back pressure, so a completely free flowing exhaust is not going to be helpful to clean and efficient operation. A muffler provides some good back pressure.

The cat installed in my Esprit is not the stock cat...it's a cat that someone hacked in there and the pipe and size is much smaller than stock. So, it needs to be dealt with anyway, in some way.

The cat puts a lot of heat into the engine bay and the back pressure provided by the cat is not helpful, so I'd like to get it out of there, hence the original question of "does anyone know of an available US-spec cat bypass pipe." Does anyone have a cat bypass pipe on their 4 banger Esprit?
There are several cat delete pipes available (with and without EBPV) and have the O2 fitting. I have a couple in the garage but they are both spoken for, I have also run 88's with a cat delete pipe. The heat difference without the cat is significant, one drawback however is an increase in the 'popping' during overrun. Performance wise I have no data other than seat of the pants feel but the noise is magical :shift: I will see if I can get the address of the U.K company.

Colin
 

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As with most things in life, everything is subjective...it really depends on the individual. One man's noise is another man's music.

This is my third time around with an '88 Esprit (second time with the one I have now) and in that time, I have done stock cat with stock muffler (the Langford used on the '88 was unique and had a much louder, deeper tone or so I've been told...all I know is that I like it), stock cat with Magnaflow stainless muffler (gorgeous, but sounded like a Buick), stock cat with Magnaflow racing muffler (like a super thin glass pack with minimal packing...I liked it, the next owner hated it and stupid me shipped my previous stainless muffler to him in Texas, he could have bought a new one for the shipping I paid), stock cat with straight pipe, aftermarket cat with straight pipe, gutted cat with straight pipe, and aftermarket cat with stock muffler which I have now.

Believe it or not, the stock '88 exhaust actually sounds pretty good, nice and robust...pretty loud for a stock system.

Anyway, as for no cat (mine was gutted) with straight pipe, I personally enjoyed it. It was super loud and had a great tone...it really screamed. With today's sound regulations, you'd be black flag'd in an instant on the race track, but for the street, it was great fun! Reactions from my good friends ranged from..."Wow...what did you do to your car...I LOVE IT...IT SOUNDS LIKE LAGUNA SECA!!!!!!!!!!" to other good friends who didn't care for it one bit.

It certainly makes the car rowdy and raunchy...a friend who is the owner of a body shop said it sounded like a Harley although I never quite saw the connection. Then again, when I test drove a stock '95 S4s for another clubmember and rev'd it up, a non-Lotus friend said it sounded like a motorcycle, so who knows...LOL

Personally, I have always loved a loud exhaust on all my performance cars so I thought it was fun and fantastic. Probably a bit too much to hear on a daily basis, but I don't use my toys for that purpose.

I have other friends that did it as well and some of them turned them back to stock real fast...one of them felt that it made his Esprit SE sound cheap. In some ways, I have to agree as it no longer sounds polished or sophisticated. I sure reveled in taching that motor out down the street though...hearing that motor scream with the blow off valve sneezing after every shift...heavenly! :)

So ultimately, the answer to your question is...it depends. Everyone has a different perception and threshold for noise. Like I said earlier...one man's noise is another man's music. You might love it, you might absolutely hate it...LOL My advice would be to see if you can find any clubmembers in your area that have a setup similar to what you are looking to do on your own car.

If this is not possible, see if you can fabricate or have one made with a flange so that you can put it on and off at will. Purely for 'test' purposes, of course, since this may not be legal in your area. On mine, I had a 'gutted' original cat from a previous owner that for sake of posting I will say, had no idea was gutted. It is illegal of course. ;)

The current setup on my car is an aftermarket cat (Magnaflow with CA EO Smog #) with the factory Langford muffler...I actually really like that muffler which is really unusual for me since factory original mufflers on my cars usually get upgraded right away. It is really heavy though, contrary to what a Lotus should have. I have a feeling that for this particular car, this will be the final setup with no more exhaust modifications as I finally found what I believe is best. Doesn't mean I don't miss raising hell with that loud combo...LOL

Since you said that the neck on the current cat on your car is smaller or in some way less than par, I say it couldn't hurt to experiment one way or the other. :)

Roy
Loud pipes save lives!
 

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Forgot to say...YMMV (your mileage may vary), but on my '88 Esprit, I could definitely tell a big difference between factory cat and no cat. Not just sound, but acceleration...seat of the pants. It ran much happier and healthier and rev'd far more willingly. It definitely ran castrated when I had the original factory old school cat which had a mesh or thing with a ton of holes in it...don't know how blocked it was, but figure it had to be partially blocked considering that the car was made in 1988...LOL Modern cats are see-through and so much better nowadays. Not quite the restriction that they once were.
 

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Oh...and with the wilder combo on the car...sometimes you'd get beautiful fireball backfires on deceleration...just like on the Escort Challenge :) I remember how during a past WCLM, we used to take delight in watching some of the Esprits with that combo breathing fire during our scenic drives. Pretty wild!
 

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Discussion Starter #13
Thank you Colin, thank you TurboR, that's helpful information.

I'm new to the Esprit, but have a fair bit of first hand (ie. me, not some paid mechanic) experimenting with exhaust systems of a very wide variety. I definitely like the Langford muffler on my '88 - seems well built and sounds good, and it's stainless, which I also like. I suspect that muffler with a straight pipe in place of the cat will both sound reasonable (sporting but not extremely loud) and help performance in a meaningful way.

I don't need to maintain a cat in place in my area (no testing for cars 25 year old or older) - the car is old enough there's no more emissions testing for it to be done. That's nice and convenient.

However, it's difficult to find an exhaust shop that will custom make a bypass pipe for fear that they will get their shop into trouble with the State environmental regulators. So, I'm looking for a US vendor for a US-spec Esprit who makes a bypass pipe. If anyone knows where one can be bought I'd appreciate the reco. I'll check with JAE and see if they can help.

Thanks!
 

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Forgot to say...YMMV (your mileage may vary), but on my '88 Esprit, I could definitely tell a big difference between factory cat and no cat. Not just sound, but acceleration...seat of the pants. It ran much happier and healthier and rev'd far more willingly. It definitely ran castrated when I had the original factory old school cat which had a mesh or thing with a ton of holes in it...don't know how blocked it was, but figure it had to be partially blocked considering that the car was made in 1988...LOL Modern cats are see-through and so much better nowadays. Not quite the restriction that they once were.
What do you mean modern cats are see through? I had the original cats in both of my Esprit's former 90 and present 91. They are both see through, nothing in them. So clean I can run a broom handle through them. Oh yeah I did run a broom handle through them. No need for a test pipe.

Bad cat whack you with a stick. lol

Cal H
 

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Cal...LOL!!!! The penalty could be a big stick or banished to a lifetime without wings! LOL

Not sure about the '90 or '91 cats, but I know for a fact that on both '88 Esprits I owned, if you peer directly into the opening of the cat, you can only see half an inch or an inch before you get to a flat piece with mesh or holes in it that completely covers that opening. On modern cats, you can literally hold them up and see right through them, just like you said about yours. I believe the '88 has a different design unlike later models that do not have that restrictive substrate. Funny that you mentioned a broom of all things...over the years, I have heard of Esprit people using the wrong end of a broom handle to smash out that substrate and make a gutted cat. :)

That's great news that your area does not require it for vehicles 25 years and older, Beerman! I wish CA had more realistic smog laws...ours used to be 20 years and older, but they changed it a while ago to 1975 and older vehicles being exempt from testing only. :(

Hoping you find a good source real soon!

Roy
 

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I've used the broom handle to whack out the clogged innards of a cat then reverse blowout the clogged mufflers. There was a time in the early 90's when some retards required all cars to report to testing sites and if we failed emissions we would have to get them fixed at great expense and 3 times and hundreds of $ they would give me an exemption form and it was good till next year. Then do the same thing again, like if it did not pass the year before something was going to magically fix them selves. After a few years of air quality test they determined it did not have any impact in MN and dismantled emission testing services. So we do not even have testing for late model cars much less cars of our vintage. Only thing is if a shop or dealer gets caught removing or altering emissions equipment there is big time fine. Not sure what happens to us as no one I know has ever been pinched for it.

BTW I have no muffler

Cal H
 

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Discussion Starter #18
Just a quick update here to close the loop on the cat bypass pipe....

The nice folks at JAE had a good looking pipe available, no doubt very high quality and a great fit, $506.00 USD. The good folks at SJ Sportscars in the UK also had pipe available which looks to be of good quality/construction as well, at a lesser cost of approximately $320 (including shipping). I ordered the SJ pipe, will see how it fits when it gets here.

I'm thankful these great Lotus suppliers had some options here as none of the muffler shops in Washington that I called wanted to touch this.

Thanks again.
 
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