At the risk of overgeneralizing, it's like tweaking any part of a system - old school thinking says that 'opening' the pipe is 'good'.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]
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:[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?
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.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?
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.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.