182 Cat bypass pipe, are they available

[qwerty]

Getting rid of the cat with a straight-through pipe ought to get a little more power, a little more economy, a little less wieght and a little more reliability. All desirable things but can it be done, has anyone done it?

It would be simple just to make a pipe and fit it but theres a sensor just after the cat. This will upset the ECU so it might need re-mapping and may invalidate the warrantee.

A simple idea turns expensive very quickly!

Anyone done this (I suspect 172 is the same or very similar) or have any ideas?

 

[CocoPops]

The 182 has a "more freeflowing" cat than the 172 and totatlly different exhaust system.

There is one person (that I know of) on here that has had the cat removed from his 182. Although gains are unknown (if any/many) at the moment as he hasnt had it RRd.

 

[rmccardal]

Hope that person is meeeeee

Yes, you can have it done by http://www.pro-speed.bizwww.pro-speed.biz give Charlie a call and he will sort you out.

Mine is still going well (no emission light after 1k running) going back to pro-speed for the rest of the system (except manifold) in early august.

I know renault have improved the system over the 172, but after speaking to charlie, he reckons he can do much better, and I am willing to be the guinea pig.

 

[dk]

Quote: Originally posted by rmccardal on 06 July 2004


Hope that person is meeeeee

Yes, you can have it done by http://www.pro-speed.bizwww.pro-speed.biz give Charlie a call and he will sort you out.

Mine is still going well (no emission light after 1k running) going back to pro-speed for the rest of the system (except manifold) in early august.

I know renault have improved the system over the 172, but after speaking to charlie, he reckons he can do much better, and I am willing to be the guinea pig.

ofcourse charlie will tell you that, you are dangling reddies in his face, he will tell you anything, hes a salesman! I really dont think it could make that difference, Renault have already done all they can to the CAT to get the extra HP of the 182 in the first place. Just my opinion, just seems like a lot of hassle and money for a phsycological improvement. Will have to see what the RR says.

 

[rmccardal]

Quote: Originally posted by dave182 on 06 July 2004

Quote: Originally posted by rmccardal on 06 July 2004


Hope that person is meeeeee

Yes, you can have it done by http://www.pro-speed.bizwww.pro-speed.biz give Charlie a call and he will sort you out.

Mine is still going well (no emission light after 1k running) going back to pro-speed for the rest of the system (except manifold) in early august.

I know renault have improved the system over the 172, but after speaking to charlie, he reckons he can do much better, and I am willing to be the guinea pig.

ofcourse charlie will tell you that, you are dangling reddies in his face, he will tell you anything, hes a salesman! I really dont think it could make that difference, Renault have already done all they can to the CAT to get the extra HP of the 182 in the first place. Just my opinion, just seems like a lot of hassle and money for a phsycological improvement. Will have to see what the RR says.

Indeed we will. I have taken a good look inside the cat, and was esepcially surprised as the build up that had already begun to form after only 1k of driving. While renault have improved the cat, they still need to plan long term, deal with noise and pollution laws. If they had their way .... there would be no cat.

You seen the exhaust system on an F1 car ?

 

[qwerty]

rmccardal, thanks for the PM - red the thread (from http://www.pro-speed.bizwww.pro-speed.biz).

So I take it you initially had a straight pipe inserted where the cat was?

What did they do with the after-cat sensor? Did they make a fitment so that it just reads the gasses without the cat, did they fit a dummy to fool it or just disconnect it?

If all it requires is a pipe cut to length, fittings at the ends and a sensor attachment, it ought to be cheap (hmmm...)!

dave182, Like I started with, removing the cat ought to improve power, economy, wieght and reliability. All the improvements will be small but should be measurable and, done right, have no down side apart from the initial cost. Must be worth it, especially for a new car, as youll have 3 years use before you have to refit the original system (as new still) for the MOT!

 

[rmccardal]

Quote: Originally posted by qwerty on 07 July 2004


rmccardal, thanks for the PM - red the thread (from http://www.pro-speed.bizwww.pro-speed.biz).

So I take it you initially had a straight pipe inserted where the cat was?

What did they do with the after-cat sensor? Did they make a fitment so that it just reads the gasses without the cat, did they fit a dummy to fool it or just disconnect it?

If all it requires is a pipe cut to length, fittings at the ends and a sensor attachment, it ought to be cheap (hmmm...)!

dave182, Like I started with, removing the cat ought to improve power, economy, wieght and reliability. All the improvements will be small but should be measurable and, done right, have no down side apart from the initial cost. Must be worth it, especially for a new car, as youll have 3 years use before you have to refit the original system (as new still) for the MOT!

The cat was cut out, flanges welded to the ends for easy reconnection.
Lambda sensor was placed in the new pipe, job done.

 

[Pete]

The second lambda sensoer isnt needed (just disconnect it) when you have a decat pipe, just the first one.

 

[qwerty]

Pete_172, thats interesting but it must do something!

If the pre-cat sensor is the main one then I suppose the post-cat one is just to confirm the cat is ok and make alterations to the engine if not? But if its just disconnected Id have thought the ECU would think the cats in a bad way and do something.

rmccardal, have you tried disconnecting that 2nd sensor to see what happens?

So the cat needs cutting out and connectors made up! Have you measured (and therefore noted) any change in mpg? Once youre happy the car has reached a stable performance and you know it well, it might be useful to fit the cat back and measure acceleration and mpg. The mpg should be easy with the trip computer!

 

[Roamer]

Quote: Originally posted by qwerty on 08 July 2004

Pete_172, thats interesting but it must do something!
If the pre-cat sensor is the main one then I suppose the post-cat one is just to confirm the cat is ok and make alterations to the engine if not? But if its just disconnected Id have thought the ECU would think the cats in a bad way and do something.

Nope, the 2nd Lambda is as you say the post cat "check", and if its not present then either the ecu knows its not there and ingores it, or it not being connected gives it an ultimately "clean" signal - which wouldnt cause any problems at all as it would think everything is 110% good

 

[rmccardal]

Quote: Originally posted by qwerty on 08 July 2004


Pete_172, thats interesting but it must do something!

If the pre-cat sensor is the main one then I suppose the post-cat one is just to confirm the cat is ok and make alterations to the engine if not? But if its just disconnected Id have thought the ECU would think the cats in a bad way and do something.

rmccardal, have you tried disconnecting that 2nd sensor to see what happens?

So the cat needs cutting out and connectors made up! Have you measured (and therefore noted) any change in mpg? Once youre happy the car has reached a stable performance and you know it well, it might be useful to fit the cat back and measure acceleration and mpg. The mpg should be easy with the trip computer!

MPG seems to be fairly similar. It always varied from about 28-32 before, and this morning it was on 28.8 when I got to work.

I havent tried unpluggin the sensor. If I get any lights on the dash however ..... *yank*