Raceco Exhaust, question..

[PHOENIXUK]

Hi, just received my track day exhaust today.... Since I am removing the CAT will the ECU need re-programming..?

[130g]

I would think not, cat is a fair bit after the ECU is done doing its thing

[PHOENIXUK]

130g said:

I would think not, cat is a fair bit after the ECU is done doing its thing

Thanks, didnt know if the lamder sensor would tell the ECU something... I just drive em.....

[130g]

Normally the lambda is either in one of the exhaust primaries or in the collector, so unless you have a setup with two lambda probes (with the last one after the cat) you should be fine. I don't even know if Caterham makes such a system, but apparently they are used on some modern cars...

[czechmichal]

I´m dealing the same problem.
I got Roadsport 175 SV, year 2009 with EU4 as i´ve bought it in Europe.
I would like to buy the complete exhaust system w/o CAT. I don´t know exactly the difference between UK and EU 4 ECU.
Would it work fine with standart ECU? I don´t want make any damage as i heard about some exhaust changes (different cars), that damaged the engine or decrease the power output.
Thanks a lot.

[130g]

Not that it is any of my business but why do you want a system without a cat?
I very recently bought a powerspeed system, and asked them if there are any performance gains by not using a cat. They answered that "there is no measurable performance gain with cat removed as we use 200 cell sports cats which are very free flowing".

But still, as long as you don't have a lambda probe after the cat, the ECU has no way of knowing that the cat is missing and will therefor run as pr. normal.

[PipeNslippers]

130g said:

Not that it is any of my business but why do you want a system without a cat?
I very recently bought a powerspeed system, and asked them if there are any performance gains by not using a cat. They answered that "there is no measurable performance gain with cat removed as we use 200 cell sports cats which are very free flowing".

But still, as long as you don't have a lambda probe after the cat, the ECU has no way of knowing that the cat is missing and will therefor run as pr. normal.

According to Caterham, CAT's will get overheated when used extensively on Track days, so I went to a Cat bypass with RaceCo to reduce noise and prevent ruining a servicable CAT

[130g]

PipeNslippers said:

According to Caterham, CAT's will get overheated when used extensively on Track days, so I went to a Cat bypass with RaceCo to reduce noise and prevent ruining a servicable CAT

Interesting...can anyone confirm if this goes for all types of catalysts or "only" for the once that Caterham use?

[harry b]

I also run a Raceco but have it combined with a 200cell sportcat typed for a 3000cc engine.
I have integrated it into the raceco, and had about 1.5Db increase of noise, still well within limits with 93Db.

After dynorun it didn't show any powerloss, so it works for me.
Maybe something to consider.

[mickrick]

The cat makes no noticable difference to performance.
I had a cat bypass on my R300. I fitted the cat, and realised the bypass was a waste of money.
I wasn't aware track days could harm the cat though
A Caterham is supposed to be a road legal track car ?
Another beauty from CC.

[PHOENIXUK]

Bypass pipe measured andcut by my own fair hand and it only fookin fits.... Exhaust now fitted, quieter, sounds so much better to me and feels quicker..hahaha

Edited by PHOENIXUK on Wednesday 8th August 09:22

[Dr Slotter]

It is more 'can' rather than 'will' damage a cat.

[czechmichal]

harry b said:

I also run a Raceco but have it combined with a 200cell sportcat typed for a 3000cc engine.
I have integrated it into the raceco, and had about 1.5Db increase of noise, still well within limits with 93Db.

After dynorun it didn't show any powerloss, so it works for me.
Maybe something to consider.

Does "no powerloss" means that you haven´t increased the power neither? So what´s the purpose of spending about 1000 quid for the exhaust system? Is the weight difference so big?

Thanks a lot

[harry b]

czechmichal said:

Does "no powerloss" means that you haven´t increased the power neither? So what´s the purpose of spending about 1000 quid for the exhaust system? Is the weight difference so big?

Thanks a lot

No change measurable. The exhaust came with the car when I bought it. Since regulations differ a bit from the UK, I needed to add a CAT to get it roadlegal. Didn't like the view of the normal exhaust with a seperate cat so came with this solution.
At the anual MOT it is always fun to watch the grinn on the face of the mot-man when he thinks the car will fail due to a missing cat.

[sam919]

I had my engine dyno'd with and without and with a 100dcpi CAT is reduced the bhp by 4%.

[czechmichal]

harry b said:

No change measurable. The exhaust came with the car when I bought it. Since regulations differ a bit from the UK, I needed to add a CAT to get it roadlegal. Didn't like the view of the normal exhaust with a seperate cat so came with this solution.
At the anual MOT it is always fun to watch the grinn on the face of the mot-man when he thinks the car will fail due to a missing cat.

Thanks, Harry.
So you were in the opposite position, you need to add the CAT
I talked to a guy, who builds and tunes JDM cars here in czech rep and he had ordered complete exhaust system for Honda S2000 for his customer. And the manufacturer literally told him, that w/o ECU optimalisation he will lose about 15bhp.

So i should change my question a little:
Is it possible that without ECU re-programming i´m not able to get the best from those exhaust systems (Raceline, Raceco etc.).
What´s the real power and weight difference when i change standart CC exhaust for Raceline etc piece by piece w/o any other changes.

Thanks guys, really appreciate you opinions.