R500 Duratec - cat bypass

[catastrada]

Does anybody knows if the cat bypass gives better performance (more power? more torque?) to the R500 Duratec?

[paul jacobs]

I've got a cat bypass pipe on my 2.3 CSR 260, and quite frankly I cannot tell if there is any difference to the power whatsoever. It also makes little or no difference to the noise level either, although I am using the larger 7" "race" silencer. To my mind the exhaust system just looks neater without the cat in the way, but it will have to go back in when the MoT comes around next spring though.

 

Frankly, I do not think, at that price, it is very cost effective, although mine was made up by a local exhaust manufacturer for a LOT less, [£60} and uses the original 4-1 collector.

 

It will be interesting to see what others think.

 

Paul J.

 

[Billyboy]

Had one on my R300 and it made no difference IMHO - also had the 7 inch RACE silencer - I would not buy another one - sold on ebay for £95.00 IIRC.

 

Does make the exhaust look neater though - and more sporty

[Adrian Williams]

Without a dyno with and without on the same car/engine it's all guess work.

 

I did this on a K R500 and lost 7 bhp and 5 ftlbs of torque with the cat fitted and the map 'optimised' in both cases.

 

On the Duratec the cat might be better but I can't beleive it will help performance. Having said that if the map CC supply is for use with the cat the by-pass probably wont show an improvement and might even loose power.

 

Either way it's hard to tell relatively small differences by driving it. You'd notice 7 bhp on an academy car but with over 250 bhp you'd be hard pressed to tell the difference on the road.

 

Adrian

[catastrada]

Thank you for your reply Adrian

[Stationary M25 Traveller]

A 4-2-1 collector provides more mid-range performance than a 4-1. Made a big difference on my meagre 160 bhp 1.8 VVC. Looks prettier too ... especially with a sports cat inside the 7" dia silencer

 

 

[Rob Walker]

Typical losses with a modern high flow cat are around 2%. The problem using a cat with a car that uses a lot of full throttle / acceleration fuel enrichment such as a tuned caterham is that this tends to overwork the cat as the mixture is constantly rich and above the ideal air fuel ratio of 14:1. I have seen the ceramic matrix melt into a solid block.

[Adrian Williams]

Two of this years competitors in the club speed championship suffered with exactly what Rob has just described. Both cars are K's with more than 200 bhp using the standard CC cat which in both cases were quite old and hadn't been fitted to the car for some years.

 

Adrian