Wild Cam vs MoT

[BUTRE]

How wild can you go reprofiling a cam an geting your car passed on a MoT?

exhaust measuring.

 

[Nick Read]

Id recommend finding a bent MOT station. Youll wreck a cat if you put a wilder cam on it anyway, what with the excess fuel that may be chucked down the pipe.

 

[BUTRE]

The cat is no problem, since Im not using it for now.

To MoT it will be in place. Even with the cat would it pass knowing it has a "fast road" spec cam?

 

[Alex M]

A difficult one, there is a fair chance a wild cam would make the car fail an emission test, assuming you need the CAT for an MOT test (what year is the car?) you will face a stiffer emissions test anyway. 3rd party performance cams usually have more overlap and duration, and while this aids breathing once the revs rise, they do tend to make an engine produce more CO and hydrocarbons at idle (and often across whole rev range).

It might be a case of suck it and see, if it fails, you can quite often get garages to go soft on emissions, especially if you can persuade them any high emissions are a result of the cam and any other mods you have, and not a tired and/or badly tuned engine. Approach a garage before hand and speak with them, for advice. You could even go for a crypton tune and study the exhaust results from that. Also get car well warmed up, give it a decent thrash, as this quite often drops the emissions for a while. Worst comes to the worst, get an adjustable fuel regulator (power boost valve),and keep turning it down a little at a time until it scrapes through the emissions test, dont let it run lean though. Dont know if any of that helps, but I prefer typing stuff on the forum than actually doing any work. Anybody else use this forum from work?



Alex M



ps just clicked that the trick with adjustable fuel regulator probably does not work on 16v as ECU would adjust the fuel according to lambda sensor in the exhaust - sorry (is this correct?)

 

[DazzF]

Well I know a guy that runs a Rally Clio with a 2.0 16v lump in it. Its runnin 290 profile cams and it is a road legal car. it passed its MOT last month with flying colours and it was a genuine MOT station.



Dazz F

 

[BUTRE]

yeap Alex M.

Since I cant remap my ECU when I want, Im concern about this. In my early days Ive killed the fuel working on the carb while on measuring CO on the MOT. Those ppl at the time were great about this.

Nowadays, this doesnt happen anymore.

My car is a 95 RTi, and Ive got the cat safely and unharmed kept in my garage. For this, It wont be a problem when comes to MoT.

Always let the car warm up real nice, and always gave it a death wish on rev until get it to MOT.