More Power Required!!!

[Dose]

There was nothing else it could have been, both O2 sensors were checked and the CAT got a once over, as well as the EGR valve, then I put the restrictor back in and it passed!!! I would love it to be something else as the airbox mod gave a bit more kick but I am reluctant to do it again on the SRi.

Got to be a 1 off then mate...My car has no issues and no one on here from what i have seen/read has had any issues what so ever

[KSD]

When did you do the mod? Mine had a good 10 months running before the MOT. Let me know

[Dose]

When did you do the mod? Mine had a good 10 months running before the MOT. Let me know

A week or som before the MOT mate

[KSD]

Hopefully you wont suffer the same fate as I did but thinking about it from an Engineering perspective ( 13 years now ) If you induced more air into the engine then you would need to increase the fuel flow to achieve the correct air/fuel ratio for maximum engine performance right? Now if you had excess air and fuel going in for combustion then the car must deal with the left overs i.e exhaust gasses at a rate much more than it normally would, so that would mean that a more powerful exhaust would be needed (in the long term) if the engine was to compensate for this alteration. My theory is based on aircraft turbine engines tho i.e one mass in results in one mass out (albeit at a different temperature and velocity) but it sounds comprehensive. Opinions please!

[Dose]

Hopefully you wont suffer the same fate as I did but thinking about it from an Engineering perspective ( 13 years now ) If you induced more air into the engine then you would need to increase the fuel flow to achieve the correct air/fuel ratio for maximum engine performance right? Now if you had excess air and fuel going in for combustion then the car must deal with the left overs i.e exhaust gasses at a rate much more than it normally would, so that would mean that a more powerful exhaust would be needed (in the long term) if the engine was to compensate for this alteration. My theory is based on aircraft turbine engines tho i.e one mass in results in one mass out (albeit at a different temperature and velocity) but it sounds comprehensive. Opinions please!

Good thoery! and true...with regards to the exhaust when introducing more airflow.. the engine would need to get rid of the burnt gasses quicker to cope so yes a larger bore would be needed through time..which to be honest most have done with replacement sytems and such like.

A remap after such modifcation would be a must in this situation to compensate for the increase airflow.

[KSD]

Get In! Sorted then, in my opinion the airbox mod is not worth it unless an exhaust capable of handling the remains compliments the mod? Im an aircraft engineer not a mechanic but it sounds logic to me in the LONG term but speaking from experience the airbox mod needs to include a performance exhaust. Opinions please! Or more technical explanations would be even better!

[Dose]

Get In! Sorted then, in my opinion the airbox mod is not worth it unless an exhaust capable of handling the remains compliments the mod? Im an aircraft engineer not a mechanic but it sounds logic to me in the LONG term but speaking from experience the airbox mod needs to include a performance exhaust. Opinions please! Or more technical explanations would be even better!

maybe a should have shut my mouth lol...

Tbh mate you hit the nail on the head most folks on here have an upgraded exhaust anyways so most wont worry but some may

[KSD]

OK, so I need a performance exhaust?

[Dose]

Meaning what mate?

Most people have an upgraded exhaust to compliment the airbox mod...and so i know have not and after reading your posts will have a think about the long term outcome me thinks with emmisions come MOT time.

[KSD]

Just put the restrictor back in a week before MOT mate, then take it out afterwards. I did not notice a real difference anyway after doing the mod but might try it on this car.