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The mkiv Supra Owners Club

Screamer pipe regs


paul21uk

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that sounds like a test for a diesel engine, as there are not any petrol cars that I know of that have a govenor, plenty with a rev limiter.

 

 

 

 

The MOT tester will rev the car as it is part of the emissions:

 

The MOT testers manual states that for vehicles first used before 1st August 1979 the compression ignition engine emissions test is put at either 2500 engine rpm OR half of maximum engine speed whichever is the lower.

 

For vehicles first used after 1st August 1979 if the engine checks are satisfactory and having removed any oil temperature probe, raise the engine speed to around 2500rpm, or half the maximum engine speed if this is lower, and hold for 30 seconds to fully purge the inlet and exhaust system. Raise engine speed slowly to maximum to check the operation of the governor. Once the engine speed has stabilised or if it becomes clear that the governor is not working, release the pedal, return to idle and stop the engine.

Prompt the meter to carry out a zero check.

Insert the probe fully and securely, in line with the gas flow. Restart the engine.

Following the meter prompts, depress the accelerator pedal quickly and continuously but not violently, to reach full fuel position in less than 1 second

 

With this I was suggesting that there may......just may be a situation where noise then becomes an issue. As most people with screamers have no problems then its unlikely but still possible the MOT tester could get over excited.

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Screamer pipe is an MOT failure as exhaust gasses are vented direct to atmosphere rather than through a cat.

 

Luckily very few MOT testers even know what it is.:rolleyes:

 

All our MOTs here are done in official DoE testing centers where the inspectors are fully trained government testers.

 

My car has been through 5 MOTs with the screamer and it has only been picked up once! That particular tester only knew what it was because he had one on his modified MR2. Luckily as a fellow enthusiast he turned a blind eye:thumbs:

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i've had mine mot'd a few months ago with a screamer pipe on a T70 and it passed with no problems. The issues i had where the HKS midpipe said 'not for road use' on it and the main showstopper was there were no cats on the car, according to regs if the car came with it then it has to have them fitted. I fitted them and it then failed again on excessive exhaust noise. He never mentioned the screamer pipe one and as I have a cast manifold I can build boost at standstill while revving, I don't know how hard he revved it but he never mentioned it and this guy marked me down as my reg plate lettering was 3mm to close to the edge of my plate so if he could of got me on anything he would have.

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...under MOT the tester will rev the car hard as part of the MOT emissions test...

 

Really? "Fast idle" is hardly revving it hard.

 

 

A screamer pipe wouldn't fail an MOT because the wastegate won't be open.

 

 

Mr Plod is a different matter...

 

The MOT tester will rev the car as it is part of the emissions:

 

The MOT testers manual states that for vehicles first used before 1st August 1979 the compression ignition engine emissions test is put at either 2500 engine rpm OR half of maximum engine speed whichever is the lower.

 

For vehicles first used after 1st August 1979 if the engine checks are satisfactory and having removed any oil temperature probe, raise the engine speed to around 2500rpm, or half the maximum engine speed if this is lower, and hold for 30 seconds to fully purge the inlet and exhaust system. Raise engine speed slowly to maximum to check the operation of the governor. Once the engine speed has stabilised or if it becomes clear that the governor is not working, release the pedal, return to idle and stop the engine.

Prompt the meter to carry out a zero check.

Insert the probe fully and securely, in line with the gas flow. Restart the engine.

Following the meter prompts, depress the accelerator pedal quickly and continuously but not violently, to reach full fuel position in less than 1 second

 

With this I was suggesting that there may......just may be a situation where noise then becomes an issue. As most people with screamers have no problems then its unlikely but still possible the MOT tester could get over excited.

Er... the clue is in the words "compression ignition". :)

 

If your MOT tester performs that test on your Supra you have a very rare model indeed!

Edited by garethr (see edit history)
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...the main showstopper was there were no cats on the car, according to regs if the car came with it then it has to have them fitted. ...
Not quite. The MOT regs actually say;

Method of Inspection

On petrol engine vehicles that qualify for a full catalyst emissions test, check the presence of the catalytic converter.

Reason for Rejection

A catalytic converter missing where one was fitted as standard.

 

So you only need a cat if you need a cat to pass the test anyway. :)

Edited by garethr (see edit history)
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Not quite. The MOT regs actually say;

Method of Inspection

On petrol engine vehicles that qualify for a full catalyst emissions test, check the presence of the catalytic converter.

Reason for Rejection

A catalytic converter missing where one was fitted as standard.

 

 

So you only need a cat if you need a cat to pass the test anyway. :)

 

Didn't matter, he failed me on excessive noise anyway. I had to find a used stock system and fit it myself and take it back within 4 days or something silly like that.

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I have 2 mot testers I know, luckily one is a good freind. My mr2 failed on a few minor faults (steering gaitors, rear lights as id blown a fuse) and failed miserably on emissions. I spent an hour doing the jobs then it miraculously passed the day after still sat on my drive :)

 

The Supra holds the record in his mot station for the worst emissions result ever, which is nice lol

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Why do people still go to evil MOT stations after many years of car ownership? By now you should have found and befriended your friendly neighborhood mot man, and sent him a bottle of wine once or twice. :D

 

You will never fail any Mot again.

 

:sly: this man speaks the truth...

 

No bugger is going to spot a screamer pipe buried in a complex engine bay. And lol at the person quoting diesel engine regs :p

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