My other half's Z is due the dreaded MOT and I'm a little concerned about the noise levels from the exhaust. She's fitted the straight through, single exit system from my old TT as she loved the aggressive exhaust note (somehow I managed to turn her into a petrol head a couple of years back...Christ knows how I managed it! lol ;)). However, now it's on an NA it's truly loud...I mean Armageddon-esque L-O-U-D loud. TBH it sounds fantastic (if occasionally annoying when cruising at speed on the motorway...) but I'm not sure whether it will pass an MOT as it is. I believe our cars are exempt from the emissions test (well the early ones anyway...I think?) so does this also apply to decibel levels, if indeed that is part of the test now? If so, what would people suggest as the easiest way to get it through? Are there any off-the-shelf mufflers that would fit or will I need to get a custom jobbie made up...she really doesn't want to change the exhaust! Any advice would be appreciated!

Not sure but i've got a bit of work to do on my V8 to make sure it passes.

 

My silver zed has straight through pipes without anything before the rear boxes and that passes year after year so i think you should be alright.

 

Is it a shorty or LWB?

LWB Nick. And the fecker is genuinely so loud it's offensive...essentially the automotive equivalent of sticking two fingers up at a nun...

 

:D ;)

I was told by the MOT tester this year that new rules were coming in soon that would mean my NA would fail on noise levels when its due again, if and when it gets confirmed I will have to get a coulpe of silencers fitted I guess, a beautiful Alunox exhaust and it has to be ruined because of someone sat in an office making rules with no idea about classic cars !!

I was told by the MOT tester this year that new rules were coming in soon that would mean my NA would fail on noise levels when its due again, if and when it gets confirmed I will have to get a coulpe of silencers fitted I guess, a beautiful Alunox exhaust and it has to be ruined because of someone sat in an office making rules with no idea about classic cars !!

 

That's more or less what I'd heard chap...not good :( A while back I was reading about the police stopping cars that were "overly loud" and testing them. Just been given this link as well: http://news.bbc.co.uk/1/hi/england/8112905.stm However, I'm still wondering if, due to its age, it might be excluded (fingers crossed :( )?

basicaly the mot reg's state that the exhaust should not be substancially louder than a vehicle with an original system in good condition, so really its down to the tester. cars are not exempt from emission test its just a different test that applies to earlier (pre 96) z's. make sure tester knows that it should get earlier test, you need to hold car revs at approx 2500/3000 rpm for later test and might bring attention to loud exhaust .

That's more or less what I'd heard chap...not good :( A while back I was reading about the police stopping cars that were "overly loud" and testing them. Just been given this link as well: http://news.bbc.co.uk/1/hi/england/8112905.stm However, I'm still wondering if, due to its age, it might be excluded (fingers crossed :( )?

 

I was told the old MOT guide book stated that the exhaust must not be excessively loud for the type of vehicle (so we passed as its not your average car ) but the new rule gives a figure it can not be above, ro mitigating circumstances.

I was told by the MOT tester this year that new rules were coming in soon that would mean my NA would fail on noise levels when its due again, if and when it gets confirmed I will have to get a coulpe of silencers fitted I guess, a beautiful Alunox exhaust and it has to be ruined because of someone sat in an office making rules with no idea about classic cars !!

 

rules have changed were now supposed to check exhaust volume while cars going through emissions check i.e. at tickover and at 3000 rpm when undergoing a bet (cat) test.

I was told the old MOT guide book stated that the exhaust must not be excessively loud for the type of vehicle (so we passed as its not your average car ) but the new rule gives a figure it can not be above, ro mitigating circumstances.

 

new rules dont give any figures as testing stations dont have any way of measuring decibels of exhaust. its basicaly down to tester to decide wether exhaust is to loud . prsonaly i tend to pass and advise exhaust noise unless it is genuinely unreasonable.

new rules dont give any figures as testing stations dont have any way of measuring decibels of exhaust. its basicaly down to tester to decide wether exhaust is to loud . prsonaly i tend to pass and advise exhaust noise unless it is genuinely unreasonable.

 

I better come to you next MOT time then !!

I better come to you next MOT time then !!

 

be a long trip mate im up in the north east of scotland, youd probably becheaper and quicker changing zorsts.

Thanks for all the comments guys, much appreciated. So it's down to the disgression of the tester (interesting to know there are no decibel meters in a testing station! You're a tester then lahsx? Cheers for the advice! :)).

 

Ok, so if we wanted to lessen the chances of being refused on this basis, is there an off the shelf "universal fit" silencer available that could be put in for the test and removed afterwards? I mention it as I could've sworn I saw a link to one for a Supra a while back...

I've got 4 silencers each side going on the V8 and a set of exhaust bypass valves for "off road use" :D

Just been sent this: http://www.japgirls.co.uk/forum/showthread.php?t=13169

yep im a manager at a testing station and a tester. you can get a bolt in baffle depending on styleof exhaust youve got fitted. or you could get a baffle made to fit. because i work for a tyre and exhaust centre we see quite a few cars that come in get exhaust changed ,go for test, then get exhaust changed back.

Just been sent this: http://www.japgirls.co.uk/forum/showthread.php?t=13169

 

yep they got that wrong as well older cars are checked at tickover but should be revved to purge the system max is 3000 rpm or half the indicated limit. newer cars bet test has a max of 3000 rpm.

A bolt on baffle would be ideal. It's for this little bVgger: http://www.300zx.co.uk/forums/showthread.php?t=99227 (I ended up buying it back from the guy I sold it to some months later!)

be a long trip mate im up in the north east of scotland, youd probably becheaper and quicker changing zorsts.

 

You could move down here, lovely part of the country !!

 

Sounds like I will be at the mercy of an MOT tester then, better find one that smiles and likes big red noisey cars !!

I've got 4 silencers each side going on the V8 and a set of exhaust bypass valves for "off road use" :D

 

getting bmw's fitted with asimilar type of system as standard, a valve in one tailpipe of each rear silencer that is closed at low rpm/ throttle and opens as revs etc build.

getting bmw's fitted with asimilar type of system as standard, a valve in one tailpipe of each rear silencer that is closed at low rpm/ throttle and opens as revs etc build.

 

Mine will be pretty similar to John Dixon's set up, a variable control inside to select the position of the valves although i was thinking of the idea of linking it to the throttle but could prove quite annoying if you're opening and closing all the time.

 

Baffles seems to be the way forward leigh, definately the cheapest option. If not i have a stock LWB TT exhaust sitting down the side of the house you can have?

should be able to get a baffle to fit that, check out apex performance they do 200sx drift parts sure they used to do separate baffles

Mine will be pretty similar to John Dixon's set up, a variable control inside to select the position of the valves although i was thinking of the idea of linking it to the throttle but could prove quite annoying if you're opening and closing all the time.

 

you could set it so as it only opens the valves at 3/4 or full throttle then it wouldnt bother you with normal drivin.

The idea is when i move to fuel injection next year instead of carb i can program the map to open/close the valves under different programs (ie town, motorway, sport, race) but i'll just be using it for a quiet stretch of road/drag track, push the button and all hell breaks loose :D

Cheers lahsx will take a look at Apex products :) Unfortunately I can't justify buying another variable control exhaust bypass as I'm already getting one for my own V8 and money is ridiculously tight as it is :( A simple bolt in baffle definately seems to be the way forward for the NA.

 

Cheers for the standard exhaust option Nick, I'll keep it in mind just in case thinghs go t1ts up! :D ;)

Oh this don't sound good

I got an MOT tomorrow and my na z32 is loud enough too scare a small country.

Oh this don't sound good

I got an MOT tomorrow and my na z32 is loud enough too scare a small country.

 

Let us know if anything is said about the noise level please.