hey guys, this is a pic of an exhaust of a 3l mivec diamante, it has the pipe on the side that closes off to restrict flow while car is warming up to speed this up, and opens once engine is warm to have better flow. i want to put it on my car, in open flow position constantly, but dont know if it would be higher flow than my stock 3.5l one. the reason im keen is if it is better i can get it cheap and its direct bolt up. the numbers on it are J20-05. been a mivec which was mitsis top engine and one of the last mivecs to control intake and exhaust cams, i figure they would of put a decent muffler on. the cars were 199kw standard. any opinions on whether it would give me the increase we see with fitting the VRX mufflers??

BUMP!!!!!!!!!! any ideas, anyone.

Sounds like a waste of time to me, look for a VRX muffler instead.

i know your right but im on a tight budget, and this will be cheap, so unless a VRX turns up at pickapart, im not getting one any time soon!! its not really a waste of time as if it flows well it will same process to put on as the vrx, im not going to hook up the valve system on it.

sounds fine to me.

Rob, How did the warm-up thing work - was it just a bimetal spring, or something more complex?

I saw that muffler in a self-serve wrecker in Sydney only recently, wondered about the weird extra pipe.

If its cheap, I'd say do it. None of the Aus market cars had that exhaust, so its had for us to comment.... but if Mivec was top-spec engine, it stands to reason you might have a slight advantage by fitting it.

um there is a cable that comes of the extra pipe and travels up the car, i think there is an exhaust sensor and some sort of switch that controls it. i read it was desinged to restrict the exhaust so the engine warmed up faster and was quieter while doing so, and when warm the valve opened allowing gas to travel around the side pipe and flow and bypass some of the can.

How much are they charging for it?

thr grand sum of $13 !!

Rob, How did the warm-up thing work - was it just a bimetal spring, or something more complex?

I saw that muffler in a self-serve wrecker in Sydney only recently, wondered about the weird extra pipe.

If its cheap, I'd say do it. None of the Aus market cars had that exhaust, so its had for us to comment.... but if Mivec was top-spec engine, it stands to reason you might have a slight advantage by fitting it.

Which wrecker?

Half interested just to see how this works :)

hey got the thing, i looked at another 3l dohc (non mivec) diamante and the number was J20-04 instead of J20-05. also on the non mivec one, the muffler intake pipe was smaller, take a look at the pic and the huge pipe going in!!! its atleast 1/2 inch bigger than mine, but the flange is the same size but slightly different angle so may need to be bent. im certain its higher flow just from the size of the pipe going in!
http://i694.photobucket.com/albums/vv302/robssei/new%20lights%20and%20mods/Image0288.jpg

are you actually going to be connecting the whole system? cable and all?

Or just the muffler?

just the muffler and leave it open position. mot keen on all the hassle to hook it up and it only restricts flow when cold which im not keen on, i want to increase flow!!!

DAMN im stoked!! i decided to give it a clean up and its made of STAINLESS!! , (see pics) also it will fit fine, only the flange is slighlt larger so will need to cut and weld a new one in, its actually the same size pipe as my exhaust, my origional muffler drops down half an inch diameter at its flange. i know it will give a boost. it also sounds hollower when i knock on the side of it compared to the old one.
http://i694.photobucket.com/albums/vv302/robssei/Image0291.jpg
http://i694.photobucket.com/albums/vv302/robssei/Image0290.jpg

good one! might sound decent as well.

The muffler has a turbocharger in it. The valve is the dump valve for the turbo. Or maybe its an afterburner? Or maybe . . . ..

The muffler has a turbocharger in it. The valve is the dump valve for the turbo. Or maybe its an afterburner? Or maybe . . . ..

looks a bit Mad Maxish. lol

Oh! Yes! I will pay that one! lol

1500+ HP when fitted. ha ha ha , well if i can get the extra 8kw the VRX exhaust gives ill be happy, dont know if having no cat will add more, i assume so but doubt its much.

Cat convertors do restrict the exhaust a fair bit, not sure if just unbolting it will give a maximum gain - retune perhaps.....

Cant believe NZ does not require cat convertors.

its a beautiful place!!! theres no emission testing at all. if you go to a pitstop exhaust place thell take it out and weld a strait pipe in for forty bucks. then they will do your warrant of fitness check if you want. and if it does come in, it will only apply to new imports. mine is simply gutted, i unbolted it and rammed a pipe through to break up the ceramic type stuff. it just falls out, its not even bonded to the side. i have a open chamber there now. we are pretty lax on exhausts, as long as it doesnt leak your right. my brother had a 3.5 inch street sign pipe with a canon on the back, strait off the extractors of his nissan cefiro and passed many WOF. and this was at the VTNZ, NZ's official wof place.

imgoing ahead with the install ive decided. thinking about it, its off a 199kw 3l, so must have great flow. plus been stainless is a bonus. i have set the valve open (its like a throttle body butterfly) and have given it a polish up underneth and on the tips. ill let you guys know how it sounds and if theres a performance increase. heres a pic
http://i694.photobucket.com/albums/vv302/robssei/Image0296.jpg

looks the goods mate!

cheers, im stoked. hoping i get a bit nicer note to it, little louder maybe. just to let the commadores know!!! its about 3 inchs longer than my standard pipe too. all the shop has got to do is cut of each flange and weld it up. all the mounts still line up. cant wait to see how it goes!!

What car did this come off again?

Might scour the wreckers trying to find one - and try and retro fit that warm up thingy-me-doobee

What car did this come off again?

Might scour the wreckers trying to find one - and try and retro fit that warm up thingy-me-doobee

came off a 3L Mivec Diamante in NZ

came off a 3L Mivec Diamante in NZ

That sucks lol

Hrm.....

Otherwise known as a Diamante 30M.

thats the one, there is a 3l dohc non mivec there too, with same system, but the pipe diameter is smaller like my origional. the side pipe design is to merge a quiet more restrictive muffler with a open, better flow design into one unit. im of course leaving it in the open flow position.

well THIS IS WHY I DO MY OWN REPAIRS!!!!!!!! i went to an exhaust place, and told him the muffler was perfect fit just needed the flanges changed. he said fine would be between $25 and $45 to do it and fit. so they started, THREE HOURS later im waiting, watching to of the biggest idiots ive met wrestle with my exhaust, they couldnt get the bolts in because they were trying to put in the wrong ones, i could see it was stripping the bolt off. so the guy got a nut and bolt combo and did it, then after getting it on they said come have a look. It was hitting the gas tank, resting on the rear crossmember and the rear muffler mount was hitting the end of the chassis!!!!! i said it was terrible, but the guy said " its done , invoice him!" well i said i wasnt paying a cent till the boss looked over it, so had to leave and come back 2 hours later (took the car). It vibrated the whole car and was shocking. you could feel it through the whole thing at certain revs. when i went back , the boss tried to tell me he had quoted just putting a flange on and i was suppose to fit. he also said it was normal for exhausts to hit the chassis and the gas tank would be fine!! This is when i got angry. i told him bullcrap. i had 3 kids that went in the car, it wasnt wof standard and i wasnt paying anything untill fixed. he decided to take a look and they heated and bent the pipe to set it right. its alot better and im happy. he only charged me 20 bucks, and i know its because he knew it was a shocking process for a professional shop to go through. god i need a welder!!! this is the only thing i cant do at home.

well THIS IS WHY I DO MY OWN REPAIRS!!!!!!!! i went to an exhaust place, and told him the muffler was perfect fit just needed the flanges changed. he said fine would be between $25 and $45 to do it and fit. so they started, THREE HOURS later im waiting, watching to of the biggest idiots ive met wrestle with my exhaust, they couldnt get the bolts in because they were trying to put in the wrong ones, i could see it was stripping the bolt off. so the guy got a nut and bolt combo and did it, then after getting it on they said come have a look. It was hitting the gas tank, resting on the rear crossmember and the rear muffler mount was hitting the end of the chassis!!!!! i said it was terrible, but the guy said " its done , invoice him!" well i said i wasnt paying a cent till the boss looked over it, so had to leave and come back 2 hours later (took the car). It vibrated the whole car and was shocking. you could feel it through the whole thing at certain revs. when i went back , the boss tried to tell me he had quoted just putting a flange on and i was suppose to fit. he also said it was normal for exhausts to hit the chassis and the gas tank would be fine!! This is when i got angry. i told him bullcrap. i had 3 kids that went in the car, it wasnt wof standard and i wasnt paying anything untill fixed. he decided to take a look and they heated and bent the pipe to set it right. its alot better and im happy. he only charged me 20 bucks, and i know its because he knew it was a shocking process for a professional shop to go through. god i need a welder!!! this is the only thing i cant do at home.


Its stories like this that make me paranoid about taking any of my vehicles anywhere to be repaired. Lucky i'm competent and confident enough to turn my hand to anything.

Glad you go it sorted though Rob.
How's it sound?

yeah i usually do all my own repairs, but with the recent back surgery and lack of a welder, i had to take it somewhere. i just dont trust others to do a good job, and so many times i have been proven right. i feel safer with the kids in the car if i do it myself. as for sound, its only a little louder, more open sounding. when ya rev it, it has more of a growl to it. as for performance there is a definite improvement in throttle response, and its gets up to speed when you floor it faster for sure. its made me want to see how a full strait through canon would go!!. im suprised such a difference can be had out of a muffler change. the old one was definitely a restriction, it went from the factory 2.25 inch at the flange, and dropped down to 1.75 inch on the muffler side of it. plus it as press bent so the bends were even less. im stoked with the improvement. and for 33 bucks all up, was a good investment. the exhaust guy was shocked i got a stainless exhaust for $13.

I thought I was the only kiwi on this site robssei, were in NZ do you live mate because Im getting a vrx muffler put on my TE soon and I would like to avoid the same hassle you had.

Forgot to mention that I test drove a couple of mivec diamantes before purchasing my 380 and I wasnt impressed. They didnt go like a 200kw diamante should. My nearly stock 380 would deal to one with out any problems, They didnt seem to have much torque and the gear ratios just didnt seem right.

Im in tauranga, Gate Pa to be exact. i went to a place off judea rd. yeah the only thing i dont like about the 30M is the 5 spd tiptronic. ive heard its a weaker box than the four speed. i have never driven one. i did have a bit of a drag at the lights once with another diamante, and had him easily and i was sure it was the 30M as it had the red badge. i love my car, so underated over here, the most fun is passing lanes, i remember a 4l ford futura was right on my ass at the start of one and i just floored it and easily pulled away, he was shocked!! also the 3.8l holdens dont stand a chance and according to wikipedia, the 3.5 has similar output to the 95-97 holden 5L V8's. albeit we are 200kg lighter!! ive never had a go with one though. whereabouts are you? im actually going to put a strait through stainless canon on the end next week. i know some are gonna hate me, but its a smaller one that will tuck up under, and only see the tip. not a huge boyracer one hanging down. the mivec muffler was only slightly diffrent note, and although was a boost on power, i want the sound of the V6 to come through!!

hey make sure to remove the cat converters on ya car when ya get the muffler done, i gutted mine and it nade a huge difference.

A 5L V8 has no chance against a 3.5L Auto... sad for them isn't it lol

For $13 you did well with that muffler bro :D Bad luck with the workshop, absolute tools sometimes ay.

ha ha it is!! yeah the place i went was shocking, i still cant believe i was actually telling them where they were going wrong, and what was not up to WOF standard. i shudder to think what someone without car knowledge would end up with. its still crap, it hangs down to low, the two pipes are uneven, and where they heated the pipe to move it, it has a big crease in the pipe with a small hole where they streched it too far. i am going to get pipe myself and get it setup with clamps, then get a shop to weld it up. or take it to pitstop and get it done right. ill post pics when i have the new one thats coming on, it should look good. i taliking with a guy about buying a set of lovell low springs for my car for $100 the set. just haveto get my brother to help me put them in (bad back). ill try post a sound clip of thge exhaust before and after. im hoping the strait through will be deep, i know ill get a bit of raspiness at high revs but it dont go there too often so not worried!!

Im in auckland robssei. I had a vrx muffler fitted to my 97 diamante wagon today. Its a 3L v6 cold air inducted KN panel filter and now vrx muffler with no cat converter so it goes well, But the best thing is its a manual and thats so rear over here. Anyway the muffler sounds really mild which is great. I thought it might improve performance more than it did, it definatly isnt going to give you 8kw extra to a 3.5 but It did help slightly. Shes done 330000kms now and still goes as good as the day I bought it 8 years ago:woot:

sweet!! 330,000!! nice. mine has done 245,000km, but after i got the car (got it christmas before last at 230,000) i found out it had a recon engine put in at 218,000km by the rotorua dealership. i was stoked!! i swapped it for a 1990 isuzu trooper i had, guy had five cars, including the diamante, none with a tow bar and he needed a tow vehicle for his boat.. yeah the manual is rare. i want a wagon as a second car, they are good looking cars. yeah i was a bit let down with the sound from the mivec muffler, a little throatier but also sounds a little like a leaking muffler!! im going for the strait through, which will be louder but i know ill be getting the max available horsepower. i did notice a big difference with the cat gutted. i wouldnt mind getting a tune once i have it all done to see what it makes but im not sure what that will cost here. i have a few other mods like adding the clear side indicaters to my glass lens paras, and debadging it. also painted the engine cover the similar to car colour, which came up nice (its my avatar) .

What car did this come off again?

Might scour the wreckers trying to find one - and try and retro fit that warm up thingy-me-doobee


hey man thier is a 30M at blacktown pick and payless, the muffler was their last time i looked, although that was a while ago, and so someone will prob be able to tell ya if its still their....
although thinking about going thier in the morning so ill let ya know if its still their. plus you can just tell the guys at the front desk its off a normal magna, and i doubt they would have a clue! haha

The 5sp tippys are strong. Ask HRD2GT, His gearbox is constantly dealing with 7000RPM allllllll theeeeeeee timeeeee...

hey man thier is a 30M at blacktown pick and payless, the muffler was their last time i looked, although that was a while ago, and so someone will prob be able to tell ya if its still their....
although thinking about going thier in the morning so ill let ya know if its still their. plus you can just tell the guys at the front desk its off a normal magna, and i doubt they would have a clue! haha

a real 30m? still got the engine?

a real 30m? still got the engine?

Pm Lynel if you want a motor he knows where one is ready to ship :)

a real 30m? still got the engine?

yeah a real 30m! haha
yeah no more engine, that was gone from before i saw it!


Ers, the muffler is still on the 30M if you want it!