Exhaust Thoughts?

[colin b]

Like Tony, I would be very wary of doing any serious modification of an engine, especially while the vehicle was under warranty.

I would also offer this thought from a very smart mechanic who looked after my cars for a few years when someone asked him about performance modifications:

"These manufacturers employ very highly skilled engineers and pay them very serious money to design these vehicles. Do you really think you or I know more about that engine than the guys who built it?"

[theblueweapon]

I just replaced the massive rear muffler near the diff with a hotdog and couldn't be happier. Just removed the rear section for a few days and noticed the difference. Try it as the turbo gets rid of most of the noise so it isn't noisy anyways. No way way the muffler was going back so replaced with a $100 hotdog. Awesome mod.

[Jaymac92]

Like Tony, I would be very wary of doing any serious modification of an engine, especially while the vehicle was under warranty.

I would also offer this thought from a very smart mechanic who looked after my cars for a few years when someone asked him about performance modifications:

"These manufacturers employ very highly skilled engineers and pay them very serious money to design these vehicles. Do you really think you or I know more about that engine than the guys who built it?"

well, yeah but emissions and quietness is their first priority, then performance

[Octaneruss]

I'm running a 2.75" from turbo to straight through muffler no cat and a 2.5" tail pipe, it revs a lot better and is awesome with the chip it tune 5. It has a slight whistle. The idea of a smaller tail pipe is as the gases cool they are less dence so this is to keep up exhaust velosity out the tail pipe and to have some back pressure, a lot of research has gone in to this in race cars but I think it has minimal gains at best, correct me if i'm wrong. Turbo does spool a little slower than standard but there is no issue when a chip is fitted. This can be corrected by a well designed dump pipe, eg: not a 3" pipe welded to the flange, stock dump pipe into cat is a pretty good example of what it should look like (just no cat), smooth transition from exhaust wheel size to actual exhaust size, like a cone. IMO -:D

[Earlyninja]

on the topic of changing exhaust sizes between turbo and end of pipe, how did people go about making them fit? Was an adapter of some sort made to go from (for example) 3" to 2.5" at a connection?

[mgc_020]

Have a 3 inch Scotts Rods Exhaust on my ML 3.2, has high flow cat and muffler. Will it sound any better if I take the muffler out?

[rohan1993]

Hey folks, my 3.2l has a diesel power chip in it... does that mean ut will be ok for 3" or should I still look for 2.75, the 3" full system with cat is 500 on ebay, straight through with cat? Or should I get straight through without cat?

[nobeachwork]

Have a 3 inch Scotts Rods Exhaust on my ML 3.2, has high flow cat and muffler. Will it sound any better if I take the muffler out?

After 2 years of putting up with a 3inch exhaust with no muff i finally put one on the other day, sounds so much better and the passengers in the back seat can actually hear me now without yelling!!!

I recommend leaving your muffler in for sure!!!

[mattz]

Hey folks, my 3.2l has a diesel power chip in it... does that mean ut will be ok for 3" or should I still look for 2.75, the 3" full system with cat is 500 on ebay, straight through with cat? Or should I get straight through without cat?

3" will be fine.
The rest is up to you.
I recently went through this dilemma myself and settled on a 3" system with stainless muffler and high flow cat.
I'm glad I did as the noise would have driven me made and its good peace of mind to have the cat and keep it legal. Would have been a pita to be pulled up and have to fit a cat later.

[rohan1993]

If you have a muffler and cat does it defeat the purpose of upgrading?

[rohan1993]

Not sure whether I want power or noise or just leave it stock haha

[ag9111]

You will not get any massive power increase's with just an exhaust, unless you plan other performance mods down the track.
It only helps to lower the EGT's in stock form.

[scumbag]

Not sure whether I want power or noise or just leave it stock haha

unbolte the muffler and see what you think takes 5mins if that.

[mattz]

If you have a muffler and cat does it defeat the purpose of upgrading?

No because the pipe is bigger and muffler and cat are high flow.

Not sure whether I want power or noise or just leave it stock haha

You'll have to work that out yourself.
If you want noise just buy a muffler delete pipe off eBay and keep your muffler for when you get pulled up or you and your passengers sick of the noise

[Stoneman]

A random exhaust question

Is it common for after market exhaust manufacturers or even exhausts shops to use the gearbox bolts for mounting?

I don't understand why the factory mounting points wouldn't be used

[ag9111]

They shouldn't as the driveline vibrations will destroy the system. That is why the exhaust has an isolation joint up near the front

[Stoneman]

Originally the dump pipe was held on by nothing except the the factory hangers underneath. it has the isolation joint as you mention, I wondered what that was called

I've had 3 dump pipes crack and now they have decided to use the gearbox bolts

So should the factory mounting points still be used as they are on the bell housing?

[jrs184]

I love my 3 inches.... Exhaust I mean. Sound isn't loud enough but the whistle is cool and it has helped the fuel
Slightly. Straight through muff and the invisible cat mod

Hi what did you do with the oxygen sensors after cat removal, anything, remove them too just leave them?? thanks John

[Tritonsam]

just brought a 3'' mandrel bent turbo back exhaust for my mn triton its a DEA performance will be interesting to see how it sounds. hopefully not crap!

[scumbag]

just brought a 3'' mandrel bent turbo back exhaust for my mn triton its a DEA performance will be interesting to see how it sounds. hopefully not crap!

what one did you get?
cat or catless?
muffler or mufflerless?

[Tritonsam]

just brought a 3'' mandrel bent turbo back exhaust for my mn triton its a DEA performance will be interesting to see how it sounds. hopefully not crap!

what one did you get?
cat or catless?
muffler or mufflerless?

i got the 3'' with cat but no muffler don't really wanna yellow sticker and a fine. its a high flow cat so it shouldn't be to bad.

[Airved]

I've had DEA exhaust with no muffler for about 6 months now. The drone in third gear is terrible and almost hurts your ears if you're going up a hill (windows down helps). I shot them an email asking how much for just for the muffler/tailpipe section and was told $200. I doubt the volume is legal, but I haven't been pulled up on it.

Install is an easy <1 hour job if you've got some deep sockets for those pesky bolts on the turbo. If you're having trouble attaching the dump pipe to the gearbox housing, it's because the hole in the mounting point is too small for the bolt. Unless DEA have fixed this, you'll see what I mean when you install it. The hangers/turbo bolts have held mine on fine.

When you're done, don't forget to check the distance between your spare and the exhaust tip. Mine was practically touching before I moved the spare over an inch or so.

[scumbag]

I've had DEA exhaust with no muffler for about 6 months now. The drone in third gear is terrible and almost hurts your ears if you're going up a hill (windows down helps). I shot them an email asking how much for just for the muffler/tailpipe section and was told $200. I doubt the volume is legal, but I haven't been pulled up on it.

Install is an easy <1 hour job if you've got some deep sockets for those pesky bolts on the turbo. If you're having trouble attaching the dump pipe to the gearbox housing, it's because the hole in the mounting point is too small for the bolt. Unless DEA have fixed this, you'll see what I mean when you install it. The hangers/turbo bolts have held mine on fine.

When you're done, don't forget to check the distance between your spare and the exhaust tip. Mine was practically touching before I moved the spare over an inch or so.

has it got a cat on it?

im actually really happy with how mine sounds with just the standard exhaust with the rear muffler removed.
with the egr blocked and an ebay " performance chip"
its actually pretty loud once its up on boost.

was considering going the DEA system with no cat and no muffler, then welding it up to dump before the rear tyres... but not so sure now as mines pretty pleasant, might just fab up a side exit exhasut for it...

done the same on a mates 2011 and its no where near as loud for some reason... not sure why mines a 09 mn ....

[Tritonsam]

I've had DEA exhaust with no muffler for about 6 months now. The drone in third gear is terrible and almost hurts your ears if you're going up a hill (windows down helps). I shot them an email asking how much for just for the muffler/tailpipe section and was told $200. I doubt the volume is legal, but I haven't been pulled up on it.

Install is an easy <1 hour job if you've got some deep sockets for those pesky bolts on the turbo. If you're having trouble attaching the dump pipe to the gearbox housing, it's because the hole in the mounting point is too small for the bolt. Unless DEA have fixed this, you'll see what I mean when you install it. The hangers/turbo bolts have held mine on fine.

When you're done, don't forget to check the distance between your spare and the exhaust tip. Mine was practically touching before I moved the spare over an inch or so.

what about sound just driving around? dont go up to many long winding hills. should get it next week so ill give you some feed back on what i reckon of it

[Airved]

Mine's got the cat because I heard people had issues with overboost when removing cat + muffler. I don't know how true it is, but that plus the possible fine was what convinced me to go cat + no muffler. I've also got an EGR block in, but no chip. I removed the muffler on the stock exhaust to see if I liked it - the volume difference is pretty significant imo.

As for driving around, yeah, it's loud and you do get used to it, but talking to people in the backseat can be hard sometimes. My girlfriend said it sounds like my car was sick I've learnt to just go easy on the throttle while the revs are between about 2200rpm and 3000rpm because that is where it is worst. Who knows though, might just be my setup.