Exhaust Thoughts?

[Bigbirdalx]

As far as I am aware, turbo diesels dont have BOV's as they dont have throttle plates.

New ones do. Old didnt.
assuming u mean throttle body/ valve

If they do, I assume they still wouldn't make vacuum. Without both, a BOV wont work.

With a EGR it wont make a vaccum behind the throttle body as the gas will enter.
block it off and it will go to -1psi before the elctronic throttle body opens and closes to try and keep a postive

[macca002]

Yep thought so.

[mgc_020]

I'm looking at putting a Scotts Rods 3 inch exhaust on. What size bung should I get welded into the dump pipe for the EGT/Pyro Gauge, are they all the same size or different depending on the brand of gauge?

[Tony]

Most are 1/8" npt or bsp (Same thread count). Few older units such as VDO can be 1/4"




I do recall one member who ended up with a 18mm bung for a O2 sensor.

[brodical]

Most are 1/8" npt or bsp (Same thread count). Few older units such as VDO can be 1/4"




I do recall one member who ended up with a 18mm bung for a O2 sensor.

Tony when you say same thread count do u mean same amount of threads cut in the same size fitting?? obviously bsp and npt are different threads ...I'm jst trying to follow what you mean by that...?

[Tryton08]

Most are 1/8" npt or bsp (Same thread count). Few older units such as VDO can be 1/4"




I do recall one member who ended up with a 18mm bung for a O2 sensor.

Tony when you say same thread count do u mean same amount of threads cut in the same size fitting?? obviously bsp and npt are different threads ...I'm jst trying to follow what you mean by that...?

BSP is 28 TPI threads per inch and NPT 27 TPI

[Cowboy Dave]

Yeah that might have been a rare error there - one is 27 per inch and the other 28 per inch.

I notice Scott's Rods themselves seem to be saying the NPT is more common http://scotts-rods-performance-exhausts.myshopify.com/collections/bung-pyro-egt-fittings

[brodical]

Ahhhh now I know why I've been seeing 27 follow some npt fittings..thanks man....

[brodical]

I no no one around my town has any thing to do with npt ....every one I've found that stocks fittings are bsp...npt is eBay for me lol.

[Tony]

I should have said similar thread count as only one thread per inch difference.

npt and bsb will work in same bung (or other way around), trust me . one thread per inch is not an issue with the tapered thread.

[djcobyb]

Old thread I know but seems to be still kicking along.

I've purchased and installed a 3" turbo back exhaust with hi-flow cat and pretty much concur with some of the really early posts on this thread. Off throttle response is a bit soft, but put your foot down over 2000rpm and watch the speedo needle dial around a bit quicker. Economy is also a lot better, I averaged about 850km's a tank on a recent trip to QLD, with gear, picked up a 2tn caravan and towed it home and averaged about 650 so I was pretty happy with that. Last time I towed something that big with standard exhaust I was lucky to get 450kms. And I haven't chipped the MN yet so can only expect to get a little better.

One thing that does bug me, and might just be might cheaper x-force exhaust system is I get this really loud "woooooh" noise when I come off throttle anywhere between 1800-3000rpm. Almoost like backpressure from the turbo or something as the dump pipe off the turbo matches the turbo exhaust diameter which is much less than 3". Anyone get anything like that with their systems? Do you think I need some work done to expand the turbo exhaust outlet?

So would I be right in saying that you recommend the xforce exhaust?

[Cowboy Dave]

I thought he was more having a whinge about the noise to be honest mate. Might be worth checking out the Scott's rods special in the sponsors section - they make a nice bit of kit and there are a few running them.

[hookS]

Is the turbine resonator muffler system available on this site? Also what difference is there between resonator turbine muffler and a high flow 3'' normal ?Are they worth purchasing, thanks for help.

[djcobyb]

Old thread I know but seems to be still kicking along.

I've purchased and installed a 3" turbo back exhaust with hi-flow cat and pretty much concur with some of the really early posts on this thread. Off throttle response is a bit soft, but put your foot down over 2000rpm and watch the speedo needle dial around a bit quicker. Economy is also a lot better, I averaged about 850km's a tank on a recent trip to QLD, with gear, picked up a 2tn caravan and towed it home and averaged about 650 so I was pretty happy with that. Last time I towed something that big with standard exhaust I was lucky to get 450kms. And I haven't chipped the MN yet so can only expect to get a little better.

One thing that does bug me, and might just be might cheaper x-force exhaust system is I get this really loud "woooooh" noise when I come off throttle anywhere between 1800-3000rpm. Almoost like backpressure from the turbo or something as the dump pipe off the turbo matches the turbo exhaust diameter which is much less than 3". Anyone get anything like that with their systems? Do you think I need some work done to expand the turbo exhaust outlet?

Just bought and fitted the same exhaust on my triton and I get the same thing now I think it sounds awesome have noticed a fair difference in throttle response and I will let you know how she goes on the turps I think it's a really good cheap exhaust.

[Belbrook]

I'm thinking of getting a 3' exhaust on my Mn. I want to stay legal so definitely want a cat but am undecided as to whether or not I have a muffler.
What do those with a similar system think about the noise level and if you did it again would you get a muffler?

[Tony]

Just be well aware, if you 3" the MN you could encounter overboost when overtaking or using lower gears on longer hills etc. (Some are doing this stock)

Some OK, but most eventually run into issues.

Reason for this is the aspect ratio of the VGT is very close to the other limits (When VGT is out of attack position) so any added fuelling in top end or change in exhaust back pressure can make in excess of 22.5 psi. Many will run up to 25psi so no chance of avoiding a CEL under the above conditions.

Only fix is either take fuel out of top end or fit a Dawes valve and custom tune MAP sensor output.

I've recently come across new V8 land cruisers with the same issue too.

[Belbrook]

:idea: Just be well aware, if you 3" the MN you could encounter overboost when overtaking or using lower gears on longer hills etc. (Some are doing this stock)

Some OK, but most eventually run into issues.

Reason for this is the aspect ratio of the VGT is very close to the other limits (When VGT is out of attack position) so any added fuelling in top end or change in exhaust back pressure can make in excess of 22.5 psi. Many will run up to 25psi so no chance of avoiding a CEL under the above conditions.

Only fix is either take fuel out of top end or fit a Dawes valve and custom tune MAP sensor output.

I've recently come across new V8 land cruisers with the same issue too.

If a chip is telling porkies to the Ecu won't that stop it or is custom tuning required?

[Tony]

The chip still allows the ECU to see 22.5psi at some point so knows when to tuck the VGT from attack.




If you were to clamp the boost more than this, they stay in attack and the boost will runaway beyond 40psi. (A side note, why you must never use 3.2ML earlier tunes on the MN) This is where the dawes valve comes in and sometimes we have to custom tune so ECU cant see the max boost (Mine is 25psi)

[Jungas]

I asked them ( MIT ) about an exhaust they said not to do the zorst but ( under the table ) a gentleman told me to put a chip on it, one that didn't show up on a diagnostic test and to take it off when it gets serviced. Exhausts will automatically no matter what void your warranty. An un traceable chip is fine if u take it off before a service and put it back on once your car is back.

I haven't had this issue with warranty, my MN recently overheated and boiled the head on a trip away, I have a stock exhaust but with all of the mufflers cut out and a dawes valve to control the over boost, MITS honoured the warranty and did a complete engine out rebuild (machined block and all) at their own cost, they knew about the exhaust but didn't even make a noise about it.

[Richard Noggin]

:idea: Just be well aware, if you 3" the MN you could encounter overboost when overtaking or using lower gears on longer hills etc. (Some are doing this stock)

Some OK, but most eventually run into issues.

Reason for this is the aspect ratio of the VGT is very close to the other limits (When VGT is out of attack position) so any added fuelling in top end or change in exhaust back pressure can make in excess of 22.5 psi. Many will run up to 25psi so no chance of avoiding a CEL under the above conditions.

Only fix is either take fuel out of top end or fit a Dawes valve and custom tune MAP sensor output.

I've recently come across new V8 land cruisers with the same issue too.

So let me get this straight, i recently put a 3 inch exhaust on my vehicle and have a chip.
Should i be running an electronic boost controller to prevent spike now?

I have an mn triton
Cheers

[Richard Noggin]

ps looking at getting a boost gauge and a egt gauge this week to monitor these too but just want to make sure it doesn't spike and cause dramas

[Cowboy Dave]

Depends to some extent on the chip. I'm not sure there is an electronic boost controller that works? Might be, I just haven't heard of one. Tony sells a setup with some hoses and valves and stuff that adds a safety at the upper end which you'll see referred to as a Dawes valve setup around the forum.

[Tony]

:idea: Just be well aware, if you 3" the MN you could encounter overboost when overtaking or using lower gears on longer hills etc. (Some are doing this stock)

Some OK, but most eventually run into issues.

Reason for this is the aspect ratio of the VGT is very close to the other limits (When VGT is out of attack position) so any added fuelling in top end or change in exhaust back pressure can make in excess of 22.5 psi. Many will run up to 25psi so no chance of avoiding a CEL under the above conditions.

Only fix is either take fuel out of top end or fit a Dawes valve and custom tune MAP sensor output.

I've recently come across new V8 land cruisers with the same issue too.

So let me get this straight, i recently put a 3 inch exhaust on my vehicle and have a chip.
Should i be running an electronic boost controller to prevent spike now?

I have an mn triton
Cheers

Not always, is sort of a double evil with these things, you will make slightly more boost with added fuelling (depending on chip as some either cut down after a burst or have already taken fuel out of top end) and free flow exhaust with out clipping the electronic boost curve. So long as the ECU can catch it, and then the VGT aspect ratio allows the boost to stay under 22psi and then run closer to 18 psi while you have the boot in, you will have no dramas. However, the EGT's will could a bit depending on the fuel curve on that chip your running.

The double evil is, if we clip the numbers on the MAP sensor, the boost target will become higher before the ECU tells the electronic over vacuum boost controller to move the VGT out of attack.

[Tony]

As CD has mentioned, it is possible to add a combination of electronic and manual boost control to the 4D56u.

If any do opt to fit a MAP sensor interface of any kind, I highly recommend a Dawes valve or similar.

[Richard Noggin]

:idea: Just be well aware, if you 3" the MN you could encounter overboost when overtaking or using lower gears on longer hills etc. (Some are doing this stock)

Some OK, but most eventually run into issues.

Reason for this is the aspect ratio of the VGT is very close to the other limits (When VGT is out of attack position) so any added fuelling in top end or change in exhaust back pressure can make in excess of 22.5 psi. Many will run up to 25psi so no chance of avoiding a CEL under the above conditions.

Only fix is either take fuel out of top end or fit a Dawes valve and custom tune MAP sensor output.

I've recently come across new V8 land cruisers with the same issue too.

So let me get this straight, i recently put a 3 inch exhaust on my vehicle and have a chip.
Should i be running an electronic boost controller to prevent spike now?

I have an mn triton
Cheers

Not always, is sort of a double evil with these things, you will make slightly more boost with added fuelling (depending on chip as some either cut down after a burst or have already taken fuel out of top end) and free flow exhaust with out clipping the electronic boost curve. So long as the ECU can catch it, and then the VGT aspect ratio allows the boost to stay under 22psi and then run closer to 18 psi while you have the boot in, you will have no dramas. However, the EGT's will could a bit depending on the fuel curve on that chip your running.

The double evil is, if we clip the numbers on the MAP sensor, the boost target will become higher before the ECU tells the electronic over vacuum boost controller to move the VGT out of attack.

Ok don't want to sound like an idiot but i have no idea what all this meant.
Chip is a tunit
exhaust is 3 "
What would you do in my situation?
If you can simplify it to the extent where you just say
Get this and get that it would be much easier for me to understand as I'm not too familiar with the stuff you mentioned above

oh and by the way thanks for getting back to me