Inlet piping

Does anyone know what this is or does?

Thinking of doing a hard pipe upgrade, but was wandering what the purpose of this tube is.

Thanks.

Have you had the tube off? Does it contain a sensor?

hey mate its just another restrictor.

"Great Scott!"
"Its the flux capaxitor Marty! Don't touch that or you'll upset the whole space time continuum!"

Nah no idea. Pull it off and see what's in it. Is it some sort of pollution gear?

it is just like a muffler except on the intake. There to keep noise down, though I highly doubt you will notice it gone. They are quite restrictive too as the inside of em is certainly not smooth and good for flow.

Rip it.

It not a sensor of any type, although it does collect oil vapour from the P.C.V.
I was surprised to see how much oil was in the intake piping, I will certainly be adding a catch can too.
Cheers

Ahh. If that's restrictive, removing it will add induction and turbine noise to what you hear when you hit the accelerator.

Don't touch the red button, Marty.

Edit: the manual says it's just part of the air inlet piping. It knows it's there, but doesn't define it. It's apparently part of the "Charge Air Cooler" (intercooler) unit, not the turbo or inlet manifold.

Most little bits and pieces like that restrictor are placed by factory on purpose so when the next model comes out if they want to up the power all they need to do is create some smoother plumbing for better air flow and other little tweak secrets they have.
When i spoke with a mazda dealer years ago i asked him about the diesel engines in the mazdas, he told me that the engines were designed with over 140kw of power in them but they were detuned so for future models to extract more power they did not have to design a new engine as yet.

I wouldnt be suprised if they use something along the lines of a dp chip built into the car to get more power on newer models.

SOLID D22 said:

Most little bits and pieces like that restrictor are placed by factory on purpose so when the next model comes out if they want to up the power all they need to do is create some smoother plumbing for better air flow and other little tweak secrets they have.
When i spoke with a mazda dealer years ago i asked him about the diesel engines in the mazdas, he told me that the engines were designed with over 140kw of power in them but they were detuned so for future models to extract more power they did not have to design a new engine as yet.

I wouldnt be suprised if they use something along the lines of a dp chip built into the car to get more power on newer models.

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I would believe that too, The new jeep wrangler (auto)has being upgraded from 410Nm to 460Nm by what seems like no more than a tuning tweak.
I'm not after power just less lag and more throttle response, I've just installed a full 3" exhaust system that disapointingly seems to have only improved top end power.

Old.Tony said:

Ahh. If that's restrictive, removing it will add induction and turbine noise to what you hear when you hit the accelerator.

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That's OK It will be drowned out by the dash and door rattles.

Get the turbo hi flowed and make it a ball bearing turbo, that will help with the lag.

SOLID D22 said:

Get the turbo hi flowed and make it a ball bearing turbo, that will help with the lag.

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Not sure what you mean by hi flowed, but I believe they are already a ball bearing turbo.

High flowing on a petrol engine means they typically enlarge the nozzle size in the turbine housing (Reducing the housings AR, aspect ratio) Presumably on deisel it will be much the same

That raises the boost threshold as you have lower exhaust gas speed onto the turbine for a given amount of flow, but you also reduce back pressure in the exhaust manifold so when you do get boost you get more power at the same boost level provided your fuelling is right.

SOLID D22 said:

Most little bits and pieces like that restrictor are placed by factory on purpose so when the next model comes out if they want to up the power all they need to do is create some smoother plumbing for better air flow and other little tweak secrets they have.
When i spoke with a mazda dealer years ago i asked him about the diesel engines in the mazdas, he told me that the engines were designed with over 140kw of power in them but they were detuned so for future models to extract more power they did not have to design a new engine as yet.

I wouldnt be suprised if they use something along the lines of a dp chip built into the car to get more power on newer models.

Click to expand...

X files stuff there.
It is more than likely there for the primary purpose of stifling induction noise to meet ADR or Californian noise pollution regs.
Solid, without a doubt you have had your head over an open carburettor on a Hemi and understand the next statement.
Induction noise is louder than exhaust noise. Combined though they will be beoyond the specified DB on a drive by test.

Do the Overseas variants of the D40 have that?

the_bluester said:

High flowing on a petrol engine means they typically enlarge the nozzle size in the turbine housing (Reducing the housings AR, aspect ratio) Presumably on deisel it will be much the same

That raises the boost threshold as you have lower exhaust gas speed onto the turbine for a given amount of flow, but you also reduce back pressure in the exhaust manifold so when you do get boost you get more power at the same boost level provided your fuelling is right.

Click to expand...

But isn't that what a VNT is doing anyway?

I spun with my fingers the turbine of a turbo that was hi flowed and had new roller bearings installed, it took about 20sec maybe more for the turbine to stop turning and it was easy to spin, i took hold of the same type of turbo but factory spec and tried doing the same thing, it was way harder to spin and stopped spinning in about 3 to 4 seconds. Big difference in getting a factory turbo to spool quick if its hard to spin in the first place, my mechanic is itching for me to do my turbo.

Aido i know your right about the induction noise, try revvin your nav with the air cleaner off, it makes a nice noise too.

Roller bearing turbos certainly spin easier. If the stock ZD30 is a bush bearing I would really consider changing it to a roller core for that exact reason. My track car has a ball bearing turbo and when it is warm you can hear it spin down for a long time after you switch the engine off. One thing is for sure, oil pressure really knocks the shaft speed around, I have been playing with my D22 to decide how much of the exhaust I want to replace and at one point I removed the system right back to the dump pipe outlet (The cat is a bugger to remove) That meant you could really hear the turbine noise. When you start it up you hear the turbine spool up significantly at idle and then just after the oil pressure light gos out, slow down noticeably. I assume they are a bush bearing job.

08KINGCAB, that is a lot of the effect of a VNT housing so high flowing a VNT would probably be far less worthwhile on the exhaust side, I have never seen one apart so I don't know if they still have something similar to a traditional nozzle as well as the VNT setup.

You can high flow the compressor side as well, but so long as the original one is fairly well matched to the engine to begin with it would probably not make a huge difference. Given that a TDI makes loads of boost at low RPM, you would probably have to select carefully to ensure that you did not get the compressor side into a surge area of the compressor map under load conditions. The deranged pigeon noises you hear a lot of rice boys cars making is compressor surge when they shut the throttle and you can actually get the turbo to do it under load if the compressor does not match the engine flow wise which is bad for performance and bad for the turbo. Compressor surge is basically just an aerodynamic stall of the compressor wheel blades.

Also, looking at Jasons ride thread, the YD25 in the D22 looks like a standard wastegated turbo rather than the VNT used on the D40/R51.

Would a wastegate solve the problem of the compressor surge?

It really depends. At low airflows even quite low boost levels can result in surge. The stupidly monstrous turbos you see on some over modified cars you may notice odd slots inside the compressor inducer/inlet, essentially they are used to bleed air back from the compressor outlet to the inlet so that the air flow rate through the compressor is increased. That effectively reduces the engine air flow required to keep it out of surge but it also reduces efficiency right across the working range.

It way well be possible to up the compressor size without surge, but on a stock ZD30 turbo the exhaust side is still likely to be the limiting factor, when you think of what airflow is required o produce 110 odd KW and then look at the nozzle in the turbine side where a ten cent piece would not fit where the exhaust gas has to go! If they hold boost right to the redline then it would be probably bypassing some through the wastegate though.