[ksfrogman]

During this DIY, I am replacing my existing Dinan Throttle Valve Body with another one. Although this baseline install starts with an existing GruppeM intake, I will include BMW's photos of the OEM filter housing as well.

The instructions to change out the OEM throttle valve body assembly are the same.

Time required: Approx. 40 minutes.

Tools needed:

Stubby slotted screwdriver
Small slotted screwdriver
Larger slotted screwdriver
Torx screwdriver (not shown) - for OEM filter housing
Phillips screwdriver - for GruppeM intake
10mm socket and 3/8-inch drive ratchet

Dinan throttle body is in the ziplock bag


Removing OEM filter housing:

Unlock plug (1) and remove. Release clamp and detach air intake hose (2).



Unlock air intake hose (1) sideways and detach. Release bolts. Remove intake filter housing (2) towards top.



Removing Gruppe M Intake:


Locate the phillips screwhead bolt near the driver's side strut tower and remove it.


Unplug and remove the connector to the air mass flow sensor.



Disconnect (retract) the air inlet hose from the CF housing.


This is what the GruppeM intake looks like removed from the car.



The engine compartment with the intake removed.


Loosen this clamp using a slotted screwdriver.


Air intake tube with silencer.




Back to the engine compartment, look at the remaining intake tube elbow that attaches to the throttle body. Remove the tiny air hose shown in the following diagram (red arrow). Pull this hose in the direction of the yellow arrow.


Loosen clamp that attaches the intake pipe elbow to the throttle valve body.


Remove the elbow.



Now you can see the throttle valve body.


Remove this connector. This is what conveys the electric signal to open the throttle valve.


Remove the 4 bolts shown here from the throttle body assembly (2). The plug that you should remove is shown in (1). Remove throttle assembly.


When reinstalling the throttle assembly (2), make sure to replace the sealing ring (1). The Dinan unit comes with a new sealing ring.




To reinstall, do the above in reverse.

[arcrox]

Have you dynoed it yet?

[ksfrogman]

Some caveats

- It helps to have good lighting. I use a retractable fluorescent shop light.

- You must remove the plastic elbow from the throttle assembly in order to access the bolt on the upper right hand corner. It follows that when you are reinstalling, you must attach the throttle assembly to the air inlet of the intake manifold before you put this elbow on.

- The plastic elbow is a critical part that must snap into place! Since you are working somewhat blindly when attaching this piece back, you may want to practice attaching the plastic elbow to the throttle body and removing it before the actual reinstall.

- Don't forget to reconnect the air hose and electrical plugs. Without them, your throttle valve will remain closed, or your MAF will not function.

The $500+ question

If you take a close look at the last photo above, the inlet diameter of this collector (as it turns) for intake air seemed more narrow than the diameter of the throttle valve assembly bore.

One would intuitively question whether the throttle body bore is the most restrictive component for the flow of intake air.

See brightened photo attachment below.

Originally Posted by arcrox

Have you dynoed it yet?

I did this on Thanksgiving morning. Turkey, gravy, mashed potatoes, wild rice, cranberries, corned bread and pumpkin pie, and days of leftovers before re-dyno next week.

[txusa03]

I dont get it? I read all your comments but it seems like you replaced one dinan for anther dinan. why? what is the diff between the one already in the car vs the one in the ziplock bag? I am not a mechanic so I do not understand. How much for the part as well?

[just4kickz]

nice write up... alotta work tho haha

[ksfrogman]

Originally Posted by txusa03

I dont get it? I read all your comments but it seems like you replaced one dinan for anther dinan. why? what is the diff between the one already in the car vs the one in the ziplock bag? I am not a mechanic so I do not understand. How much for the part as well?

The 1st Dinan unit produced lower than expected dyno results. Click on the dyno link in my sig. Intuitively, this did not make sense unless the modded throttle valve was not opening correctly. Other variables secondary to DME inputs from the multitude of sensors (e.g., radiator outlet temperature sensor, charge air temperature sensor, coolant temperature sensor, evaporator temperature sensor, fuel temperature sensor, exhaust backpressure sensor, intake pipe pressure sensor, engine collant temperature sensor, blah blah blah) may be at play. I refer you to the previous thread and links to Steve Dinan's white paper regarding Dynamometer Testing and the Modern BMW Engine.

This seems to be the logical next step.

[mosport70]

Outstanding write-up. Quality post as usual frogman.

Surely this will find its way to the DYI file!

[RodyP]

can we delete the silencer in the air intake pipe and does it have an big effect

[ksfrogman]

Originally Posted by rody

can we delete the silencer in the air intake pipe and does it have an big effect

That would be a nice project for you. Buy a spare intake pipe and plug up the hole. I'd be careful not to use anything that would dislodge and ruin your engine. It would have to form an airtight seal, be durable, withstand some heat, and adhere to the plastic composite material.

Do it and let us know how it sounds.

[RodyP]

i will do it next week, can't wait for the results, how does the trottle body preforms ? i'm considering it

[ksfrogman]

Originally Posted by rody

i will do it next week, can't wait for the results, how does the trottle body preforms ? i'm considering it

I can't tell at all. The open differential mod made a huge difference, but the throttle body swap seemed so inert that only a dyno might reveal a change.

One more idea you might consider. You could use a metal flat washer and long bolt. This would plug up the hole, and you wouldn't have to worry about pieces dislodging into your intake. You might use high temp silicone to seal off the other end of the bolt to which you would fasten a locking nut or nut/lock washer.

Here's an "x-ray" drawing:

[RodyP]

thanks for these ideas.. i will make a d.i.y when i'm done i'm thuesday at my local body shop so i will try, where dit you get the open diff ?

[Jason]

Great write-up Michael, thanks for sharing. Added to DIY master list - http://www.e90post.com/forums/showthread.php?t=1721

[///Matt]

Originally Posted by ksfrogman

I can't tell at all. The open differential mod made a huge difference, but the throttle body swap seemed so inert that only a dyno might reveal a change.

One more idea you might consider. You could use a metal flat washer and long bolt. This would plug up the hole, and you wouldn't have to worry about pieces dislodging into your intake. You might use high temp silicone to seal off the other end of the bolt to which you would fasten a locking nut or nut/lock washer.

Here's an "x-ray" drawing:

This would cause a turbulence in the intake flow... no good. If you found a way to make the portion of the bolt/washer that protrudes into the intake boot flat, then cool.

Also, speaking of turbulence, that's the secondary job of the silencer. It lowers noise AND acts as a buffer for intake pulses.

[ksfrogman]

Originally Posted by ///Matt

This would cause a turbulence in the intake flow... no good. If you found a way to make the portion of the bolt/washer that protrudes into the intake boot flat, then cool.

Also, speaking of turbulence, that's the secondary job of the silencer. It lowers noise AND acts as a buffer for intake pulses.

Good info. If you look at the inside of the pipe, it's anything but completely smooth, particularly with the ridges from the telescoping plastic. The portion that the bolt head would rest would be contained within the recessed area, not protruding into the air channel. Of course, a flat, and round bolt head would be better than a hexagonal one that protrudes.

[///Matt]

I agree that the inside of the boot is not exactly flawless, but keep in mind that it's tuned, and engineered, to run the way it does. =)

[ksfrogman]

Another interesting observation is that the Fujita intake, which several believe actually decreased power, replaces this entire piece with a metal tube. The Fujita adapter that goes into this pipe to the throttle assembly is very cheap looking with the same inner diameter on either side of the adapter, despite the different outer diameter male ends that attach to the adapter. The additional variable is that the Fujita has its own opening for the MAF sensor.

[uhaulball]

so are u saying the fujita performed poorly because of the lack of a silencer?

[raybenz2011]

Originally Posted by ksfrogman

The 1st Dinan unit produced lower than expected dyno results. Click on the dyno link in my sig. Intuitively, this did not make sense unless the modded throttle valve was not opening correctly. Other variables secondary to DME inputs from the multitude of sensors (e.g., radiator outlet temperature sensor, charge air temperature sensor, coolant temperature sensor, evaporator temperature sensor, fuel temperature sensor, exhaust backpressure sensor, intake pipe pressure sensor, engine collant temperature sensor, blah blah blah) may be at play. I refer you to the previous thread and links to Steve Dinan's white paper regarding Dynamometer Testing and the Modern BMW Engine.

This seems to be the logical next step.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
One quick Question Sir Ks frog man! Did it Help and Where are the pics????? or could it have been cleaned?? and you missed a sensor like the infamous mass air flow sensor blah

[jokers_greg]

Originally Posted by raybenz2011

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
One quick Question Sir Ks frog man! Did it Help and Where are the pics????? or could it have been cleaned?? and you missed a sensor like the infamous mass air flow sensor blah

+1 for this thread revival

[willfx]

When I replaced the Throttle Body for my e90 320d it made a huge difference.
Didn't knew, but my old one it was broken I think since now the car works smoother.

[SID2GO]

Originally Posted by ksfrogman

During this DIY, I am replacing my existing Dinan Throttle Valve Body with another one. Although this baseline install starts with an existing GruppeM intake, I will include BMW's photos of the OEM filter housing as well.

The instructions to change out the OEM throttle valve body assembly are the same.

Time required: Approx. 40 minutes.

Tools needed:

Stubby slotted screwdriver
Small slotted screwdriver
Larger slotted screwdriver
Torx screwdriver (not shown) - for OEM filter housing
Phillips screwdriver - for GruppeM intake
10mm socket and 3/8-inch drive ratchet

Dinan throttle body is in the ziplock bag


Removing OEM filter housing:

Unlock plug (1) and remove. Release clamp and detach air intake hose (2).



Unlock air intake hose (1) sideways and detach. Release bolts. Remove intake filter housing (2) towards top.



Removing Gruppe M Intake:


Locate the phillips screwhead bolt near the driver's side strut tower and remove it.


Unplug and remove the connector to the air mass flow sensor.



Disconnect (retract) the air inlet hose from the CF housing.


This is what the GruppeM intake looks like removed from the car.



The engine compartment with the intake removed.


Loosen this clamp using a slotted screwdriver.


Air intake tube with silencer.




Back to the engine compartment, look at the remaining intake tube elbow that attaches to the throttle body. Remove the tiny air hose shown in the following diagram (red arrow). Pull this hose in the direction of the yellow arrow.


Loosen clamp that attaches the intake pipe elbow to the throttle valve body.


Remove the elbow.



Now you can see the throttle valve body.


Remove this connector. This is what conveys the electric signal to open the throttle valve.


Remove the 4 bolts shown here from the throttle body assembly (2). The plug that you should remove is shown in (1). Remove throttle assembly.


When reinstalling the throttle assembly (2), make sure to replace the sealing ring (1). The Dinan unit comes with a new sealing ring.




To reinstall, do the above in reverse.

could you repost the images please