[SDemetris]

Originally Posted by cuco

Hmm, so it requires some additional machining and fab. Can anyone with a spare TB take it apart and take pictures of the butterfly assembly?

I just did with my phone so theyre not great quality. Idk what tool i would need to take apart the butterfly. ill mess with it tomorrow or something. Let me know if you want me to take some more from any angle

[SDemetris]

ok so i took the plastic cover off the gears that connect the electric actuator to the flap. i can just take off the idler gear between them but i cant find a way to remove the gear that is on the same shaft as the flap. i think im just going to get a little violent with it and see if nothing breaks. its not really worth much anyways. ive never heard of anyone's going bad and needing a replacement

[cuco]

Thats a weird looking TB, lol. Can you take pics of the harness plug and the side of the TB showing the shaft that holds the butterfly? Update: take pics of the gears! Thanks.

I found this thread were a guy measured the ID of the TB vs. the ID of the intake manifold inlet part that connects to the TB. The TB is ~77mm and the intake inlet is ~79mm. This means the intake could make good use of a 79mm TB.

http://www.e90post.com/forums/showthread.php?t=819355

[SDemetris]

Pictures of the gears

[cuco]

Nice! Looks like the butterfly is plastic with a metal core. I'm wondering if it snaps on/off the shaft.

[mapleridge]

Jokers_greg just brought to my attention that the TB between the 330i and the 328i are different. Anybody compare the two?

[Surly73]

Originally Posted by SDemetris

Actually that is not necessary in our cars since the tb is open all the time. we dont need the plate at all in reality. but for every other car that isnt a n52/n55, yes that would have to be done

As I read through this whole thread I was thinking ^this^.

Valvetronic means the t-body is there only to build initial vacuum and as a failsafe for Valvetronic failure. I'd be pretty skeptical that BMW would have undersized an open-all-the-time throttle body to create a restriction.

[cuco]

Originally Posted by mapleridge

Jokers_greg just brought to my attention that the TB between the 330i and the 328i are different. Anybody compare the two?

yeah, from what I've read on other posts, the plug is different and the buttefly on the 330 is the traditional design (metal plate with screws).

Originally Posted by Surly73

As I read through this whole thread I was thinking ^this^.

Valvetronic means the t-body is there only to build initial vacuum and as a failsafe for Valvetronic failure. I'd be pretty skeptical that BMW would have undersized an open-all-the-time throttle body to create a restriction.

I don't think it's undersized, I think it's the size BMW agreed would be correct for the amount of CFM the engine is able to handle in stock form.

I've also read that the butterlfy works as a failsafe for valvetronic failure. So in theory, a 328 stock TB can be bored a couple of mm's bigger without having to modify the buttefly diameter. My concern is, how will it work if there's valvetronic failure?

[mapleridge]

Originally Posted by cuco

yeah, from what I've read on other posts, the plug is different and the buttefly on the 330 is the traditional design (metal plate with screws).

Did you read anything about the diameter?

[SDemetris]

maybe the reason dinan only has the TB listed under the 330 is because its the only one that the plate easily comes off of b/c it screws on as someone said. Just a though

[cuco]

Originally Posted by mapleridge

Did you read anything about the diameter?

Yeah it's also 76mm, same as ours.

Originally Posted by SDemetris

maybe the reason dinan only has the TB listed under the 330 is because its the only one that the plate easily comes off of b/c it screws on as someone said. Just a though

+1

Hey did you have any luck removing the shaft and butterfly? I was thinking that maybe the shaft and gear would slide off after removing the butterfly.

[SDemetris]

Originally Posted by cuco

Hey did you have any luck removing the shaft and butterfly? I was thinking that maybe the shaft and gear would slide off after removing the butterfly.

I pretty much put all my weight (like 200lbs) on either side of the butterfly, hoping it would snap off the shaft. I think the flap is a thin sheet of steel ( you can kind of see it in the holes in the black plastic) that has 3 pairs of little tabs that were CNC welded onto the central shaft. It would be a real PITA to get that off. It would be possible to grind the tabs off, bore out the TB then weld the flap back on.. Or i suppose if you're feeling really bold you could just cut it off and leave it like that.

[cuco]

Originally Posted by SDemetris

I pretty much put all my weight (like 200lbs) on either side of the butterfly, hoping it would snap off the shaft. I think the flap is a thin sheet of steel ( you can kind of see it in the holes in the black plastic) that has 3 pairs of little tabs that were CNC welded onto the central shaft. It would be a real PITA to get that off. It would be possible to grind the tabs off, bore out the TB then weld the flap back on.. Or i suppose if you're feeling really bold you could just cut it off and leave it like that.

I did notice that the shaft itself is pretty beefy with the tabs, also the back portion of the flap has a rib structure that makes the whole butterfly assembly beefier than a traditional butterfly assembly. All of that translates to less air volume passing through the TB.

[andrey_gta]

reference to Dinan TB
http://www.e90post.com/forums/showth...t=dinan+intake

take not how the casing looks different, no clips & how flap is attached

My 128i's flap was metal, not the plastic style

[kimoboy]

Any update, has anyone bored their N55 TB.

[rjahl]

Before you guys go nuts here, take a look at the attached data log from a Z4 with a stock induction system and about 10,000 miles on a Mann filter.

This is measured in the manifold by the stock MAP sensor. It's a little jumpy but it shows that the stock induction works pretty well. The car is consuming something like 730-740 Kgs of air per hour at the top end.

You can work out the HP loss from the pressure drop and its not much. Changing one component is not going to make a noticeable difference.

I don't see the throttle body or the stock air filters limiting anything on a stock motor. A better manifold can help at the high RPMs but you will lose at the bottom end IE, the N54 manifold swap that's been discussed on another thread.

Do your own research.

BTW, I think the the throttle bodies (328/330) are incompatible electrically. Different signal system to the DME. MSV70 vs. MSV80

[Rival]

in past cars no one ever really saw gains unless they were FI engines or max NA builds.

IDK for sure tho, but this is one of the last upgrades id be buying.

[BudVlad]

N54 TB is slightly larger and it bolts directly on N52/N53 manifold. Electrical connector is the same. I had it on my N53 manifold and it works. I have N54 TB because I’ll be installing N54 intake manifold.

[stewey]

In the land of charcoal deletes and rev motoring tubes would it make any sense to remove the flap and shaft altogether?

[rjahl]

Originally Posted by stewey

In the land of charcoal deletes and rev motoring tubes would it make any sense to remove the flap and shaft altogether?

Not a good idea. If the DME senses any fault with the sensors the Valvetronic will go to the default failsafe setting at full throttle or full lift.

The throttle body is then the only control and Without a working throttle body things could could get really interesting.

[stewey]

Haha um, yeah that could be interesting!

[rjahl]

Originally Posted by stewey

Haha um, yeah that could be interesting!

Oh ya, forgot to mention.

You will not gain any power by removing the throttle plate.

I seriously doubt a larger throttle body will do anything either. At least not on a stock motor.