intake manifold coolant bypass

[sacramentophil]

I'm figuring this is how BMW decided to heat the intake air, right?
http://memimage.cardomain.net/member_images/6/web/642000-642999/642770_16_full.jpg
Is there any problem with bypassing it? There's no other "hidden" function that I'm not aware of, is there?

[hotdog19d]

why do you want to bypass it?

[sacramentophil]

It's an old trick to get more power, by lowering the intake air temperature.
here's a li'l more info: http://www.s2000.org/Trooper/manifold/

I'm just not familiar enough with this Bimmer, so I want to make sure I'm not going to mess mess anything up. It's always something that you don't even know you don't know that'll come back to bite you in the arse.

Like that gizmo on the other side of the piece in the photo, the vent valve I believe. Does it need the heat from those coolant lines in order to do its job? What if it didn't have that heat?

[sacramentophil]

Another question...does anyone know who sells a phenolic or teflon insulating spacer for the M44s intake manifold (keeps the IM cool where it's bolted to the hot cyl. head)? It only makes sense to do both of these mods at the same time.

[GDB]

Another question...does anyone know who sells a phenolic or teflon insulating spacer for the M44s intake manifold (keeps the IM cool where it's bolted to the hot cyl. head)? It only makes sense to do both of these mods at the same time.

I have been looking and have not found anyone that sells a phenolic spacer. Although there are a few places that sell sheets of phenolic material.

[Jared]

I'm figuring this is how BMW decided to heat the intake air, right?
http://memimage.cardomain.net/member_images/6/web/642000-642999/642770_16_full.jpg
Is there any problem with bypassing it? There's no other "hidden" function that I'm not aware of, is there?


The picture isn't working at the moment, are you talking about the coolant lines that run through the throttle body?

[sacramentophil]

No, they run through the little plate that's sandwiched between the upper and lower halves of the IM.

I didn't find any coolant lines on the TB...did I miss something?

[TiPerformance]

Shouldn't have a problem with just bypassing the coolant lines and leaving the spacer on there. I believe the spacer also serves as a Oil seperator, which is the black thing.

As for the spacer I haven't heard of anyone making one for the M44, After market parts are almost non existant for the m44. Everything has to be custom made.

[KIRASIR]

1) The heater is not used to heat the air. It is there to prevent the build-up of ice on the insides of the manifold.

2) Even if the heater does raise the temperature by .xx degrees, the adaptation algorithm in the ECU will remove any gains you could've archived with this mod.

You are wasting your time.

SL

I'm figuring this is how BMW decided to heat the intake air, right?

Is there any problem with bypassing it? There's no other "hidden" function that I'm not aware of, is there?

[sacramentophil]

1) The heater is not used to heat the air. It is there to prevent the build-up of ice on the insides of the manifold.

2) Even if the heater does raise the temperature by .xx degrees, the adaptation algorithm in the ECU will remove any gains you could've archived with this mod.

You are wasting your time.

SL

1) I'm aware of the intent, but I'm in no danger of having ice build up in my junk. Therefore, I would like to prevent the secondary effect of this design, which is to rob power.
2) This is a basic tuning mod which everybody from the ricers, off-roaders, and Mustang Johnny has been doing for a long time.

Following your logic, I suppose an intercooler is a waste of time for a turbocharged engine?

[KIRASIR]

a) These ricers, off-roaders, and Mustangs do not use the same ECU as we do.

b) Show me a dynosheet where any gains were made by disconnecting t/b heater.

c) Compaing a t/b heater to an intercooler is like comparing applies and oranges. One is a tiny plate with barely any surface area while the other one is a huge heatsink.

Don't take it too personally. Your time is your own to spend.

However, think about this: if these cars show zero gains after 'upgrading' to CAIs, cat-backs, etc.; Do you really think you will get any HP by removing the t/b heater?

Unfortunately (sometimes fortunately), our ECUs dynamically adapt the mixture based on the environment. This holds true at WOT as well. Some of the tricks that used to work with older, simpler ECUs no longer work.

Cheers,

SL




2) This is a basic tuning mod which everybody from the ricers, off-roaders, and Mustang Johnny has been doing for a long time.

Following your logic, I suppose an intercooler is a waste of time for a turbocharged engine?

[sacramentophil]

Okay, I'm sure you're more familiar with these engines/ECUs than I am. I've only had this car for about a month and it doesn't even run.
So, is there no intake air temp. sensor that the ECU would use to adjust the amount of fuel accordingly?
I've decided that I will leave the coolant lines intact, because I will drive this car to Tahoe, Seattle, etc. and I don't want my throttle plates freezing open.
But, I would like to use a phenolic or teflon spacer where the lower IM bolts to the head...sort of a compromise.
Thanks for your input.

[KIRASIR]

There is a temp sensor in the air box that is used for some of the calculations.

The point is that pretty much no matter what you do, the ECU will adjust your mixture to the settings that are most efficient (fuel, emissions, etc) for a given environment. You can slap a brand new sparkling high flow exhaust on your car, dyno it, see the gains of 5 hp then dyno it again in couple of days and see absolutely no difference from stock or in some cases even lower hp numbers. This thing is way too smart. :)

My advice to you is to start saving for DASC or some other forms of FI. :D

The manifold spacer is a good idea but the end results are questionable for the same reason as the t/b heater. Also If I remember correctly there is already some kind of a gasket between the head and the manifold.

SL





Okay, I'm sure you're more familiar with these engines/ECUs than I am. I've only had this car for about a month and it doesn't even run.
So, is there no intake air temp. sensor that the ECU would use to adjust the amount of fuel accordingly?
I've decided that I will leave the coolant lines intact, because I will drive this car to Tahoe, Seattle, etc. and I don't want my throttle plates freezing open.
But, I would like to use a phenolic or teflon spacer where the lower IM bolts to the head...sort of a compromise.
Thanks for your input.

[GDB]

There is a temp sensor in the air box that is used for some of the calculations.

The point is that pretty much no matter what you do, the ECU will adjust your mixture to the settings that are most efficient (fuel, emissions, etc) for a given environment. You can slap a brand new sparkling high flow exhaust on your car, dyno it, see the gains of 5 hp then dyno it again in couple of days and see absolutely no difference from stock or in some cases even lower hp numbers. This thing is way too smart. :)

My advice to you is to start saving for DASC or some other forms of FI. :D

The manifold spacer is a good idea but the end results are questionable for the same reason as the t/b heater. Also If I remember correctly there is already some kind of a gasket between the head and the manifold.

SL


The phenolic spacer should work. The ecu should not adapt anything besides adding more fuel. It would have the same effect as driving your car on a cooler day. And the gasket that is already there does little to nothing to prevent heat soak.