[Taskmaster]

Originally Posted by Three_thirty_I

You will need an OBC2 cable (K+DCAN) and then search google for INPA - there are loads of active links. Alternatively, most online sold cables include INPA and various other tools.

Well, I know what I'm doing tonight! Thank you so much everyone!

[Taskmaster]

Found the problem I believe - DISA #1 is stuck in the open position. The flap should be closed by default, correct?

[mike-y]

the flaps are actually open when the car is off, but immediately close when the car is turned on. so if it's not closing, it sounds like it isn't receiving power, or is just not working at all.

before I installed the 3-stage IM, I had the two DISAs sitting on top of my stock manifold, plugged in to the harness, and I watched how they worked when I revved the engine.

car off = both disas open
car on = both disas close

at idle and low rpm, both Disas should be closed.
small disa opens at ~3200* rpm or abouts and stays open above that
large disa opens at ~4200* rpm or abouts and stays open above that.

*note I did this a couple years ago and don't remember the exact rpms.


Also, NEW Disa valves bought from BMW will ship in the CLOSED position. Once they are connected to power and are cycled once, they will then default to the open position afterward, when power is off.

[Taskmaster]

I think this one is stuck open, it won't move at all. No way I can test it without another E90 - so I guess I'm going to try and replace it and hope for the best.

It would explain why my dyno looks how it does though.

[mike-y]

yeah, if the little one is stuck open, you'd lose low end power. good luck!

[Three_thirty_I]

Sounds about right mike-y. When I replaced both DISA actuators, both the new actuators were in the closed position (to prevent damage while not fitted).

Both new DISA actuators as they were when I bought them.



Now this is interesting. Here is the large DISA actuator, new on the left and old on the right. Old one is open which corresponds with what you said above in terms of being in this position when the engine is off.



But now here is the small DISA actuator, again, new on the left and old on the right. Both are closed which does not follow what you said above. It was then supposed to be open. So now I am wondering if that one was indeed faulty. The green rubber gasket around the flap on both sides had pieces missing as you can see.



Before I bought the new parts when I was still trying to confirm that I had an issue with the DISA actuators, I had tested their function via INPA and was able to get each actuator to open and close, which you can hear in the vid above. But now I wondering why the small one was still in the closed position when I took it out. I didn't close it with my fingers or anything like that, and the car had run as normal before the job was done. I wonder if it was not intermittent - that is, sometimes I would feel a distinct loss of power from pretty much 3200 rpm to 4500 rpm or there abouts.

[Taskmaster]

Well, the small DISA (#2) opens first, at 3200RPM. You can see it on my graph, the small one is actually functioning and opening at that point. The larger DISA (#1) should only open at 4400RPM - mine is ALWAYS open. Meaning that there is a surplus of air from idle to 4400RPM which shouldn't be there, it also explains why when #2 opens, the powerband goes flat until 4500RPM when the runners should be completely open anyhow.

No idle issues here, just a flat powerband.

[Three_thirty_I]

Originally Posted by TheAxiom

Well, the small DISA (#2) opens first, at 3200RPM. You can see it on my graph, the small one is actually functioning and opening at that point. The larger DISA (#1) should only open at 4400RPM - mine is ALWAYS open. Meaning that there is a surplus of air from idle to 4400RPM which shouldn't be there, it also explains why when #2 opens, the powerband goes flat until 4500RPM when the runners should be completely open anyhow.

No idle issues here, just a flat powerband.

Well, it would definitely be affecting the desired induction, I am not sure if in straight forward terms it would mean or result in a surplus of air at all revs up until 4500 rpm when it is supposed to open. I don't understand it enough, but in my view, the combination of engine speed (breathing) and which flap is open and which is closed will affect the intake resonance. So if that large flap is stuck open it will most likely cause what you have here.

Since it is more accessible than the smaller DISA actuator, you could remove it and test it visually with INPA. Or for that matter, I am sure you could block the hole where it fits, and run the engine to see what it's doing. But, I would firstly see if it IS actuating or not when told to via INPA, then try and work out why the DME is not controlling it.

[Taskmaster]

I bought a new valve and plugged it in, turned on the car and it closed instantly. Now to install it...

[Taskmaster]

F***. I just took out the old and put in the new - the OLD ONE WORKS...
But I replaced it anyhow, and the new one works...better? The low end seems to have gotten sharper and the midrange meatier. As for the changeover, I still don't hear it, but the delivery seems more linear.

We'll see what dyno says.

[Three_thirty_I]

Originally Posted by TheAxiom

F***. I just took out the old and put in the new - the OLD ONE WORKS...
But I replaced it anyhow, and the new one works...better? The low end seems to have gotten sharper and the midrange meatier. As for the changeover, I still don't hear it, but the delivery seems more linear.

We'll see what dyno says.

So I wonder what was preventing the old from working? Glad that you have it working now though! I had a suspicion that the low end would also be better. As for the changeover sound, I cannot say that I have ever been able to notice it, just a general increase in induction and exhaust noise overall.

The acid test would be a follow-up dyno run to see what is happening on the power/torque curves...

[Taskmaster]

Originally Posted by Three_thirty_I

So I wonder what was preventing the old from working? Glad that you have it working now though! I had a suspicion that the low end would also be better. As for the changeover sound, I cannot say that I have ever been able to notice it, just a general increase in induction and exhaust noise overall.

The acid test would be a follow-up dyno run to see what is happening on the power/torque curves...

I actually have no idea, because I would love to have the money I spent on a this one back. I'm going to invest in the cable as well as the software just for any future issues I might run into.

I'll say this though, now the car feels as good (if not better in some places) than it did when I had the tune on it, I wonder what it will be like if I reinstall it?

Going to try and dyno the car this week and see what the final verdict is.

[avocet]

My 3 stage had an obnoxious flat spot that, at around 4500rpm, would ramp up so hard it would trigger traction control in the wet.

This was with aa tune. Before the tune I had a pbx with no issues working with the 3 stage.

I was ready to the the tune it was so shitty. AA never responded to any I my inquiries.

I reset ALL adaptations and went on a several hundred km high speed road trip. Problem solved. My car drives like it had a different engine.

[Taskmaster]

Originally Posted by avocet

My 3 stage had an obnoxious flat spot that, at around 4500rpm, would ramp up so hard it would trigger traction control in the wet.

This was with aa tune. Before the tune I had a pbx with no issues working with the 3 stage.

I was ready to the the tune it was so shitty. AA never responded to any I my inquiries.

I reset ALL adaptations and went on a several hundred km high speed road trip. Problem solved. My car drives like it had a different engine.

I don't have a cable to reset adaptions, so I'm SOL anyhow. I'm going to rent some dyno time on Wednesday or Thursday and see what's up.

[Taskmaster]

On the dyno now, we'll see.

[Taskmaster]

Torque and mid are up compared to last dyno, and that's without the tune.

[Taskmaster]

No idea dude, because my car LOST power. Fuck this, I'm going back to stock.

[Three_thirty_I]

Sorry, a copy and paste from your other thread:

For this to work properly, shouldn't one have the software upgraded to make use of the 3-stage intake? Honestly asking since I am not really sure myself but would think that this would be the case...

As it stands, it does seem that stock was a lot better and more linear.

[Taskmaster]

You should make more power with or without a tune. I didn't.

[Three_thirty_I]

Originally Posted by TheAxiom

You should make more power with or without a tune. I didn't.

Hmm, that's strange then. Is there not someone with a similar car and conversion that you can do a direct comparison?

[AMG KLR]

Originally Posted by TheAxiom

You should make more power with or without a tune. I didn't.

Get a tune then give up!

[Taskmaster]

I have one already, contacted AA and going from there.