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DISA Valve alternative solution

40K views 18 replies 8 participants last post by  stylinexpat 
#1 · (Edited)
I've had the dip in the 4K RPM range in my 01' 330i just like everyone else. I had the ESS VT1 and it seemed to diverge from the ESS 330i test car with respect to horsepower. On the dyno, my car and the ESS test car would be even up until about 4K RPM and then the ESS car would take a substantial lead to redline (30 - 40 RWHP) The number one suspect was the DISA Valve. I replaced the DISA valve and zero'd my ECU knock adaptation. I then switched SC's to the ESS TX2, the car is running perfectly as well as the idle. One solution to the DISA valve is to simply remove it. The only real function of the DISA valve is to give you a little more torque at low end. I removed the DISA valve and did some tests. I didn't feel any loss in Torque and the car revved up to redline very smoothly, I didn't feel any stagger at 4K, only the dyno will tell the story. If you were to blindfold me, I couldn't tell you whether or not the DISA valve was hooked up below 3800 RPM's.
Technik came up with a very nice looking aluminum DISA hole cover to install should you remove the entire DISA valve assembly (5 minutes, and two torx screws) I have a different solution that is easy and allows you to keep the DISA valve inplace. The DISA valve is electrically held closed by the ECU (normal function is for the ECU to close the DISA valve from idle up to about 3800 RPM's) After 3800 RPM's, the DISA valve opens until redline. My solution is to leave the DISA valve in but simply remove the electrical connector. That way, the DISA valve will remain open all of the time and will not cause any problems with knock sensors "hearing" something and messing up the knock adaptation. When you remove the DISA valve or simply remove the connector, you will get a code but no CEL's or SES lights. The car is running great in open and closed loop. So, simply take the connector off of the DISA valve, try it out, if you don't like it, plug it back in. The only real way to completely solve the issue though, is to remove the DISA valve or connector and reset the knock adaptation. YMMV :str8pimpi
 
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#2 ·
Simply unplugging the connector won't do much (we tried this), since the flap is still in the path of incoming air and will create the "vibrations" (as noted in the April SB), which the ECU interprets as knock. You have to remove the flap itself from inside the chamber.

But either way, the DISA valve should not be a problem for cars with MS42 or MS43 (E46 MY 1999-2003.5), so you shouldn't have a major dip issue at 4K to begin with.
 
#4 ·
Mr Paddle.Shift said:
Alan dude,

EveryONE has the dip. Once you have to seen the dip caused by a MS45, then our MS43/MS42 dips will seem very trivial. There has been a long discussion about this a while back.

Thanks for the replies, just trying to help, I'll probably just remove the DISA valve and fabricate a cover like Technik manufactured...
 
#6 ·
A friend of mine here in Taiwan just asked me to try the following: He said that remove the DISA Valve cover and just remove the inside plastic flap part and put the stock cover back on again and it should be running fine. He says that this is waht they do here in Taiwan on the BMWS and they all seem to run just fine with no dip? I don't kknow about this , anyone here try this out?
 
#9 ·
stylinexpat said:
A friend of mine here in Taiwan just asked me to try the following: He said that remove the DISA Valve cover and just remove the inside plastic flap part and put the stock cover back on again and it should be running fine. He says that this is waht they do here in Taiwan on the BMWS and they all seem to run just fine with no dip? I don't kknow about this , anyone here try this out?
stylinexpat,
What I did was take the DISA valve out and cut off the flap and "cage" that it sat inside leaving a flat plate. The shaft isn't metal, it is plastic and can be cut with a hacksaw in about 2 minutes. I then took a Dremel and smoothed down the remining 2 3/4" round area. I put some epoxy in the center area of the plate to prevent leaks as well as a tiny holy near the edge of the round plate. I put a little blue gasket goo around the circumference and put the DISA valve back in. After 300 miles, I can't feel or hear the transition at 4000 RPM's nor notice a loss of torque down low. I am waiting for ESS to send me the correct pulley for my TX2 and then I will do a dyno and post the results, that should tell us alot.

DISCLAIMER: Technik and Mr. Paddleshift dude, not trying to question your info, I appreciate your responses.

I have a question. If this issue is purely software, then why is Technik making the CNC DISA cover plate??
 
#10 ·
thekubiaks said:
DISCLAIMER: Technik and Mr. Paddleshift dude, not trying to question your info, I appreciate your responses.

I have a question. If this issue is purely software, then why is Technik making the CNC DISA cover plate??
As has been discussed many times, this is not an MS42/43 issue...meaning all E46 from 1999-2003.5 DO NOT have this 4K dropoff in power. The DISA valve engages and disengages just fine on all non-MS45 cars. This is why getting rid of the valve on your car makes no sense...you don't have the problem to begin with.

I have a boosted 2002 330 running MS43 as well and the transition at 4000 is perfectly fine. It's the 2004 330 that has the problem, which is why we CNC'd this plate to verify if it's a hardware issue or software issue...clearly it's a software issue, since even with the DISA valve completely removed, there is still a dip at 4000, with timing retardation till 5000.

Therefore I strongly advise anyone with a 3-wire MAF E46 (this means you have MS42 or MS43) to leave your DISA valve alone and surely don't start hacking it to pieces.

For the 5-wire E46 crew, I would just sit tight and give us a little more time to break apart the code and see exactly what BMW wrote into the knock tables that causes this problem to begin with. The plate we have will get rid of most of the harsh dropoff @ 4K, but there is still a noticeable loss of power till 5000, with or without the DISA valve...especially under load in 3rd and 4th gear.
 
#11 ·
Solid said:
But it does help right, even it's a little? Might make a good interim solution, tell you fix it for us, or bmw does :)
If you can remove the flap without actually breaking the valve itself, then by all means experiment with it, however, if you don't have the ability to clear knock adaptation, then you will not notice any difference.

Either way, the DISA valve is a $250 part, which we plan on keeping as part of the SC system, so I wouldn't break it since you will need it if you decide to upgrade to our software down the road. We just have to sort through the incredible volume of data inside the DME to figure it out.
 
#12 ·
thekubiaks said:
stylinexpat,
What I did was take the DISA valve out and cut off the flap and "cage" that it sat inside leaving a flat plate. The shaft isn't metal, it is plastic and can be cut with a hacksaw in about 2 minutes. I then took a Dremel and smoothed down the remining 2 3/4" round area. I put some epoxy in the center area of the plate to prevent leaks as well as a tiny holy near the edge of the round plate. I put a little blue gasket goo around the circumference and put the DISA valve back in. After 300 miles, I can't feel or hear the transition at 4000 RPM's nor notice a loss of torque down low. I am waiting for ESS to send me the correct pulley for my TX2 and then I will do a dyno and post the results, that should tell us alot.

DISCLAIMER: Technik and Mr. Paddleshift dude, not trying to question your info, I appreciate your responses.

I have a question. If this issue is purely software, then why is Technik making the CNC DISA cover plate??
I think that it must have something to do with both of them because even when BMW changes the DISA Valve they have to change the software or reprogram at least. The guy here in Taiwan told me that it was the DISA Valve that caused the ECU to go off at 4000 RPM'S. I'm wondering if anyone did a DYNO before and after the DISA valve flap mod, so that we can see what gains if any were resolved by modifying this flap. Apparently though there are a few people out there have the ZHP car that do not have these dips. Is this problem in some ECU'S only or what? It's like some ECU'S out there have some Viruses or something in them. Technik, I would love to see a DYNO after that mod you came up with. Would be really nice if it showed an improvement. Count me as a cutomer for the part and any software tuning that has to go with it.
 
#13 ·
Andy,

I don't have to run a dyno, because I can still feel the loss of power at 4000 even with the DISA valve completely removed and all adaptation settings cleared.

The problem is software related. The DISA hardware hasn't changed since the E46 first came out in 1998/1999...therefore, something in MS45 causes this. We made the plate just to verify this and it's true.

I think BMW doesn't care to fix it, since they have already issue 3 bulletins on this and can't seem to get rid of it. The "improved" DISA valve listed in the last bulletin is the same exact part, there is no difference whatsoever, which leads me to believe BMW doesn't want to fix it or they can't. Who knows.
 
#14 ·
Don't know if this is related or not but I just took my car in for my 15K service and the rep told me they need to order a new DISA valve b/c mine was not opening and closing properly. I had complained about the dip and they updated the DME yesterday but they also need to replace the DISA valve.

They couldn't replicate the dip in a test drive but they updated the software nevertheless. I think enough Fanatics have gone in by now to request the software that my service rep already knew about the software upgrade.
 
#15 ·
Technik said:
Andy,

I don't have to run a dyno, because I can still feel the loss of power at 4000 even with the DISA valve completely removed and all adaptation settings cleared.

The problem is software related. The DISA hardware hasn't changed since the E46 first came out in 1998/1999...therefore, something in MS45 causes this. We made the plate just to verify this and it's true.

I think BMW doesn't care to fix it, since they have already issue 3 bulletins on this and can't seem to get rid of it. The "improved" DISA valve listed in the last bulletin is the same exact part, there is no difference whatsoever, which leads me to believe BMW doesn't want to fix it or they can't. Who knows.
Just to be perfectly clear . . .

For those of us with boosted 2001 330i's that feel a drop in torque at 4000 RPM, replacing the DISA valve with your manufactured replacement part will not do any good?
 
#16 ·
drhendrix said:
Just to be perfectly clear . . .

For those of us with boosted 2001 330i's that feel a drop in torque at 4000 RPM, replacing the DISA valve with your manufactured replacement part will not do any good?
It helped me out, I think my car runs better, but there are other opinions that say that it doesn't. I'm happy with how my car is running and won't put the DISA back in. YMMV
 
#17 ·
drhendrix said:
Just to be perfectly clear . . .

For those of us with boosted 2001 330i's that feel a drop in torque at 4000 RPM, replacing the DISA valve with your manufactured replacement part will not do any good?
You are supposed to feel a slight drop @ 4000, that is normal (see dyno below). 2001-2003 325/330s do NOT have a DISA problem. There is absolutely no reason to change anything. It will only rob some of your low-end if you take it out.

<img src="http://www.technikpower.com/dyno/sc/wyu_S1_tuned.jpg">
 
#18 ·
DISA valve opens at 3550 rpms. The SIBs talk about them being noisy (early cars) if thats the case unplug it while the engine is running and a noise would go away. MS45 cars have have small troubles. We had a car that would run great until the DISA valve operated then it would barley idle. Cycled the key car runs great. The SIB says put a new DISA valve in if it fixes it yay, if not FEDEX the dme to bmw in NJ so they can fix it internally. With MS45 Dinan requires you to send the dme to them so they can modify it before you program it cause it wont work otherwise.
 
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