90 bmw 325 m50 swap

gunni · September 20, 2011, 08:09:48 PM

IÂ´d reccomend you change your boost line arrangement.

the constant boost line should be connected to side or bottom of the wastegate so that any boost lifts the valve. This is then totally seperated from the valve, Y connection a bit away from the solenoid would work nicely.

The top part should be connected to the solenoid so that when you start opening the solenoid it bleeds pressure to the top port pushing down on the valve simulating a stiffer spring. I.e the other part of the Y is feed into the solenoid and to atmosphere. By applying duty cycle the pressure stops going to atmosphere as much and starts pushing on the wastegate valve. This way has worked very well for me in the past.

GintsK · September 20, 2011, 08:38:05 PM

It is not possible to run both chambers form one 3-port solenoid with no additional orifices to atmosphere. It is joke! It might be some control at initial boost phase. But after that pressurized chambers has nowhere to bleed pressure. Means further control is not possible.

Yes it can be done with 4-port solenoid. Or two solenoids with opposite tubing connection. I tried second for oversized 60mm W-gate - works with no issues. With parallel electrical connection. PID.

Gints

DevInAz · September 21, 2011, 01:26:38 AM

Thank you all! ;D I will fix this issue tomorrow and update everything.

DevInAz · September 23, 2011, 09:19:08 PM

This is the new setup for my boost controller. I drilled and taped another line just for the lift part of the wastegate. The Solenoid now has one open port and one port that goes to the top of the valve. Here are some pictures.

DevInAz · September 23, 2011, 09:41:02 PM

This log is with my refdc at 60.

DevInAz · November 03, 2011, 04:59:49 AM

I've run into yet another problem. The boost control problem was that I had the refDC way too high. Anyway my new problem is a misfire at 4k rpm and 135kpa. I've checked and changed my spark plugs to no avail. I've pulled timing out of my ignition map and moved my VE table back and forth trying to find the problem.

I previously burned two of my ignition drivers so I wired up all the cylinders in pairs of two. Every part of the map runs great except for the 120+kpa parts of the map. I've racked my brain over this and can't figure it out.

http://www.box.net/shared/t95e1ohbsxk9a74h9nky

Here is a highlighted part of the map. The problem is there but the log doesn't really show anything. All I can say is it seems like a rev limiter but its not.
Hopefully someone can shed some light on something i'm not thinking about. Maybe a setting after whiching to 3 ignition drivers? i'm not sure.

gunni · November 03, 2011, 10:26:53 PM

Can you not replace your dead ignition drivers or use the two remaining ones?

Are you able to drive at higher boost at higher rpms without any problems?

DevInAz · November 04, 2011, 01:28:10 AM

I bought new drivers and soldered them in but they still don't work. We think the processor is damaged.

Nothing over 4k and 130kpa works. Everytime I hit the gas and it goes beyond both of those two parts of the map at the same time the vehicle feels like its misfiring badly but looking at the log it doesn't show anything. I've tried looking at all the individual fuel injectors but nothing stands out.

we changed the number of ignition drivers back to six and that didn't fix anything. What ever it is its very consistent above both of those two values. I will continue looking but was hoping someone would see something in a log that I didn't know about.

GintsK · November 04, 2011, 07:51:38 AM

Most probably processor aren't damaged: between IGBT and ATmega there is another chip. Have you LCD? Did you use P259 outputs? Those are driven by same processor pins/resources.
Try to change that chip. 74HC259D.

DevInAz · November 04, 2011, 03:40:00 PM

Hey GintsK,

I don't have an LCD. I was using ignition drivers when they burnt out. The chip 74HC259D controls the ignition drivers? I can order up one of those.

That would fix one of my problems but not this studder that i'm getting. I'm going to put a fuel pressure gauge on it and see if its fuel related at all.

I'll update tomorrow.

MWfire · November 05, 2011, 05:42:20 PM

you drive two coils with one output?

DevInAz · November 07, 2011, 04:06:48 AM

Quote from: MWfire on November 05, 2011, 05:42:20 PM
you drive two coils with one output?

yes I am. I have 6 coils on plugs and use 3 ignition drivers in total. Each driver controls 2 coils. I would love to fix the driver issue.

I figured out the misfire. It was a bad fuel filter. I put a fuel gauge on it and it held 45 psi consistently but wasnt getting flow.

GintsK · November 07, 2011, 06:08:01 AM

Oh, no!.... [about driving coils]. This is not good idea!

Are you sure about fuel as misfire cause? IIRC your datalogs didn't showed lean. Or pressure loss was compensated in VE map?

MWfire · November 07, 2011, 01:30:06 PM

Quote from: DevInAz on November 07, 2011, 04:06:48 AM
Quote from: MWfire on November 05, 2011, 05:42:20 PM
you drive two coils with one output?

yes I am. I have 6 coils on plugs and use 3 ignition drivers in total. Each driver controls 2 coils. I would love to fix the driver issue.

I figured out the misfire. It was a bad fuel filter. I put a fuel gauge on it and it held 45 psi consistently but wasnt getting flow.

That is very wrong way. Every coil needs own driver.
You are lucky that you can drive till 0.3bar of boost.

DevInAz · November 08, 2011, 08:08:40 PM

The fuel filter was deffinatly the problem. I've ran the car again and my original problem is all gone and the car is running great.

I would love to fix the ignition coil problem but i'm not sure what to do. I don't want to send in my VEMS for repair because the car will be down and we are daily driving it right now.

If all I need to do is order the chip i'm all for that. This one - 74HC259D

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90 bmw 325 m50 swap