Low budget 318IS turbo build: Need technical help (:

[van_rea]

Hi folks,
august this year start to assemble my turbo E36 318IS project. So far all the parts are in the engine bay and the car is running but have a problem two problems:
1. Turbo surge
2. When I drive the car(or just pressed gas pedal when car is in idle) and goes over
3000 rpm and lift my leg of the throttle pedal, car goes off.
3. Still not remap my ECU.
So let me first say you about, what was my parts and what is my goal for the car.
The goal is to go around 200 whp ( max 12psi) and top mounted turbo. So I get fuel injectors from Saab (Bosch 280150431 ~340cc) , turbo is TD04-13T from BMW with 10 psi actuator from Golf 1.8T. And want only to remap my ECU for now and if I like the car after the build will go for a bigger turbo and injectors and MegaSquirt. I used 52mm turbo pipes, 25mm Blow off,  gauges for oil pressure and temp and for boost pressure. All parts in the engine are stock and the compression is 10:1( will go to around 8.5:1 if will upgrade the project after that). So everything is done except the ECU, but the man who will make my ECU is worried about that my turbo is still surging from the compressor side.
About the first two problems.
Initially the blow off was placed between intercooler and AFM, then I moved it between turbo and intercooler. That helps and reduce the surge a little but still if I change gear after 3500+rpm its blow air from the turbo again and from the BOV.
I looked around the forum and see that most people remove the AFM but they used MegaSquirt. I also read a positive opinions about AFM and see the builds with Air Filter->AFM->Turbo->IC->TB->Engine and like mine Air Filter->Turbo->IC->AFM->TB->Engine. So I think that isn't the problem and I notice that when I lift the throttle the AFM close his "gate" entirely, after that the turbo surge and the engine stops. So I play with the AFM wheel, but no luck. I trying to roll up it as hard as I can but its close right  after release of the throttle. I tried also to release it to the end without success.  When i disconnect the pipes before the AFM the cars have no problem to run and the turbo is running fine without any surge. I checked my ICV, cleaned it up, changed all my vacuum pipes with a new one and removed DISA.
My questions are:
1. Is the turbo surging because of the AFM "door" is closing, or I need to change my BOV with a bigger one( I think to buy a 50mm)
2. How to adjust right my AFM and is that need to be done from the ECU or with the AFM wheel.
3. Do I need the vacuum reservoir, and where goes the blue pipe that goes from the tank to the cockpit (there is one black that comes form TB to the tank and one blue that goes to the cockpit, also a cable plug with a cable ) If i need to remove vacuum reservoir, do I need to change some value inside the ECU.
4. Can someone give me already ready fuel map for my build or help me with some advice(maybe a good forum topic where have more info and will be a good start for a newbie)  how to tune up it myself, because I worked like a PC programmer and will be very interesting for me to try adjusting it myself

Also if anyone have any other suggestion about what can cause those problems I will be glad to read about them and try to fix them

Sorry about my bad english but, I hope you will understand the most part of my "novel"

[SkidMark]

Hi there! Merry Christmas !! I think your turbo is surging because it is producing boost with no place to put it. (Throttle plate closed) you may need to install a Bosch bypass valve. It is open under vacuum and allows the pressure to be bypassed and recirculated  into the intake. They come stock on all vw and audi turbo cars. Google bosch bypass valve. I run one on my supercharged m42. Basically whats happening, i think, is, the turbo makes more boost at idle than the cars engine can use. If this pressure has no place to go it loads up the turbo causing surge. The surge is also very bad for your turbo. Dont get me wrong I am in no way a turbo expert, this is all theory, based on shit i have read. I was going to turbo my car before i installed the supercharger. It is all the same principal tho, boost is boost. Without the bypass valve in my setup the supercharger was very LOUD, indicating it was loading up. Basically, surge... Hope this helps.... Skid

[van_rea]

2. How to adjust right my AFM and is that need to be done from the ECU or with the AFM wheel.
3. Do I need the vacuum reservoir, and where goes the blue pipe that goes from the tank to the cockpit (there is one black that comes form TB to the tank and one blue that goes to the cockpit, also a cable plug with a cable ) If i need to remove vacuum reservoir, do I need to change some value inside the ECU.

[varg]

If your AFM is located before the turbo, you need to recirculate your bypass air between the AFM and the turbo, otherwise when the bypass (blowoff) valve opens the car will run extremely rich and possibly stall. If your AFM is in the boost piping, you need to locate the bypass valve before the AFM and can dump to atmosphere. If you are experience compressor surge when you let off, the blowoff valve isn't venting enough air, depending on what type it is it may be adjustable, but I don't know what you have.

Unfortunately I don't know anything about re-mapping and tuning the stock ECU so I can't help you there, I didn't bother to do this and am building a megasquirt 2 for my turbo 318is. The project is underway, but as I finish I will post as much information about my megasquirt setup and tune as possible in my build thread on r3vlimited so that others will have access to that information.

[van_rea]

Hi all, and thanks for the replays. Two days ago my new BOV arrived (Tial 50mm). I mounted it between the turbo and the intercooler, but still have surge again at high rpm(4000-4500). Because of that I decide to change my turbo (TD04-13T)  with some else.
What turbo will you recommend for 12PSI with a stock compression rate (10:1) ?
I read thru the forums and the most common choices are Garret T25 or T28 and Mitsubishi TD05. I found one T28(TB2809   OEM:1441175F00) from Nissan SIlvia => click is it will satisfie my needs and will it surge on my engine (the Silvia has a 2.0L 16v engine 200HP it's a pretty identical with my M42 engine ) ?

p.P.: Is this -> click ebay turbo will match up my configuration.