95 turbo questions

95sdm3 · #1 (**permalink**) 10-05-2002, 07:59 PM

i have some friends at a shop that are going to turbo my 95 m3 with a stand alone engine management system. has anyone had any problems with theirs. any input would help.

thanks,jeff

jderry · #2 (**permalink**) 10-09-2002, 08:16 AM

more specifics are needed in regards to your question.

Are you asking if people have had problems with stand alone systems?? or, are you asking about custom turbo setups w/stand alone systems, etc...

95sdm3 · #3 (**permalink**) 10-09-2002, 11:29 AM

the big question is what is the most common problem with a turbo bmw. i have had expierence with other types of cars that are turbo so i know the generics about a custom turbo set up on a non-turbo car.

have you had expierence with stand alone systems? is it really necessary with a obd 1 car?

thanks jeff

jderry · #4 (**permalink**) 10-09-2002, 11:45 AM

I think there are varying opinions. I think an adequately programmed chip is sufficient provided you have someone skilled that programs the chip. The benefits of a stand alone system would not be fully utilized by someone like me. I am rather the type of program it to work, and once it does, I don't like messing with it.

If you are familiar with out cars that are non-aspirated and become aspirated, those problems that they experience are also similar problems associated with bimmers. The primary worries is detonation/pre-ignition; however you want to label -- e.g., the engine blowing up. It seems that with a well-programmed chip, and water injection, you can easily run 17 lbs of boost on stock internals. I believe this should yield you around 400+ rwhp and 400+ ft*lbs of torque which is adequate to most people.

If you REALLY want to push the envelope, I think you are talking about major engine work, JE pistons, pauter rods, etc. My compression is 8.5:1 with a 2.0 mm stopper metal head gasket. I would also go with arp head stud kit, etc. OBD-I yields more favorble power gains than OBD-II -- and is much more friendlier to tune than OBD-II cars (it seems at least).

I have not used a stand-alone system with my bimmer. I used one in my MKIV and MKIII; BUT, I was constantly playing around with the boost levels, changing out injectors, fuel pumps, etc. I do not play around with the bimmer as much....so, I personally do not think a stand-alone system is worth the money. I think it IS worth the money if you plan on changing your boost levels, changing your injectors, changing your HFM size, changing your fuel pump, etc...b/c then it would be a useful tool. But, if you are building a system to say run 12 lbs at lo-boost and 17 lbs at hi-boost (that's what I am aiming for) with water injection. Once you build up everything else to handle it, probably larger injectors...maybe a larger fuel pump, etc....I don't see the need for a stand-alone system. Others may disagree; but, once you achieve the A/F ratio you want, really no sense in fooling around with it. Again, if you want to upgrade to say a T61, or a hybrid T3/T4 (is that even possible??)...then perhaps stand-alone is something you might want to consider....

Other problems, heat...but that is generic to all F/I vehicles. Moreso with the bimmers b/c you have to fit the FMIC -- pipe the BOV back in, probably use an external wastegate...depends upon the size of the HFM you are using....etc...etc....people always worry about the longevity of owning an aspirated vehicle; but, hell, how many people ACTUALLY keep a car for MORE than 5 years, not many....

AA has proven to be excellent in programming chips for turbo cars. I am sure there are tuners that are just as good; but, for a no-hassle approach, I think AA is one of the better companies.

Hope this answers your question; but, this is only MY opinion -- others may completely disagree with me on this viewpoint.

95sdm3 · #5 (**permalink**) 10-09-2002, 11:57 AM

since you own vw's then you probably have heard of atp, or advanced tunng products in freemont cali. my friend is getting a link stand alone in his mk3 golf vr6 with a t4 turbo system.

since the price of our bimmers are a lot more than other cars that, to fix and so forth, that i would be that same as you as in that i would not mess with the boost levels either. i would lower the compression with a 2mm head gasket. how did you lower your compression? i am actually looking at a system that that would do 10-12 lbs lo-boost and 14-16 lbs hi-boost. i want this car to still be streetable.

thanks jeff

BMWGuy206 · #6 (**permalink**) 10-09-2002, 12:05 PM

Jeff,

Curious but what kind of turbo kit do you have?

95sdm3 · #7 (**permalink**) 10-09-2002, 12:24 PM

my m3 is not turbo yet. i have about 8 months still. my friends are desigining a custom setup for me.

which turbo system from aa do you have?

BMWGuy206 · #8 (**permalink**) 10-09-2002, 03:14 PM

I have the OBD2 Turbo Kit. Stage 2 turbo and stage 2 intercooler.

95sdm3 · #9 (**permalink**) 10-09-2002, 05:37 PM

what output do you have?

i know that aa is very reliable for their kits, and besides the main difference of you being the obdII and 3.2L motor, have you had any problems with the motor/reliability of the car?

thanks for all of your guys' input!!!!!!

jderry · #10 (**permalink**) 10-10-2002, 04:51 AM

Well, since you want to run 12 lbs at lo-boost and probably 17 lbs at hi-boost like me. How are the leakdown and compression tests? If you are going to lower compression, consider JE pistons/rods, etc... technically, stock internals will hold at LEAST 17 lbs of boost -- I believe OZ is running 22 lbs of boost on stock internals in the mcoupe...whether the engine will last more than 1 year, not sure...but I am assuming you will run 17 lbs only once in a while, maybe once a week at the most....so, 12 lbs i perfectly fine I believe.

You will need water injection (thanks Jon for helping out with that)...Jon (bmwguy206) seems to be very knowledgeable about this and so does Mark (M3turboCA). I believe they do all of the work on their cars and could provide good feedback to you regarding any questions you might have.

My compression was lowered with a 2.0 mm stopper MHG. ARP head bolts and stud kit was also used for insurance. You will also need probably 42 lb injectors (maybe 36 lb injectors are okay; but, at 17 lbs of boost, I would begin to wonder), possibly a larger fuel pump (depending on how old yours is).

I have never aspirated a VW, I owned a golf GTI before, hella fun to drive; but the MKIV and MKIII are supra's (the latest generation and earlier generation).

What type of turbo are you going to use??? What size A/R? internal/external wastegate? are you going to use a hybrid BOV? My whole developmental goal now is to reach 400+ rwhp safely without using the nitrous intercooler. Mine is the 20g mitsubishi -- I believe a T61 will fit -- I've heard of some ideas of using a hybrid turbo, or even a DUAL turbo setup. I think the T61 will spool slower -- but, you will gain more power at the top-end. I would prefer quicker spooling....hence, the head job, port-matching, downpipe, etc...

Still though, my turbo doesn't really kick until about 3500+ rpm's. I WISH I could get it to kick around the 3000 rpm range...that would be SWEET....

What do your friends say about the benefits of a stand alone system versus having a chip that is programmed?

m3wannabe · #11 (**permalink**) 10-10-2002, 08:21 AM

95sdm3 · #12 (**permalink**) 10-10-2002, 11:18 AM

the size of turbo i want is actually a t4 ball bearing. it may spool a little slower than the 20g, but the ball earing can make that up a little. i would use an external wastegate.

are most bmw's that are turbo reroute the BOV back into the intake? why dont they just vent it into the atmosphere?

if my friends at the shop could achieve a setup like you said with 400 rwhp and a spool up at 3000 rpm would be great.

my friends at the shop mostly use stand alones for obdII cars. i, personally feel that a good programmed chip would do well for a obd I car.

jderry · #13 (**permalink**) 10-11-2002, 03:54 AM

T3/T4 setup, you get the faster spool-up with the benefits of the bigger power of the T4??

You could use a hybrid BOV which I believe is around $500

...so, that might be a little extravagant just to get the PSHHHH sound...

From what I remember steve telling me and others, the BOV is plumbed back in because of the MAF sensor... I believe if the air is allowed to vent the car will run extremely lean ...and when you come to a hard stop, the car will completely stall.... I've heard of some running with the open BOV's...but, they still have to watch out for stalling problems...

stimpee · #14 (**permalink**) 10-11-2002, 04:12 AM

James,

The car will actually run pig-rich for a second when the metered air "blows out". The DME measured the air coming in, added fuel for it, but the air is no longer there, so the extra fuel creates a VERY rich condition.

This often is enough under the corresponding low/no load condition to kill the engine.

Steve

jderry · #15 (**permalink**) 10-11-2002, 05:12 AM

So much information to learn....

Hopefully one day, I can talk about things knowledgeably...