E39 M5 Turbo LS getting started questions/I will try to keep updates on my build.

**get dustd** · 03-11-2016, 12:01 PM

Hi everyone,

I have a really nice s50 swapped turbo e34 that I have been building for the past year. It makes well over 450whp and is a blast. Sadly, it will be up for sale this summer if my friend does not buy it. I love the car but I wanted more power and creature comforts and already had my next build in mind…then an Avus blue M5 with all the facelift upgrades popped up on craigslist in November…

I have had this car for 4 months now while piecing together the drive line (killing me not driving it). I am hoping to get my short block together by the end of May and I have some nice mildly ported and surfaced LSA heads ready to go on the Lq4 I am waiting on. It will receive forged 10:1 internals and I am going to slap those LSA heads on with an ls3 intake. Not sure about the oil pan yet. The turbo will be a T4 based BW s480 with 92mm turbine wheel and 4” downpipe from Midwest turbo. I did not want to deal with a 5” downpipe and huge inlets and outlets. Not sure about placement yet, will see when I get it in the car. I am buying a Pro EFI setup from Sound Performance and having a custom harness made to run TCS and all the fun stuff that the ECU can do. It will be an e85 car with a second very big pump coming in with boost only. I have a TR6060 that is getting carbon blocker rings and bronze fork pads and driveshaft shop is making the shaft. That’s what I have so far.

I am ready to start selling parts off the M5 and I need advice so I do not sell anything I will regret. I drove the M5 for a week and I also test drove a 528i. I am going to swap to the 6 cylinder front end and bilstien is going custom valve me 4 struts and I will use an aftermarket sway bar up front. Or should I sell front and rear and go all aftermarket? What about that cool subframe brace, would that fit the 6 cyl. subframe?? Aside from those questions, I think I am going to sell the entire subframe with the engine and transmission for 6k with the wiring harness and the DME. All accessories and driveshaft included with my aftermarket intake (maybe). I am going to keep my Dinan cat back and try to connect it up as it has dual 3” inlets.

I am really nervous about getting rid of the DME and wiring harness. I have read so many threads and so much info on this swap I think I confused myself. The reason I am scared is because I have seen people using standalones keep the DME and use the stock sensors in the LS1 to run the gauges for the input to the standalone to kick up idle for AC. I want to keep AC and keep the automatic climate control and keep the stock gauge cluster working. I know I can run the gauge cluster by having someone who has the software re program it to receive analog signals but I can’t confirm if the m5 cluster will work like that for all inputs. So let’s start with that. I will post pictures of both cars soon.

Thank you for reading and any input you can give,
Joe

**RVAE34** · 03-11-2016, 12:14 PM

Ha! I also sold a turbo E34 to build an LS E39

I can't help you with the A/C or gauges as I used a gauge driver which is unavailable to the public but I know Clay and some others worked around this. I believe there is an E39 wiring thread in here somewhere that should help. Good luck with the build and looking forward to updates!

**get dustd** · 03-11-2016, 12:59 PM

Yea that thread is confusing and does not really answer my questions. Big fan of your build, Clay's, Shitzos awesome fab work, and the Unatural thread currently running. Read them many of times for info. I need some clutch packs for my e34 diff before this half mile event coming up so I was hoping to catch Clay on the phone at work and pick his brain a bit.

My old m3 that the s50 is from (that car is Road America dedicated now with an ls)

And for credibility my big block Duster

**zr6sbc** · 03-12-2016, 10:36 AM

I would hang on to the M5 driveshaft. Not sure it will handle your power, but you may want to go two piece and it's a great staring point.

**unnatrl** · 03-12-2016, 06:17 PM

Originally Posted by zr6sbc

I would hang on to the M5 driveshaft. Not sure it will handle your power, but you may want to go two piece and it's a great staring point.

I second this. I tried the 1 piece route and discovered it hits the ebrake cables that run through the trans tunnel.

**get dustd** · 03-13-2016, 01:44 PM

Alright i will hang on to that until its figured out. What about that subframe brace? Anyone know if it will bolt up? The dme/wiring is the big question i would say. From what ive found the cluster cannot be reprogrammed so this is the big issue. It would suck to have a hacked up harness with dual sensors for everything but it sounds like that may be the case. Please please tell me i am wrong.

**unnatrl** · 03-13-2016, 04:24 PM

Originally Posted by get dustd

Alright i will hang on to that until its figured out. What about that subframe brace? Anyone know if it will bolt up? The dme/wiring is the big question i would say. From what ive found the cluster cannot be reprogrammed so this is the big issue. It would suck to have a hacked up harness with dual sensors for everything but it sounds like that may be the case. Please please tell me i am wrong.

I can't offer advice on the subframe brace. Generally, the cluster shouldn't be an issue. The oil temp gauge is the only part that might be difficult. PA Soft 1.4 will allow you to decide the cluster for analog signals. You may have to run wiring and add pins into the plugs at the back of the cluster, but that seems to be common I'm the E39 swap. I had to add a pin for the tach. My coolant temp wires were already there. If it's a 2003 cluster, it doesn't allow you to change the VIN. It should program fine otherwise.

**RVAE34** · 03-14-2016, 08:24 AM

M5 subframe braces will bolt up to a non M5 E39 chassis. You can code the cluster so that shouldn't be an issue.

**get dustd** · 03-14-2016, 09:59 AM

Okay. The cluster is a 2000. I believe I have a buyer that says its going into an e34 so that would be cool. The last question is, am I safe getting rid of the DME and wiring harness while keeping the automatic climate control?

**RVAE34** · 03-14-2016, 10:30 AM

The DME has no use with an LS swap. I used a CAN BUS gauge driver (translator) to make my cluster and A/C work but cannot comment on how some of the other guys got their A/C to work though. The gauge driver is currently unavailable. But IIRC, Clay got his to work. I seem to recall some people using the A/C light to trigger the GM compressor.

**get dustd** · 03-14-2016, 11:52 AM

Yea it makes sense to me but on the pin out for my DME there are like 5 or 6 pins that are associated with AC. I would assume even with the fancy digital climate control it is similar to a module and runs itself so all it really should need is the wire to kick on the compressor and maybe an input back to it for a low pressure cutoff (maybe?). Anyone know what power steering regulator spring to run with the bmw rack? Also, knowing how the servotronics steering feeling is artificial...couldn't you try to replicate that feel with the rack by lowering power steering pressure slightly?

**nsogiba** · 03-14-2016, 12:40 PM

I was able to get my AC to work with NO DME or BMW engine wiring harness in the car. You really don't need the DME at all.

Depending on how fancy you want to get, you can use the BMW IHKA to trigger the GM PCM to turn on AC, or use a regular toggle switch. You will have to figure out what kind of input your GM PCM is looking for and feed it that signal. My swap used an Express Van PCM so it was analog (which was sweet). Just a 12V input I think.

Lots of good info on here, many smart people who have done this swap before, so don't be afraid to ask questions. That being said most of the info is already out there, so do your homework as well.

**get dustd** · 03-14-2016, 01:24 PM

Well that pretty much answers all of the what should I sell questions... I am having trouble finding many other people that have done this with a standalone computer so that is where I am finding the lack of information for AC stuff. If there is one output from the IHKA to turn on the system, then the GM computer must watch AC pressure's and receive other to kick the clutch on and off as needed. I will figure that out with the shop selling me the ECU I hope. I will update again when I get the engine out and the long block/trans done.

**nsogiba** · 03-15-2016, 11:30 AM

Correct, the GM PCM handles all the "what-if's" of pressure, clutches, etc.

If you like to live dangerously you can just bypass all that and wire up the clutch directly, but then you have no protection against the system pressure being too high or too low, refrigerant leaking out/blowing up the compressor, etc.

**RVAE34** · 03-15-2016, 02:30 PM

My knowledge on the exact details is limited (I had a friend hook up all my A/C stuff) but I am using the E67 GMPP stand alone ECU kit. Although my A/C is triggered with the gauge driver using the CAN signal, from my understanding, the cluster/HVAC module still use the CAN data within the BMW system to control and manage the A/C based on all the information it receives. Basically, the gauge driver tricks the car into thinking all the BMW stuff is still in place. In fact, I actually have an issue where when the A/C cuts on, the engine hunts idle when coming to a light. It seems my friend forgot to wire it up so that the GM PCN knows the A/C is on and to adjust the idle accordingly. This truly should tell you the control of the A/C is all in the remaining BMW systems in place after removing the engine harness and DME.

**nsogiba** · 03-15-2016, 03:05 PM

^Brandon, the GM PCM has programming that tells the engine to bump the idle when the AC clutch is engaged, so that you don't have that stumble. It's adjustable in the tune. That's the beauty of using the factory GM computer to control it over the standalone/gauge driver stuff, since someone already did all the heavy lifting.

You don't really have to "trick" the car into knowing that the AC is there. As long as the clutch gets engaged (regardless of signaling technique) and refrigerant starts pumping, the chassis/IHKA doesn't have the slightest idea what's going on, as long as the snowflake button is on. No reason to reinvent the wheel when the OEM systems are already in place. I forget why you used gauge drivers but it seems easier to just reprogram the gauge cluster once to receive analog signals, add pins, and then it just "works".

**RVAE34** · 03-15-2016, 03:26 PM

I must be incorrect in my understanding of what is going on. The gauge driver was super easy for my friend to hook up and program since his company makes it. That was my reasoning. And he did very little work to make the A/C work as well. It also cost me $0

I would have been left to my own devices if I had to code the cluster. Electrical is not my forte. I will follow up with him and my tuner so I can make sure my info is correct. Last I was told, the PCN did not know my A/C was cutting on and was why the idle would not correct. Regardless of the tune. If there is no trigger wire that tells the PCN the A/C is running, I am definitely wrong on this. This convo was also months ago.

**Schitzo** · 03-15-2016, 03:38 PM

Originally Posted by RVAE34

Last I was told, the PCN did not know my A/C was cutting on and was why the idle would not correct. Regardless of the tune. If there is no trigger wire that tells the PCN the A/C is running, I am definitely wrong on this. This convo was also months ago.

I see the PCN ordeal affected you; it did me too ;-)

**RVAE34** · 03-15-2016, 03:44 PM

I wonder if this is different because of the standalone. I don't recall my E67 harness having any connectors for the A/C so perhaps that is the disconnect here. Again, it's been a while since I have looked at any of this. Sorry for any confusion my vague statements may have caused btw.

**nsogiba** · 03-15-2016, 07:05 PM

wtf is a PCN

**get dustd** · 03-16-2016, 03:14 PM

RVA, T
The fact that your idle does not kick up does tell us that there is a simple signal the bmw climate control sends that just gives the compressor power. That is good information for me. The ProEFI is a really good system and all the Supra guys use it so I am sure I can split that signal (or even run it through the proefiecu) to let the ecu know to kick up the idle slightly. (unless they run it along side the stock ECU which means I am in trouble...hmm that makes me nervous)

The question is if the pro efi does at least accept the signal to kick up idle, will it read a pressure switch to know if it is low or high or to cut it off at full throttle so I don't pop the system and freeze out my tires at a bad time.

**rao** · 03-17-2016, 08:35 AM

The cluster can be reprogrammed.

There is not a simple signal from the BMW climate control cluster; it is digital. Not that big of a deal, but it takes some work.

The M5 driveshaft is the way to go - a 540 driveshaft is even better, and cheaper

I have no idea why some one would choose an aftermarket ecu when the factory GM one is so capable, but I suppose people like to make things more complicated.

Good luck, the cars are fun when they are finished.

**get dustd** · 03-17-2016, 08:59 AM

Originally Posted by rao

The cluster can be reprogrammed.

There is not a simple signal from the BMW climate control cluster; it is digital. Not that big of a deal, but it takes some work.

The M5 driveshaft is the way to go - a 540 driveshaft is even better, and cheaper

I have no idea why some one would choose an aftermarket ecu when the factory GM one is so capable, but I suppose people like to make things more complicated.

Good luck, the cars are fun when they are finished.

So the A/C is trigger is not a 12 volt signal its off of the Can BUS line? Is that car 2 channel?

I am going to try and get up over 8-900WHP with this build though so I don't think I want to deal with the BMW shafts. The second phase of the car will probably be a custom 9" center with reinforced sub frame and big axles so I can drag race the car on a sticky tire. That center would be longer so I can just have the shaft cut and re balanced so I figure I might as well start with a stout one now.

The reason I want the ProEFI is because I live right behind Sound Performance and I am totally sold on the Pro EFI 128. The ECU has a built in speed sensitive boost controller, adaptive flex fuel tuning that is far beyond what the GM ECU is capable of, customization traction control, change on the fly power level settings, and many options for outputs for boost referenced cutouts aux fuel pumps etc...It is a hell of a system.

I am going to run a nice in-tank pump with a big secondary magnafuel pump that kicks on with boost and run the car on e85 most the time. I want to be able to cruise around with like 6xxwhp and then turn it up for racing by just pressing a button. I fell in love with half mile events and want to be able to drive the car to the mohave mile and things like that reliably.

**RVAE34** · 03-17-2016, 09:02 AM

Originally Posted by rao

Good luck, the cars are fun when they are finished.

It's all fun and games until your car is cut in half on purpose

**get dustd** · 03-17-2016, 09:08 AM

Yea, I need to stop finishing them then selling them. I can't believe I am about to put that e34 up for sale right when I got it the way I want it. I am kicking around keeping it but why do I need a lesser version of what I am building? 3 toy cars is really expensive.

(For when its broken and because of the classic headlights and flip forward hood is the correct answer I believe.)