The 15 Y/O Turbo M42 Build Thread (Now Holley EFI Terminator X Controlled)

[Good & Tight]

and my target AFR table.

You better fatten up those afr's above 100kpa or it's gonna go boom in a hurry. Under boost it should be 12.0 and under. Post up your timing table you buttchug.

[wazzu70]

true, but its been done and It can be done. Ive come to the conclusion that if I want my car to run properly im going to have to tune it myself. If you want something done right these days its really the only option (at least this is my experience with tuning so far)


Ive taken the car to be dyno'd TWICE, and it still idles poorly and wont start. It runs fine when driving and pulls like crazy under boost. It just seems like the guys that did my tune didnt really care about the fine details and I guess thats where I come in.

My target AFRs at idle are 13.4 ish. Either warm or cold it seems to want more fuel to idle smoothly, especially when I kick on an accessory and put extra load on the charging system (cooling fan or distilled mist)


If I give it more fuel it seems to have better throttle response too. I donno, ill wait for some tuning pros on here to chime in because Im well aware that I am NOT a professional at MS.

I wish you lived closer, I would want a ride in your turbo beast :) I would also help you sort out your issues!

IMO a tuner who doesn't bother with dialing in starting and idle isnt a tuner at all. You cant only do the easy part and pass on the hard part.

I will see if I can DL TunerStudio and help get some things sorted out. I have been curious what TS is like anyway :)

[Dj Buttchug]

If your coils are wired into the same voltage source as the ECU that would not be good then.

Both ignition and injection have issues at lower voltage. Injectors need more open time and ignition needs more dwell.

Does MS have battery voltage compensation?

its a straight pnp unit so all chassis wiring/engine harness is OEM, and yes MS does compensate voltage. there are several settings directly related to it that I have left un touched so far

I wish you lived closer, I would want a ride in your turbo beast :) I would also help you sort out your issues!
IMO a tuner who doesn't bother with dialing in starting and idle isnt a tuner at all. You cant only do the easy part and pass on the hard part.

I will see if I can DL TunerStudio and help get some things sorted out. I have been curious what TS is like anyway :)

I would really appreciate it! It would be nice to have someone make changes to my tune while driving. Its hard to do both ha
but yes I couldnt agree more, Its really a shame because I paid a LOT of money to have this done properly. I didnt just spend countles hours research and fabricating to have a car like this be anything less than turn key. :(

[Good & Tight]

Your afr table should look like this. Use the auto tune feature also, it allows you to drive and tune at the same time.

[wazzu70]

Your afr table should look like this. Use the auto tune feature also, it allows you to drive and tune at the same time.

Truth!

[Dj Buttchug]

timing table up



G&T Is there any particular reason why my afr table looks nothing like what you posted other than the guy that tuned my car has no idea wtf hes doing? lol

[Good & Tight]

timing table up



G&T Is there any particular reason why my afr table looks nothing like what you posted other than the guy that tuned my car has no idea wtf hes doing? lol

Your timing looks high also, I'm no expert on 4 valve head tuning but I know for a fact the require a lot less timing than a 2 valve head. I'll see if I can dig up some timing maps for you.

[Dj Buttchug]

Your timing looks high also, I'm no expert on 4 valve head tuning but I know for a fact the require a lot less timing than a 2 valve head. I'll see if I can dig up some timing maps for you.

thank you for the help. It is appreciated greatly:D

[wazzu70]

Starting/base AFR table should look something like this (in lambda values):


Timing for a 24V boosted motor should look something like this:

[Dj Buttchug]

interesting. Im going to start making changes to the timing and fuel but i want to focus just on the start up and idle first before I move further.

[e30guydownunder]

For you startup issue it just looks like not enough enrichment. Admititly I am on E85 so it is a bit but at 10-20 degrees Celcius I am running up to 200% enrichment. Generally it will be linear.

For sure I would be running richer. We tuned for a flat 12.0 AFR on my thing when on boost. I also think that your ignition values look quite high when on boost. But this really needs to be done on a dyno to know exactly what is going on.

[MF DOOM]

Here's my map for a m42 turbo,

107% load = 22psi
100% load = 20psi
i think 42% = 0psi

these are old maps which i have since changed a fair bit

Ill load mine tonight. I know i have a datalog somewhere of my idle settings. Are you using an icv? Im not running one on mine and it idles smooth as can be at 500rpm. Cold starts are perfect. Hot starts have issues because of what e30guy mentioned. Needs more enrichment. but anyways, heres theses. hopefully theyre useful

[Dj Buttchug]

thanks for the tips guys. Im not running an icv. My req fuel settings also raise other questions.

When I use the req fuel calculator and enter the engine specifics I get a value of 3.3 ms (open injector time)

My original tune was 6.0 ms.

Hoping to have the idle and start up dialed in today. thats the first step, Ive created like 3 different versions of my tune all with minor changes so ill burn those in and test them out. If things go south I can always load my original tune back.

[wazzu70]

I thought your VE numbers looked low. If the req_fuel is off it will really screw with everything as its the main variable used in the calculations!

What size injectors do you have?

[Dj Buttchug]

my injectors are 970cc

If im using the req fuel calculator correctly it breaks down like this

engine size 1900 cc
4 cylinders
injector flow 970cc
afr 14.7

which yields a 3.4 required fuel calculation. this is no where close to 6.0 which was my original starting point

what do i do wazzu??