M20 B3x Naturally Aspirated Stroker build past, present and future

[digger]

Awesome read Digger! I was the one emailing you not that long ago - I have an almost identical 325iS with M20B31 in Sydney.

I think I will be speaking to Rama in November when he is back in the country about ITB's.. He installed an EMU for me a few months ago.

I only made 143kw ATW at port hacking auto which I was a bit disappointed with but there is always room for improvement!

hi nick, i remember any progress....?

[digger]

I dont really understand why your saying alpha-n doesnt have enough info for the engine or is hard to tune? The only thing it cant do is compensate for atmospheric pressure or altitude but most stand alone ecu's have a function for exactly that. But at the end of the daty the difference it makes is SO small its hardly worth turning on unless you plan on going to relly high altitudes, and could be quite easily enabled to get pretty close with a couple test drives and AFR meter etc.

Your factory one..... of course i can understand its not going to work well because your primary load sensing device is still sitting on you workbench! :nice: which is testament to the motronic that it even runs well enough to drive at all!!.... on what is maybe a limp home mode???

An aftermarket ecu on the other hand can be well tuned using Alpha-n very easily, my tuner loves them! because he can access the whole map and simply run up all the load bands on the throttle pedal with perfect stability and no jumping around. Temp, ASE and other compensations need to be set up but no different to speed density etc. Maybe on an inertia dyno it might be a PITA but I havnt heard of anyone who uses one down here.

I can down load my datalog and my AFR's pretty much draw a straight line from one end to the other. I know its a race car but i drove an alpha-n tuned road car for years too, again cold hot winter summer never worried it. I never used atmo comp or closed loop, which would certainly take care of any little inconsistencies if you were really worried.


Edit: .. Actually Digger you car is a daily driver and has been Alpha-n for a while now, line any tune it always takes a bit of refining, but how has it been to drive around?... compared to speed/ density?
and its an ECU thats not all that good at holding a tune particularly stable i found.

somehow i missed all this.

it drives alot better on alpha-N and ITB than ever when its tuned properly, the only downsides so far is fuel economy by 10% ish but then again with small exhaust leak tuning to O2 at light loads in open loop will be affected by false reading and it will run richer than optimal so i will reserve judgement to when fixed. might be that i use a bit too much throttle now ;)

[AussieTemplar]

Awesome read Digger! I was the one emailing you not that long ago - I have an almost identical 325iS with M20B31 in Sydney.

I think I will be speaking to Rama in November when he is back in the country about ITB's.. He installed an EMU for me a few months ago.

I only made 143kw ATW at port hacking auto which I was a bit disappointed with but there is always room for improvement!

[nando]

Digger's running standalone though. Motronic wasn't really meant to run Alpha-N in anything other than a limp mode. I'd bet Digger's ECU is 10x faster than Motronic was.

[e21jps]

Yup. I tune on DynoJet, it has load capability. Makes it nice when you can hold an RPM/speed and get the map to stay in the block. Makes over all tuning better, but as you said, light throttle/cruising may need some touch up. I tend to do it just opposite. Tune for idle, light cruising/drive ability, then go to the dyno to brush it up and do a power tune. People keep asking why the 24v ITB's weren't on the dyno yet, but wasn't easy to get the stock Motronic to behave. Would be good for light load in one gear, then if bogged a little more than normal in the next the AFR's where everywhere. Had to find a balance, now I see why everyone wants so much for Alpha-N tunes, RPM and TPS aren't enough info for the ECU in reality, so it just takes time.

I dont really understand why your saying alpha-n doesnt have enough info for the engine or is hard to tune? The only thing it cant do is compensate for atmospheric pressure or altitude but most stand alone ecu's have a function for exactly that. But at the end of the daty the difference it makes is SO small its hardly worth turning on unless you plan on going to relly high altitudes, and could be quite easily enabled to get pretty close with a couple test drives and AFR meter etc.

Your factory one..... of course i can understand its not going to work well because your primary load sensing device is still sitting on you workbench! :nice: which is testament to the motronic that it even runs well enough to drive at all!!.... on what is maybe a limp home mode???

An aftermarket ecu on the other hand can be well tuned using Alpha-n very easily, my tuner loves them! because he can access the whole map and simply run up all the load bands on the throttle pedal with perfect stability and no jumping around. Temp, ASE and other compensations need to be set up but no different to speed density etc. Maybe on an inertia dyno it might be a PITA but I havnt heard of anyone who uses one down here.

I can down load my datalog and my AFR's pretty much draw a straight line from one end to the other. I know its a race car but i drove an alpha-n tuned road car for years too, again cold hot winter summer never worried it. I never used atmo comp or closed loop, which would certainly take care of any little inconsistencies if you were really worried.


Edit: .. Actually Digger you car is a daily driver and has been Alpha-n for a while now, line any tune it always takes a bit of refining, but how has it been to drive around?... compared to speed/ density?
and its an ECU thats not all that good at holding a tune particularly stable i found.

[MPLFoster]

sub'd

incredible work.

[LJ851]

bump

[digger]

Where'd you get this beauty from?

burns stainless

[CorvallisBMW]

accumulating bits and pieces

Where'd you get this beauty from?

[digger]

suspension is taking precedence ATM

[LJ851]

What is new, digger?

[JinormusJ]

Did I mention I like this thread?

[ForcedFirebird]

since I know that you do a lot of tuning

46 pulls in 4hrs yesterday, but the results were fantastic.

[digger]

Interesting, I didn't even realize how many different types of dynos are out there. I had to search that to understand what you meant. haha They come in both hub and roller, but that type of dyno seems to be the better option regardless of the configuration.
.

dyno dynamics are roller type and the most common used in oz by far, the other common type here is mainline.

hub would be ok for cars that struggle for traction and long tuning sessions. the cost for a power run on a hub type was 2-3 times that for a roller due to the setup so unless you spend alot of time on them....

a hub dyno will produce prettier numbers though....

[ForcedFirebird]

i've only every had mine on a eddy current dyno so you can load it up real heavy or really light.

last full tune i had was last year with the first Alpha-n for the dbilas setup. it needed no adjustment whatsoever on the street it was brilliant straight off the bat

sometimes the very light load and throtle transinets need to be done on the street but above this it shouldnt need it unless you are getting some serious ram air

Yup. I tune on DynoJet, it has load capability. Makes it nice when you can hold an RPM/speed and get the map to stay in the block. Makes over all tuning better, but as you said, light throttle/cruising may need some touch up. I tend to do it just opposite. Tune for idle, light cruising/drive ability, then go to the dyno to brush it up and do a power tune. People keep asking why the 24v ITB's weren't on the dyno yet, but wasn't easy to get the stock Motronic to behave. Would be good for light load in one gear, then if bogged a little more than normal in the next the AFR's where everywhere. Had to find a balance, now I see why everyone wants so much for Alpha-N tunes, RPM and TPS aren't enough info for the ECU in reality, so it just takes time.