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I haven't blown up any engines yet and I also have tuned more than one engine.

We had best leave it at that though because I am not going to get sucked into one of your childish arguments.

Maddog wrote:I haven't blown up any engines yet

We had best leave it at that though because I am not going to get sucked into one of your childish arguments.

Nor have I jackass. You started it with your "do some reading comment". Yes, you need to back off.

Dan,

Sorry for the ugliness that maddog has started in your thread.

You are right on track getting a TPS installed. Next step, WB O2 sensor.

I'm going to stick a narrowband in there just for now, because I have one laying around. That should get me closer.

Well crap. The narrowband is dead. It makes no more than .3 volts when hot. I guess I'll be ordering up a wideband tomorrow. This car is really kicking my ass...

With a boosted engine using Alpha_N, you MUST use the Hybrid_Alpha_N setting (See Advanced Settings) with Megasquirt, because the throttle position bears little relationship to the amount of air going into the engine. Alpha-N is for naturally aspirated engines ONLY, the Hybrid Alpha-N adds the MAP value into the fueling algorithm, (obviously the map sensor will need to be connected to the inlet manifold, engine side of the throttle plate) so fueling is increased with boost pressure.
Please Note: There is no extra table or any other settings other than selecting the option in Advanced Settings. It is simply used to add the MAP value to the equation.
To use Hybrid Alpha_N simply set your Constants - Control Algorithm as Alpha_N and set the ini file in MegaTune as Alpha_N, see HERE.
Hybrid can then be used if it's set in Advanced settings, see HERE.

Hybid Alpha-N =

PW = REQ_FUEL * VE * TPS * MAP * E + accel + Injector_open_time

Normal Alpha-N =

PW = REQ_FUEL * VE * TPS * E + accel + Injector_open_time


I know I have no idea what I'm talking about. I know maddog already told me you are working with MS2. But for what it's worth, this comes from the MS extra manual and might help to understand why BOTH tps and map are important on a boosted engine;
http://www.msextra.com/manuals/MS_Extra ... htm#alphan

My piggy back that failed terribly used speed density only and the car had the throttle response of a Q-jet Olds wagon. And that's tuning with a wideband. Speaking of which, I would wait until you get a wideband and not even waist your time installing the narrowband. Just an opinion for ya!

I've always used speed density and not Alpha-N.

turbodan wrote:Well crap. The narrowband is dead. It makes no more than .3 volts when hot. I guess I'll be ordering up a wideband tomorrow. This car is really kicking my ass...

Welcome to the world of stand alone ECU and tuning. Its gonna be fun! BTDT and have the bullet ridden T-shirt to prove it.

Maddog wrote:I have tuned several engines with megasquirt without using TPS because it was going to be a huge PIA to get one in. It isn't absolutely necessary. I find that TPS engines will be a little more responsive and I like to use it as a reference when I am looking at datalogs. You will not damage your engine not using a TPS sensor. You can dial it in without it. BMW engines are pretty easy to install TPS sensors in, particularly when using the volvo sensor. You just need to make a spacer plate and you are good to go.

If you are going to use the basic fuel enrichment settings with megasquirt, you will have to use MapDot only without a TPS sensor, but I usually find that easier to tune Anyway.

I do however strongly recommend a wideband O2 sensor. Again, its not required. You could tune with a narrowband, but a wideband will give you a lot more information and really help you determine how your engine is running. I would not do anything WOT until you have some kind of O2 sensor in. Thats a recipe for detonation and blown headgaskets.

There are 2 features that really require TPS, IMO

1) Idle advance (much better idle with fixed advance)

2) Overrun fuel cut (for weight transfer in spirited driving and fuel economy around down)

And for reviewing datalogs

I think the M52 TPS is the same as the volvo

I set everything I could find to speed density and MAP instead of Alpha N and TPS. The MAP based fuel cut sucks, so thats a good reason for a TPS right there.

The funny thing is that the TPS I picked up brand new says "Made in W. Germany" on the casing. Old stock?

So I made a new VE map, and it feels like 95 percent as driveable as the old setup. The power is better too, especially on the top end. I might not be needing an O2 after all. I will need a bigger fuel pump, as I'm running out of fuel over 160 kpa. Still no audible detonation, it just cuts out. All in all its much improved since yesterday, still just using the MAP and IAT sensors.

Dan, I'm glad you got it running better. I'd love to get a copy of your msq file sometime.

It was doing pretty good, now its getting shitty again. I'm going to work on it some more this afternoon. I'll send you a copy as soon as I'm satisfied with the tune. I think I'll just buy a WB and do it the easy way. F*ck this guess and check stuff.

You will thank yourself after you get it installed and calibrated. It makes tuning a breeze.

FYI for anybody reading the m30 EH TPS won't work on an m20 engine as it spins the wrong direction. For an m20 you need the early e34 525i EH TPS from a car with the m20 Bosch number 0280120402

rs4pro3 wrote:FYI for anybody reading the m30 EH TPS won't work on an m20 engine as it spins the wrong direction. For an m20 you need the early e34 525i EH TPS from a car with the m20 Bosch number 0280120402

Does it matter if it spins the wrong direction? I think that MS will compensate for this when you set up the TPS values. I could be wrong. Also, I'm using the TPS out of a hyundai. It's tiny and can be readily found at the PnP in my area.

I think the problem would be that the TPS signal would be ass backwards. MS is looking for a signal that increases with throttle opening. If the M30 tps spins the wrong direction, the only way it would work would be to install it so its indicating WOT when the throttle is closed and vice versa. I'm not aware of any way to configure MS to utilize that signal.

The TPS is a simple voltage dividing potentiometer... swap the power and ground to reverse its function.

I made a whole lot of progress today. I disconnected the BEGi RRFPR and turned off the EAE, or enhanced acceleration enrichment, feature in Megatune. Just to see what it would do. I wasn't sure if I needed the RRFPR anyway with the MAP based fueling system and 30lb injectors.

The first thing I noticed with EAE turned off was that it ran better at all throttle positions and loads. At WOT under boost it was great. The changes I made on the VE tables affected the powerband exactly like they were intended to. And it ran the same in all gears, no different between first and third. All I have to really do is tune the ignition timing map a little bit. it hasn't detonated yet, so theres probably more in there.

If it ran like this a few days ago I wouldnt have sprung for the wideband o2. Its that good. The EAE was killing the driveability and fighting the tuning. There might be a way to utilize that feature, but right now its far better without it.

I disconnected the BEGi RRFPR

Let me know if your going to sell that.

Jay