Ok after I made the device for the wideband to attach to the muffler (pic if you want it..) me and dad tested all the p-cars with the new wideband tool from Innovate motorsports. He bought it so dad can tune his racecar when he gets the piggyback system working.
Sweet little tool!!!

But it shows me that I have multiple problems. Im running a little rich. I thought I was not getting enough airflow, so I cleaned my air filter but that didnt do much. I took off the airbox, but it was just a tad bit. Ok, I should be running 14.5 or so parts air to part gas. But im running 12.5 at a steady 3k. Idle is eratic.. I turned the knob down all the way on the ECU yesterday, and it helped a little. but I went to start my car today, and it wouldnt run with the AAR closed.. So I raised the ECU knob a little and that fixed it. Under full throttle, (Even though I dont get max hp) Im running about 12.4 or so A/F ratio.. Which is good. ..

So, what do you guys think I can do??

Andrew

14.7 is Stoi....thats the point where the engine is running cleanest..

We want POWER.....12.5 is a bullseye for power. When we dyno cars (racecars) We set a/f at about 12.5 or a tad richer, and then play with timing to find max power...

Not sure what your question is though? you showing 12.4@3000 which is good!

could the idle problem be ignition related? vacuum leaks?

Im happy with what im getting under full throttle..

But when Im driving around normal, Im running too rich.. under 13.5.

Ie holding 3k for 20 seconds in second gear for example..

Help?

Andrew

Sounds good to me, actually. Our engines don't particularly like stoichiometric mixtures. Those tend to run hotter, while rich mixtures run cooler. Cool, within reason, is good...

--DD

Ok I getcha..

The graph is pretty unstable.. It would be better if I had some more gadgets with this new toy (I can buy them.. probably will) so I can use rpm, throttle, boost and stuff..

This was just for me to test. I'll use it alot more when I do my engine transplant.

Thanks Dave

Andrew

sounds like you are right on. At partload say 3000rpms you should be at 13.7 to 1 as the fuel is part of the cooling charge on a air cooler engine,
12.5 at WOT is again right on!!!
If you change the a/f mix to leaner you will be dropping valve seats.


Geoff

Oh shoot, I changed my adjustment.. Now I have to fiddle with it tomorrow... crapola.

I hope you make sure the machined plug (WOT stop) is contacting the diaphram or you will be looking for a new MPS.

Or did you switch to Megasquirt?

Geoff

I havent messed with that. Just the ECU knob.

Stock FI

Im thinking of going to megasquirt, because Im thinking of doing megasquirt for the Subaru engine.

I havent set the TPS.. or dwell or whatever.. What all should I do for adjustment?

Andrew

If that thing uses a standard wideband O2 sensor, it is not designed to be just stuck in the tailpipe. Your readings could be all over the place due to that.

Tailpipe adapter

Yup.. It can be done that way. Besides we checked it on the stock car. and it was seriously perfect.. crusing 14.7. WOT 12.5

Andrew

I also just recieved my Innovate Wide Band system complete with auxilary input cable (RPM, MAP, TPS, etc). I haven't used it yet but noticed that there might be a problem using it on my 951. It comes with a cigarette lighter plug in to heat the O2 sensor. If I remember right the cigarette lighter on the 951 is larger than normal and ordinary cigarette lighter plug-ins don't fit. I'm going to have to check it out. Is there such a thing as an adapter for the cigarette lighter?

Andrew,
The ecu knob just controls the idle mixture - nothing more. If we're talking about your 914, then no, you don't wan't to be running at stoichiometric - that's too lean for our motors. It's fine for a Honda Civic, but too lean for an aircooled VW. Bleyseng is right-on IMHO. Your numbers sound just about perfect.

-Ben M.

ps - How do you like the LM-1? It's right up there at the top of my want list. I just wish it wasn't another $100 to add rpm to the datalogging. This thing would be so sweet for tuning PEFI (dump rpm/AFR data to graph or spreadsheet). Cool.

-Ben M.

The tool so far has been a pleasure to work with. about a min warm up, then go for a drive.

The cig lighter thing has not been a problem for either of our 944 turbo's (we checked both of them with the unit).

The ECU knob is just the idle ehh?

Well that explains my idle problems today!!

I didnt drive the car today because the car was idling at stock rpm's. Warm.. It hasnt done this yet. Soo maybe I fixed my high idle problems? maybe I havent.. I'll go for a drive today and figure it out.

So far, it was hunting at idle after I let it warm up. Normally with the AAR manually on it will idle at 2k warm, then I plug the AAR off and it will idle at 1.5 or so, and I drive it fine like that. Today it was idleing at 1.5 for a second, then it droped down to .9.. Dont know whats the deal, I played with the idle screw on the TB, but I was in a hurry, so I just took dads car.

Andrew

Andrew, you should get a EGT gauge to use in conjunction with the WB A/F.... An EGT gauge is an invaluable tuning tool also.....

It appears the innovate unit can take & store other data...Im sure with some doing it could record EGT readings also..if only as mV, then you might have to make some conversion using Excel etc...

Whats an EGT guage?

I cant use any other guages till I get an adapter for rpm, boost, ext.

Which I really want!!

Hmm maybe I could plug the Gtec into it as well! now THAT would be sweet!!!!

Andrew

EGT=Exhaust Gas Temp

Its helpful to able to compare and correlate sources of information when tuning an engine...

A/F and EGT are checks and balances...

everybody thinks to lean conditions cause "hot" cylinder temps, they do to a point, until there isnt enough fuel to support combustion, then EGT gets cold again......

so you get your A/F where you want, then assure EGT is aceptable, then play with timing to get peak power at any given RPM..

The Stock injection doesnt allow adjusting for any of the parameters.. if you go with SDI Megasquirt... or any other EFI you will be able to tune the engine for max power at every RPM...

The more info you have when tuning... the better...

Common misconception. There are adjustments, they're just hidden.

But yes, a modern system is more adjustable.

G.

When tuning my MS I used a wide band O2 sensor. A couple of things:

1) What you really need to do it right is a dyno so the load can be constant and you can slowly increase rpms. The graphs then allow you to tidy up the variations in AF ratio and the engine really wakes up.

2) Datalogging helps to visuallize the areas where you are lean or rich

3) You can gather way too much information. These things (O2 sensors) can sample very quickly and tend ramble up and down some, so apply some kind of filter to the data if the system doesn't do that already.

4) To do it right you need to know at a minimum rpm, O2 and load (for MS manifold atmospheric pressure). It certainly would be great to know EGT. It would be nice to know intake temp and the rest of the engine info (oil temp, CHT. and oil pressure). Although it's probably too late already if these go way high.

5) Exhaust gases can confirm you have it set up right.

Dave