Has Anyone Evern Bothered To Try?

[550]

Ok, zazzn, if you don't understand it then try it. Thats all you can do.

[zazzn]

This was posted by an annoymous poster privately to me.

The ECU does use the MAF sensor right up until the sensor max's out and all this talk on the forum about the 4k cut off is rubbish. Cars canuse speed density to measure pressure and calculate air density using this and air temp, or they can use a MAF sensor to provide volume flow. Finally they could use TPS alone and run an 'Alpha' setup which uses the throttle position to calulcate load etc.

I think someone has come up with the 4k and now all and sundry believe it to be true, which it is not.

They have confused closed loop and open loop points when checking RPM. When the ECU is running in idle to mid power band the ECU uses the lambda sensor to provide fuel correction to the calculated fuel value. At the mid to max power point, the ecu goes open loop and this correction is not applied to the calculated value. Therefore if the MAF sensor is not reading correctly this is compensated out low down by the correction factor. When the correction factor is not applied the true MAF value then impacts on the fuel delivery, hence AFR readings. I suspect that it is this transition that has been wrongly interpreted by some people. What they should be doing is having an A okay car, no leaks etc, and change their existing 'high mileage' MAF sensor with a brand new one.

Something I'd like to add about the E-manage. Someone said it can't be used in the Volvo because it's 5 cylinders? You simply run the car as a 6 cylinder because there are 3 ignition cycles. We where told when it first came out that it would not work on my type of supra with the 7m-GTE. Not only did we get it working but we also where able to the timing adjustment working as well.

Anyways, it's obvious there are some people here that just regurgitated what they hear/heard. They have NO wrenching time no experience and pay someone to do their work. Some people that are truly interested and some that are just ignorant of change. It’s no wonder there are so many people making big power that don’t stick around, because all they get is flamed.

I now know what I need to know anyways, after I have a custom downpipe created I’m simply going to jack the boost up clamp the signal or the maf or use the s-afc to power the values and compensate 2x for the fuel 1x for the lower values and another 1x for the extra boost I’m running.

Thanks to all that helped and thanks again to all he flamers out there.

[550]

well if it works.. let us know and set us straight. There is only one way to prove something wrong, and that is to do it.

[lax01]

OK, since the question I asked today was eriely similar to this (guess I should have read this entire thread), I'll ask it again here...why is it that AFCs work in EVERY OTHER CAR but ours? Its not like we have special ECUs that are resistant to custom maps...as this is obviously not the case...

Here's how I see the forum logic right now:

1) Get a chip as this is the only way to tune our cars without going standalone management...

2) Else you're screwed

I just can't stand to believe that this is the truth...

Why does it stop at 4k RPM? Has anyone ever answered this? After this it goes to preset maps that are based on the previous O^2 readings, correct? And its MAF-dependent before the 4k rpm cutoff? Is there anyway to make it so that the fuel-curves are MAF dependent?

And to reply to Doug in my thread, I haven't read most of the stuff in the Performance Forum because its mostly people reiterarting sh*t they don't understand and is usually misinformation at that...I'm striving to understand how my car actually works and why it seems we are so dependent on chip-tuning...you say you want to spread the Volvo tuning community? well lets start by educating the current community so that they know actual information....I'm not trying to attack anyone personally, I just think we need to make the information uniform and clear so people know that they are giving good, accurate advice. Obviously zazzn has some good ideas and is really stretching people's current beliefs (which stresses people out)...anyways, Education is key and I think we need some of it about now...

[Guest DougK]

Josh, as we have explained a dozen times and proven: The maps are fixed. Its really not that uncommon. AFC's will not work. You need some sort of piggy back that actually modifies maybe POST ECU (ie dastek or civinco)... those work, the AFC doesn't. This leads me to believe that the ECU completely ignores the MAF and 02 sensor (maybe with the exception of IAT's) at WOT.

[lax01]

so these fixed maps...what are the variables that decide these? Or are they just static maps after 4k RPM (as in doesn't change depending on the current MAF and O^2 sensor readings?)

If you say this is common, can you give me some examples of other OEM engine managements like this? I'd like to do more research with those communities...

[Guest Guest]

Can anyone answer:

1. How much the ECU can compensate for variations in the o2 sensor or the MAF?

Normally, ecu's can move the base fuel trim ~+-15%. Has anyone tried to read the fuel trims before?

2. For the developers (or others) who have been able to read and rewrite the hex code within the ecu, have you been able to locate the lines where the ecu switches off the MAF, and reads the fuel maps directly?

3. What determins the pulsewidth changes with respect to the hard coded fuel map above 4k rpms?

OK, since the question I asked today was eriely similar to this (guess I should have read this entire thread), I'll ask it again here...why is it that AFCs work in EVERY OTHER CAR but ours? Its not like we have special ECUs that are resistant to custom maps...as this is obviously not the case...

Here's how I see the forum logic right now:

1) Get a chip as this is the only way to tune our cars without going standalone management...

2) Else you're screwed

I just can't stand to believe that this is the truth...

Why does it stop at 4k RPM? Has anyone ever answered this? After this it goes to preset maps that are based on the previous O^2 readings, correct? And its MAF-dependent before the 4k rpm cutoff? Is there anyway to make it so that the fuel-curves are MAF dependent?

And to reply to Doug in my thread, I haven't read most of the stuff in the Performance Forum because its mostly people reiterarting sh*t they don't understand and is usually misinformation at that...I'm striving to understand how my car actually works and why it seems we are so dependent on chip-tuning...you say you want to spread the Volvo tuning community? well lets start by educating the current community so that they know actual information....I'm not trying to attack anyone personally, I just think we need to make the information uniform and clear so people know that they are giving good, accurate advice. Obviously zazzn has some good ideas and is really stretching people's current beliefs (which stresses people out)...anyways, Education is key and I think we need some of it about now...

←

[Slater]

What everyone should be doing insted of dicking around with stupid piggyback and hack mods is work collectively on modifying the Volvo ECU itself. The PGMFI.org guys did it for the Honda ECU, and now they have dozens of freeware fullblown standalone engine mgt that uses the factory ECU, only reprogrammed with all sorts of new features - full datalogging, launch control, nitrous control, true boost tables, rev limit changes, VTEC crossover point changes, full idle control, realtime emulation for on the fly tuning, injector resizing, A/F autotuning, wideband support, virtual dashboards, speed gov. removal, abilty to enable/disable sensors like the 2nd 02, ELD, coolant sensor, etc etc. All you need is a $50 chip burner and a $5 EEPROM and you can burn your own maps all day long. Check out all of the tools at http://forum.pgmfi.org/. A lot of it is Honda related, but 75% of it can be applied to Volvo ECUs.

I'm quietly working on my own Volvo ECU project (just bought an ECU from ebay to start playing with), but if all of these smart people worked together great things can happen. The EFI Honda community couldn't have done it without the work of many people. But it will never happen if the Volvo community doesn't do the same. 3 years ago the Honda community was like the Volvo one is now - the ECU was a big secret black box that only a handful of companies knew how to make chips for and they soaked people for it. Then the right people got fed up and started playing, starting with crude hacks like disabling sensors and changing a few HEX values that controlled things like the revlimiter, etc. Now look how far they came.

All of the bandaids in the world won't be better than modifying the ECU directly. I mean, the stock ECU kicks butt - the flash chip can be reprogrammed on the fly for crying out loud. Everyine is bitching about how pig rich the aftermarket maps run, and paying for ridiculous retunes when it takes about 30 seconds, etc - wouldn't it be nice if you could tune your own car like a big boy instead of going to mommy and daddy and hoping it works like we do now?

BTW, if anyone is interested in helping, we need people familiar with assembly programming especially, as well as computer programming interfaces, PROMs, soldering/desoldering on ICs, 8051-family microcontrollers, EEs, anyone familar with Bosch Motronic ECUs (even Jetronic experience would be useful), and someone with enough electrical experience to be able to understand everything in the microcontroller datasheet like it's nothing. There is an group on Yahoo that has a number of people VERY knowledgeable on hacking Motronic/Jetronic ECUs - the group is Alfa75 but you can't go over there expecting to be spoon fed all of the information, and they aren't very helpful to newbies or non Alfa folks. But it's a matter of convincing the 1-2 main guys to help out with some information.

BTW, it would be REALLY useful to find whomever wrote the OBD2 ECU information on Volvospeed. Who was it, where did they go, why did they never finish the articles, etc? My guess is they figured out how easy it was and how much money they could make and wanted to protect the information so they quietly started their own company selling chips for Volvos...

- Slater

[BlackT5]

I agree 100% Slater. Something like Hondata for Volvos would be ideal. A piggyback that could be tuned on the fly via laptop.

I have very minimal knowledge when it comes to this kinda stuff, but i'm very keen to learn. Someone like EOBD (and others) could provide very valuable input i'm sure. Like you said, we need people to help work through this stuff if we are ever going to make any advancements.

[JCviggen]

To be honest i think the community is much too small. But it'd rock of course if something like that ever came about

[Guest DougK]

Hi Slater, my name is Doug. Im glad to meet someone with common sense here.

Couldn't agree more.

[lax01]

So now I wish I went into electrical engineering

I don't have much experience in software programming and/or on-board hardware but I am more than willing to learn...I think we are on the right track, we just need more engineers to help us get over the hump of understanding the ECU, after that, nothing is impossible...

[Slater]

To be honest i think the community is much too small. But it'd rock of course if something like that ever came about

←

It doesn't take an army of people, just a handful. Hondata was made by ONE GUY. ONE. He just happened to know a crap load about assembly programming and was a car nut. He has the title of the fastest Honda in NZ (a CRX). He's easily made a few million on it.

The people that wrote Uberdata from scratch was ONE GUY. Chrome was ONE GUY. ECU Control is 2 guys. And there are about 10 people total that were really instrumental in getting the freeware Honda PGMFI movement off the ground and to where it is today.

The Volvo community is "small", but believe me if a tool was readily available that allowed anyone to tune their car PROPERLY and themselves, the "small" group would get much bigger real quick. Also, you would see the prices of the commercial chips drop considerably just like it did for Hondas.

Remember, as these cars get older and cheaper, there will be more and more people buying them. All of these kids nowadays are computer whizzes and can program circles around us old time computer gurus. I don;t know what it is, but it's amazing to see what a 13 year old can do. I don't know what you were doing when you were 13 but I wasn't programming Java scripts and websites, and writing Linux drivers. Did you know that THE Yahoo web mail password encryption/security code was written by a 14 year old kid?

All we need is 2-3 knowledgeable people and this thing will be well on it's way to reality. Who could REALLY help is someone who currently does Volvo ECU chipping - Oliver at ST, Bill @ Upsolute, etc. They could provide a huge leap for us vs starting by ourselves from square 1. But something tells me they are going to be that willing to help with this project...

- Slater

[Slater]

I agree 100% Slater. Something like Hondata for Volvos would be ideal. A piggyback that could be tuned on the fly via laptop.

I have very minimal knowledge when it comes to this kinda stuff, but i'm very keen to learn. Someone like EOBD (and others) could provide very valuable input i'm sure. Like you said, we need people to help work through this stuff if we are ever going to make any advancements.

←

Hondata is not a piggyback. It's uses the Honda ECU itself. No e-manage, no safc, nothing like that. Like the aftermarket chips for our cars, you replace the stock Honda ROM with a EEPROM, make changes to the Honda code itself and stick the chip in (you can see my empty 28-pin socket in the middle photo below). All of the features I listed are available stock right in the Honda ECU, including datalogging. All you're doing is changing the stock Honda values (fuel maps, disbaling sensors, enabling other sensors, etc.) The boost maps were not there stock - they were stuck in an unused portion of memory and the MAP pointer was changed to point to the boost maps instead of "freak out limp home mode" when the MAP detected positive manifold pressure.

For the datalogging, the traces are on the PCB but you have to solder headers on, and then enable datalogging in the ECU that is disabled by default. Actually, if you saw the pictures on ECUControl's website, that was my ECU I sent them pictures of after I modifed it with a serial port for datalogging:

The serial adapter was $20, and they have USB versions now too.

- Slater

P.S. - the Volvo uses a 512k chip, but the Volvo rom image is only 64k. That means there is PLENTY of room for all sorts of new features that don't exist currently. The sky is the limit. Nitrous control, water injection, higher boost tables, any shift points you want, etc, all controlled 100% by the stock Volvo ECU! No piggy backs or external sensors to trigger that stuff. You could even make the car startup with the tranny in Sport mode instead of Econ like the V70R - it just a matter of finding the right hex value and chaging it to the right value. Like I mentioned before the unused portion of the chip is where all of the new Honda features were added. They even have a programmable shift light indicators using the stock check engine light!

[The Stig]

Slater, what you're talking about sounds absolutely terrific. I'd love to help, but I'm not a tech wiz like the rest of you. However, I wish you guys the best of luck, and hats off to all of you involved, we owe you big time.