Big, bigger, biggest......turbo!

[Billman]

The thing is, is there any device that can work together with the Stock ECU system, so you can easy change the fuel and the boost pressure steps and the advance but when you are about to make a mistake (knocks ect) it takes control and goes to safe mode!

That would be fantastic!

Maybe mihnea or paul can work on something like this! Manufacture a Simple User interface for windows, or on a standalone display module and 2 chips with cables so it can be connected directly to the ECU (Fuel and Boost chip)!

[AnLe]

billman: I have two times succested mihnea to do this kind of product, He gives all kind of bull for answer I believe that he just cant.

Knock control is fine thing to have, but when you change something, like go for 2.5 mod or use different em im and cams, who is the wisard that says knocking sound is the same?

If you wanted, you can use maf for aftermarket ecu, just plug it to the map sensors place 0v is no air and 5v is full air, it is good way to get right amount of fuel to engine when you know BEFORE combustion how much air there is, but then again there is huge amount of correction to the altitude, pressure, moist (?) and temperature, and even the bad batch of gas.

Its different story for the wrc and etc dudes, they can put 10 engines to the dyno, make the knock and measure right tones, they can afford it.

[kwlw]

That would be fantastic!

Maybe mihnea or paul can work on something like this! Manufacture a Simple User interface for windows, or on a standalone display module and 2 chips with cables so it can be connected directly to the ECU (Fuel and Boost chip)!

Why they should do that ? Who gonna pay to cover expenses ?

Also I suspect that real time map change is not possible in Motronic 2.3/2.3.2 (not sure however). Seems that you need a reboot/reinit every time you change something.

Sau
BTW there are some projects of doing that, seen something like that in 20vkruemer mailing list.

[Billman]

Maybe it is not soooo expensive, i dont now! It was just an idea! And a reboot or something like that is no problem!

What is this krümmer list?

[Billman]

@AnLe

My problem is not the Maf! I just would like to make changes to the ECU program myself! If for exsample i put a bigger Turbo i would like to alter the Boost and fuel figures to match it!

And to be clear: I dont know how to do all these stuff but i really would like to do it with the backup of the Standard ECU features! My car is a daily driver, has Aircon and all the Stuff, I Dont like to strip all the wires on my car and pay a fortune for something completely stand alone!

[BRY]

The choices you have are;
1) learn how to program the Motronic
2) pay someone else to program the Motronic
3) replace it with something easy to program and has safety features built in.

[AnLe]

billman, I know what you mean, I have same problem, the home made chips are not so versatile of tuning bigger injectors or after that making idle run better.

usually just little tuning more or less fuel, maybe tinkering with advances.

I took the hard road, bought an Haltech, run it with distributor.

E11 haltech should run I5 but i'm not the one to try it.
Finnish ecu Tatech should do the job also, and with reasonable price,
but yet again, I will not sacrifice my car and money to the testing.

kwlw: lisensing the tuning software and using standard copy protect bases would make the money flow to mihneas direction. The real money is 1.8t and 2.7t engines, giving up the knowledge of I5 will not hurt the business, only create more of it, but there is some kind of rule of the thump that people that knows they thing in cars, usuallu dont know anything about money, and vice versa.

[whakiewes]

If you want to stay piggyback, there are many viable options that are another level above the S-AFC. I have used the Perfect Power SMT-6, and looking to hopefully use the SMT-7 soon. Its a piggy back that has the ability to alter both fuel and timing signals. Variables are +/- 20%, so you can advance/retard timing 20%, adjust fuel levels +/- 20%, but with only a 20% increase over the stock injectors...or else you have to be rechipped for larger injectors. It can only alter the signal 20%. It has 600rpm tune points, all the way up to 10,000 rpms. Works great, and is very easy for a beginner to use.

Knock can be controlled with the MoTeC M4. It has a knock feature, slightly different than that of the other ECU's. When it detects knock past a certain point, it essentially cuts off the throttle, similar to a traction control system. No ECU has the ability to control knock such as retarding timing as the factory. I bet though if you had the right connections, you could get someone to write a software log for that on about any ECU.

At 2bar plus...28-XXpsi of boost, anything in your system is a problem. Small things that a lot people don't look at are the bends in a high boosting turbo system, such as reducing the number of 90 degree bends and such. You want intake tract to be as straight as feasibly possible. Another thing to consider are the bends you have. Are they mandrel bent? Crushed bends kill airflow...this also goes for your exhaust. Here are the problems with keeping a MAF...it requires you to plumb it into your compressor intake track, so with a tubular manifold or a huge turbo, sometimes this becomes a problem. Running a T04S cover with a 4" intake...now you have to plumb it down to fit it, so restricting your airflow in...no point in having 4" of intake if only 2.5" of air can fit in it. MAF on a general note a restriction. Those screens don't help with flowing air, and when you remove them, the MAF generally doesn't have enough disruption to get the most accurate reading, and this is when knock starts to set in. MAF's also aren't as accurate as Manifold Absolute Pressure (MAP). Ever see a Honda with a MAF? There are reasons why they have cars from the factory that turn 9000rpms without a problem. Talk to any engine builder, and he will tell you Honda makes a hell of an engine. To control this, they need a very sophisticated ECU, and they only rely on MAP sensors. MAF's run out of signal once you hit a certain point, as I have read many times on this forum. So what do you do? Have a larger MAF rewired to work...whats that going to cost you after you have it done 3 times? Not including if you start blowing out MAF's. When your tuning a MAF, your tuning the air that hasn't even touched the turbo yet, so you are only guessing the intake manifold temperatures vs. the turbo inlet temperatures. With a MAP sensor mounted directly on your intake manifold, you can tune for specific temperatures and pressure. Everything I stated above allows a much higher level of tuning. Being able to get a perfect 12.5:1 AFR on a MAF car is hard...I have done it night and day on a MAP car. I can't even start on the benefits of switching to a standalone ECU vs. piggyback/stock.

Have you ever seen a 1500hp dragster? One of the guys that run the 500+CI V8's with massive blowers on them. Take a guess at the compression ratio of those bad boys. Those are what I learned to build engines on....most start at 11:1, with the 1500hp guys at or around 13.5:1. They top this with 30psi of hot air from a huge blower. Reason...well there are many, and I definantly don't know all of them. A higher compression ratio yields you a better, cleaner burning of the air/fuel, and in turn is hotter, which then spools the turbo faster. An 8.5:1 CR is great for tuning, but in the world of engine efficiency and turbo's, thats the only thing its good for. The 50psi Supra's run 9.5:1 CR's. The problem with the higher C/R is you stand a greater chance for knocking because its that much harder to tune for. 8.5:1 there is a lot left unburned, so you can mess up timing, fuel, air, whatever and be okay for the most part. With 11.0:1 almost the entire batch of fuel/air is cleanly burned with nothing left. Many car manufactures tried to overcome this using a EGR(Exhaust Gas Recirculation) valve to reuse the unburned fuel for better efficiency. The goal in any engine, NA or turbo or to is to burn every molicule of air/fuel. This creates the most power and the most efficient use of your fuel.

Now as to what someone else stated. When you advance timing, you are changing what I call, some may be different, the effective compression ratio. What this means is that with an 8.5:1 CR, there is so much unburned, that you can advance the timing 10degrees, and burn 10degrees more worth of fuel/air, as you actually ignite the air/fuel well before it hits TDC. This essentially changes the effect compression ratio as it starts igniting at half of TDC, so your really firing like a 10.0:1 engine. This in turn gives you that more full burn of the fuel, but there is still some left over. Even on 9.5:1, you still have a lot more room than you would think. Two different theorists find two different solutions. On lower boost, 20psi-under, 8.5:1 is fine, because you can advance the hell out of the timing, and take the most advantage of the mixture. A 9.5:1 would be better because your chance of knock is a lot less, and you can take advantage of the higher compression at lower RPMS. At higher boost though, you have to look at the options. 8.0:1 would yield the most tunability, could run some wicked cams, advance them a lot, and probably get the same power as the other options. 9.5:1 will give you MUCH better drivability under boost, and in turn would also give your turbo that much more spool. Even with 8.0:1, your not advancing the timing 10 degrees at idle, your advancing it at different places throughout the RPM band. So your underboost drivability is going to suck. Reason why big power guys run big compression ratios : its simple...they need the most to get their engines running. A 1500hp drag V8 still makes 900hp without the boost. Supra's with 100mm turbo's running 1500hp need all they can to get up to boost. So they go with two options, nitrous or higher compression ratios. Just as a disclaimer, I wasn't telling you to go with that on your setup. I was suggesting that if I was going to build an 800hp reliable setup, thats what I would go with. I have never been a fan of advancing the time to compensate, as its like useing a thicker headgasket to lower compression when just about everyone knows that using lower compression pistons is the right solution.

I unfortunatly don't have any hard data about the intercoolers, only trial and error. You can take my word for it, of you can save some money. I would venture to say with 30PSI, there would be enough of a restriction at the intercooler to build up enough pressure to fill all of the cylinders...kinda the opposite of what you want though. The design atleast is there...you don't want long or real thick intercoolers because the tend to heat themselves up, but when you have enough pressure, it fills the entire area, and needs more. The best route regardless is a liquid to air intercooler, but that nescitates the use of a lot of different parts.

I have to go to class now, but I will comment more on my thoughts/theories later.

[Jeffer]

@ wes

you have very interesting knowledge I must say. You're new to the S2forum and writing screens full, wich is good ofcourse, but I like to know how you mastered al this. Is this your profession, hobby, interest? Just for my sake to know in what perspective I need to read this

Thanks

[AnLe]

few notes:

Your honda example, they make fine motors, but they are not good items to compare,
they have been using wideband lamda from 93 or sumthing.

Don't bring methanol and alcohol cars in to the conversation, that have no other use than drive 1/4 mile fast.

I have watched one dyno session with 300hp 1.8t engine, it got 2-4kw less power when maf was plugged off and std ecu was used, the maf is not so critcal to the new
wideband and exhaust temp controlled engines.

[whakiewes]

This all a hobby moreless, but I have attended two years of technical school and am A.S.E. certified. I have attended many engine theory and design classes. I am currently enrolled in a university for business right now...with that said, take what I say with a grain of salt. I have tuned and built several BMW's, a 1.8t, and a few other cars. I have never worked on an Audi 5, so what I have stated is all theory!

Meth and alc. cars aren't to far off from C16 fuel. That said, I understand its like comparing apples to oranges...but still an example nonetheless.

I don't understand what you mean about the 1.8t. It ran better with a maf or without, or do you mean you removed the screens? I don't have much experience with 1.8t, I only installed a chip, intake, exhaust, and KO4 turbo. I did somw fine tuning of it via an SMT6, but that's all.

As I have said before...you are the guys with the experience. What works on my BMW might not work at all on a 3b. When talking about C/r and engines there are still a lot of variables to consider...combustion chamber design, rod length, piston design, ECU, turbo, cams, etc...I was only speaking theory.

[Chris M]

Interesting reading and it sounds like you've done your homework. Either way you look at engine tuning, any new ideas or thoughts should be welcome. It sheds a new light on possible ides'a and theorys.

Cheers,
Chris

[Billman]

@BRY

I would like to know how to tune a Motronic but unfortunately i have no source for this knowledge!

[Audi500HP]

Wes im agree with you in some issues, but I have to correct the main differences between MAF and MAP controled Cars.

First: S2 ABY use both ones, and check both ones all the time, it use Both to make a mathematic equation to calibrate the best injection curve, priorization the MAF input. When something its wrong with the MAF, the Motronic unit will compare with the MAP (in the ECU) and the temp sensor (over the intake manifold)

Second: MAF vs MAP, you can see more Map cars NA than turbo, but there is some exceptions like Supra, Rx7, Lancia delta, Alfa romeo 155 Q4. The main differences came in the perspective of how you measure the MASS airflow, Directly (MAF) and undirectly (MAP). Every system have some advantages and disadvantages.

MAF works measuring the air directly by a constant wire (or a piece of metal) wish is suplying with a constant current, heating by this, change it electric resistence by the flow of air, so also its gone be affected by the air temp......... with this it kill two birds at once.... air flow its in constant relation with air temp and the resistence or impedance that is changing into this instrument. Benefits: IT REALY MEASURE THE MASS of air thats its getting into the system (engineering term for engine). So in simple words, every change before and after the throttle will be sense by this instrument, like cams, exhaust, big valves, head works, etc........... ITS A FLOW metter.

MAP will generate the same data of the MAF undirectly, taking the info from the air temp and the pressure in the intake manifold...... its good in the way that delete the restriction generated by the MAF, but its BAD in the way that it NOT gone SENSE any differences DONE under the intake Manifold, like CAMS, exhaust, etc Why? EXAMPLE: I f you change your CAMS, your Engine its gone BREATH much better, so its gone swallow more air than with the stock cams, so to preservate the intake pressure the wasgate its gone spin more the turbo to compensate that, so you are gone maintain the same pressure in a system that BREATH MORE........... so if you only took the info from your MAP it will appear the SAME pressure, and the ECU will not change the fuel-ignition.

SO the ECU loose the chance to compensate with more fuel (until you touch the intake pressure), and you will be in risk to detonate by lean air/fuel mix......

the MAF sense that changes and enrich the fuel curves.......


HOW i now this?, cause i have prepare Supras, and RX7s and I recieve education in phisics for this in the worst way MEDICINE........... the MAF its an instrument that we also use in ICU into the artificial breathers, and even worst, we have more variants, like the amount of O2 that we can change, jojooo, and more, a nightmare of phisics. Every thing That I have wrote can be Check into the BOSCH Motronic Book..... go and buy it.

[Audi500HP]

Why Toyota doesnt use a MAF? are they stuped? NOP, if you dont change anything in your car, nothing wrong it gone happen....... thats why the rise boys who knows about this buy a S-AFC, MAP-ECU, or remap the ECU inmidatly after any change in the engine...... ......the problems with remap, its you have to do it with EVERY change.......... not funny until standalone system or good quantity of money to pay for some tuner to do it for you!