SAFC vs. E-Manage

[Zrun]

The ECU overriding piggyback is very real in toyota cars, because you can check long term fuel trim using odb2 sensor, and it will fluctuate due to driving pattern and tuning. If driving pattern is largely the same, then when you go to WOT, it should be consistent.

 

Full replacement is the best way to go, but too much $ and trouble. I am happy with cruising at stoich and save petrol. Only want to make sure WOT has power!

[Sheltie2306]

The original ecu overriding piggyback will happen to all OBD2 compliance car, if someone mess up the fuel map in the close loop region with piggyback. I ever spoke to one of the local professional tuner, and he don't seem to understand this too.

 

I am lucky to have this ecu that is piggyback when less then 20% throttle, and switch over to standalone above 20% throttle, kind of best of both world. Don't need to worry about idling, cold start, etc. Also don't need to worry about the fuel trim, original ecu override, because once over 20% TPS, it becomes standalone and takeover everything.

[Zrun]

what brand and model is that?

[Zero]

I'm not touching my timing, because it is dangerous to have bad timing, and not realizing it.

 

Advance timing is for NA cars, retard is for turbo or supercharge, when they go to high boost they want to retard timing to prevent knocking.

 

 

Thanks for the info.. learnt something new...

[Zero]

haha.. mine is n/a only.

 

Depends what kinda mods your after. I've seen 12 secs cars running on unichip. If your looking to do heavy modifications such as turbos as big as VF22 or TD05 FMIC 750cc injectors and boring cylinders etc. Than you'll need a top of the range replacement ECU.

 

SAFC would be the budget way of squeezing power while piggybacks are slightly more expensive than the SAFC 2 because you get to play with other settings that Mr Zrun mentioned.

 

Hmm... i will not be putting in any turbos becos sg sux. Perhaps modification on my current engine and im looking for a mit ecu for my 4g15 engine.

 

Guess i will be finding the correct ecu 1st...

[Sheltie2306]

It's the utec with new firmware : http://www.turboxs.com/stiutec.shtml

but for rex and evo only

Edited June 15, 2005 by Sheltie2306

[BMW320i]

Remember to leave ECU the last mod you install to prevent retuning cost.

[Slowpoke156]

The advertisement says 20%, but I am able to tune the MAF signal up to +-50%, but how much it translates to duty cycle is unknown.

 

E-manage alone sucks (5rpm points). With support tool to connect to laptop, you can do the 16x16 map, and you can set your own intervals on both axis, even as low as 100rpm. Due to the large support, there are many clone harnesses and cable you can buy cheaply, and you open yourself to the all the features of e-manage at a low cost.

 

Regarding UNICHIP, does it guarantee that they will fix your car if UNICHIP causes your engine to fail, since they are the only one that fiddle with it? UNICHIP tries to differentiate themselves from piggy back systems, but I cannot get any clear answers how much better are they compared to other piggy back systems. Some basic questions are, is it possible to tune close loop operation? If not, tuning WOT only is a simple matter that any tuning device can do (splitsec, safc, e-manage).

 

One good thing about UNICHIP is that it comes with the ECU harness so that you can just plug and play. That alone is good enough for many people to pay the premium.

 

MAF signal has nothing to do with duty cycle. Duty cycle refers to injector opening timings.

 

Realistically, there has never been a successful claim against any aftermarket ECU company where engine failures are concerned. Be it Unichip or Greddy's E-Manage, they can claim all they want but at the end of the day, there are so many odds against you that you will NEVER be able to claim. Check out the overseas tuning scene and you will know what I mean.

 

There is no clear answer as to whether the Unichip or E-Manage is better. It is a question of preference, tuner's ability and suitability for the car in question. What works for you will not work for others. E-Manage works in close loop because it has the benefit of being able to fool the MAF signals. Unichip does not have this ability, hence closed loop tuning is only possible for ignition maps, not fuelling. Fooling the MAF signals is not what I would do; I already know of 2 cars that blew up their big ends because E-Manage constantly fooled the ECU and did not allow it to retard timing even in dangerous situations. So much for being "capable".

 

Open loop tuning is not only for WOT situations. Many modern ECUs recognise part throttles at higher revs as open loop too, hence a map to provide factory defaults. You can drive at 60% TPS at 4000rpm and it's already in open loop, though this varies from car to car. WOT is NOT a necessity. If you think SAFC can tune as well as the other aftermarket ECUs in WOT mode (even if it's purely just WOT mode), I'll put my money down and let you prove it to me on a dyno. There is such a thing called resolution and speed of correction, pre-emptive speculations and error detection. You get what you paid for, SAFC is purely eye candy, nothing else.

[Slowpoke156]

Unichip is a closed loop.

 

If I were you I'll screw whatever piggybacks there are and go with the Motec, Autronic or ECUtek.

 

Closed loop only in certain cars, particularly those without lambda. Else, it's only open loop and only ignition timing in closed loop. Very clearly stated in Unichip's manual, unless someone else claims he knows better than Unichip themselves

[Zrun]

>> MAF signal has nothing to do with duty cycle. Duty cycle refers to injector opening timings.

 

Yeah. E-Manage does not touch duty cycle at all, it just alters MAF signal up to 50% and the ECU should react to alter the duty cycle. (Ideally, powerful piggy back should generate duty cycle, however, at that point, line between piggy back and standalone is blurred)

 

I put the "capable" in quotes, because it is a bad idea in general to tune AFR during close loop. E-manage and SAFC allows that, but ppl should just avoid that. Regarding those cars that blew up because of e-manage, that's just irresponsible tuning. E-manage allows AFR and ignition adjustments, people with some experience should be able to create a safe and good map. Ignition timing that are overly aggressive is very dangerous. One bad tank of petrol can cause alot of problems.

 

I've no experience with SAFC.. so, maybe SAFC is eye candy.

 

There's the issue of "guessing" when the car goes into closed loop. On toyota cars, it is only at WOT, because I used to have a AF meter. If you can find a formula to determine close loop, you should tune accordingly using your tuning system to take full advantage.

 

Here's what I know about e-manage......

 

Resolution: E-Manage has 16x16 map.. If you have trouble around 3-4k rpm, you can zoom into that region and use however small intervals you wish, however, you only have 16 intervals. Say, 3000, 3100, 3200, 3300, will use up 4 slots.

 

Speed of correction: Do you mean how soon the effect of tuning shows up? On e-manage, you are tuning MAF signal, so the response may be 200rpm late. There's a feature on E-manage that shows you which box of the map you are at. It is very cool because it runs all over the 2D 16x16 map, and the reaction is very fast.

 

pre-emptive speculations: E-manage is dead stupid on this. Stuffs like acceleration enrichment, engine braking fuel cut, knock sensor retardation are all delegated to stock ECU. (That's why piggy back is cheaper)

 

Error detection: E-manage does have some minor diagnostic lights. It is a simple piggy back, I don't see much problems that can go wrong. The main concern is the reliability of the wirings. Also, error detection is delegated to stock ECU.

[Slowpoke156]

The 2 engines that blew up was not due to bad tuning. They were tuned by one of the best tuners in Australia. Everyone swears by them. The problem is that of unforseen circumstances. There are situations that require failsafe maps which piggybacks are not capable of. If you fool everything including the MAF signals, then you're really asking for it.

 

There is no guessing whether or not the car is in closed loop. Any reputable tuner will have wide band O2 sensors and best coupled with OBD sensors to see if the ECU is making reverse corrections. I've tried with Bosch and FIAT diagnostics to see what happens, it is dead obvious, there is no guessing. If you need to guess, you shouldn't be tuning the car.

 

That said, all products have their strengths and weaknesses. It's a matter of finding what works for you! Happy tuning!

[Zrun]

As far as I know, all piggy back systems tune using air signal (MAF, MAP). (split sec, e-manage and safc) I think it is the standard because air signal is the most responsive signal as the ECU reacts instantly to add/subtract fuel.

 

I think you misunderstood what I mean by "guess". With a OBD2 + wbo2, you still need to guess. You may experiment and find out that at 99% 4k rpm you are in open loop, but you don't know about 85% 6k rpm, or 85% 5.99k rpm. What I mean by guess is to experiment to find the general rule of thumb when the ecu will be in open loop. Unless a your tuning machine can grab a open loop signal from the ECU and jump into play whenever the signal is caught then you don't need to guess. I cannot do that, so my "guess" is at >95% throttle, then my piggy back will only come into effect.

Edited June 17, 2005 by Zrun

[Sheltie2306]

 

 

Edited June 17, 2005 by Sheltie2306

[Vtim]

This topic too technical for me to read at this hour

[Sheltie2306]

I decided to delete the previous post, don't want to get misundertood and ended up with framing war.

Edited June 17, 2005 by Sheltie2306

[Sheltie2306]

Come to think about it, most stock ecu switch from close loop to open loop under 2 conditions, rpm and TPS. I know e-manage's mapping have rpm as one of it's axis, but how aobut % of TPS ? i.e. do you have a mean to control which part of the map is within close loop and which part within open loop ?

Edited June 17, 2005 by Sheltie2306

[Sheltie2306]

>MAF signal has nothing to do with duty cycle. Duty cycle refers to injector opening timings.

 

The stock ecu use MAF signal to decide the injector duty cycle. Piggyback will alter the MAF signal and thus indirectly alter the injector duty cycle, isn't it that way?

 

 

>E-Manage works in close loop because it has the benefit of being able to fool the MAF signals.

 

E-manage, like all other piggyback "can work" in both close loop and open loop. However, the tuner should neutralise the fuel trim as close to 0% as possible in close loop region, say if you have a larger than stock injector, so that the long term fuel trim will not fluctuate in the open loop region.

 

>Unichip does not have this ability, hence closed loop tuning is only possible for ignition maps, not fuelling.

 

I never tune unichip before, but from conversation with unichip tuner, it should be the same as e-manage.

 

>Fooling the MAF signals is not what I would do;

Fooling the MAF signal is how the piggyback works, isn't it? What's you understanding of how piggyback alter fuel then?

 

 

>I already know of 2 cars that blew up their big ends because E-Manage constantly fooled the ECU and did not allow it to retard timing even in dangerous situations. So much for being "capable".

 

That's probably the tuner try to advance the timing too much such that eventual net timing is still far beyond the safty margin even the original ecu has retarded to its allowable range.

 

>Open loop tuning is not only for WOT situations. Many modern ECUs recognise part throttles at higher revs as open loop too, hence a map to provide factory defaults. You can drive at 60% TPS at 4000rpm and it's already in open loop, though this varies from car to car.

 

Yes, agree. But I had seen piggyback that can seperate map region based on TPS and rpm, so you can clearly know where's the open loop and where's the close loop.

 

>WOT is NOT a necessity.

When we floor, isn't it WOT

 

>If you think SAFC can tune as well as the other aftermarket ECUs in WOT mode (even if it's purely just WOT mode), I'll put my money down and let you prove it to me on a dyno. There is such a thing called resolution and speed of correction, pre-emptive speculations and error detection. You get what you paid for, SAFC is purely eye candy

 

No comment

[Zrun]

Here's e-manage map. By zero, it means no alteration to MAF signal.

 

You can go + or - 50%.

 

Note the resolution on either axis can be changed. E.g. TPS, I set to 95%, was 100%, this is because e-manage reads WOT as 100% and sometimes shiver back to 99%.. so it is dangerous to switch back and forth. RPM, I change the resolution so that I can better control the AF line.

 

Note that only the last line is non zero, because I guessed that the rest of the map is in close loop, no point tuning it, screwing up the long term fuel trim.

Edited June 17, 2005 by Zrun