I agree. Definately a must for peak performance on a forced induction vehicle.

 

I am not familiar enough with the GIAC to comment maybe someone who has it can....?

 

"No dynos to back it up" ????

This from the "Show me the numbers?" dude!!

It sounds like all of the rest of the comments you read on this site, if the results don't match someones preconceived ideas something must be wrong with the results. Very funny coming from you Andy

 

I'm Mr. Subjectivity now. j/k

This goes back to earlier discussions about the problems with band-aids (like the AFC and Unichip) compared to proper ECU tuning. When you start intercepting and corrupting signals between the ECU and its sensors, all sorts of bad things can start happening. For example, the Unichip alters the signal from the crank position sensor to fool the ECU into advancing or retarding the ignition timing. Well, the ECU happens to be monitoring the speed of the crank very carefully at specific positions to check for misfires. If the Unichip shifts the signal too far, the ECU may thing there is a misfire even if there isn't. To compound the possible problems, once you start sending false signals to the ECU, diagnostic readings are no longer reliable since the ECU does not have an accurate picture of its surroundings.

The APEXi S-AFC is intercepting the MAP sensor signal to the ECU, telling it that boost is lower or higher than reality. The ECU then sends the "incorrect" injection signals to the injectors. Not the right way to go, IMHO.

 

GIAC does the same thing, just in the ECU and it is not adjustable.

Dave

 

So now what do I do?

 

Nope. Chiptuners like GIAC change the actual lookup table inside the ECU. Let's say the stock table has an injector pulse width of 15 ms at 5,000 rpm and 100% throttle. The GIAC may speficy 13 ms under the same conditions, to provide the right fueling with the big injectors. The ECU is still seeing the actual MAP sensor data (uncorrupted) and diagnostics are not affected. See the difference?

 

GIAC and other software companies also change many other things,
This could be good or bad.

Dave

 

I'm going back to my original statement.....set a custom tune date with GIAC and send my Unichip to Randy and compare dynos.

 

They are doing the same thing, just two different ways of going about it.

Dave

 

Good plan.

 

No, you are still incorrect. The actual quantity of fuel may end up being the same, but the piggyback is bypassing the factory safeguards. Since the piggyback is corrupting the signals, they can no longer be trusted by the ECU. Let's say the ECU has a limp mode routine when the manifold pressure gets about 18 psi at a certain range, to protect the engine. With the piggyback in place, the ECU will not know it has hit that limit since the voltage clamp in the piggyback is corrupting that signal. So, the ECU may think the pressure is only 12 psi and everything is fine, whereas in reality it is outside its safety range. The ECU also uses those signals for load calculation signals that are sent to the ABS controllers and others. With the piggyback corrupting that signal data, other components in the car may not work properly. Lastly, piggyback like the Unichip and Apex-i, which do not drive injectors directly, have no way of increasing the rev limiter or performing operations outside of the rev range specified by the factory. With proper chiptuning, the tuner can map out data points and raise the rev limiter with ease.

I realize that chiptuning does not currently offer the sort of user-adjustability that piggybacks do, but how many MINI owners with Apex-i or Unichip have made any adjustments themselves? I prefer sticking with tuning done the correct way, without hacking into wiring harnesses, corrupting signals, etc.

BTW, a true standalone could offer the best of both worlds, direct control of outputs, accurate measurement of inputs, as well as user-tuneability.

 

There's a 205 whp SAE correct MCS running around in Phoenix. BTW, he'll be at Vegas for AMVIV. He owns an apexi, but has yet to install and tune it. It's going to be nice to see what it does when the apexi is tuned in.

 

To this I do agree.


The object in both cases is to alter air/fuel ratio. The safeguards you speak of are in the prevention of detonation. The ECU does little or nothing about this until a warning signal is received from the knock sensor and this is not changed by a piggy-back unit. The Apexi AFC also monitors knock sensor information.


Dave

 

the idea situation would be to bolt on the so-called tuner products, like head, cam, throttle body, etc. and then start the real tuning which consists of your-car-specific fuel map and ignition tweaking. The Apexi is a bandaid, but it got me there; the Giac is a fixed solution and probably ideal if you get it real time tuned precisely for your car on your car on a dyno (like at Helix). Any other fixed map solution is only an approximation based on some other car. The even more-real tuners do the above, then take the head apart, maybe the block, and based on their many years experience and the dyno performance, further modify the hard mechanical components, like port shape, combustion chamber shape, piston crown shape then re-tune.

 

AHHH! I figured this is what was going on! You mentioned that the GIAC seemed smoother but less eager. I was going to ask if this was at less than full throttle. But I think you just answered my question.

LET ME CLEAR UP THIS ECU THING FOR EVERYONE..."Eagerness" or ECU "throttle response" or "punch" at anything less than WOT is THE OPPOSITE OF SMOOTH! You can't have both - it's one or the other! Get it???

Here's a trick that many ECUs use and even many car manufacturers. To make their car or ECU seem more powerful, they increase the PERCEIVED performance at partial throttle.

For example, with my stock ECU version when I first got my MINI - with no mods, if I pressed the gas down 50%, the throttle opened up about 75%. Press the pedal down 75% and the throttle opened about 90%. It made the stock MCS seem VERY quick. Yet after breakin when I started flooring it, I realized that the difference powerwise between pressing the pedal 3/4 of the way versus pressing it ALL THE WAY was very minor. 3/4 throttle seemed quick for only 3/4. But WOT was only a hair more powerful. And disappointing which eventually led me down this dark side of modding.

Many of the aftermarket ECUs appear to do this. When you give it 20% gas, the throttle opens up 50% and it feels like your MINI is ready to take off and eager to run and revs more willingly and yada yada yada. All they're doing is making the ECU less smooth and less precise by tricking you into thinking you have more power than you do!!!

The GIAC ECU does something completely different. They go the other direction from stock and make every tiny pedal movement give a tiny bit more throttle. So when you press the pedal down 20%, the throttle opens 20%. When you press it down 45%, the throttle opens 45%. 90% down, 90% throttle. That's why it's SO SMOOTH. You can't have both guys! You really can't.

It's amazing how smooth it is and I love it. On the way home tonight I was seeing just how smooth it actually is. I can drive at any fraction of a mph. If I'm cruising through town at 30, I can give it a tiny bit more gas and go 30 1/2 and cruise there.

What's even MORE AMAZING, is that I can give boost super smooth. With the stock ECU, if I was accelerating slowly at 3 PSI and gave it a little more gas, it would jump to 8 PSI and then 5 PSI, etc...the stock ECU was very choppy. Well with the GIAC, I can be accelerating at 3 PSI and then accelerate at 3 1/2 PSI - even 3 1/4 PSI! It's that precise - it's amazing! I have never driven a car before in my life with such control and precision!

So you guys need to decide for yourselves. Do you want a powerful, totally refined, super smooth performance car or do you want a tweaked ECU that tricks you into thinking your car is fast and lively. I'll take the real thing - thanks!

 

Explain "tricks you" again please.

From what I know there are no GIAC dyno results posted. But there are tons of others from different vendors. No if you tell me that all are wrong and bogus I could believe that the other ECU chip tuners and piggy backs just trick you. And I am not talking about dyno plots provided by the vendors direclty ;-)

BTW....I am not saying the GIAC ECU flash is better or worse than other flashes.....something I can not say because I do not know.

Alex

 

All That is nice but on further driving the car it is puny at WOT as well. The car is not nearly as strong. I did some more driving today and spoke with GIAC. It seems that the software may not be able to accomodate all my mods. We reflashed the ECU and nothing much has changed. I checked my error codes. The same ones that I had with the UNICHIP and the 15% which was way stronger at all RPM than what I currently have. I have error code 1237. Which is a sensor. This may be throwing the GIAC off. I took the car to Global at 6:30 after messing (trips to R Speed and Euro-tech) with his for several hrs today and they are going to try to get me in tomorrow to fix/replace the sensor. Again even with the error code (1237) the Unichip was very strong. I really think that the GIAC map is not ready for the head/cam etc. That is not to say that it could not be custom tuned but the GIAC tuner in Atlanta has no experience with MINIs (mine was his first) They are a VW/Audi house, and Randy has all the experience in the world with Minis. If Eric/Helix was in the neighborhood I would feel different. I'll let you all know how it goes after the fault code is dealt with. GIAC has offered me my $ back as well as Euro-Tech. I am waiting for the error code to be fixed....who knows that may turn the whole thing on.

 

I'm not talking about dynos b/c I'm not talking about WOT, right? I'm not even saying that the GIAC is more powerful at WOT - we don't know - we don't have same car dynos to compare. I'm saying that MANY trick you at partial throttle. If you tapped your throttle and you car moved like you just pushed the throttle down 75%, you'd be pretty amazed wouldn't you? That's what they do. That's what I'm talking about.

 

Well that's a different story. You may be right SpiderX, you may have too many mods for a generic tune. While I think the GIAC is absolutely perfect for the intake, exhaust, and pulley mods that it was designed for, once you start getting into heads and cams you probably need a custom tune. Look at the JCW ECU. If you load that on to an intake, exhaust and pulley MINI, you'll lost SIGNIFICANT power over stock (and yes I've seen the dynos). Yet the ECU works well on the WORKS MINI. So changing the head probably makes a big difference with ECU tuning.

 

I love this thread - so much teaching... so much learning

 

UNICHIP will override some problems as Andy stated above as it clamps whatever voltages it needs and modifies signals as it sees fit. Its essentially a sensor simulator. Not sure what that sensor failure is but its definately possible that fixing it may fix your problem

--
Cheese

 

I hope so but I'm losing faith.

 

By the way it is not just me. Brian at Euro-tech was less than impressed particularly with the throttle response, which is very weak, and Hector at R Speed said "I don't like the way it is running."

 

I'll see you at the Dragon, by then I hope to have it all sorted out.