Last post on Jul 20, 2009 at 9:18 AM
You are in the Speed Shop Tuning and Modification
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Performance Mods, Engine
May 10, 2005 (11:24 pm)
Actually, that doesn't sound unreasonable to me. Aftermarket tuning chips don't typically add fuel, they usually remove fuel to lean out the fuel mixture at WOT. The OEM settings are generally quite rich at WOT to avoid any detonation issues. The aftermarket chips will remove some of this conservatism by leaning out the fuel mixture and/or being slightly more aggressive with timing. So you don't need more air, you are just optimizing the power of the combustion process and playing a little closer to the line on detonation.
#36 of 84 Re: . [fredmcmurray]
by Mr_Shiftright HOST
May 11, 2005 (10:30 am)
Well that's sound reasonable but they must enrich at some point in the power band or how would one justify the claims of HP in the mid-range? If a chip just gave me power at WOT I'd find that rather useless for anything except nutso driving--which I LIKE but which I can't be doing 95% of the time. I'd like a chip to give me the "sweet spot" when I'm pulling 3,000--4,500 rpm.
Also if a chip is leaning out at WOT and you are adding boost to the turbo, that sounds ver-y risky. Fuel is also a coolant as I'm sure you know.
May 11, 2005 (12:55 pm)
I said WOT, not just at redline. A good chip will give you power throughout the rev range, not just at redline. But chips can only influence the open loop part of the engine control, which is typically anything over 90% throttle position. Below that, the ECU is in closed loop mode, constantly adjusting the fuel delivery to keep the mixture near stoiciometric (14.7) as indicated by the O2 sensor. The chip can't mess with that and you wouldn't want them to. If you are at partial throttle and want more power, you just push a little harder with your right leg. It's when you have it mashed to the floor and still want more that the chip will provide it.
And, yes, if you are increasing boost, the chip programmer needs to take that in to account. If you have a chip programmed for stock boost and then you crank it up, you may have the opportunity to rebuild your engine sooner than you had planned. A number of MR2 guys found that out the hard way. Heck, the programmer even needs to know what octane gas you are running. If you are in California and running 91 octane gas on a chip that was set up for the 93 octane gas available in other states, you may well be on the wrong side of the detonation limits.
#38 of 84 Re: . [fredmcmurray]
by Mr_Shiftright HOST
May 11, 2005 (3:45 pm)
Oh, the expensive side of detonation limits.....I've been there.
Okay thanks for the clarification....yes, I was equating WOT with redline...duh....
I've heard 14.7 is not really ideal....more like 13.1 or so....
#39 of 84 That depends upon which mode you are talking about.
May 11, 2005 (11:33 pm)
At partial throttle, closed loop operation, you have to run at 14.7. That is the ideal for low emissions. Any lower and you'll have excessive hydrocarbon emissions, any higher and you'll have too much NOx. The O2 sensors on every production car I am aware of are Lambda sensors and can only detect a narrow band around 14.7.
But at high throttle positions, when you go into open loop mode, the ECU will determine fuel requirements based on predetermined tables or maps. The mixture ratio will vary depending on several factors like load (or throttle position), air flowrate, engine speed, etc. Typically, the mixture ratio will be higher at low and high RPMs and lowest in the midrange RPMs where detonation is most likely. 13:1 is probably a reasonable value for a normally aspirated car. 12:1 or maybe 12.5:1 is the highest you'd probably want to go on turbo-or super-charged car.
Every factory ECU equipped car I have seen runs below 10:1 in the midrange RPMs, which is why a little leaning out produces some fairly significant horsepower gains.
#40 of 84 ntroperformance chip
May 26, 2005 (10:30 pm)
I just recently purchase a chip for my 01 Tundra but I can find the IAT, MAF, or the CTS sensors to install it. Can anyone help me?
Jun 01, 2005 (11:42 pm)
keanu - you really need a set of shop manuals to make sure you have the right connections . I'm not sure if you have the 6 cyl or 8 cyl but if you have the V8 and the Tindra layout is the same as my Sequoia, the Mass Air Flow (MAF) sensoris right next to the big black box to the left of the engine that the air filter goes into. There is an electrical connector right on top with five wires coming out it. I'd guess that the signal for the Inlet Air Temperature (IAT) sensor is also in the connector. I'm guessing that CTS stands for Coolant Temperature Sensor but I'm not sure where that is. You really need the manuals and electrical schematics to be sure.
That said (and of virtually no use), I'd be very, very leery of using that "chip" on my car. It really isn't a chip so much as a device that is external to the ECU. I honestly don't think it is possible to properly design a chip and sell it for $27.50. Real chips go into the ECU and alter the programming of the ECU. They require a lot of reverse engineering of the ECU programming and a lot of time on a dyno with a wide band O2 sensor. This is time consuming and expensive. That is why real chips typically cost around $500.
The ads for that "chip" don't tell you anything about what they do. I would suspect that based on the fact that they are connecting to the MAF, IAT and CTS, that they are merely altering the airflow input to the ECU causing a slight leaning of the mixture ratio and advancing of the ignition timing. This could be a recipe for disaster. It's not a matter of thinking, "Well, it is only $27.50. If it doesn't work it is no big deal." If you start detonating, it could get to be a big deal very quickly.
Frankly, I'm surprised that ebay let's them advertise on their service. The ads state that it doesn't affect your warranty because it can be easily removed before you bring it to the dealer. To me that is recommending fraud and I wouldn't think ebay would want to expose themselves to that.
#42 of 84 Tuning Chips for 2003 A4 3.0
Jul 08, 2005 (10:33 am)
Has anyone installed tuning chips in a 2003 A4 3.0 Quattro Tiptronic? If so, what chip manufacturer did you use, what was the cost and how much HP and torque did you gain?
#43 of 84 Re: For the most part chips don't do anything [deplorableone]
Jul 16, 2005 (8:23 pm)
Your return on investment is low. E.g. Jet Performance Stage 1 investment is $249; advertisement states a result of 20 horsepower boost; not true. Maybe 5 to 10; is that worth it...; it is when a hundredth of a second means winning; in ten quarter mile runs with and without the chip i found no difference; i went for nitrous which added 75 horsepower for $600...; now that is a return on investment...; I believe if you can program your own chip for BMWs and Porsches or Vettes you might see a difference...; there's so much you can do to out perform chips...
#44 of 84 Hypertech IIIs
Jul 29, 2005 (10:47 am)
New to the forums so I was wondering if anyone had any thought on using a hypertech III on the 05 duramaxs??