Computer Chip?

[pushinthelac]

Whats up everyone, I am a new member here. I own a 95 SLS black on black. My father and i are thinking about putting a computer chip in it that says to enhance the performance. The gas mileage will go up and the horsepower, and it will juss make it altogether run better. Is this true? Please give any info if possible.. thanks

[Adrian]

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[pushinthelac]

I am going to get it from the dealer. Would u recommend putting it in?

[Adrian]

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[Adrian]

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[Bob D]

Whats up everyone, I am a new member here. I own a 95 SLS black on black. My father and i are thinking about putting a computer chip in it that says to enhance the performance. The gas mileage will go up and the horsepower, and it will juss make it altogether run better. Is this true? Please give any info if possible.. thanks

The following was composed by a GM powertrain engineer. The guy was directly involved with the design and development of the Northstar system. (There's more in the archives under "chips":

">The PCM in the vehicle is a digital computer that reads the various sensors and inputs the information to a computer algorithm or program, The program uses a variety of logics to calculate the fuel delivery, spark delivery and a whole host of other control features like idle speed control. The program refers to certain "calibration" values that are stored in various lookup tables. Usually the calibration values are what an aftermarket "chip" modifies.

The aftermarket chip maker will eliminate or compromise certain settings to give the engine more power or the vehicle the illusion of having more performance.

An example might be on a vehicle without a knock sensor the aftermarket tuner will add spark advance to increase power slightly while including the instructions with the "chip" that you MUST use the best premium you can find. There is a little power here the manufacturer left on the table to make the engine less prone to damage from detonation. The aftermarket chip maker will capitalize on this while eliminating any margin of error for fuel.

Another example is delaying application of the TCC to make the car feel more "lively" at part throttle. But it isn't any faster as the TCC is disabled at full throttle anyway.

Another trick is to disable the EGR in an "offroad" aftermarket "chip". This also makes the engine feel more powerful at part throttle but the fact is that the EGR is disabled at full throttle anyway so the car will not be any fasster at full throttle with the "chip"

One place the aftermarket chippers have an advantage is with a turbocharged engine with a PCM controlled wastegate. The chipper can command more boost that will make more power up to the limits of the turbo outfit. In this case an aftermarket chip CAN make more power and this is the area the diesel (cummins, powerstroke, duramax ) chippers exploit. They can really bump the boost and fuel up on the diesels (a diesel's power is controlled by the amount of fuel injected)

Fundamentally, on most of the late generation fuel injected cars there is little or no power left on the table by the manufacturer in the "chip". At full throttle the correct amount of fuel and spark is commanded by the factory calibration and things like EGR that impede performance are turned off. About the only thing the chipper can do is to disable abuse protection features, disable the speed limiter thresholds and raise the rpm cutoff etc.

Remember, an engine is an air pump. However much air it pumps determines how much fuel can be burned and how much power can be made. More fuel will not make more power...you need the air to go with it and "chips" cannot make more air (except the turbo example above....) IF you modify the engine to flow more air...i.e...camshaft, head porting, headers, etc... THEN the chip can put more fuel in and make more power. But just a chip alone in late model cars cannot make more power.

The OEM rarely if ever runs an engine lean at full throttle as some people theorize and some chippers imply. The reason is the pistons will burn at full throttle if lean, the spark plugs will over heat and cause preignition and the catalyst will overheat. So all production engines are run rich to very rich depending on the wot maneuver and the lenth of the wot maneuver. A Northstar, for example, will run at about 12.5:1 A/F on a snap WOT on a 0-60. Max power on a Northstar is at about 13.5:1 but you can't run there for more than about 5 seconds without melting something. 12.5 doesn't cost any power and cools things a bit. After about 20 seconds at full continuous WOT the mixture richens to as rich as 10.0:1 to keep the pistons from melting and teh plugs from causing preignition. The catalyst also needs to be this rich to eliminate any extra air to "shut it down" momentarily at the high thru put situation so it doesn't melt down. The 10.0:1 operation causes about a 3 percent torque loss....the cost of keeping the pistons intact. A chipper might eliminate this richness on extended operation to pick up a little power and top speed but you run the risk of hurting something severly. In a case like this the chipper might specify racing cold heat range plugs....but the poor pistons are still unprotected....

Hope this help your understanding. It is impossible to say what any given "chip" has in it for modifications. A chip for the 4.x engines might give a little as that engine had no knock sensor and could benenfit from a little more spark....but you can do that by turning the distributor...no chip required. A "chip" for a Northstar is doubtful for more power from what I have seen. Some might eliminate the speed limiter which could be useful but otherwise the engine has the correct fuel and spark with the OEM chip. All if can be is the correct amount...no such thing as a more "aggressive" fuel or spark calibration if the original is correct.... "<

bill

[Adrian]

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[gibson]

I tuned my previous turbo car for almost 3 years before buying the Seville 2 months ago.Along with open air filters,performance exhaust's,lowering springs and sport shocks I also got a "chip" manufactured for MY car.

Now,on a 200 hp turbo car that gave me a total of about 235-240 hp with a boost upgrade and changed ignition curve

(included with the exhaust and the open filter that MUST get cold air to function properly).

As you may know the computer adjusts the fuel itself to a certain level.This is what you get with a chip to a turbo car without changing to much.

I would never put money on a chip for a non turbo car ! You will get a couple more hp IF the chip is made for YOUR car on

a rolling road !.And even then I don't think you will notice the difference between 300 hp and maybe 307 hp at full trottle..

My advice is to forget it,but it's a free world

[Dasher]

Adrian: Keep in mind that this comes from someone who knows nothing about the subject; but, given that you did have a chip that improved performance, it seems there are chips and then there are chips. If each chip is programmed differentlly how can you be sure that a new one will work like the one you experienced even if it's made by the same people (could be it's programmed differently)? Could be expensive to keep trying chips until you found one that worked?????

[KHE]

What can I say? I have had experience with a chip and know that they help....period.

So you have dyno data before and after the installation of the chip or are you just perceiving more power from the chip?

If it was that easy to gain more HP, it would have been incorporated in the factory chip.

[Bob D]

Come on Bob D.  You should know by now that one of your famous Bbobynski quotes is not enough to make me back down.  What can I say?  I have had experience with a chip and know that they help....period.

Actually Adrian, that excerpt form the archives was for the original poster, and the rest of the readers. I was already aware by the tone of your post that your subjective chip results pretty well convinced you, and you were sold on the concept..And that's OK, knock yourself out, it's your money..

For the benfit of the original question, I just though we might introduce some engineering facts into the equation..

[pushinthelac]

Thanks Bob d. Information is a little helpfull, but i think i wil still get the chip. And it is from a performance manufacturer not the dealer.

[ed blaq]

If chips really do work then how come so many of us won't put one on our Northstars??????? BECAUSE THEY DON'T WORK

[Bruce Nunnally]

I agree the proof of the pudding is in the tasting. If you can test the car, preferrably on a chassis dyno but otherwise with a g/tech-pro or AP-22 accelerometer before/after that would be interesting.

[KHE]

If a chip could actually make that much of a HP gain without compromising reliability, the factory would have included it in their PROM years ago...

The Northstar makes 1+ HP per cubic inch. The engine is pretty well maxed out as is. BobD's post has the engineering facts.

[Bentham]

I think the 'chip lovers' have the same mentality as the 'K&N lovers'

But, if you're happy with it, that's all that matters -- as long as it doesn't do more harm than good to your caddy. Good luck!

-Eric

[Brad]

Let's not get too carried away with HP's either. Some will note a recent post from Guru on the benefits of torque for a quicker Caddy, not HP.

I agree with BobD's and Bruce's post though. If someone could post testing results like Bruce did with the air filters, I imagine most would find it quite useful and informative.

[Adrian]

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[TDK]

Pro = Some hp and top end limit removed

Con = voids warrenty, may cause engine damage, legal problems if involved in accident. Paranoia fans agree , this goes with other saved "crash data". First evidence a sharp attorney will secure against a wealthy client's family...

Your call I guess ?

[KevinW]

By getting more power, you get more harshness.  There is some power compromised to gain drivability as well as emissions.  Some of the chip companies say their chips are for offroad use only.  The reason for this...to get more power, emissions may need to be compromised.  Some don't do this.  By saying driveability is compromised to create more power, I don't mean all the time.  Maybe just during WOT there is a bit more harshness.

Harsher WOT transmission shifts are not indicative of more engine output. The EPA does not regulate exhaust emission during power enrichment (heavy throttle), hence the manufacturers are free to use the optimal spark and fuel settings. If an aftermarket tuner, for example, disables the EGR system, then this is something that would affect the exhaust gas composition while cruising. Such a modification may alter the throttle gain at small throttle openings, leading one to think the car is more responsive, but the peak power would remain unchanged, since there's no EGR in the unregulated WOT mode in any case. Raising the minimum VCC/TCC engagement MPH may improve throttle response in certain speed ranges, but again, the WOT power is unchanged. The offroad clause also circumvents the need to have their product certified, which is a very costly process.

The "chip" companies do very little validation testing. What works on a dynamometer does not necessarily translate to the street, unless of course, you run your car for 30 seconds at a time between 15+ minute rest periods LOL. Frequently, their recipe of numbers will not work well on all engines under all conditions. They are OK, in most cases, for concrete changes, such as increasing the fuel cut-out speed or altering shift points.

When someone orders a chip, they make them the chip from the same program.

You'd be surprised at how little is changed in some cases. I examined a Hypertech chip for an Olds V8; they just changed a few bytes to increase the WOT spark advance by a couple degrees, about as effective as loosening the distributor hold-down and rotating it a bit.

Bruce got a half second gain in the 0-60 in his 1992 STS with a Fastchip, K&N panel filter, and Mobil 1 synthetic.  He also gained about 9/10 in the quarter mile.  Yes, this was on a 4.9 but a chip used with a Northstar will give similar results.

The 4.x series of engines do not feature a knock control system; there's some margin in the spark settings if suitable fuel is available. I doubt a similar gain could be achieved in the case of the Northstar.