Edmunds Answers

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  • avatar zaken1 01/30/12 3:32 pm PST

    The Hypertech programmer that brentlyk recommended is a top quality unit; it is not one of the cheap imitation "chips' that are falsely promoted all over the internet. The main benefits of the Hypertech are that it resets the spark timing for maximum efficiency, and then corrects the fuel mixture to match the new timing settings. This is a scientifically valid approach; and Hypertech develops their products after extensive experience with dynamometer testing and actual road experience. Summit Racing is one of the best sources for these units.

    You might also gain further benefit by going to E3 brand spark plugs, along with a Davis Unified Ignition matched coil and plug wire combination. Summit sells all of those items.

    A Gibson exhaust system would add even more to this package. Gibson is one of the only manufacturers who designs their exhaust systems for improvements in the normal driving range; rather than for all out racing. And they really work. Even better with the full system than with just the cat back.

Answers

  • MrShift@Edmunds 01/28/12 8:00 pm PST

    Gas mileage? No.


    Improved performance? Very marginally, nothing you'd really notice. The little HP you might gain with a CAI would only be at wide open throttle and that's hardly the place for good gas mileage. Your air intake is restricted by a throttle plate anyway.

    CAI only begins to be of benefit when combined with other modifications. Your engine is like one big TUBE---just opening up one end a little bit doesn't matter...you'd have to work on the middle and the back as well to really get anywhere.

    You might try synthetic oil--that could give you maybe 1 to 3 % better mileage; also don't warm the truck up on cold mornings...give it 30 seconds and just drive slowly until things warm up. Check tire pressure and put it to maximum allowed.

    Also a tune up might help as would changing out your air filter if it's dirty. But all of these suggestions are very incremental at best.

  • brentlyk 01/30/12 10:39 am PST

    By it's self not really. I started my "quest" on my 01 1500 just after purchasing it(HORID performance and economy) I put the cold air intake on..then a flowmaster muffler(not full exhaust) then purchased a hypertech programer for it.. INCREDIBLE difference.. no more kicking down on straight stretches of road to maintain freeway speeds AND picked up a GOB on mileage. I've hit over 18 on the freeway several times and am VERY happy with this setup. I ALSO programed it w/the performance setting as was advised. With this package you wont be dissappointed. I'm not.

  • MrShift@Edmunds 01/30/12 11:53 am PST

    Programming can work well but you should carefully read up on HOW the re-map is working on your engine to make sure the engineering is sound. If it costs $69, it's not good. Some only do simple changes in engine timing and shift points, and even that can help, but the best programs costs quite a bit of money and are quite sophisticated.

  • zaken1 01/30/12 3:32 pm PST

    The Hypertech programmer that brentlyk recommended is a top quality unit; it is not one of the cheap imitation "chips' that are falsely promoted all over the internet. The main benefits of the Hypertech are that it resets the spark timing for maximum efficiency, and then corrects the fuel mixture to match the new timing settings. This is a scientifically valid approach; and Hypertech develops their products after extensive experience with dynamometer testing and actual road experience. Summit Racing is one of the best sources for these units.

    You might also gain further benefit by going to E3 brand spark plugs, along with a Davis Unified Ignition matched coil and plug wire combination. Summit sells all of those items.

    A Gibson exhaust system would add even more to this package. Gibson is one of the only manufacturers who designs their exhaust systems for improvements in the normal driving range; rather than for all out racing. And they really work. Even better with the full system than with just the cat back.

  • MrShift@Edmunds 01/30/12 4:36 pm PST

    At best what could you hope to get out of an exhaust system? Maybe 10-12 HP?

  • zaken1 01/30/12 4:53 pm PST

    Gibson says between 10-20 HP; but that is not the real measure of how much you get out of their exhaust systems. Because these systems increase torque in the normal driving range (in contrast to most other manufacturer's "mainly for racing" designs) there will be a substantial increase in fuel economy and overall driveability. And this advantage will be there at all speeds and loads.

    Source: http://www.gibsonexhaust.com/truckandsu
    v...

  • MrShift@Edmunds 01/30/12 5:14 pm PST

    10-20? That's quite a spread. Depends on application I guess.


    I think one mistake people make when doing mods like this is that they read the claims for HP increase on each component (which may be legit) but then they ADD UP the HP claims for each component, as if to say "okay the CAI gives me X, the injectors give me Y, the exhaust gives me Z, so now I have a total of XYZ.

    Doesn't work that way.

  • zaken1 01/30/12 6:30 pm PST

    One of the less commonly understood reasons why the performance created by a series of engine modifications often does not add up to the sum of all the items is that ANY modification made to an engine causes a change in the engine's air/fuel ratio. There is an optimal air fuel ratio for each engine; which may or may not be the ratio that was calibrated into the fuel metering system by the manufacturer. If a modification moves the engine's air/fuel ratio closer to the optimal point; it will improve performance and mileage. If it makes the ratio go leaner or richer than the optimal point; it could end up reducing the power or economy. When setting up a heavily modified race motor, and running it for the first time with the original tuning settings and new performance parts in it; we used to say "The worse it runs when it first is tested; the more power potential it actually has."

    I have seen modified motors that required an increase in carburetor jet sizes of TEN steps larger than stock, in order to reach the optimal air/fuel ratio. When the jetting is that far off; an engine will run very poorly; and will be likely to overheat or self destruct if it is driven hard. But once the mixture is corrected; it will have FAR more power than it ever had before.

    Most engine modifications cause the air/fuel mixture to go lean at heavy loads. If you make one modification to a stock engine; the amount the air/fuel ratio changes is often just enough to put it closer to the optimal point (most factory stock settings are made a bit on the rich side; to create a safety margin for variations in production tolerances, fuel quality, and driving styles). So that modification is perceived as "working real well." If three more modifications are then made to that same motor; it is likely to end up leaning the mixture three times as much as the first one did. But the computer on computer equipped vehicles cannot compensate for that large a mixture change; so the mixture will end up going way too lean (and the check engine light will be triggered) On a non computerized engine; the degree of leanness will be even worse. Most people do not use exhaust gas analyzers, nor do they dyno tune their engines after modification; so they do not even know in which direction or how far the mixture went off. This is why so many enthusiasts come to believe that there is little that can be done to substantially improve the performance of a stock engine.

    Professional engine builders and racers know that you cannot successfully modify an engine without at least measuring and correcting the air/fuel ratio. Serious competition also requires correcting and optimizing the ignition timing curve and spark plug selection to match the engine modifications. This is the secret of race winning performance. There is a classic example of what happens when a this rule is ignored on a heavily modified engine. Shirley Muldowney was one of the first women to go into professional drag racing. During the 1960's her husband, Jack Muldowney, built a rail job for her; with a heavily modified, fuel injected Corvette motor in it. The first place they ran this car was at the drag strip in Englishtown, NY. Jack had been drinking before the run; and was feeling pretty confident. As Shirley drove the car to the starting line; Jack listened to it and decided that it was running too rich; so he walked over to the car and readjusted the injection to a much leaner mixture; without measuring the amount it had changed. Shirley then started off on the car's first run: She got about half way down the strip, and was doing about 100 MPH, when the power began to flatten out. Shirley was not familiar with this symptom; and kept her foot all the way down on the accelerator. Soon; a spray of oil began blowing out of the breathers on the valve covers; which increased until it completely covered her face shield and clothes. The engine's oil was being pumped out of the crankcase as a result of a hole having been burned through a piston by detonation; which was caused by the too lean mxture. Needless to say; this was a lesson she never forgot.

    I would strongly recommend to the truck owner who posted this question; to dyno test the truck and optimize the ignition timing and fuel mixture if he makes more than two modifications to it. Only then will it be possible to benefit from the full effect of the changes that were made. I should have said that in my original recommendation.

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