Quote:
Originally Posted by rdkarthik Temperature signal modifiers - They cannot give 15% to 20% bhp gains. They do make a small difference, but not in significant percentile gains.
Map sensor signals modifiers - They can better part throttle peformance, but again cannot give 15% to 25%
ECUs- Tuned for the specific engine, gains can vary from 5%(stock engine) to more than 30% (fully worked on, with all mods). |
Sir,
I'm sorry, but you are misleading TBHP users on several points, this one, I must address. You may indeed be correct regarding percentage gains, though no one that is serious about dyno testing, or selling a product, should be quoting in percentage gains. For example, a 5% bolt-on gain on a Nissan 350Z is nearly impossible for a single mod. 5% of 306 hp is over 15 hp, and just not going to happen. Why? Because the car is tuned fairly aggressively from Nissan. The exhaust is free flowing, the ECU tuning is aggressive, the intake is efficient, etc. Yet, some companies are quoting gains in terms of 15, 20, 25%, and even more.
Onto the products you mentioned above...both Temp and MAP piggybacks have the potential to increase power gains in the 15-20 hp range, sometimes a bit more, depending on the vehicle. Is that typical? No. Most gains are in the 8-14 hp range, but making it seem like both are rather ineffective is not correct. It is true that reprogramming your ECU is going to give you the most flexibility, and like a slightly higher gain...you have a lot more to work with, but you also have a higher price (generally). You also have a mod that is permanent. You can't turn it off, and you can't unplug it. Pros and cons to both...the right application depends on the person who is doing the mod, and what their needs are. An ECU flash should yield a higher gain than a piggyback module, and a full set of underdrive pulleys should yield a higher gain than just a crank pulley...but the higher power gain is not always the correct choice for a particular person, and shouldn't be considered the default choice.
A good rule of thumb -> anything that seems to good to be true, usually is.
You can "fluff" the issue anyway you like it. The goal, regarding ECU tuning, is changing the air/fuel ratio, and the appropriate timing adjustments to compensate. You can use any flashy terms that you want, but that's the goal. With a piggyback unit, you have to keep the oxygen content in the exhaust, post mod, within a range that is acceptable by your o2 sensors, or else you will get a check engine light, and in a late model car, the gains will begin being tuned out by the ECU, to bring the exhaust oxygen content back to an acceptable level (this is where MAP piggybacks usually fail - the MAP signal has such a profound input on the a/f ratio, the fuel mix becomes too rich, and is tuned out after a few hours of driving). Same goal with reprogramming the ECU, the only difference is that you can alter what the "acceptable range" of exhaust oxygen content is within the ECU...this "cheat" isn't unlimited...the range programmed by the automaker is for emissions - you are still limited by what is physically effiicient (i.e. going further than 13:1 on a naturally aspirated car is just going to lower your fuel economy, cause a knock, make the exhaust black, and cause power gains to being to fall off, since the car can't combust the fuel thoroughly). Now, if you want to kill your rev limiter or speed limiter, reprogramming the ECU may be the way to go - don't push the car more than a few hundred RPM over the factory rev limiter, and going past the speed limiter is just unwise - but if thats your goal, that's your call.
Sorry for being wordy, just had to dispel this myth. It doesn't matter how you do it, just so that you stay within a) the tolerance of the o2 sensor, and b) the limits of physics - Temp, MAP, and ECU Flash all have the potential to do it.
And here's another -> someone made the comment about a car working as a "system" - good advice. The better a car breathes, the better off you will be in your modding endeavors. Start with intake and exhaust, then go with something to bring your a/f ratio back inline (it will most likely be running lean after those mods), either a piggyback Temp or MAP module, or an ECU flash, whichever fits your goal and your budget. Then go from there. If you want to go further, underdrive pulleys are usually a good buy. If your budget is in the $3,000+ (USD) range, you might as well go forced induction - just keep the boost reasonable to prevent engine damage, unless you have a serious budget, and are going to build your engine first.
Spark plugs, plug wires, grounding kits -> mostly creating imaginary gains. Yes, they do provide some benefit, but in terms of whp, they are quite small.