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Originally Posted by nextlevel350z 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. |
My point exactly!! Okay, then why does the write-up of your product in autocar march issue page 31 claims 15% to 20% iomprovement of torque and pick-up? Quote:
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.
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totally agree Quote:
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.
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Like you said, its is not fair to talkabout bhp improvement. Cars with 300 or 400 bhp, the claims may be fair.. but NOT on cars we have in India. Is'nt a rough percentage gains a much better figure? Quote:
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. |
Since you are discussing products (mods pls feel free to edit if necessary)
Price- Standalones are available for price a little more than your product
Flexiblity of install - There are standalones that can be plugged in and off i.e. not permanent
Driving modes - These standalones also can be switched between "stock" and performance modes
The point in question is about claimed percentage gains, not about which product suits better. Quote:
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. |
All the stuff you mention about closed loop AFR control does not apply to all cars. There are many ways to get over them too.
With all due respect, going lower than 13:1 DOES NOT CAUSE KNOCK, BLACK EXHAUST or DROP POWER. Sir, have you ever even tried to tune an engine????
True regarding overrevving, it should not exceed engine limitations BUT again, its very car specific. Quote:
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. |
a) Almost all cars come OE with narrow band sensors that do not exceed 1000mv at roughly 0.9 to 0.8 lambda.
b) Agree
I still dont see any concrete justification of your product claims.
Last edited by rdkarthik : 7th April 2007 at 10:57.
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