Hi Scott,
I'm no technician, so don't take my word for anything, but I'm always interested in 'cheap tuning'.
However, I'm not too sure about this mod.
First of all, it does not seem to be a very popular way of 'tuning' your car, given the fact that I find it quite difficult to find references about it or its results on the internet. Nobody sells it like they do other tuning options.
Second, I ran into this little FAQ part below. For a totally different car, but I guess any car uses the IAT info in the same way: to adjust timing:
http://www.fordchip.com/faq/faq.htm#15
and a quote from it:
quote:
IAT = Intake Air Temp sensor.
ACT = Air Charge Temp sensor.
These are two different names for the same sensor. The EEC uses these sensors to help determine ambient air temps. These sensors are always mounted after the MAF and before the cylinder heads. On most newer Fords they are mounted in the inlet tubing before the throttle body. Beginning in the late 90s Ford started using an integrated MAF/IAT design. This design now has a 6-wire MAF vs. the old 4-wire style.
FordChip highly recommends that any blown car remount the IAT/ACT to a position between the blower/turbo and the throttle body. By doing this the EEC will be able to see the temp of the "boosted" air and can be calibrated to remove spark only as necessary under boost. This is a great benefit and safety measure for blown cars. In hot weather the EEC will be able to "see" the air temps and can pull the necessary timing. On those cool days the EEC will allow you to run as much timing as possible safely. This prevents a car that was calibrated on a cool day from "knocking" when the weather gets warm. It also allows max power on those cool days.
To me this suggests that your modification might alter the amount of 'spark', by causing the ECU to read a lower temp than actual. But as the FAQ above explains, that might cause your engine to 'knock', ie ignite the gas/air mixture to early or too late, causing additional strain and wear on the engine. Doesn't seem good to me.
To me, 'good tuning' in this respect involves changing the _real_ air temp. So lowering it, to allow more oxygen rich air to enter the engine. The ECU will adapt, as it should. But 'cold air intakes' (which are sold for this purpose all over the internet) usually only yield a max of 10% power.
So if this chip claims up to 20, then it must do some hefty alteration of the air temp reading, which simply cannot be good.
I'd proceed with additional caution. You could install it (probably easy anyway) and at least listen to your engine. If it starts ticking, you know it won't be good in the long term! Be warned. And be warned of the usual false ebay claims too
Cheers,
Edo (NOT a technician, I repeat)
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(2003 Silver 1.4 Tdi Exclusive(SE), 95bhp/235Nm chiptuned by ABT, black interior, sport seats, heated mirrors, JVC KD-SH909RB cd-receiver, Infinity Kappa 63.1 + Vifa on-dash tweeters, 12" Subwoofer on 300w Amp)