Hi,

I have seen on eBay a resistor mod available to increase HP on the car.

Has anyone tried it or know much about it?

Des.

There not worth it. There are a couple of ones around, one increases the fuel and the other increases the timing. A good tune will do better.

As said. Its a cheap "hack" in the cars electronics that simply provides more fuel, and/or timing. Your basically dumping more fuel in per unit of air, and its not tuned. You run the risk of detonation.

It assumes that these cars mixtures are either on the lean or the rich side, and just adjusts the mixture by a fixed percentage.

Cheap, dodgy, potentially dangerous. Wouldnt touch it.

they are more of a ignition timing change. connected inline with the AIT (air intakle temp sensor) they fool the ecu into thinking the air is cooler and so it advances timing. in some cases they also add fuel which isnt ideal.

they can work good on some cars and on others not as good. if u do this run it on 98 octane fuel or at least premium to avoid pinging.

i wouldnt touch it
not worth the risks

even if you're car is dumping more fuel into the cylinder... it's not neccessarily a good thing...

i've seen back to back dyno of a stock starlet before and after of stock ecu VS aftermarket installed and tuned ecu

there was a 9% increase in power. that is a bit. but still, in the end you're going to have a little bit of power.
now if only 9% was available from a toyota ecu to a complete stand alone microtech $1100 ecu with proper tuning, how much do you think you'll get by using a $5 part and just randomally advancing the timing / fuel mixture?

get a tune... or get a piggy back comp(most cars are a bit on the rich side for saftey well turbos anyway) so by leaning it out a bit u can get gains but u have to lean it out on the dyno etc not just as a percentage casued by a resistor. after upgrading cold air intake pipe and filter, extractors exhaust, and along with soem new spark plugs and leads. run it on good fuel u cna bump up the ignition by 1-2 degrees, above this ur lookin at cams, head work, higher compression(more boost if its turbo) and a custom tune either of the factory comp(some u can some u cant) or a piggy back or whole new computer... spend the money on a new set of ignition leads or a tank of premium.