Jammasterjames 0 Report post Posted March 14, 2006 (edited) A guy on Trademe is selling under the heading: "BMW computer chip +45BHP VariPower" Its not a chip, its a potentiometer that connects to the ECU. By turning it (changing the resistance) it is supposed to alter the fuel injection setting giving you a choice between power or economy. The dude is trying to sell it for $85 NZ..... but if you look on ebay, its less than 7 USD to buy. Has anyone tried something like this? It sounds dodgy to play around with the fuel injection using only a potentiometer...... Here's the trademe ad: This works in largely the same way as a chip (such as those sold by Superchips) but does not require opening of the car's Electronic Control Unit (ECU). Instead the kit attaches to the wiring which is easily accessible under the bonnet - which in turn leads to the ECU. This kit also gives you fully adjustable control of the power your car develops. This way you can have power OR economy! This kit makes the ECU supply ever so slightly more fuel to the cylinders and slightly advances the ignition. Together this gives you much more power The power boost is varied by turning a knob mounted to a high quality potentiometer (similar to a rotary volume control). This can be mounted in the engine bay or surface mounted in the passenger compartment. A great talking point - and it works! This is a full, comprehensive kit containing - Connectors to connect the system wiring to your vehicle wiring. - A high quality potentiometer (and knob) that can be mounted on any part of your dashboard, kept in the engine bay or tucked away under your dash. Enough wire is already attached to the potentiometer to mount it anywhere in your car. Ready assembled! - Ties to keep everything very neat and tidy. - Full colour photograph instructions You will only need a screwdriver and scissors (or wire cutter) to fit! If you want to mount the control in your dash you will also need a drill to make a neat job. If you want PROPER power gains and the convenience of a fully variable control then this is for you. Average under bonnet fitting time 5 mins. To wire to dashboard as well (if you want to) about 20mins. This will not work on Diesel fueled cars and only fit to a turbo or supercharged car with an air/fuel ratio meter. This will suit all petrol fuel injected cars (all cars from 1989 have to be fuel injected to use catalysts which need electronic fuel measuring) Edited March 14, 2006 by Jammasterjames Quote Share this post Link to post Share on other sites
Carl 3 Report post Posted March 14, 2006 I was reading, probably on R3V, that you can alter a potentiometer on the ECU to adjust the fuel for different locations. Not sure if true as haven't seen it in the Haynes but it probably does the same thing and if it was an actual "performance" modification you'd have heard of it a long time ago. Stick in the pile along with the turbonator Quote Share this post Link to post Share on other sites
E30-323ti 66 Report post Posted March 14, 2006 You can adjust the ecu with a variable resistor, this works best on L-jet cars as the effects of chaning the percieved efi air or water temp sensor output will change the fuel map, on the L-jet ecu this does not effect the ignition timing as it does on a motronic ecu. This is good for fine tuning but not for gaining bulk HP as advertised. Quote Share this post Link to post Share on other sites
danutt 4 Report post Posted March 14, 2006 i think im gonna get one just for the fun of puting sumthing that makes even the smallest difference in my cabin to play with wat alot of fun should amaze the bitches haha jokes does it even work Quote Share this post Link to post Share on other sites
conrod 1 Report post Posted March 14, 2006 go on, do it, you know you want to! :thumb: Quote Share this post Link to post Share on other sites
E30-323ti 66 Report post Posted March 14, 2006 DIY it, the parts are like $3.50 from DSE or JAYCAR. Quote Share this post Link to post Share on other sites
Guest Andrew Report post Posted March 14, 2006 i think im gonna get one just for the fun of puting sumthing that makes even the smallest difference in my cabin to play with wat alot of fun should amaze the bitches haha jokes does it even work where are you going to wire it into? Quote Share this post Link to post Share on other sites
2002 1 Report post Posted March 14, 2006 Wire it in series with the coolant temperature sensor, this will fool the ECU into thinking that the engine is running cooler than it is so it will make the mixture richer. It sort of worked with my old Toyota rally car but changing to a Link worked much better. Note: It's probably wise to put a switch in the circuit that will short the resistor out of the circuit, I had one a cheap one fill up with dust - then car didn't run at all. Make sure you get a linear variable resistor not logarithmic Quote Share this post Link to post Share on other sites
danutt 4 Report post Posted March 15, 2006 any body here know how to diy it??can you post pictures of the proceedure or even a quality link to how its done...step by step?the vehicle i want to perform it on is my 318i auto e30 i know i know but im keeping it for now just wanna do this to it to see if itl make a difference the car feels like its leaning out near redline...help? lil bits done: pod filter and heat shield performance muffler at the end of exhaust(not big bore) thinking of putting a chip in help appreciated Quote Share this post Link to post Share on other sites
Guest Andrew Report post Posted March 15, 2006 what year 318 - and it won't do shite if its 88+ Quote Share this post Link to post Share on other sites
Jammasterjames 0 Report post Posted March 15, 2006 Some one should buy one from e-bay and post the instructions here..... make it easy to DIY....... or as we say in Compton: "Ghetto Modify" :pimp: Quote Share this post Link to post Share on other sites
conrod 1 Report post Posted March 15, 2006 Some one should buy one from e-bay and post the instructions here..... make it easy to DIY....... or as we say in Compton: "Ghetto Modify" :pimp: We were waiting for you to buy the trademe one, and show us the way!...... Quote Share this post Link to post Share on other sites
danutt 4 Report post Posted March 15, 2006 DIY it, the parts are like $3.50 from DSE or JAYCAR. how do you do it? Quote Share this post Link to post Share on other sites
Guest Andrew Report post Posted March 15, 2006 how do you do it?since you won't listen to anything we've asked or try to tell you - i'll tell you how to do it regardless what year your car is.buy a variable resistor from jaycar - attach 2 wires to it - wire it into the red/green wire and black/yellow in the engine bay (in the engine loom to car loom plug) Turn resistor to max and get 45 hp - its that easy. Quote Share this post Link to post Share on other sites
Jammasterjames 0 Report post Posted March 16, 2006 would prolly help to get a multi meter and work out what value of resistance to use on the pot.... Quote Share this post Link to post Share on other sites
kerrynzl 3 Report post Posted March 18, 2006 Just unplug your O2 sensor that'll richen it [if economy is ya thing ,just solder a 1.5v bettery across it] Seriously boyz dont F**K with these things. The main advantage of a chip is "altering the advance curve and lifting the rev limiter" The theory is "HORSEPOWER IS THE SIZE OF THE BANG MULTIPLIED BY THE NUMBER OF BANGS PER MINUTE" just get more air through it & let the electronics do their thing. Quote Share this post Link to post Share on other sites