So I'm thinking about purchasing a GFChip from gfchips.com for $69. My rig is apparently supported ('93 4Runner). Just curious if anyone else has tried one.

I did a quick search here on the forum and yielded no results so I apologize if this has already been discussed.

 

Don't waste your money, only thing that thing will do is richen the fuel mixture resulting in poor mpg while not adding any power. adding power to a vehicle especially to a 3vze is not cheap, so if you want more power the best thing is to trade or buy something else or do a motor swap.

 

Scam.




The logic is correct. Typically, these things are just a resistor to mess with the IAT/AFM signal, which actually leans out the mixture. I have heard of reclocking flapper-door style AFM/MAFs on early FI systems and re-timing for similar results.

Closer to stoich does mean more power and better mileage. But there's a reason that ALL engines are tuned on the rich side (closer to 10 or 11:1 at full tilt, depending on the setup), the mixture will burn very hot, and possibly pre-detonate.

Lean mixture will do this to pistons:

those are not broken, they're melted. This was on our rally car last year, tuned to run as close to stoich as possible. But with the stock subaru fuel rail setup, there's a pressure drop on cylinders 2 & 4....combined with some slightly lower octane fuel than the engine was tuned on....




SOME engines actually are tuned very rich from the factory, and leave quite a bit of power on the table for whatever reason. The Subaru SVX 3.3l H6 is one of those. A good engine management system and great Tuner can reliably get more power and efficiency out of them. But you're looking at about a $2k setup by the time you're finished to do it right.


It might work, but IMO you'd be stupid to drop the $70 to try it.

 

Please do not waste money. I did and mileage was worse.