5 replies to this topic

[porcupine73]

Hi, I was wondering if anyone has tried the 'VENOM 400 Performance Control Module'. I see Summit has them for various Subaru's.

The instructions say the connections needed are power, TPS signal wire, and MAP or MAF signal wire. My guess is that when the thing detects you're really getting on the throttle, it manipulates the MAP or MAF signal to trick the ECU into running a little richer temporarily. Any thoughts? I might like to give it a try but it's nearly $300 so I'd like to know if anyone has had success with it first. Heck for that much you could nearly slip in a 50 shot of NOS.

[NoahDL88]

If it tricks the ECU into running rich, its going in the wrong direction, the Subaru fuel map stock is a bit on the rich side, It turns out that a lot of tuners when programing the SMT6, they lean out the mix a hair, and that makes the computer much happier.

[porcupine73]

Thanks for the info Noah, I wasn't aware of that about the Subaru fuel maps. I was just thinking about reading somewhere that the optimal A/F ratio for economy is like 14.1:1 or something, but for performance it's like 12:1 so I just assumed the Venom would try to make the system run richer.

[nipper]

Thanks for the info Noah, I wasn't aware of that about the Subaru fuel maps. I was just thinking about reading somewhere that the optimal A/F ratio for economy is like 14.1:1 or something, but for performance it's like 12:1 so I just assumed the Venom would try to make the system run richer.

the optimal fuel air ratio is the same for performance or economy
http://en.wikipedia..../Air-fuel_ratio
14.7:1, thats why we have all this neat and fascinating computer equipment under the hood. You get the best performance and ecnomy from fule at this ratio. The rest relies on valve timing and other design factors.

Since it has simple wiring, its not a chip, its just a more sophistacted way to fool the ECU, not unlike what you see on ebay, instead of you turning a knob, itdoes it automatically.

nipper

[porcupine73]

Thanks for the info nipper. I'm not really sure how this venom gadget works then. Yah those gadgets on eBay are interesting, especially the 'voltage stabilizer' for more engine power, I think my favorite is the 12V squirrel cage blower 'turbo'. That wiki article is interesting, I saw it says "in Naturally Aspirated engines maximum power is frequently reached at AFR's ranging from 12.5 - 13.3:1"

[Virrdog]

the optimal fuel air ratio is the same for performance or economy

Not quite. A very lean mixture will get the best gas mileage (but this increases nitrous-oxide emissions). On Autronic stand-alone ECU's they have a highway mode that can be used with very tight tuning. It lets the car run up to 16:1 ratios under light load. So you have 300+ whp monsters driving around on big turbos that can get 30 mpg on the highway.

Also some of the newer "green" cars are going towards a leaner mixture for the higher mileage with extra emissions systems to reduce the Nox side effect.

And the Venom 400 is snake-oil. Avoid it.