Well i did my De-k swap about 5months ago and i just recently got my RPM switch and i was reading up and a couple people say its really effective to have it kick in AT 4800 BUT ITS REALLY EFFECTIVE with a raised rev limiter so i was practicing my launches (on a closed course) and i noticed as i shift into 2nd my rpms drop to about 4300 so i chose to activate it at 4100.

So do you think i should leave it a 4100 scince i still have the factory rev limiter (6500) and use the vias as much as i can?????

 

Thats probably too low because you are still making good power that low in the rpm band before the switch over. The usim would make power until 5k+ before it fell on its face. If you shift faster the rpms wont drop so low.

 

Trust me i have a Short throw shifter and i shift pretty good if you see my track vid i can hold it down lol but since ive had the Vi hooked up i get really bad torque steer on my launches and i take it up to 6500 and as i Chirp 2nd gear it drops down to about 4300-4400

 

you should have it set between 4800-5100

you would need to dyno to confirm whats best for your car, for my car it was 5k and I think D it ws 49k

 

oh ok are still going to the dyno this year?

 

either dec or jan

 

When I dynoes my car my power dropped off at 4800 so thats where I set my vafc-II at.

 

yup somewhere around there, before that your still making good power. A dyno will really tell you the best point for setup. zip tie method.... one open one closed activate at the crossover.

 

I got mine setup at ~5100, im unable to see it on any of my dyno's which means its perfectly smooth.

 

You're thinking of this too much like nitrous. Switching early is making worse use of the VIAS, not "more" use. As everyone else has said, it's going to be slightly different for each car where the activation point needs to be (a dyno is the best way to tell), but there are other things to consider as well. First of all, in my experience, RPM switches can all be different in how quickly they react. For example, on my '95 when it had an 00VI, I went from having a digital MSD switch set at about 4800 to having an Apexi V-AFC2 set at 4900. They both achieved the exact same result power-wise, but obviously I had to use different settings to get the same result.

My advice to you is to just pick a number somewhere in that neighborhood (let's say 4800 to start) and floor the car in 2nd gear from a lower RPM (I get the impression you're a 5-speed, am I right?). This is going to sound corny, but FEEL how the power comes on. Obviously at lower RPM's it will be slightly more sluggish but if you can FEEL the crossover point, then your RPM setting needs changed either up or down. Keep switching it around until you can't feel the crossover anymore. It should be smooth enough that you don't feel it.