hondafrvr

damn thats crazy!

are you positive there are is no harm to the engine? because if it was this easy why would people buy stuff to lower vtec point...

there should be a DIY on this!

B serious

Because lowering the VTEC point without fuel correction will actually make the car slower.

If you lower the VTEC, you need to have the car tuned. If you supply the solenoid with power, regardless of oil pressure, VTEC will operate.

The ECU is what usually controls VTEC. It looks @ oil pressure, tps, rpm, cts, etc. to operate VTEC. With the switch idea, you're just bypassing it all. The engine does not create enough Oil pressure to engage VTEC very low. There is a danger there. Engine speed should be atleast 3k RPM for safety reasons alone.

Know how the S2000 "lacks torque"? If you open the ginormous VTEC lobe at low RPMs....you're going to have LESS torque than you allready have.

The fuel tables dont call for a big cam down low. The S2000 is sensitive to say the least.

You will lose power. Your car will be slower.

S2-3456789-K

am i reading this wrong or are the above statements contradictory? sorry if i'm misunderstanding soemthing

jimknapp

Okay, Serious, I'll admit that I don't know anything about stock mapping. I only use an after market ECU and we custom map only for idle and WOT, no cruise, no emissions, nothing else. So my comments are only for that environmet.

I have experimented on the dyno with turning on VTEC as low as 2000 RPM. Also I have used a toggle switch to turn it on at say 5000 RPM in first gear, made a pass with it on the whole time and then forgotten to turn it off after a run as the engine returns to idle. Hence the change to a micro switch under the throttle pedal.

Leaving the VTEC switch on at idle didn't and doesn't seem to hurt anything. There's just a lot of racket from the valve train as the little pistons inside the rockers try to make up their "minds", and it does sound really weird.

If you run the engine up from say 2500 RPM with the VTEC on it is just a hopeless mess until about 3800 - 3900 RPM at which point it settles down and begins to make some power. By 4000 it is pulling clean. So I come off the line easy (not a lot of traction on the salt anyway) and lean into the throttle and if I'm lucky push to WOT at about 3800 anyway since the engine just goes right on up past 4000 almost immediately.

And again I caution we are doing custom mapping, but I've found VTEC to make more power than no VTEC from 4000 to 9500. Above that, I believe all the extra weight in the valve train begins to cost you power, but you need different cams at that point anyway as you venture on up into the 10,000 - 11,000 zone.

Keep thge shiny side up,

Jim

B serious

I was saying that if you bypass the ECU controls and supply the VTEC solenoid with power at ANY RPM, it will engage.

Then I went on to say it's not a good idea at very low RPMs.

S2-3456789-K

the vtec solenoid only opens a gate that allows oil to pass through and activate the vtec mechanism. like you said, it still requires sufficient oil pressure, so the gate will open, but due to lack of oil pressure, the vtec mechanism will not engage. is that what you're saying?