Who has this on their car? Does it do anything?

 

Unfortunately I don't have an answer, but I'm sure someone who does will reply.

The reason I did reply is to tell you that I edited your title to V-TEC so you don't get flamed

 

It wouldn't be the 1st time:P

 

lol...

 

the V-TEC controller (APEX) is supposed to set the v-tec in your car to kick in at lower rpm's. For ex. a stock cl-s 's v-tec kicks in at 4800 rpm, so that's when you get full HP, but... with the V-TEC controller you can set the v-tec to kick in at like 2500 rpm and you'll get full horsepower earlier... the problem with that shit is that you burn more fuel, so you gotta buy gas more often...unless you just set the V-TEC controller when your gonna race...

 

i hope u meant v-tec controller, i neverheard of v-tec timer...

 

It's called a check engine light will pop on and put your car into safe mode....making you slower...if you set the VTEC engagement point lower than stock.

 

I heard you could lower it to around 3100 and be fine?? Have I been lied to (bastards)...

 

worthless IMO.

 

Anyway of tricking or retarding the computer so it wouldn't know that V-tec was kicking in at lower rpms?

 

So do you think that is the trick to the S2000, I've heard that it has increased timming.Do you think they just used a v-tec system that kicks in at say 4200rpms and runs all the way up into their high rpms? Just a thought. PS. wouldn't that increase wear and tear on pistons?

 

You can force the engagement with some "parts", but the cams have different profiles for a reason…

You would just lose performance by doing what you want to do (with some exotic exceptions)

If you ever had a 3/4 street or full-race cam, you would know what I'm talking about...

The long duration, high lift cams make for piss-poor low speed operation; the gas just doesn't have enough velocity to "fill the cylinders" at lower rpms. (There is more to all of this, but that is one of the salient points.)

The car will NOT be at its best and will lose HP in 90% of most situations. The old 3/4 street cams would barely idle at 1000-rpm and the race cams would be useless until 5-6K.

You can drop the engagement point a bit (so I've been told), but it is a small amount (and you need a good dyno tuner)...

 

Not the pistons, but it would increase wear on the valvetrain. At my local Acura dealer there is a nice exploded-view drawing of how vtec operates. On the valve side, there is a pin that engages the higher profile cam, giving the engine a different charateristic. I've not explored the intake.

To build on what EricL said in the previous post, an engine gets max performance when it has a completely filled cylinder (or overfilled in the case of super and turbo chargers) with a TURBULENT fuel-air mixture.

At low RPM's, if the engine can breath (inhale) too easily, you get a more laminar (less turbulent) flow into the cylinder. These do not combust as quickly or efficiently. A nice two valve, push-rod engine generally doesn't inhale for $hit, giving a very turbulent flow, so it makes great power (torque) down low. Get up high in the RPM range, and the same setup is starved for fuel/air mixture - no power.

An engine with 4 or 5 valves per cylinder, and/or only having high lift cams, will have a much easier time filling the cylinder, so at low RPM's, the fuel/air mixture is not very turbulent - less power (torque). However, when the RPM's climb, that 4 or 5 valve engine is still able to breathe, but is now getting a more turbulent flow. Combustion efficiency goes up, power goes up, smiles get big!

The point of VTEC is to give the engine two performance characteristics. This is accomplished with two intake cam profiles. The low profile / low RPM cam gives the valves just enough lift at low RPM to fill the cylinder w/o strangling the engine. As RPM's climb, a different (higher) cam profile is engaged, giving the valves more lift. This lift is necessary because the fuel air mixture must travel at much higher velocities to fill the cylinder. At these higher velocities, the engine would be strangled by a low-lift cam, hence the higher lift VTEC cam.

Hence, if you engage VTEC too soon, the cam profile will be such that the fuel/air mixture will not be turbulent enough to generate maximum power (torque).

 

Nice post jdl75.

I don't learn something new __every__ day by reading these boards, but I think I learned a few basic things from that one.

 

So basically we just need to find a way to increase the redline in our car by oh say 2,000 rpms Any ideas

 

Lots of timing and fuel..

 

more valve springs, lighter pistons and crank and rods...

 

Removing the rev limiter and fuel cut-off?

 

would disconnecting/removing the rev limiter take away power, i also heard somewhere that if we diconnect/remove (not sure how it works) takes away power from the car...

 

You will have to wait for one of the ECU piggyback units or a full replacement ECU (like the AEM unit) to kill the current rev limiter.

Someone may know something, but I sure don't or haven't heard of anyone killing the limiter with the "non-programmable" chip that is "supposedly" in our "computer".

As a note:

1. With the stock setup, you sure wouldn't get much out of doing that anyway -- the torque drops off and I don't see anyone selling replacement gear change sets...

2. If you do add headers, CAI, and the other current "goodies", the torque curve is dropping away after 6100 rpm (or close to that point). Without changing the gear ratios, there would be little point in doing the work. The optimum shift point for a car with: headers, CAI, etc is around 7000-7200 RPM (right at fuel cut-off). There is a possibility that a few hundred extra revs might help out with an ECU upgrade, but that dynos will need to be seen first.

Finally:
If you removed the rev-limiter, you would NOT necessarily "remove" any power from the top end... You could be in for a nasty surprise as you would sure be able to find out where the engine came apart...