I've had my s2k for about a week and something I've noticed is that the vtec activates at 6000rpm. Now I just traded in my 01 prelude and both are 2.2 litre engines. The preludes vtec kicks in at 5200 and it has 200hp. Now any time someone adds say, 40 extra hp they will add a vtec cotroller to activate it at around 4800rpm. This improves the performance. The s2k already has this extra hp but it takes the vtec in the other direction. I'm thinking it must have something to do with the low gearing.-------- I apoligize in advance if the answer is painfully obvious.

 

1. the redline on an s2k is higher then on a prelude..
2. it's more fuel efficient when it come on at 6k then at 5500 or whatever...
3. no way in hell did you get 40extra hp out of a prelude by lowering vtec
4. and you're not gonna get much extra power if you drop the vtec on the S...

 

Matbe I should be more specific. This is an 05 s2000 so they both have an 8k redline. When I said add 40hp I mean s pistons, headwork, bolt-ons things of that nature. Lowering the vtec will give you more hp from 4800 on up, giving you amore linear power curve on the dyno.

 

its understood, but your comparing 2 different platforms of different natures.

 

Elaborate, please.

 

s2000 vtec weakkkk!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by texx &raquo;</TD></TR><TR><TD CLASS="quote">Matbe I should be more specific. This is an 05 s2000 so they both have an 8k redline. When I said add 40hp I mean s pistons, headwork, bolt-ons things of that nature. Lowering the vtec will give you more hp from 4800 on up, giving you amore linear power curve on the dyno.</TD></TR></TABLE>

1). Honda engineers know what they are doing to get the most power and driveability out of their engines while maintaining longevity.

2) Lowering or raising VTEC does not necessarily make HP. Every motor is different.

You have a lot to learn. No offense.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by roadawg &raquo;</TD></TR><TR><TD CLASS="quote">

1). Honda engineers know what they are doing to get the most power and driveability out of their engines while maintaining longevity.

2) Lowering or raising VTEC does not necessarily make HP. Every motor is different.

You have a lot to learn. No offense.</TD></TR></TABLE>

i dont kno much of s2000 engines but i know damn well that honda put VTEC there for a reason...i think you shouldn't question honda, they know what they are doing

 

Vtec activates higher to keep the lower end torque and power up. Once the airflow is at its higher point and higher velocity, then the engine needs a bigger lift and longer duration cam to make the most power and torque. Take a gs-r and the vtec is lower at 4400, but the intake manifold is on its longer runners which helps keep the torque up then switches to a shorter path to increase top end. Since the s2000 has shorter runners, a lower vtec pont would hurt that torque because the air can't build up enough velocity to be efficient on the larger cam lobes. So if anyone wants to add, please do.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by roadawg &raquo;</TD></TR><TR><TD CLASS="quote">

2) Lowering or raising VTEC does not necessarily make HP. Every motor is different.

</TD></TR></TABLE>

nope, but if you lower it on the s2000 your going to burn the solinoid out faster...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Francesco &raquo;</TD></TR><TR><TD CLASS="quote">nope, but if you lower it on the s2000 your going to burn the solinoid out faster...</TD></TR></TABLE>
huh?


anyways, there's so many factors that determine where you VTEC will be engaged at. One of the most critical factors, or most influential rather is definetly the cams themselves. the duration, amount of lip, and overlap that you're going to have when comparing the low rpm lobe to the higher rpm lobe is a factor. look at the low rpm lobe for example, it makes better low end power and torque then the high rpm lobe in lower rpms, but as your start to take the revs higher, and say...you kept VTEC at 7900 when the redline is 8000, in the upper rev range, the engine would perform well...not well. (i'm on nyquil so please excuse me if i ramble). the low rpm lobe is designed for low rpm power and tq. on the flipside, if you lowered vtec to 1500 rpm, so you were always on it, because of the design of the cam (high lift, long duration) this is horribly suited for low rpm driving. this would be very bad. VTEC is not the cure all for cancer, lowering VTEC will not NET you more power. Tuning the VTEC engagement point may net you more power on a heavily or mildly moddified engine...stock, no.

then as someone said earlier, the intake runners to play a part in this. a butterly design which is used in MANY cars give gives you the best of both worlds, added length for low rpm driving and increased torque, and short runners for higher mid/high range power. blah blah blah, then we can go on and on w/ header type, exhaust system, timing, fuel (a/f ratios) etc etc etc...

but there are VTEC "killing" valvetrains setups, such as the "vtec killer" from toda. which lightens up the valvetrain a hell of a lot when ur looking @ a b18c or b16 motor, these basicallly remove the entire assembly which is used for the low cam lobes, and you're "in vtec" all the time. but then again, they say this is for off road applications only, because really, you wouldn't drive a car like this. its solely a racing application, not for the street.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SimbaDogg &raquo;</TD></TR><TR><TD CLASS="quote">
huh?


</TD></TR></TABLE>

i was getting into the lowering the vtec point and how its not always a good thing for the car. thats all

 

lol...man u must not know anything about vtec.....u dont just drop it down and expect a gain...the vtec is set at 6k or 5700 on ap2 for a reason...buy a vafc and drop it down to 4k...i will bet you money that u will be slower!!! and the motor is built for high revving so if u expected a torquey motor than u picked the wrong car...it is a track car not a drag car...!!!

 

roadawg I'm not trying to say that moving the vtec increases power. But when you change the characteristics of an engine by adding hp ( by whatever the method ), moving the vtec is one more step in tuning the engine. All I asked is why 6000? Thanks for the input.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by texx &raquo;</TD></TR><TR><TD CLASS="quote">roadawg I'm not trying to say that moving the vtec increases power. But when you change the characteristics of an engine by adding hp ( by whatever the method ), moving the vtec is one more step in tuning the engine. All I asked is why 6000? Thanks for the input.</TD></TR></TABLE>

It has to do with engine dynamics.

What is the degree of the overlap of the cams, both on the "big" lobe, and the "normal" lobe, valve lift, compression ratio, etc.. all play a factor in determining VTEC engagement.

The idea behind VTEC is to keep a steady, flat torque curve, while achieving maximum gas mileage all while having the ability to make high end power.

Engaging VTEC @6000 RPM tells me that the motor continued to make great torque on the "normal" lobe(s) all the way up to 6,000 RPM, then when the engine began to lose torque running on the "normal" lobe, bam, the solenoids lock the the "big" lobe in place allowing the motor to deliver another ~2,000 RPM worth of healthy torque.

When the engine begins to lose torque running on "normal" lobe(s), the "big" lobe kicks in. That is the idea. It's all about stretching the torque curve as far as it can go, working with the lobes on the camshaft.

As one modifies an engine, it needs to go on a dyno to see how the motor is responding to the changes in air flow, ignition timing, fuel maps etc... The only time VTEC should be changed is on a dyno with somone who can see the torque curve.

 

I think that the engagment point is perfect, because the transition on the Ap2 is much, much more smooth than it was compare to the Ap1.

 

i/h/e and ems + tuning...thats all i want...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SimbaDogg &raquo;</TD></TR><TR><TD CLASS="quote">i/h/e and ems + tuning...thats all i want...</TD></TR></TABLE>

good choice

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg6 Sukkah &raquo;</TD></TR><TR><TD CLASS="quote">s2000 vtec weakkkk!</TD></TR></TABLE>
good contribution

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by roadawg &raquo;</TD></TR><TR><TD CLASS="quote">

1). Honda engineers know what they are doing to get the most power and driveability out of their engines while maintaining longevity.

2) Lowering or raising VTEC does not necessarily make HP. Every motor is different.

You have a lot to learn. No offense.</TD></TR></TABLE>

werd. give the honda engineers there due. they have more r&D and a bigger budget then any tuner and any internet tech on this board.

 

I don't know why it's at 6krpms (VETC), but if you're driving it hard, through corners, curves, when I start to accelerate through them, that's when I need it! I'm not surprised that Honda actually designed the S that way. Oh, that's also why I bought mine

 

What are you guys on ?
If any of you have looked at a baseline dyno or an s2000 dyno'd with bolt ons u'll notice that the power jumps str8 up when it hits vtec.
What texx is saying is that the engine will have a smoother powerband, which it will, it will also have more midrange power because you will have vtec where none existed before.

If you're curious why honda put it so high. Think about the stock gearing and fuel consumption. Who wants to cruise at 75mph in vtec !?!
On my freinds RSX type S with boltons and a K-pro, we made about 35 or 40 hp at 5krpm by dropping the vtec from 6k to 4.2k .

 

do u have a vafc on a s2k...i dropped it down just for fun and it was slower...the vtec as everyone already said is set at the point for a reason...at 6k the car just fawkin pulls like a mother...now when u drop the vtec down without tunning it will jus make noise and not pull like it does at the 6k point...it may work on a civic but not on the f20c

 

I owuld imagine it would be slower if you moved the vtec with a v-afc. I was talkin about a hondata k-pro(standalone).
If you use an ems the base map will get you about 220= hp at the wheels and it drops vtec.

 

I appreciate replys. I believe some of you think that I,m talking about moving the vtec for no reason. Honda probably has it in the perfect place. But if you increase low end hp and tq you can activate it sooner and benefit. Look at the j's racing website for example. They boast a 20hp improvment over stock with exhaust header'test pipe and ecu. The ad says clearly that the ecu improves by changing redline and vtec locations but this only becomes benificial when you add hp or change the engines power curve which in this case are the same thing .