VTEC VS i-VTEC?

H22Insd · #1 05-01-2004, 02:43 AM

I dont know much about them, so thats my question? What exactly is the diffrence between i-VTEC and VTEC.

The reason why i ask is because; A friend of mine owns a RSX-S, and they come with i-vtec, and he wants to race my 94 VTEC. So i was just comparing his car and mine.

Would i beat him anyway? I have a CAI, strut bars exhaust, and VAFC set at 4rpm

He has exhaust and CAI

nick-

strodda · #2 05-01-2004, 03:32 AM

im thinking he would beat you. just curious, have you ever tuned your car? setting engagement to 4k wont help much. try hittinh vtec in 3rd or 4th and youll notice the lag created by vtec being set so low.

H22Insd · #3 05-01-2004, 03:39 AM

have u ever drivin a 94 lude vtec? 94 was the fastest year for the 4th gen prelude production. It was singled out over 92,93, and 95,96. Everyone says ill smoke him, well everyone thats been in my car

H22Insd · #4 05-01-2004, 03:40 AM

guess well find out ...

prelude97 · #5 05-01-2004, 03:40 AM

what i heard was that the ivtec is weaker then regular vtec (dont know if its true) my bro has a 3.2 tl it dosent really feal like the vtec kicks in like on my lude. but i think this race will depend on the driver but i think the rsx will take cuz its much newer and it still has all of its power

H22Insd · #6 05-01-2004, 03:42 AM

REALLY? Well my friend does not like his i-vtec. When my VTEC kicks in my car jumps back, and throws me in my seat, it douns like a turbo is on my car when the windows are down. The previous owner of my car told me the car has around 210 hp at the crank. im esitmating my car around 190 and i would beat this rsx, but like i said.....well find out sunday

strodda · #7 05-01-2004, 03:43 AM

ive never driven an actual prelude before... it would be close, but hes got a little more power and you both weigh in about the same. probably comes down to the drivers.

i think that previous owner is full of it. youre not going to make 20hp from an intake and exhaust. but do tell what happens after you race. im curious.

prelude97 · #8 05-01-2004, 03:44 AM

oh and plus the older ludes are stronger then the newer ones so who knows. hope u win

H22Insd · #9 05-01-2004, 03:51 AM

strodda; ya i will most likely post it up. i am very interested in finding out,. because this kid talks.. lol

strodda · #10 05-01-2004, 03:54 AM

well im not sure who will win, but i hope you smoke his ass.

whtteg · #11 05-01-2004, 10:52 AM

The main differences in VTEC and i-VTEC are that the VTEC motor spins counterclockwise and the VTEC motor spins clockwise. The main performance difference is that the i-VTEC has a timing chain instead of a belt, and an ECU adjustable cam gear on the intake cam, this allows the ecu to advance or retard the intake cam for better performance and a better torque curve. By being able to adjust the intake cam while the motor is running the ecu can adjust valve overlap to obtain a smooth power and torque curve. Also the ecu adjusts the intake cam timing in relation to the temp of the incoming air too. Basically the RSX-S will have better power than the prelude because it can adjust cam timing to optimize hp and tq output while under acceleration.

*edit* This was not to be confused with "more" hp but "better" hp by having a better hp and tq curve.

rubix777 · #12 05-01-2004, 05:31 PM

so the main difference between i-VTEC and VTEC is that i-VTEC continuously adjust the valve and timing, while regular VTEC just switches from the lower lobes to higher lobes and adjust timing?

whtteg · #13 05-02-2004, 12:11 AM

Quote:

Originally Posted by rubix777

so the main difference between i-VTEC and VTEC is that i-VTEC continuously adjust the valve and timing, while regular VTEC just switches from the lower lobes to higher lobes and adjust timing?

Basically, only that VTEC motors can't really change the cam timming except for when VTEC cross over and the motor starts using the larger lobes. The i-VTEC motor can actually change the cam timming like you would with an adjustable cam gear on a normal motor, but the i-vtec can do it as needed and while running.

510prelude · #14 05-02-2004, 01:40 AM

ok from what i've herd and please correct me if im wrong. Is the in simplest terms I-vtech is spread through the entire RPM band and vtech kicks in at a certain rpm. I also herd the I-vtech also makes it so that you run on 2 cylinders when you idle to save gas or something.....

rubix777 · #15 05-02-2004, 02:19 AM

I haven't read anything about using 2 cylinders to save gas during idling, but the variable valve timing part is similar, if not the same, as the VVTi in Toyotas.

I'm surprised that none of the other Japanese makes have chosen to use two sets of lobes on their cams.

So Honda got the VTEC lobes first, and Toyota got the VVTi first

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