what do they have that the Tib doesn't,
i know they got V-tec, but what exactly is V-tec anyway.
and why do they clame to be so much faster than us, i saw a SI that said it had a 1.6 in it.

I kill on EX's all the time, and all they got is a 1.6 V-tec

there's no SI's around here for me race, so i don't know how fast they actually are.
smile.gif

 

If I understand it right. VTEC is the use of two rockerarms. With low rpms the first rockerarm goes down to a certain point. At higher rpms the VTEC kickes in and pushes two rockerarms down even further to allows more into the cylinders. But all that doesn't mean much in the Civic SI. I believe that they have next to nothing for tourqe. Like 111 torque compaired to the 160 hp. Little bit one sided. I have beat many SI's with my Tib having only exhaust. Though I have lost to a few with good drivers. Moral to the story....They arn't ****! HondaEater

 

VTEC in "performance" Hondas, like the Prelude, is included as a performance gain. At high RPMs, it does raise the valves more to let more gas in and out.

But VTEC in Civics is included mainly as a fuel efficiency gain, instead of performance. Hence the farce of it all...these Civic ricers think they've got an awesome powerhouse under their hood because they have VTEC, which makes big-brother Prelude perform better.

There are others on the forum that can explain all this in greater detail....

 

Valve Timing Electronically Controlled.

The camshafts in VTEC-equipped cars have three lobes per cylinder. A specially built set of locking rocker arms ride across this special camshaft... An oil pressure solenoid (the VTEC solenoid) pumps oil pressure into the locking pins on the rocker arms at a certain RPM, and when the pins lock up, the rockers start riding on the third lobe instead of the "normal" other two.

The "normal" pair of lobes is geared towards idle quality and fuel mileage. It's quiet, it doesn't suck gas, and it doesn't really have any more character than your local Civic DX. It has been noted that if you keep an S2000 out of VTEC while drag racing it, it pulls 11-second 0-60mph times. Ouch.

The "vtec" lobe sits between the two normal lobes, and when the rocker pins are locked by the VTEC solenoid (ie at the activation RPM) then you get a cam that's geared for more lift and more duration. This cam profile sucks gas, isn't very quiet, but makes considerably more power than the "normal" lobes.

The problem is, VTEC was not originally meant as "die-hard performance", but rather to allow a very gas-miserly car to still be able to move around in an acceptable fashion (ie without being a TOTAL dog wink.gif ). VTEC is now used for both -- better fuel mileage in those cars targeted for that audience, and better peformance for the other cars.

The Civic Si is directed for the latter, as evidenced by it's generally ****ty gas mileage (25mpg is the best my friend Joel has seen out of his).

VTEC is simply a method to allow your car to have two distinctly different cam profiles, swappable by RPM's. You would essentially find the same power by installing a set of beefier (not by a whole lot) cams into your Tib or Elantra.

-Red-

 

You should be able to beat Si's but watch out for SiR's they are a different story. Got beat by one at the track, was very dissappointed.

 

Please notice that the person asking is from the USA, in which the Si = 160HP B16A2. In Canada, this would be the SiR model...

The Si you are referring to in Canada = USA EX model (D16Y8 I think, or D16Z6)

-Red-

 

Ok, so you say it has low torque, but high HP. Ever wonder how they do that?

Si owners can thank VTEC for that one. The formula for calculating HP is (torque * RPM) / 5252 = HP. So 111 lb-ft might not sound like a lot, but add that to an 8200 RPM redline, do the math, and you've got a winner. Without VTEC the engine wouldn't be able to keep that torque that high in the redline, hence the B18B (LS, non-VTEC) having 140hp and the B18C1 (GSR, VTEC) having 170hp. Get it?

Let's do a little experimenting here. Let's give the 2.0L Beta a form of VTEC. Now, instead of the 140 lb-ft (at the crank) dropping off drastically around 6000 RPM, let's pretend that our version of VTEC keeps the torque at the same 140 lb-ft all the way to the same peak torque of the B16A, 7000 RPM. Plug that into the equation so you have:

(140 * 7000) / 5252 = 186.6

All of a sudden the 2.0L Beta jumps from 140hp to almost 190!

That's what the B16 has that we don't sad.gif .

And while we're on the subject of B16s, check this out:

 

Actually Red VTEC stands for "Variable valve Timing and Electronic lift Control" The VTEC isn't a true shortened version - Don't ask me why it just is. VTEC was originally designed for NSX and trickled down to the lower models. The actual purpose of VTEC is to allow a road legal car the convinience of excellent gas mileage at low RPM and Performance at the top end. Also, by using this method they are able to extract horsepower gains not normally capable in a regular engine. This is because if a non vtec engine were to use the same vtec performance lobe as the only lobe then gas would suffer tremendously and emissions would be effected because of such a large lobe at idle and low rpm. It's Hondas shot at getting the best of both worlds. Gearing in the latest designs allow RPMS to land in VTEC on every shift when pressed to redline. The VTEC lobe is activated through the ECM. As far as the Prelude theory of it being a more race bred design as opposed to the civics dohc VTEC, They are pretty much the same design with the exception of the .4l. These cars are nothing to laugh at. They come out the box with decent times and have an aftermarket army to pee your pants for BUT they aren't gods. JDM actual favorite car maker is Toyota and then Nissan. Honda only ranks third under performance because their engines have a fatal performance flaw - they were primarily built for NA not FI. Why they became so popular in the states i don't know. There is much more to fear on the streets such as American Muscle! An SS is a scary thing. Here in Texas they rule the streets - Stangs, Ro's and Vettes alike. When you look at them the hondas look like just another spit in the bucket. A 13sec Z28 is a dime a dozen here in Texas. It's no shock to see a 12 or 11 either. Hell, I've come across more than 6-10 sub 10 V8s at street night. Your question shouldn't be what's VTEC, it should be " how the hell am I going to find a replacment for displacment?!" smile.gif Answer: TURBO!!!!!!! PS not trying to step on anyones shoes - just saying what I know.

 

PS difference in EX and SI are that the SI holds a DOHC VTEC and EX is a single cam VTEC. The extra cam on the SI allows for 35hp extra - big difference.

 

Ok, well here's the thing, how can a Tiburon beat a Civic Si? This is beyond me. Don't Civics weight like 2200 lbs. whereas Tiburons are at least 2700? Si's also have more horsepower (160) to our 140. So isn't the power to weight Ratio in Honda favor. Also is there any such talk of such an engine being manufactured for our Tibs? Just to level the playing field. Also if you notice, Vortech has a Supercharger for Civics that produces over 270HP. While we're just shooting 250. Whats wrong with this? Why can't we have the same options as a Honda?

P.S. Why are Tiburons-subcompacts and Civics are compacts, and yet we weigh so much more? Where do we pick up all of this weight? A Tiburon isn't really all that light, when compared to some of the cars in the same catagory.


I want a VTEC Civic, or just massage a GS-T motor in there. Or how bout a 1.3L TT Rotary? lol