Why Honda Vtec high rev low torque?

[Quantum]

just for knowledge, pardon me ignorance

noticed honda vtec engine can produce high hp compare to other maker same cc engine, but the max torque is lower and the max torque happens at higher rev , a typical example as:

 

Civic 2.0 vs Sylphy 2.0

155hp/6000rpm vs 133hp/5200rpm

188N.m/4500rpm vs 191N.m/4400rpm

 

Does it mean vtec engine is poor low end sprinting, especially not suitable Singapore driving condition?

Edited February 28, 2007 by Quantum

[Snookium]

My Ek3 on paper is 130HP

 

and do a dyno and realise that it is only mere

 

HP = 121

Torque = 130

[Rickster]

Hmm...I'm a noob in the area of VTEC too...but I heard some of my frens mentioned that the VTEC is a hi-revving engine and thrives on high revs.

[Snookium]

SO during traffic turn green , i always find myself lag behind unless i open vtec as compare with those 1.3cc-1.6cc

[Iziz]

Dun just base on paper specs, the shape of the torque curve also plays a part.

 

Think of Vtec as a "turbo", the power comes when the Vtec is on.

Edited February 28, 2007 by Iziz

[Quantum]

dose "open vtec" mean boosting rev over 3.5k/rpm by flooring accelerator?

if like that, the FC will be jalat yeh

[Quantum]

Torque = 130

indeed very low torque, even lower than current most popular 1.5L/1.6L altis, sunny, lancer, vios, latio..etc

[Jacf]

how U on VTEC? high rev on moving off ?

[Silveratenza]

Basically what i experience is that once you rev more than 3k, you will feel there is a slight surge forward and engine becomes very loud...

 

even when cruising at 90-100km/h, if you wanna overtake, just ram it and u feel as though there is a fifth gear change...(although ES5 only 4-speed)

[Falc]

just for knowledge, pardon me ignorance

noticed honda vtec engine can produce high hp compare to other maker same cc engine, but the max torque is lower and the max torque happens at higher rev , a typical example as:

 

Civic 2.0 vs Sylphy 2.0

155hp/6000rpm vs 133hp/5200rpm

188N.m/4500rpm vs 191N.m/4400rpm

 

Does it mean vtec engine is poor low end sprinting, especially not suitable Singapore driving condition?

 

3Nm is like drop in a bucket to draw conclusion lor.

But even if bad for sprinting, just start off slowly and give good FC!

[Jacf]

understand that Vtec meant to perform at high rev.. but normally cars are recommend not to travel at more than 3000rpm for long distance. meaning travel over many km at high rev abt 3 to 4k rpm. so can the Vtec engine take the high rev constantly for long periods? will the engine be damaged?

[Turbine]

[reply]

dose "open vtec" mean boosting rev over 3.5k/rpm by flooring accelerator?

if like that, the FC will be jalat yeh

 

2 types.

 

1. Vtec High Cam kicks in at 6K rpm - 8K rpm. Any "VTEC" engine which red lines less than 7.8k rpm does not have High Cams Vtec. Used in EG 5 6 8 9, EK4 9 and 3??, and all type-r's etc etc....

 

2. 12 > 16 Valves VTEC. It change from 12V to 16V at ard 2.5k rpm or 3k rpm, this is to improve FC not concentrated on power. Now all Honda uses this expect Type R's.

 

Vtec growl only No.1 haves.. the rest doesnt.

[Silveratenza]

Revving to 3k and above are for the short burst of acceleration...when back to cruising, the rpm will drop back to 2k range...

 

For auto, I dun think we can drive constantly at 3k and above...unless it's more than 120km/h...

[Eyke]

Does it mean vtec engine is poor low end sprinting, especially not suitable Singapore driving condition?

 

yes, unless you don't mind rev'ing past the VTEC "open" rpm everything you want to sprint from standstill.

 

the older VTEC engines are very much like racing engines where they rev high for power.

 

but newer VTEC engines are designed to be more city-driving friendly, ie. more torque at lower revs.

[Chemz]

most engines can sustain their rpm range, that's wht the engine are built for, power distribution throughout a given range.

 

it's only when u push beyond the redline for sustained periods where it will cause probable damage

[Felipe]

just for knowledge, pardon me ignorance

noticed honda vtec engine can produce high hp compare to other maker same cc engine, but the max torque is lower and the max torque happens at higher rev , a typical example as:

 

Civic 2.0 vs Sylphy 2.0

155hp/6000rpm vs 133hp/5200rpm

188N.m/4500rpm vs 191N.m/4400rpm

 

Does it mean vtec engine is poor low end sprinting, especially not suitable Singapore driving condition?

 

i think when yr sprinting, high end matters most. after all, sprinting is abt flooring throttles

[Turbonetics]

My Ek3 on paper is 130HP

 

and do a dyno and realise that it is only mere

 

HP = 121

Torque = 130

 

bro,the HP=121.torque=130 is it on wheels?

if its on wheels,then i think its impressive.

[Turbonetics]

how U on VTEC? high rev on moving off ?

 

if you are asking about the old school Vtec,it works like this.

when you rev the engine to around 5000rpm,the ECU with the help of the Vtec solonoid will activate the rocker arms inside the engine allowing more air to flow into the engine.

iam not sure if the new Vtec(12v-16v) engine have this Vtec solonoid.