from my understanding honda first started out making bikes. so when they started making cars they brought some of that technology over to car manufacturing.
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from my understanding honda first started out making bikes. so when they started making cars they brought some of that technology over to car manufacturing.
yes :wave: i like cars that go VROOM :thumbsup:Quote:
Originally Posted by ProECU
camshaft profiles have alot to do with it as well.
Every seen how alot of old skool cars have really lumpy idles and don't run very well low down. They have very aggressive profiles, so will only run well in the higher part of the rev-range.
And as what has been said before power = rev x torque
simarly, most std engines run the opposite, smooth idling and low rpm running but sacrifice hi-end power.
honda took it a step further with VTEC. A very mild cam profile for low down, but they've added a 3rd lobe which is an aggressive cam profile. This swtiches over. So essentially when the low down cam is getting to the end of it's "power band" the agressive one is just comming into its power band.
This is the exact reason why you shouldn't lower the VTEC cut-over point, as the aggressive cam profile will not be in it optimum. Which can actually make the car slower.
Typical honda drivers.. ...... ... .. .
Thats not totally accurate information.
quite often on modified hondas with "lumpier" cams, the engine demands a lower vtec point. Ive seen it on the dyno.
This is due to the different fueling requirements for economy vs power.
You will see the vtec lobe can make power earlier when tuned correctly.
Quote:
Originally Posted by ProECU
really? on modified one's cutting the VTEC in eariler is better? i would have thought the more modified the later the VTEC cut point because it wouldn't run efficiently outside it's power band.
info taken on board.....I don't know much about honda engines specifically. Just engines in general :)
ALTHOUGH....what i said in my previous post was in regards to a std engine. It wouldn't matter where the VTEC cut in, it would still make the same amount of power in the end. The dyno graph's would look very different though :)
This thread is back from the dead..... :thumbsup:
A year after it started :)
This totally depends on a cam by cam basis mate. But even with "stock" cams such as CTR or ITR cams there may be benefits in lowering/increasing the X-over point totally depending on other factors.Quote:
Originally Posted by rev-tech
In any case the decision of the X-over point is not decided by how "big" the cam profile is but by the area under the power curve and the A/F curve.
VTEC = A Reving machine that never goes anywhere until you need to change gears. Insanely fun if u dont mind revving but not go anywhere...
Supercharger = A torquey powerhouse that looses to water wheel in a revving comp. Torque galore but boring to drive.
Turbo = Torque and Revs. Why doesnt honda copy the yank's modified car scene and wack a turbo on a typeR. That'll teach the s15s and WRX's a good lesson...
Sh1t.. Im talking nonsense.. need to sleep..
gnite