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This is one thing which I am yet to find reasons for...
Why do Hondas of all car manufacturers seem to have this reputation for building cars which seem to rev high..good example is the S2000.
Is it coz they got it from F1 or is coz they passed on technology from their bike subsidiary?
First-class engineering, lots of R&D and F1 technology...
:)
The fact that they don't want to go the turbo path (VTEC is their answer to that) have meant they have to make more power by revving higher. Amd this they have done very well.
Also most of the cars they release make power up high with low torque down low (civics and integra's are notorious for this), however the S2000 is an exception.
Most Honda's are setup like this from factory (to make power up high in the RPM range) and hence why 1.6s make 88-96kW.
also honda engines are generally small in capicity (sub 2l), therefor light. And the lighter you can get the engine the the higher you can get the rpm.
Also honda's are probably the highest engineered jap motor company. As well as non turbo, f1 and bike hertige.
So these all add up to higher rpm.
This is why things like american and aussie shit v8 high litre engines have a relatively low rpm (even the v8 'supercars' have a redline of like 7500rpm)
Thats because they run pushrod setups (most american V8s) which aren't able to rev as high as their overhead cam counter parts.Quote:
Originally Posted by Dxs
As for the V8 supercars, one of the restrictions/regulations is that they have a cutout at that RPM so the playingfield is 'even'.
i stand corrected :wink:
i still stand by the shit and general weight comments though :twisted:
HONDA stands for
Hold
On!
Not yet
Done
Accelerating...
sorry dude from clubrsx.com
took ya material... :D
well with regards to Honda engines, I know that Honda is the largest engine maker in the world, producing more engines than any other manufacturer.Quote:
Originally Posted by Dxs
Honda engines are usually oversquare, (shorter stroke, larger bore) then other engines of the same capacity, Allowing them to change direction more quickly. Hence they can rev higher.
Power = torque times by rpm.
therefore
revolutions is the only replacement for displacement.
:D
so is turbo-charging :)Quote:
Originally Posted by crx_16x
Dunno about this, the EB and EN engines wern't, but an EB could be made to rev to 8000 with enough work ;) Mugen did it in their formula cars. I have a feeling the ZC was also undersquare - I'll have to check that :?Quote:
Originally Posted by Hadean
Real reason why they rev so hard?
http://home.iprimus.com.au/cuchulain...ndarebuild.jpg
:lol:
I wonder how many Hamsters are in my DC5R???
oh btw, there really is such thing as a hamster driven car. Some dude had a bunch of these hamsters running in a cage driving an electric motor. The electricity generated by these hamsters were driving an electric motors at the wheels of this car, and presto: u have a hamster powered car...
nicely worded.Quote:
Originally Posted by crx_16x
Hondas are known to be,
Hiroshima screamers...
HONDA:
History Of No Dramatic Acceleration.
--> I guess the above sums up my car in its entirety.
Setanta your right about the ZC being undersquare the d16a8,
(zc in a different guise) had a bore/stroke of 75/90.
This will normally make engines sluggers and not revvers.
I would like to see what my d16a8 would be like with a c/r of around 11 or so :twisted: ........
Turbo is one way to make more power it does so by making more torque. In theory increasing the displacement of the engine by compressing more air into the combustion cycle.....
instead of increasing the rpm of the engine the turbo creates more torque.
more torque more power....................... (i think!!) :P
Anyway the answer to the question,
"Why do honda's rev so high?" is simple.
To make power. To make power you either need to increase the rpm of the engine or increase the torque of the engine.
Correct me if i am worng...
James.
simple...becuase it's a Hondah!!!
theres a few reasons for this, mainly bore and stroke
you'll find that smaller capacity engines use a larger bore : stroke ratio. in cases of the Honda engines, the stroke is rlatively small by comparison to rival engines, to counter this it has a larger bore. bore being the surface area of piston head.
cars with a larger stroke travel more per revolution, thus giving them more power down low, however are unable to match this at higher rpm where each revolution travels further and thus takes more time and energy. by lowering the stroke the trade off is less torque, but an ability for the engine to rev harder further up the redline as instead of long throws of the crank, your now getting short quick throws. obviously this benefits a variably timed cam valve system, where if the cams operated at full potential down low, the car would suffocate on the extra air and would not cumbust correctly, meaning less power or complete engine stall. so full combustion of the air at high revs suits variably timed engine with a larger bore and smaller stroke
also Honda VTEC engines are usually mostly hand made, thus alloying them to build them with more accuracy then a machine. cars are built with certain tolerances from the manufacturer, by limiting the amount of tolerance outside the manufacturing process, you are maximising the engines potential by eliminating the loss of power brought on thru kinetic engergy lost through friction, drag or any other resistant forces
another interesting fact is the the type r ports are actually hand finished and the heads are assembled by hand before going into the car!
no other mass produced car offers this!
love my civ, Kills anythig off d MARk!!
Honda made a F1 engine in late 1965 that reved to 12,000 prm, 1.5l V12 engine ( RA 272E ) producing 230 ps @ 12,000 outclassing many rivals of the time.
in 1962 they released a 492cc engine in the S500 producing over 40 ps @8000 rpm and the never to be released s700 pumped 72 ps @ 9500 rpm from a 682cc dohc
I guess there small engines revving high, but there competitors then could not match
Honda with same capacity engines
honda have always been known for there high reving smooth engines
it's without the yet!Quote:
Originally Posted by Tofu
and apology not accepted lol.. :D :wave:
Honda B series :thumbsup:
Historically it seems, Honda has been in persuit of economical, small displacement engines, and only recently have they ventured into the 2.0L + class.
It is known fact, Horsepower is proportional to rpm and as per crx-16's explanation of Power = Fxacc,then it stands to reason the higher the rpm, the more Power ANY motor will make.
It appears Honda have chosen this route of small displacement engines & high rpm motors to couple their relatively small cars of the past.
As an aside note, the reason why these rpm's are attainable is due to 2 factors.
Bearing quality & Rod length. Honda factory bearings are of such great quality, that other non-honda hot-rod enthusiasts commonly machine their cranks & block journals to suit honda bearings. Wear properties on these pieces is simply awesome.
Secondly, Rod length as most of you know also dictates not only piston position, however by way of forst & second order differenciating also dictates piston speed & position. Attached is a utility I put together to highlight this phenomenon. Hence we have a situation of long rods = lower piston velocity/acceleration at any point over time, compared to a motor with a smaller rod length.
Typically Honda has chosen most of its engine combinations in this manner.
Take for example the B16B motor. The Rod used in this block is (from memory) is around 139mm, A R/S ratio of 1.8, larger than any other B-series motor, and we all know how high this monster can rev.
Cheers
ProECU
May I ask where that data is from and how it was taken?
Thanks!
I derived the data from mathematical & physical formulas based on circular motion.
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