Deleted03.15

It just came into my head earlier, you've got the stated output of 240bhp but what is it at 5600rpm? how much 'gain' does the vtec engagement give afterwards?

chrispayze

It's a bit of a moot point because the reason for the 'kick' isn't a jump in power, but actually a slight dip in the curve just before VTEC. So the question isn't 'how much extra power does VTEC give?' but 'how much is lost just before VTEC?'.
Also, VTEC doesn't instantly give more power. It enables a cam profile that suits high revs, so it effectively prevents the engine running out of puff at high revs and keep increasing power as the revs rise.

Nottm_S2

Just look at a power curve

https://goo.gl/images/BxKcR1

Bodyboarder1981

..... so I guess what chris is saying is ..... not a lot before and a bit more when you keep revving it ...hahaha

i very much doubt they actually made 240bhp , even when new .

I guess a dyno graph would show the power at the related rpm.....

im guessing 160bhp at 5500 .....

richmc

Looks like about 155bhp at VTEC crossover, my car is bog standard. Peak BHP at around 8700RPM

Nick Graves

I'd have 'apportioned' it based on 237 @ 8,700, which is about 149.

It's never quite that linear, but is a rough approximation.

Santenay

According to the power graph for my car, it puts out 153bhp at 5500 rev/min and 178bhp at 6000 rev/min. Peak bhp is 247.7 at just under 8500 rev/min

Chuck S

What the heck is "calculated flywheel horsepower" Only power that counts is st the rear wheels.

-- Chuck

Nick Graves

It's a rule of thumb to try to determine flywheel BHP. Since every dyno will produce different results (and even then vary according to the weather) it's all a bit 'pinch of salt.'

People like to determine their base line, compared to mfr.s claims, to see how much better/worse they've made the engine by tuning it on the next run.

Useful-ish for that, I suppose. Especially since mfr.s figures are often 'out'. I don't think any RX-8 ever posted 237 BHP even on a good day, and a lot of TurboWhangDangDoodles are 'modestly' rated.

s2konroids

THey make circa 150BHP before vtec, and most dyno stock between 220 and 230 BHP. They also dont rev to 9000RPM its just shy of this.