Hey guys,

I have an F23 stock except air intake. The other day, i was messing around the road and went full throttle at 2,000 rpm in 2nd. when it hit 2,500, i noitced a power and sound increase, like a "kick" that would be noticed on a B series or other DOHC VTEC engagement. But I know that VTEC even on an F23 is not supposed to be that low in the RPMs. ? ? ? ? ? ? ? ?

has anyone heard this too? It always happens and is very noticeable especially with the intake.

Thanks!

 

Should be arround 4500 - 5000 rpm I think.

 

On the F23, the VTEC comes on at a wide range of RPM, depending on throttle position.

 

Should be at around 4500 and shut @ 4200... Is it an f23a1?

EDIT: I just checked with a honda mechanic and he told me that the vtec could be activated as low as 2000rpms and it shuts 200-300rpms lower than the rpm it went on...
and, not to reject jon's point of fuel saving (which make sense since our cars are not mean for performance), but the mec said it was for performance purposes.
The mec is a 50something year old man that has been working on hondas all his life...

 

Yeah its an F23A1. Thanks for the quick replies, guys!

 

I've got an 02 with the F23A1 in it as well and i swear it starts to pull harder right around 3k RPM when you're wide out in 2nd... VTEC seems to really kick in in the 4k range as suggested though..

 

if i remember correctly vtec kicks in around 5000-5500rpm on a 98-01 accord. but it varies a little bit. cause in first gear on my 99 accord vtec kicks in hard at 4000rpm but i have a good amount of mods including an Apexi SAFC2. and that Apexi SAFC2 makes a big difference i think i gained 20 or 21hp with the Apexi fuel program. i smash on b18 swapped hatches all day long. dont get the Apexi VAFC2 which is the vtec one. it only works when you got a turbo on your accord. i hear a couple good things on the VAFC2 but more bad because it messes with the vtec or something like that. So I went with the Apexi SAFC2 and works like a charm.

 

You can't tell when VTEC kicks in on a F23 engine. VTEC is for fuel savings purposes, not power purposes on this engine. It comes on as low as 2200 RPM. A guy over on the 6thgenaccord.com site wired a light directly to the ECU to show every time VTEC came on. It came on as low as 2200 RPM.
Anybody who says they "feel it kick in" is imagining it. Yeah you can feel it on a DOHC because it is there for power, but you cannot on an F23.

 

Yeah that makes sense... I also read that some VTECs have a multi-stage system...kicking in at 2,500 then all out at 4,000 depending on throttle position, speed, etc. Still don't fully understand, but hey, it's still vtec...

 

vtec on sohc is almost point less. Your intake valves open up more on vatack but not the exhaust valves. DOHC both intakes and exhaust valves open more when vatack is engaged.
110% correct sir!
you can't feel the cross over on any sohc engine.