In changing the vtec cross over point lower in the rpm range, what happens after you are out of the range? Ex. 3000-5800. Are you still producing power after 5800, or staying at the max until you redline? Thank you

 

The stock VTEC engagement is at 5800, meaning VTEC is from 5800 rpm to redline. When you lower it's engagement point, it just means that VTEC is from the new engagement point (say 3000 rpm). It still lasts all of the way to redline, which is also usually raised.

 

what exactly is the question? are you asking about setting a vtec changeover window, instead of a single set crossover point? and if so, what about it?

 

^he's curious if you're still in vtec beyond the upper window. as in he thinks that 5800, is the end of vtec basically. and the answer is no. beyond 5800 its going to stay in vtec.

 

i thought there was no limit as to how high you can set it?

 

Yes, that's what I was asking. Thank you

 

well u can put the upper window above 5800, but that would cause valve train damage. you have to remember that you are re-writing the code of the ecu. so once you program it, its going to do the exact that you inputed.

 

I just ordered my flashpro...are there any harmfull possibilities on changing the crossover?

 

no just change the low vtec engagement. Dont mess with the upper one. It should stay at 5800rpms. low can go as low on N/A to 4500.

 

keep in mind that changing the crossover will probably require changing the fuel and cam timing in the rpm range that was affected by the change.

how would raising the vtec crossover cause valvetrain damage?

 

^i was talking about the upper window, not the lower window. any honda owner knows that over 6k on low profile causes valvetrain damage.

 

<-- here's a honda owner that's never heard this before. what's damaged and why?

 

^ever heard of valve float? maybe you should read up on some things on tov.

 

i have heard of valve float. how would raising the vtec crossover above 6k cause it to happen?

 

^the motor isnt designed to run above 6k on low profile. thats why people who have brains should know never to beat on a cold engine. i heard different opinions on what causes it on hondas, but the most common i've heard is something with the lost motion assembly and im guessing wat happens is when the motor is rev'd so high on low profile, the valves come up too fast and the lo profile cam isnt aggressive enough to catch the retainer in time and hi profile cam is aggressive enough to catch the valves coming up before any damage is caused.

 

so you don't know how or why, but you do know that it's a bad idea. gotcha

 

well there's a debate on what actually happens, but most people on tov were stating what i said.
i can sense your sarcasm.

 

got any links?

 

really, he just explained it, you just fail to read it.

 

No...no he didn't. He said "I heard..." a lot. lol

 

Quiet in the peanut gallery

 

 

ok since your being such a smart *** about everything why the hell do you want to know? are you going to RAISE your vtec above the stock setting or something?

 

since i've never head that raising the vtec crossover point damages the motor before, i figured i'd try to find out if there's any truth to it. are you never curious about anything?

 

I think on some of hondata's tuning videos they say don't set the vtec too low because you may lose oil pressure and not above 7000 or 7500 because it may cause cam lobe damage but I haven't watched them in awhile.