I'm driving a H22 accord.

I knew from reading earlier posts that the vtec engages at roughly 5500 rpm, with a p13, while the vtec is engaged at an earlier stage in the F23, perhaps around 4000. I know that one can manipulate the vtec setting with the use of a VAFC, Hondata, EMS, and/or other piggyback and stand alone units.

How many of you have changed when the vtec is engaged, and to what rpm?


Thanks a lot.

 

4850 mine is set to, it will vary for each engine,

 

if you buy my vtec controller, you can play with it and see what u like the best

 

4,500 on mine

Check my sig for my dyno

 

4600 on my V-AFC

 

i did a jdm h22 conversion and swapped out the whole ecm. i heard a rumor you could adjust the rpm the vtec kicks in if you have a jdm ecm. anyone know anything about this and how to do it?

 

i have mine at 4.4k, stock jdm cams

 

5100 here, chipped p28.

 

I think the vtec kicked in around 4K rpm, when I had the F23, and it feels as if mine is kicking in around 5500 rpm on my H22, P13. Yeah, so I think my next move would be to lower it to around 4300-4500 rpm.

Now, do you guys recommend the VAFC, Hondata, or the EMS?
I know that the EMS is a stand along unit, and that the VAFC is a piggyback compatible with any vtec engine, correct? While the Hondata only works with certain ECU's. Can I use a Hondata with the P13?

Thanks a lot.

 

I've got a related question:

Does adjusting the vtec cross-over affect the long term reliability of the engine? If not, how many miles have you guys had your cars w/ the modification?

 

Yeah, 5500 with a P13 is pretty much standard. I got a Spoon controller set to around 4700. I tried it way down and my car felt that it was peaking too early - totally **** for driving! I wouldnt go any lower than 4500.

There are guys on here that can give you the 'science bit' on why but basically an H22 will lose power if you set it too low. Give ur lo-cams a chance to get to their max effeciency/power before kicking in the hi-cams, otherwise you're just robbing ur car of power.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -Bionic- &raquo;</TD></TR><TR><TD CLASS="quote"> Yeah, so I think my next move would be to lower it to around 4300-4500 rpm.

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i wouldn't go any lower than 4500, unless you show an improvement. You have to get it tuned on a dyno so its done correctly. You can't really determine what your setting should be until you dyno it. When i got my vafc tuned they tried to set the crossover at 4300, you could see a dip in the power curve, and could be felt whill driving. But every engine is different, generally i have heard that 4700 is a good place to start, and then adjust from there.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -Bionic- &raquo;</TD></TR><TR><TD CLASS="quote">Now, do you guys recommend the VAFC, Hondata, or the EMS?
I know that the EMS is a stand along unit, and that the VAFC is a piggyback compatible with any vtec engine, correct? While the Hondata only works with certain ECU's. Can I use a Hondata with the P13?

Thanks a lot.</TD></TR></TABLE>

that all depends on the build you are going for, AEM EMS for a completely custom set-up (i.e. engine build, big turbo setups, etc). The vafc is more for bolt ons, for example its a good way to extract some more power from the mods you have done, but it does have its limits. The hondata is a rechipped ecu ( i believe p28 and p72's) they chip the ecu so it can control functions like a standalone.

Theres alot more to be said about all three options and if i stated anything incorrectly, let me know. I only have first hand experience with the vafc. My advice to you is whatever you decide, search for it in the archived content. if you still have questions start a new thread.

As far as setting vtec engagement too low, heres a simple explanantion.

people think that you can gain power by making VTEC engage at low rpms (3500,3900, etc.). Well you won't, the way VTEC works is by giving the best of both worlds, higherlift cams for up top, with low lift cams for down low.

 

I have a few non-stock modifications, specifically OS Type-S pistons and a stage 2 crower valve train.

Mine dyno tuned to be best at 4800 with a V-AFC. The motor did not like going any lower than that, as the power would be sluggish until about 6500 at any lower setting. Top end was the same, the curve was just not as desireable from 4800 to 6500. Remember, if you adjust the VTEC crossover, you also need to adjust the fuel settings to accomodate the fuel requirements.

As stated, it is best to do this on the dyno.

 

i tried it higher and lower and found it is best where honda put it on the h22

 

Thanks guys, good information.

Well, it's obvious that I could not simply set the vtec at 4500 rpm and then call it a day. I do understand that the air/fuel map has to be tempered with, and one can only find the best results through the dyno. I did not need that to be explained to me.

Can I use a Hondata with the P13, or do I need to buy another ECU? Does anyone know if the featurs on the Hondata also exists on the EMS i.e, launch control and full throttle shift?