Like the title says, at what rpm does i-vtec engage?

thanks

 

Search, been covered. I'll be nice though, it engages at 2200 RPM's. From 12valve to 16valve mode.

 

sorry i did search for it for bout 10 mins.

thats kinda early for vtec to engage, can u tell me why they made it so low

 

Yes, because we got a watered down version of the K20. The K20A3 was made like the VTEC-E of the older engines. It runs on 12 valve mode under 2200 in order to reduce polution at idle. Therefore, it's LEV2. The only thing that changes while you mash the pedal is the timing that the VTC controls.

 

Interesting. However the K20a3 is the RSX K20A2 minus the V-TEC on the exhaust side, and lower compression pistons 9.8 k20a3 versus 11.1 k20a2. The K20a3 is V-TEC on the intake side. V--TC which is the I=intelligent in I-Vtec controls cam timing and has nothing to do with 12v to 16v mode as I have never heard of the I-VTEC's doing any such a thing. I-VTEC has parameters that are measured by the ECU that adjust cam timing to suit whatever driving condion and deliver optimum power, and give it the ability to meet LEV2, this is one of the reasons the new k series have better midrange and torque distribution than the older V-TEC's. The V-TEC engagement question on the 03 Civic SI is a very good question and the phrase 'search' should not have been regergitated out as it is so often. V-TEC engages at 4800 rpm for the K20a3.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gerhard_001 &raquo;</TD></TR><TR><TD CLASS="quote"> The V-TEC engagement question on the 03 Civic SI is a very good question and the phrase 'search' should not have been regergitated out as it is so often. V-TEC engages at 4800 rpm for the K20a3.</TD></TR></TABLE>

Can you quantify/prove that (the 4800 rpm point)? Nearly everything I've
read (from others and from Honda's own info) has the crossover (from 12v to 16v)
at 2200ish rpm (it varies under load, IIRC).

Other than that, good info in your post.

 

Ok, I already mentioned most of it except maybe the compression ratios. You can argue all you want but VTEC is set at 2200 rpms. If you didn't know about the 12v to 16v mode, you should read about the K20A's. It's straight from Honda.

http://asia.vtec.net/article/k20a/index.html

Need more? Look at the middle of the page.

http://www.superhonda.com/foru...08177

 

Ugh. Its been re-told so many times:

Here is Hondata's explanation:
http://www.hondata.com/techk20general.html

and Targa250's excellent explanation:
http://www.superhonda.com/foru...05867

Between these two posts you can get a good idea, in simple terms how i-Vtec works for the A3s and A2s.

 

please search first...