SiR-DC2

Also what ECU is it, I thought VTEC on a sohc was at 5000, mine is at 5700 and my revlimit is at 7500, my ecu is a P2P. Anythoughts? Is this correct? Just curious, I would search but rather hear other opinions. Thanks.

willyboyK20

On mine it comes on right around 5600-5700. With my ebay cai you can really hear the switch over.
However, on 96-00 ex the redline is around 6800 rpm. The earlier ex's (92-95) redline was 7200 rpm
How are u shifting at 7500 rpm on the obd-2 computer?

RyanEJ8

For the P2P 5500rpm=VTEC, 6800=Redline, Fuel cut-off is a little bit above redline around 7000rpm. The stock tach is a little off.

For the P28 same VTEC, redline at 7200rpm and the fuel cut-off is a couple hundred rpm above that I am assuming. It seems to go a little farther than my P2P, but I haven't hit the rev limiter yet.

vladd

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">For the P2P 5500rpm=VTEC, 6800=Redline, Fuel cut-off is a little bit above redline around 7000rpm. The stock tach is a little off.

For the P28 same VTEC, redline at 7200rpm and the fuel cut-off is a couple hundred rpm above that I am assuming. It seems to go a little farther than my P2P, but I haven't hit the rev limiter yet.</TD></TR></TABLE>

i always heard that on the p28 vtec kicks in at 4500? however, i've never driven in one, so i wouldn't know from experience. you're right about the p2p. according to the stock tach, my cutoff is at 7200.

RyanEJ8

Yeah I have also heard the P28 VTEC is at 4800rpm before, but have more commonly heard 5500, but I guess more commonly doesn't necessarily mean its right.

eg6turbo

i have a p28 obd1 and it comes in at 4900 dyno proven...it could be 4800 but around there for sure it could activate at 4800 and i see the gain on the dyno graph as 4900...i dunno i say 4900 tho...

RyanEJ8

I wonder if the earlier engagement of VTEC on the P28 could actually hurt performance then?

vladd

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">I wonder if the earlier engagement of VTEC on the P28 could actually hurt performance then?</TD></TR></TABLE>

i'm sure the vtec point is tuned to the engine, honda should know enough about their engines to know when to set the vtec engagement.

RyanEJ8

Yes, but I am using a P28 with a D16Y8, which would normally use a P2P, so it is not the same engine.

vladd

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">Yes, but I am using a P28 with a D16Y8, which would normally use a P2P, so it is not the same engine.
</TD></TR></TABLE>

oh ya, i forgot about that. i thought you were just talking about a stock d16z6 with a p28.

RyanEJ8

Yeah, I'm wondering, maybe when I put in my Hondata, I should set VTEC back to 5500rpm, if it is indeed at 4800rpm.

SiR-DC2

That's f'n nuts. I know how inaccurate tachs can be but at say 5600 I can hear VTEC, BUT on my dash, it goes all the way to 7500 on the dash, I understand the ecu is right and the tach MUST be wrong but damn, being so accurate at 6000 rpm and off at 7500 makes no sense to me. Oh well...
VTEC SOHC 5600
Revlimit 7200
Redline 6800