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Vtec lag

Posted: July 3rd, 2003, 8:32 pm
by e7
I just installed my vafc and lowered my vtec hitpoint to 5,300 rpm but there seems to be a huge lag until it hits 6,000 rpm. Anyone have suggestions for this problem?

Re: Vtec lag

Posted: July 11th, 2003, 9:59 am
by ITR325
What do you mean lag?? Lack of power, or you can;t hear the changeover?

Posted: July 11th, 2003, 10:03 am
by Trey
Definitely need more info like the person above asked.

IF you mean lag either way though I suspect you are watching the stock tach which will be off. In act a good way to test how off it is is to redline it till you hit fuel cut once. Your car is truly not revving past 8500 although you might see 9000 on your tachy.

Re: Vtec lag

Posted: July 11th, 2003, 12:05 pm
by Erik B
Dont mess with VTEC unless you have aftermarket cams...Honda didn't just come up with a VTEC point for no reason.

Re: Vtec lag

Posted: July 11th, 2003, 1:59 pm
by Trey
Erik B wrote:Dont mess with VTEC unless you have aftermarket cams...Honda didn't just come up with a VTEC point for no reason.
Your right but their reason seems to be more ecomony driven. Most people are truly making midrange power with VTEC at 3800-4100 RPMS (THis is not to suggest this works with the setup in question). It is to say the Type-R generally makes more power with much lower VTEC crossovers.

Trey

Re: Vtec lag

Posted: July 11th, 2003, 3:08 pm
by shivers
Trey wrote:Your right but their reason seems to be more ecomony driven. Most people are truly making midrange power with VTEC at 3800-4100 RPMS (THis is not to suggest this works with the setup in question). It is to say the Type-R generally makes more power with much lower VTEC crossovers.

Trey
I think the crossover point depends on mods and tuner as well. I've seen great results with a JRSC and crossover in the mid 3000 range and I've also seen Toda Spec Bs and crossover in the mid 6000 range. Both power curves were smooth and the crossover point was hardly noticeable.

Posted: July 11th, 2003, 3:11 pm
by Trey
Jun III's cross over over 6000 rpms also now that i think aboout

Re: Vtec lag

Posted: July 20th, 2003, 5:04 pm
by ITR-00-1457
Actually depending on your tuning JUN III's crossover should be at the stock point. With a JUN ecu it remains the same but the red line is moved to 9500 or 10,000 depending on application.

Re: Vtec lag

Posted: July 20th, 2003, 10:42 pm
by e7
It's just a lack of power, but I can still hear the vtec. I do have stock cams so I guess maybe that's the problem. I just thought with the vafc I could of changed it thanks for the help

Re: Vtec lag

Posted: July 20th, 2003, 10:54 pm
by e7
It's the lack of power, I can still hear the change over. I just thought it might of been my fuel settings not anything to do with the cams, but now I think I might change that over too thanks alot guys

Re: Vtec lag

Posted: August 9th, 2003, 12:37 am
by 98 Supercharged R
This might be a retarded reply but if your running synthetic oil it could be the problem,I talked to another guy with a type r and he said synthetic doesn't work good on vtec engines cause of the vtec silinoids(yeah i can't spell)and how synthetic is too sticky or some crap like that

Re: Vtec lag

Posted: August 11th, 2003, 11:22 pm
by Jan Niemi
If you change the VTEC crossover point with the VAFC, you absolutely must adjust fueling as well. Start with -5% HI, +5% low, once you get this right you will definitely notice a difference, I have VTEC set at 4800, and on boost she just takes off as soon as the transition occurs. It's all about the fueling. If you need more help with specifically adjusting the VAFC let me know, make small changes, if you don't have access to a dyno it' s not worth the engine damage.