Ok I made the power i wanted too, but i have a nasty dip after vtec. I really wanna get rid of this but couldnt figure out how too. I am running a h22 with a prospeed header, stage1 cams, Skunk2 Intake manifold. Please help..

 

What ECU are u running? Total timing? I am assuming u are talking about the dip in power from 5500-6000 RPM correct? Well its either going to be timing or fuel or combination of both. Your graph does indicate a very lean at 14 AFR at around 5K and richens up. That could be partially the reason here, but consider the substantial loss of power here I am more inclined to think its more timing. Also I wanted to ask why u are running your car so lean? almost 14 AFR at 7500 RPM? Living a bit on the dangerous side it looks like. Also someone correct me here but arent the HP and torque curves supposed to cross at 5252 RPM??? Something seems off with this dyno.

 

good observation and i agree with the AFR i run VERY NEW VERY STRONG NA MOTORS AT 13.3max

 

I didnt do any of the tuning. I even said something to the guy that was tuning and he claimed 14 was safe. For the ignition timing its set to stock so i think like 16. And the cam timing is +2 on the intake 0 on the exhuast. I am using a p13 with vafc. I also added fuel from 7k up prior to leaving the dyno. The first run was baserun with no adjustments on the cam gears.

 

thats damn good power...whats the total setup?

 

Jdm h22
obx stage1 cams
Skunk2 Intake Manifold
Prospeed header
Skunk2 Cam gears
Aem altenator pulley
Ebay Intake With K&N
fidanza flywheel
2.5 exhaust
Soon to have uberdata and some good tuning.

 

So has anyone else had a dip after vtec similar to mine...
Also the reason they dont cross down by vtec is bc the torque graph is based on diffrent #'s.

 

you can tell that as he leaned out the motor with the vafc, it also pulled timing as well ... since map reading affects fuel and timing maps.

when you go with a custom ecu, you'll see a better improvement. If you want a custom eprom for now for your p13, pm me ...


Greg

 

I use to have a bad dip too. But then I got rid of the balance shafts, put in Type-S pistons, and raised the V-TEC. Same ECU. I'm not sure why it went away. The engine was fresh and re-tuned.

Comparison:


Try adding fuel after VTEC and bring it down to 13-13.5:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ranta18 &raquo;</TD></TR><TR><TD CLASS="quote">I use to have a bad dip too. But then I got rid of the balance shafts, put in Type-S pistons, and raised the V-TEC. Same ECU. I'm not sure why it went away. The engine was fresh and re-tuned.

Comparison:


Try adding fuel after VTEC and bring it down to 13-13.5:1</TD></TR></TABLE>
didnt the balance shafts add vibration under acceleration? Also how does this hurt longetivity?

ohh yeah sorry to jack the thread.

 

I already tried to add fuel after vtec and it makes it bog. Im starting to think its the vtec crossover bc people said with the prospeed header most get best results raising the crossover.

 

I didn't notice any added vibration. There is a good balance shaft thread in the Prelude forum.

You also want to raise the VTEC point with the cams. They will make power later on and probably require you to raise the crossover.

 

holy **** ****.

that is the power of h22

 

sick

 

mine does that on nitrous it might be rich at change over.

 

Another big dip. I used to have a Prospeed Header, but it was one of the first ones made with the thinner 18g steel and it cracked on me. Didn't get around to getting the thicker 16g ones yet. Looking to switch to better IM and Header and hopefully it'll make things better.

 

i had that kinda dip on my last dyno and backed the timing down it smoothed it out and i picked up power.i would try to back it down a bit i would say about 2-3 degrees.good luck

 

the reason the curves dont cross at 5250 is because they are scaled different on each side.....

a real tuning, and a resized dyno sheet will fix that problem.....

 

matix-- trying to setup a dyno day for some people down here. shoot me a pm or give me a call if you are interested. At first look, it's about $75/hr or we could rent the whole day. Let me know.

Adam

 

Do you have the SAE numbers by any chance?
That dip is related to the S2 IM, I had the same dip with mine before.
So I got rid of it and now Im running ITBs.

 

youll have a hard time getting rid of the dip with a p13 and vafc
as cheeta said when adjustments are made on the vafc it tricks the MAP in to thinking the value is different then what it really is ..since your ecu depends on the correct vaccume to choose the timming and fuel for that peticular reading its never goign to be quiet right

get your self a good tunner and a p28 ,p72 ect and youll be able to clear it up ..the reason i think the vafc is the problem is due to the fact your dip ends up reading high in powerfrom 5k to 5500 where most "dips" show a loss in power

this looks like the ecu trying to run one way and the vafc doing its thing
i bet there is another 10 horse in there too

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VSBB6 &raquo;</TD></TR><TR><TD CLASS="quote">Do you have the SAE numbers by any chance?
That dip is related to the S2 IM, I had the same dip with mine before.
So I got rid of it and now Im running ITBs. </TD></TR></TABLE>
Its made 203 sae corrected.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">youll have a hard time getting rid of the dip with a p13 and vafc
as cheeta said when adjustments are made on the vafc it tricks the MAP in to thinking the value is different then what it really is ..since your ecu depends on the correct vaccume to choose the timming and fuel for that peticular reading its never goign to be quiet right

get your self a good tunner and a p28 ,p72 ect and youll be able to clear it up ..the reason i think the vafc is the problem is due to the fact your dip ends up reading high in powerfrom 5k to 5500 where most "dips" show a loss in power

this looks like the ecu trying to run one way and the vafc doing its thing
i bet there is another 10 horse in there too </TD></TR></TABLE>
Yea I already got rid of the p13 and vafc. Im running uberdata on a p28. Just waiting to goto the dyno with darknight and turbogixxer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VSBB6 &raquo;</TD></TR><TR><TD CLASS="quote">Do you have the SAE numbers by any chance?
That dip is related to the S2 IM, I had the same dip with mine before.
So I got rid of it and now Im running ITBs.
</TD></TR></TABLE>

This is incorrect information. There should be no dip, it is simply b/c the tuning was done via VAFC. If it was done w/ a ems it could've been tuned out. As much as I don't like the skunk2 manifold, you can't just place blame like that.

 

sweet ..cant wait for the new numbers

you guys cant make me wait for weeks dammit

 

We have 3 guys, including myself, that are a definite. Two of us need to get our **** installed first. Looking June 18th or June 25th as good dyno days.