JR filter (or whatever aftermarket filter)
Bored out throttle body (ProFlow, Spoon, etc.)
Headers (Mugen, HKS, Spoon, etc.
Exhaust (HKS, Mugen, Comptech, etc.)

these parts by itself doesn't lend to very much gains in performance when tested one by one on the dyno. However, working in concert, these parts make a noticeable difference.

was that comment way out to the left field? or did it stay in the ballpark?

 

I'LL LET YOU KNOW MY FIRST IMPRESSION ON THE FILTER IF I CAN FIND THE B@STARD IN THE UK!!!

 

It's in the ballpark providing you can prove it with some dyno readouts - it's quite possible that working in concert some of the above items may actually negate the effect of the other (assuming they are not set up properly to work together).

 

I think your right. Even just the Headers made a difference to me. All those together side by side your definitly gonna say WOW.

 

[QUOTE]Originally posted by Pinky
[B]I think your right.

 

mingster,

You need to add a fuel pressure regulator and an air/fuel mixture sensor.

 

2/19, I'm having the V-AFC installed, it'll do the trick (I hope). R&D Dyno will tune it for me.

 

Mingster
let me know how it goes. If it as an effect I'll do mine (in other words your the test rabbit) hehehe

 

Richard,

I would advise developing a test regimen before actually hitting the dyno. Given that R&D charges $100/hr, maximizing your test time is well worth it. I spent an hour on R&D's dyno today tuning my other Honda and managed to pack in 17 runs while tuning A/F, timing, etc., but only because I put together a flow chart ahead of time. (BTW, their wideband O2 sensor works great, but you have to weld in another bung on the header, something I won't be doing on my S2K).

In your case, you'll really be concerned primarily with WOT mixture. While the AFC-VTEC also has part throttle control and VTEC activation point control (if memory serves), those should be secondary for you at this time. With your scientific/engineering background I don't think you'll have any trouble developing a routine. For example, test #1 (after a new baseline is set) should be adding a set amount of fuel across the entire rpm range at full throttle. Then compare the results. If power is gained, then add more fuel and test again. If power is lost, try subtracting fuel, etc. You may find that you'll have to go different directions at different rpms, but if you have a plan, you'll get a lot done. Gradually you'll zero in on the right mixture.

After you've done that, hit the VTEC point. The easiest way I've found on other controllers is to simply lower the VTEC point to an obscenely low level (say 4500 rpm). Then compare that curve with the stock curve and see where the hp lines intersect and that should be your VTEC point. Of course, you'll have to worry about VTEC enrichment as well, but just pick a number and see how it works.

Hopefully those that have already done some tuning on their S2K's will provide their test regimen for your perusal as well. Especially since the AFC-VTEC is somewhat more complex than other controllers. Pay close attention if they offer up advice.

For those advocating adjustable fuel pressure regulators, you might want to investigate how long term and short term fuel trim work on OBDII equipped Hondas. While the S2K is all new and I haven't put an OBDII scantool on one yet, I suspect that like past OBDII Hondas it has a long term and short term fuel trim value. This value is determined during closed loop operation when the ECU looks at what it expects A/F mixture to be based upon the injector pulsewidth/MAP input and what it actually is at the O2 sensor. In the short term, it makes immediate changes to ensure a proper mixture. If, over a period of time there is a consistent trend to the short term trim, the long term trim value is altered (for example, if injectors gradually become clogged over time and the ECU has to add pulsewidth to compensate for a lean mixture, the long term trim will pick up that addition and short term trim should move back towards zero). I can't tell you how long short term or long term is (I don't know), but these things do exist.

If I've explained it clearly, then hopefully you see the _potential_ problem with adj regulators or fuel controllers that affect fuel trim all the time. Because the ECU takes that trim it learns at part throttle and, AFAIK, applies it to WOT too (after all, if you're running lean at part throttle, then you're probably running lean at full throttle). That means that over time, any fuel alterations you've made with fuel pressure should be trimmed out, unless the car was incapable of adjusting to the optimal range before (e.g. the mixture was still too lean after pulsewidth was maxxed - more pressure would help here). This also explains why many Hondas can see hp gains in the range of 20-30% from bolt-ons, headwork, cams, etc. without any changes to the fuel system. Keep in mind this stuff is not concrete, as many factors come into play, but it's something to think about. If you've dyno'd with an adj regulator, go back a week later and see if the gains are still there. I'd be curious to know.

UL