STAIN

Thats some nice gains with N/A, good job

J's headers, no-cat single exhaust really punches out some numbers..

vyets

Thats bloody awsome mate power curve looks useful now *inspired!

Siggy

I love these kinda builds, bolt-on power mods iwthout touching internals concentrating on the twisties. Making alot of the gains by stripping the car and modifying suspension, making it a drivers car and not all about power.

Car looks amazing too man, i read most of your thread, any thoughts of gearing it at all?

mcopley

Yep, I do want to put in 4.44's and an OS Giken LSD... but I'm waiting for the diff to break before I take the plunge and rebuild it all

MAD828

Before and after dyno looks awesome!

Also were both dyno runs performed on the semi slicks?

mcopley

Yes, the R888's were on the car.

Here are my Apexi NEO settings for anyone that's interested;

mcopley

Ok, so now I'm a little concerned

I went to a honda dyno day yesterday, and the dyno operator wasn't very happy with my afr. According to their sniffer it was about 17 at idle and around 14 average through the rev range (I don't have a print out of the afr). They could near a knock at idle, so they added +5% fuel (using the NEO) at 500, 1000 and 1500rpm. They did this for both the lo and hi throttle maps. This brought the idle afr back down to around 14 ish and also picked up some good gains (10 hp peak). The knock also appeared to go away.

I will post up the dyno chart later...

My question is though, the knock that they could here at idle seems to still be there, even though the afr is 14. They reckon that it's still too lean at idle, but I've read on this forum that the factory ecu tries to keep the idle afr at 14.7? Should I be worried?

Secondly, the dyno chart I posted a few weeks ago showed my afr was between 11.7 and 12.9 for the whole chart, so what's changed here?

Lastly, the +5% on the lo throttle tune (bringing the afr back to 14) is just temporary as the ecu will learn around this. So what can I do for a more permanent fix?

honda9krpm

A couple of comments

-Most engine won't run at AF of 17:1

-Car rarely knock at idle because there isn't enough load on the engine

-If your neo is the same as what the VAFC used to be, it's not effective during close loop (ie idle or cruise). It's only effective at WOT (wide open throttle).

Sounds like someone is pulling your leg or doent know what's he was talking about

mcopley

^^^^ I would tend to agree with you if it wasn't for the following;

1) I was watching the AFR readout on the screen when it was showing 17. I also saw it drop to 14 as they added fuel in the lo throttle tune. The VAFC / NEO is affective in close loop, but only temporarily until the ecu learns around it, right? I'm assuming that's why the knocking went away in the workshop and has now come back again after I got home.

2) I also saw them dyno another S2000 (with a Greddy EMU) later in the day and saw the readout at 12.5. This makes me think their afr sensor was accurate...

I don't know what's going on

mcopley

Here is the dyno;