Apexi S-afc Thread (questions, comments, advice, etc.)

[Ziggymidget5]

I know i'm not the only person wondering about the electronic aspect of increasing HP. I have a H23A so i was wondering if anyone had advice on whether or not i should try to get an S-afc and if it's hard/expensive to tune. My other option with this money is a ceramic header from DC probably. Feel free to talk about the V-afc or other electronic devices. Thanks all.

[prelude48]

Im also told the V-afc is hard to tune and its recomended(cantspell) that you use a Dino to tune it, as for the header i would go for that,no tuneing required,easy install and looks good but i guess its your call.

[Ziggymidget5]

Yea, that's kinda what i've been thinking too. I just wish i had my header now so i could put it in while i'm replacing my radiator and there's some extra room in the engine bay. oh well.

[AcesHigh]

You will always gain some horsepower if you tune an AFC correctly on a Prelude; the car was tuned conversatively for emissions and reliability.

The SAFC and VAFC are blackboxes that alters the signal to and from your ECU to make your engine components run more efficiently. However, the two AFC's have severe limitations and are only good with lower to mid level modifications. Interupting ECU signals sometimes create a snowball effect and can cause a whole load of problems.

With that said, the VAFC/SAFC are still two very good piggybacks that will help you squeeze out that extra amount of power. Even a stock Prelude can net around 5whp. Another plus is that they are incredibly easy to tune, about an hour at a dynonameter and you'll be set to go. They are also easy to install, and greatly help novices learn about automotive tuning.

If you are feeling brave, you can also check out the Hondata s200. It provides datalogging capabilities and nearly complete control over your car. It is more difficult to tune than an AFC. The most difficult to tune (but the one that provides the most control) is the AEM EMS, which does away with your ECU altogether and works on its on in place of the ECU as a standalone. It's more difficult to tune than Hondata because there are more variables you can change, much like Hondata is more difficult to tune than an AFC because it has more variables you can play with.

And the DC-S header won't do you much good.

[Ziggymidget5]

Hmmmmmm...well if i have a 1995 Si with CAI, Cat-back exhaust, and soon some AEM pulleys, how much power do you think i could safely find with the SAFC? Are there any bolt-ons that make the SAFC more worthwhile? And i live in the middle of Illinois, so i'd really have to look hard, maybe drive somewhere to find a Dyno tuner, but how much do they usually cost to tune a SAFC? Thanks for the good info Aces.

[AcesHigh]

Takes about an hour, dynos usually cost about $100 an hour. Typically "tuning" means pushing your engine to immediately before the point it where can't handle anymore (typically when it begins to knock [see faq on detonation]). All cars are different, and its tough to say exactly how much you'll get out of it. Some people get more, some people get less.

And I don't recommend the pulleys. You can start working on your fuel management. The SAFC can't control fuel pressure, but it can indirectly affect it.

[Northern Sun]

H23A

there is such thing as h23a
a1/a2 and f block as japanese replacement.

Vafc u dont need since u dont have vtec, unless u gonna go with frankenstein h23vtec, safc alters afr pretty much and advance timing while doing it, aem pulley are waste of money unless u got 97 automatic. dont expect too much from safc, get more goodies and tune it with wideband

If you are feeling brave, you can also check out the Hondata s200. It provides datalogging capabilities

u can get that directly from p13/14 ecu, data loggin is only good if u got chip burner and run more than i/e ,but then again burnable chips are probably mappable for basic 8x8 table, hope it helps, Northern Sun

[SiGNAL748]

Originally Posted by Northern Sun

there is such thing as h23a
a1/a2 and f block as japanese replacement.

Vafc u dont need since u dont have vtec, unless u gonna go with frankenstein h23vtec, safc alters afr pretty much and advance timing while doing it, aem pulley are waste of money unless u got 97 automatic. dont expect too much from safc, get more goodies and tune it with wideband



u can get that directly from p13/14 ecu, data loggin is only good if u got chip burner and run more than i/e ,but then again burnable chips are probably mappable for basic 8x8 table, hope it helps, Northern Sun

This thread is almost 2 years old...

[honda_racing101]

Good lord. Lock this now.

[Northern Sun]

damn ..., got too excited , lol; in that case, people can use that info either way, couldn' find what i was looking for, i will remember to check post date next time that's it for now N.S