i have a 98 Honda Prelude/H22A4 originally running a chipped P72(integra GSR) ECU. The car really bogged the engine down because it was a custom mapped for my friends car via Yoshio from Toronto(one of the top tuners in Canada, who also owns a Dynapack ). The map i was running on the P72 was made for a different engine setup so i would feel a lot of bogging in the ranges 1500rpm~6000rpm when it started to go into Vtec.
After running this setup for about a month i got sick of all the bogging on the low end of the power band and decided to get my Apexi Vafc to lean out the fuel mixture in hopes of solving my problem and gaining more low end pull. Keep in mind at this point i'm still running the P72 chipped ECU, just modifying on top of the chipped map via the VAFC. I took it to a dyno in Calgary(Davenport/Dynojet) to tune my Vafc. Nice guys, too bad it took them 4hrs to tune it @150hr w/wideband (Vtec cross over point, fuel map, cam gears, and playing with the distributor(yea i got OBD1 distributor)). However, they cut me a deal on my tuning to 400Cdn. At the time i thought ah what the heck it's one time thing to fine tune my car and make sure it's not on the verge of blowing up, so cool....
One cool think i really liked about the Vafc is i can make changes on the fly. So everytime i was on the highway from Edmonton to Vancouer or Seattle or whatever id' raise my vtec point to 6500rpm so i'd save gas on the highway. Cool cool
My review of the Apexi Vafc, it's a handy tool i used it for about a year and i really liked it. for what it is, a quick and easy tuning tool i have to say for the money($400~500Cdn) you can't go wrong. However, i think this is more for a person with simple boltons, and want to do the final tuning to get the most out of their mods. Then, after one year i wanted more, i thought that i could gain EVEN more low end pull and more power in general, and that it could be found in the ignition map.
Now at this point i decide to sell my P72 ECU and my Vafc and get a P28 (Civic Si)ECU and run Hondata on that. The reason i did this was because the P28 was much cheaper and i need the extra money from selling my ECU to buy the Hondata.
If you guys wanted to run with Hondata you would need these few things:
1. *P28 ECU 175Cdn+75Cdn to prep/socket the board for Hondata.
2. OBD2 to OBD1 conversion harness $210Cdn
3. Hondata S200 $485Cdn
4. Tuning time on the dyno
* Because i no longer hve a dual runner intake manifold i could run with a P28, for those Prelude/GSR owners out there that still want the usage of their dual runner butterfly plates it would be recommended you run a P72(GSR) ECU.
At first i just ran my P28 with Hondata's(S200) h22A chip (a bit more aggresivly mapped than stock). I did feel some difference compared to my P72 w/vafc tuning. I did feel like it pulled a bit better probably due to the slightly more aggressive ignition map across the board. I drove around with it for about a week or two with Hondata's generic H22A NA chip. Next thing i threw it onto to the dyno to do some fuel tuning. To my suprise i did my entire fuel map (full throttle and part throttle) in 2hrs. I think it was fast because i can hold load with our particular dyno(Dynapack), meaning if i'm tuning for a specific rpm, say 4000rpm, i can look at my air fuel ratio, press the throttle a little bit and then progressively more and more till full throttle. Eventually tuning air fuel for all throttle positions at the 4000rpm level. Then move onto 4500rpm, 5000rpm, 5500rpm and so on and so on until my whole fuel map is totally tuned. I was basically doing it at 500rpm increments, but when i have more time i can actually tune at 250rpm increments to even more fine tune the fuel/ignition map. Keep in mind that a VAFC1 can only tune on 8pts from 0rpm~8000rpm or wherever your redline is, and the new VAFC2 has 12pts to tune from. Thus Hondata can fine tune much more throughly than any of the piggy back fuel systems out there on the market. Hondata is basically modifying the stock Honda ECU and customizing what Honda has done, to match up with a modified engine and fine tune it for performance vs economy(compromised performance from the factory.)
I went for a drive and the feeling was night and day. I could really feel the power a lot more on the low end. It's hard to explain just feels like throttle response is more crisp. Like when i press on the throttle it just starts pulling almost instantly. Unlike stock where it's a nice gradual pull, just feels more strong i guess. Even today i am still constanly refining my fuel/ignition map, that's the good thing about Hondata it's such a versitile system for tuning, and extremely user friendly. I have datalogging that's kinda neat to have and watch your vehicles sensors but not necessary for someone that just wants to get their car tuned and out the door. It's more of a monitoring device, more a luxury item than a necessaty. Well, it's good to have during tuning which we have here at the shop. I think if your just an average joe it's an option that's not really needed unless you want to try some tuning yourself.
I really liked the fact that i could raise my vtec point on the highway with the VAFC, but for the Hondata system i can't do it on the fly. The way i got around this was to burn two chips, one with my regular vtec point the other with a high vtec point. So i just pop in the chip with the high vtec for trips, then when i get into the city pop in the regular chip. It's not hard pulling chips in and out so it's not too bad to do this. The other really cool thing with Hondata is that i can set it so my AC turns off at a certain RPM or Throttle position. So say i'm cruizing in the summer with my AC on and i set it to go off at 5000rpm. Once i feel like punchin it the AC will automatically shut off when i go into Vtec, or i can set the AC to shut off whenever i go into full throttle(100% throtte). This was one of the really cool features i really liked, next to the ease of use
This is what a Hondata fuel/ignition map looks like
RPM on the side, and throttle/load % on the top.
This is how it looks on your lap top and the little cursor moves around as you run the car. For a video of the map in use
CLICK HERE You'll see how the cursor is following along on the fuel map (rpm vs load/throttle percentage). Makes tuning so much easier when you can see what is actually happening.
So Hondata for $945 vs Vafc for $400~500Cdn which is about a $500Cdn difference. I would say in my experience, that the Hondata system is for someone that has done some internal work and really want to get the most out of their engine, or for the hardcore enthusiast that just likes playing with the engine and trying to see what maximum potential they can get from it.
The Vafc would be more geared towards a person that just does boltons and has bought all their boltons and is looking for the next level of performance, heh, or someone that just wants a cool toy in their car, but then again a laptop in the car is pretty cool too
All and all i have learned one very very important thing from all this. That tuning is of the utmost importance to gaining maximum potential of what you already have. I guess it's almost like unleashing the power from the engine, if you don't do it you never fuell the full potential that could be. After feeling my tuned Hondata chip vs my original Hondata chip it's way different, then if i compare that to my original vafc/P72chipped ECU, NIGHT AND DAY!!!
I hope this has helped some of you understand a little more of what Hondata is and how tuning can really effect the performance and reliablity/longevity of your engine.
If you guys have more questions please let me know.
I forgot to mention that if you have OBD2 car with OBD2 wiring harness(96+), you will need a OBD2 to OBD1 conversion harness in order to use the P28, P06, P72 ECU's, basically all compatible OBD1 ECU's for your application.
OBD1 cars would be from 92-95, if you have a vehicle with the 92-95 wiring harness you wno't need to purchase the adapter harness, and can basically just plug in the OBD1 ECU and go.
Oh if you don't know what OBD stands for, it's On Board Diagnostic.
Linear Mode
