AEM EMS or Hondata??

[daboynblu]

aem ems and hondata are really two different monsters. it all depends how much time you want to invest, and how much of that time is going to be your own, or with a tunder (or on a dyno).

as far as more R&D into hondata? eh, i'm not sure about that. aem did just recently design the ems from the ground up, based pretty much on what everybody wanted. they continue to add new features, free; and they're only a rom-update away.

hondata will get you from not-tuned to tuned much more quickly than aem ems. by this, i mean start to finish. this is because you're already starting from a stock honda map, and you're only modifying what you need to in order to make the car run. in the case of JRSC's, this means very little part-throttle tuning, as the car's essentially acting like stock until you cross over into positive manifold pressure.

now, on the flipside, aem ems will require you to massage the entire map. this is where the time comes into play. if you feel like learning to tune yourself, then this is the way to go. you can buy a cheap wideband setup, and have at it, and get pretty good results. you must, however, also deal with air-intake temp fueling compensation, cranking fuel, entire ign map massaging, etc etc. expect a lot of time. if you don't feel like doing all this yourself, then ems probably isn't the way to go, as you'll easily spend a tuner 20+ hours doing all this for you.

then there's always all the gee-whiz features the aem ems has to offer... but they take time to seup as well. these include traction control, water injection mapping, full nitrous control and tuning, boost control (not for JRSC's without additional hardware), and making coffee (not really, but who knows what to expect with next rom update).

the one thing i don't tend to list as differences is WOT dyno tuning. this is because, surprisingly, neither system takes much longer than the other, when in the hands of an experienced tuner.

[JRCivic]

I agree with everything that "Daboyinblu" just said with ONE exception:

The AEM, with all of its amazingly wonderful bells and whistles has one whale of an achillies heel when compared to the Hondata system: It only has ONE fuel table and ONE timing table !!! This is NOT the proper way to tune a VTEC Honda engine (especially not a DOHC one) !!! One must have the ability to tune both the fuel and timing curves for EITHER lobes seperately...

This relates to a question I was asked a few weeks ago by a heavily mis-informed customer...

"I just put a VTEC head on my D15B7 to make a MINI-ME... can't I just use my stock computer and run my VTEC with a push-button on the shifter ?!?"

I looked at him in total disbelief and said "NOOOOO, not if you want it to do anything more than make VTEC noise and run LEAN !!!"
[img]graemlins/sure.gif[/img]

I guess some people really just DON'T GET IT...

[daboynblu]

very true, forgot about that issue we had.

however, i did have a crazy idea on the drive home from dyno-day. if you ever tune another vtec aem ems car, it might be worth trying out.

you could change the nitrous output to control the vtec solenoid, and then use the 3-D nitrous fuel/ignition map to tune the high-cam, and use the "main" fuel/ign map for the low-cam. the result would be completely independent fuel/ign maps for the different cams.

if i get bored some day, i might try it. i'm 99% confident it's a viable option.

[JRCivic]

I suppose that is a possibility...

Hmmmmmm,
How would you actually ENGAGE VTEC ??? Doesn't the Nitrous control have to be "activated" by some external source ??? If so, you would have to hit a button or something to engage VTEC...

I know there is a provision for a TPS engagement point... however, it still has to be "Armed" to reach the possibility of engagement.

[daboynblu]

you can set the "activate nitrous" (or arming) switch to "always on"... then you can make rpm, TPS, MAP, vehicle speed, or any combination thereof be the trigger.

<font color="#a62a2a" size="1">[ January 29, 2004 02:10 AM: Message edited by: daboynblu ]</font>

[JRCivic]

OK then...
This would mean we would have to completely RETUNE the car with VTEC turned off first. Then, engage VTEC using the TPS above say 50% and 2000 rpm... and TUNE the Nitrous (VTEC) fuel and timing maps.

Do-able... but a whole lot more work than the Hondata system.

heheheheh

[daboynblu]

LOL... i just can't win with you [img]tongue.gif[/img]

i concede, hahaha.

probably best left to people that like to waste tons of time with this piece.

[InfamousGSR]

When I said more R&D I meant because of the base maps that hondata offers for JRSC's which are really good maps.

[98ZexGSR]

Ok, I'm sold for the Hondata system. I'm just sick of check engine lights and the car running too rich at part throttle like going up hills and stuff. Which options should I get? This is what I was thinking:

Base S200: $295
Boost Capability: $200

Do I have to get the OBDI converter since my car is a 98?

[InfamousGSR]

You can buy S200 with boost option for $425.
You need a OBDII to OBDI harness which is 75$ shipped and make sure you get one with lifetime warranty. Also you need a ecu since your ecu is a obdII ecu. Your choices are a a P72 which is off a older gsr, P30 which is off a del sol vtec 92-95 or a P28 which is most common and it comes from 92-95 civic ex/si's.
P72= knock sensor, IAB(intake butterflys), Vtec
P30= knock sensor, vtec
P28= vtec

The knock sensor isnt really needed because the sensor only works up to 5,000rpm. Also you can buy a P28 ecu from a junkyard and they go for $100 and then you need someone to socket the ecu. When you buy the S200 it comes with the stuff to socket up the ecu. Jeremy green can do it but not sure how much he charges.

<font color="#a62a2a" size="1">[ January 29, 2004 10:32 PM: Message edited by: InfamousGSR ]</font>