I just joined this site after randomly running into a bunch of people at the NJ meet last week. I wanted to know what I should do about a computer when I get my turbo put on in a few weeks. Unfortunatley, the Hondata unit (wich I was seriously looking into) doesn't make a harnass for the SH, just the base model. Plus the Apex AVC-R i'm getting won't do everything I need for proper tuning. The only suggestion I've gotten so far was from my shop about a piece called the Missing Link. Aparently it "fools" your computer in thinking that there is no boost so the check engine light wont go on. But it cant be programed, so it'll only be temporary. If anybody has any info about piggybacks or stand-alones for the '98 SH, any feedback will be appreciated.

 

The only one that I know that is attempting this at the current time is Schwett and he's running a JRSC setup. E-manage from GReddy MIGHT do the job but I haven't seen it in action so I can't truly say. There's a few other units on the market currently, but you'd want ones that modify the signal AFTER the ECU and not trying to fool the ECU into doing things.

 

Maybe you should try the AEM EMS. The only thing is you have to find someone that can tune it properly. It's very stafisticated. If you don't tune it properly your car is done.

 

Yeah, I was thinking of going the AEM route, but I've herd some horror stories about it. Some guy had it on his turbo lude and only put 220 to the wheels after <U>60</U> dyno runs! So I'm sure they did a lot of tunning. I will look into the GReddy unit. Is that a stand-alone or just a piggyback?

 

Greddy is a piggyback. Greddy and EFI PMS are your only options if you want to keep the ATTS. I've heard about Unichip as well, but haven't heard of any successful implementations on Preludes.

The AEM EMS does not support ATTS.

 

the hondata issue isn't the harness; the base and SH ecu have the same main harness. the issue is an additional harness which contains a data line to the ATTS computer; the contents of that signal have not been duplicated yet, and i really doubt they ever will be.

your options are :

1. hondata, aem ems, etc, and just lose the ATTS. (becomes a 40lb dead weight)
2. lots of indivual piggybacks to control timing and fueling. you can use the VAFC hack to get good control over 440cc injectors, any of a number of boost depending timing retard devices, and either a mechanical check valve or an electronic map limiter. personally, if going this route, i'd recommend the vafc, 440cc injectors, and a j&s. the j&s has timing retard per boost and a built in map lmiter.
3. EFI Systems PMS. i have this system, and like it a lot. ATTS still works, except when it shuts down under boost after a long hot drive. this has happened to me a few times, and has nothing to do with the PMS, it's just that the ATTS unit was not designed to handle 60% more torque than an N/A h22 can belt out. the PMS is a very simple system; it does not have the bells and whistles of the AEM, nor the popular cult following of the hondata. it works great though, you can tune it yourself, on the fly, from a ghetto controller or your laptop (highly recommended) without "burning chips" or any other such nonsense. i plugged mine in, set it to pull 40% fuel across the board for the bigger injectors, set it to add 8% per psi of boost, retard half a degree per psi of boost, and the car started, idled, and drove right out of the gate. you can also do the usual stuff with the curves, adding or subtracting fuel and timing per RPM and per throttle position to get the most power and driveability. personally, i like it a lot. no problems so far related to the unit itself. this system is NOT very popular on hondas though, so YOUR RESULTS MAY VARY.

with the PMS setup, you also need a GM 3 bar map sensor (very cheap) and a missing link or electronic map limiter (for whatever reason, the system does not hide the boost from your stock ECU.)

 

where can i get more info on the pms (hopefully its not as much of a pain in the *** as my girls pms). i like the sound of it the way you described. does it come w/any base maps? i really want the zdyne secu, but it doesnt ever seem like its coming out! this is for my soon to be done, built and turboed 93'vtec.

how much do they go for?

 

http://www.efi-systems.com

a good guy to buy it from is jim helbing, motorvations motorsports, you can reach him at (205) 854-8458, wheelking@webtv.net


[Modified by schwett, 9:49 PM 8/19/2002]

 

the missing link is pretty much a fancy check valve that blows off excess air before the boost hits your MAP sensor....

I would look into a greddy emanage setup as it can support bigger injectors and can control timing (with $50 add ons i think).... I think it can also support greddy's aux. injector system..... you can also keep the ATTS.....

 

Thanks for all the info. The EMI PMS sounds real good, and it seems like you're not having any real problems with it. The only question I have is are you able to control vtec with it. I know the greddy e-manage has vtec controls. But regardless of which way i go, i'll still need the missing link, right? I'm still kinda split between the two.