I'm not sure if any of you guys know me, I'm jdogg over on honda-tech and i'm the same wadzii from the aem forums.

Anyway, I finally got an s2000, after almost 10 years of wanting one I finally got it.

I must say the car is amazing and I do love to drive it; however, there were a few things that irratated me from the beginning. I wanted to fix these things before doing any other mods. As of now the car is completly stock with just the
air-box lid removed.

The first thing was the horrid low end response, lack of power is one thing, but crappy response is another. The 2nd thing that bothered me was the bucking while in traffic. I had the car for about 4 hours when this first poped up. I did
the common fixes found here but nothing really fixes it. And the last thing that bothers me is the crappy mileage, i havent seen better than 25mpg even with 100% highway driving.

All these things felt like a tuning issue to me. I use my scan tool to monitor the datastream and saw nothing abnormal in the logs that would indicate a bad sensor or anything like that.

So, since its what i do, the next thing I did to the car was put an aem ems in it.

First things, I am using a 1050 ems with the a few wires moved to work in the s2000.

This is to give my insight on tuning this car along with issues and such that I see.


Once the car was running I noticed that the base 1052 calibration runs the car very well. I do not like how they did the ignition map, but being a base cal thats acceptable.

I used the AIT voltage calibration that was posted over on honda-tech thanks to candymanjl (probably posted here as well), and I left the coolant temp calibration alone, as it seems to be close enough. The AIT fuel trim is typical of most cars, i dont have much time in tuning that, its a base that i have come up with over the years. Same goes for the warm up enrichment table.

Typically I use the "boost-comp" method to tune everything, but with the s2000 that just didnt work. The partial throttle fuel needs are much different than pretty much any other honda motor. To deal with this the first thing I did was switch
to a TPS based fuel map (still boost-comp'd). Once I did this I was quickly able to dial the fuel map in to "close enough" so that I could consentrate on getting the ignition map right.

I dont have a loading dyno at my disposal so to get the ignition map right I had my girlfriend drive the car. Under partial throttle the ignition map is what gives you drivability and response, something she is good at noticing. I make a
change and she goes "eww that sucks dont do that" or "wow thats easier to drive". So with girl at the wheel I arrived at the current ignition map.

With the fuel close enough and the ignition map "girl" approved the car drives 1000times better. I can drive the car in traffic below 3000 rpms with no bucking at all and it has enough power to leave it in 6th gear and actually drive the car.
This all fixed my first 2 issues, but unfortunatly I have only been able to achieve 26mpg.

Tonight I will be going to a traditional speed density setup, taking throttle completly out of the fuel calculations just to see if I can improve mileage as I am very happy with the driveability and response.

No dyno time as of yet. I'll be down to RLZ soon to get it on the dyno.

I have posted up my current tps based boost comp'd calibration.

Remember this Calibration will not work on your car so dont try it!!!!!!!!!!!!!!!

http://forum.aempower.com/forum/inde...c,25147.0.html

http://forum.aempower.com/forum/index.php?...7.0;attach=5832

 

this is a shame, I almost wanted to get the EMS for my car after reading this. I then reached your giant red text and was saddened



If you don't mind me asking, how did you learn so much about tuning? I've always been kinda curious.

 

the aem ems will work perfectly fine in your car, My calibration will not. you can look at it, and do what you want with it, copy it etc, but it will not work if you dump it into a 1052 ems.

I have been professionally tuning cars since 2002

 

First mod - standalone ECU. That's hardcore lol

Do you think its the fueling or timing down low on the stock ECU that makes the car such a pain to drive, or maybe a combination of both?

 

More notes:

This engine is nearly impossible to cause a lean pop/miss at crusing loads. Because of this I have a feeling tuning for max mileage will be hard.

the idle on the car was crappy with the stock ecu, and its crappy with the ems. I think it may be a mechanical problem with the iac or throttle body.

Lastly, i need a new clutch, 2step at 7000 rpms resulted in a smoked stock clutch. woohoo

 

I think its more timing than fuel.

at partial throttle this thing will drive good pretty much no matter how much or how little fuel it has.

it seems to me that its a compensation issue with the stock ecu, i think the ecu starts pulling timing when intake temps or coolant temps start to rise.

I have seen as much as a 10-15 deg difference in coolant temp from highway crusising to stop and go traffic. Ait's obviously go way up in traffic, but they always stay on the "hot" side.

when i get around to making a jumper harness so i can easily plug in the stock ecu ill do some more testing with my scan tool and see what i can see, but dont hold your breath for that!!

 

Welcome Wadzii!!

Yeah the AEM calibrations for the IAT are pretty far off. Was the thread on HT by camuman?

My EMS was tuned by a local guy, MASE. Before I got gears, the car was consistently getting 31mpg on the highway. Something else may be wrong with your car if your AFRs are good. Might want to check the usuals...plugs, low tires, etc.

 

^ or put air box lid on

Sick post man, subscribed!

 

Yeah, subscribed too.

Sounds like you knows what you's doing. How you monitoring AFRs?

 

I have an aem wb guage in the car to monitor afr.

Im going to be making/testing a few cold air intakes when i get down to rlz for dyno time. If it takes a while to get back down there ill try putting the air box lid back on and see what happens. I really thing this motor wants a much bigger intake than is available, we will be testing a few combinations to see.

Negcamber... i think that was the thread on HT, ill find out for sure so i can give credit where credit is due! Was your car na or boosted? Boosted cars are easy to get good mileage. I do have crappy autolite plugs in the car.. thats all I could find when I got the car the stock plugs were SHOT. I'm usually pretty good at mileage.. my gsr (which is for sale btw) gets almost 40 average, that motor is close to stock with 190k on the clock.

I did some logging this morning and found some interesting things.

I changed over to a "traditional" speed density map to see if i can coax more mileage out of the car. Overall i cant really tell a difference driving so i'm not going to bother posting the map

however i did do a WOT log today and found some interesting things.

I did see some knock above 8400 rpms, but the biggest thing is the POSITIVE manifold pressure below 5500 rpms and very little vacuum at higher rpms. (normally with stock engines there is a significant ammount of vac at all rpms and ALOT near redline.) I think some of the vac past 8400 is due to the knocking i'm seeing. I changed the timing map and ill get another log on the way to school tonight.

I think this may be part of the reason bolting on header and such dont make much power. the stock parts are VERY well matched.

I think a well matched intake manifold, cam and header would pick up tons of power, but one or the other.. not so much.

here is a screenshot. the actual log is posted in the aem forum thread that linked above. The dashed line near the top is at 0 psi manifold pressure. you can see that the map pressure is above or very close to that for most of the pull. Vtec comes in just to the right of the cursor where you can see the knock noise jump up a little.



edit: I just noticed that you can see the clutch slip in the log... that was a 2nd gear pull with a full throttle shift to 3rd.. it took a LONG time for the rpms to come down. haha