ihiryu

Hey guys it's been awhile, but I purchased a car at auction, and it runs, but runs a bit rough. It's got ID1000's, AEM EMS V2, Wideband, OMNI 4 bar, and it's running about 6 lbs.


I took a look at the map, and while the fuel looks pretty dialed in, timing is a bit awkward. Regardless if I pull or add timing, it just feels really sluggish, unless it hits vtec. Even in boost (it gets boost really down low), and AFR's look great. 14's at idle, and light cruise, she starts to see boost (literally when you go WOT, at any given RPM), and AFR's slowly taper off, 1-3 psi, 13.5-13.1, then anything above that we see 12's. So AFR's are on point.

I added a bit of timing down low, and nothing, pulled a bit of timing from where I added. There's no knock (knock sensor shows low voltages). I'm too afraid of adding a ton of timing even though I'm not seeing knock. I'm relatively new at tuning, but not super noob (My daily is a turbo miata, running megasquirt, I tuned myself).


https://www.dropbox.com/s/h251aem3q0...iming.PNG?dl=0

The timing looks like ass, but it's because I was racking my brain on what it could be. VTEC engagement is at 5300, so it looks like they pulled timing, and when VTEC hits, it adds like 14 or so degrees.

s2000Junky

yep fuel sounds perfect. Your ignition timing looks way too far retarded for only 6psi however. I always use the factory s2k ecu timing map for relative comparison which ive seen as high as 35 degrees of total advance at redline WOT, however 30 degrees is a typical average, so thats what I base from. With that and a general rule of retarding 1 degree of timer per 1lb boost. Yor timing table should basically show 24 degrees total advance at peak rpm WOT and add a degree of ignition further down the rpm range yo go, with your first degree of pulling timing really at the stock vtec engagement point at 6krpm, because the motor wants MORE timing in the area of the lowered vtec point to the stock. As for vtec transition, 5300rpm is nothing, I make power at 3800rpm on my N/A set up and ran as low as 3500 when I was supercharged. There is about 6 degrees total advance difference between 5800-5900 rpm where the factory transition happens NOT 14, so that should be cut in half. We are assuming that the issue yo are experiencing is all timing related though, which it may not, bt there is def some room for improvement with timing, so get that dialed in and then your fuel changes to go with it, since that will happen a bit. then can see how it goes from there. ** the stock base comptech kit that has been on the market since the s2k was introduced and been reliable as hell pulls no timing on its 6psi kits, runs factory timing jst fyi. so at your boost level, its really not imperative. Id say base any retarding corrections on your weather, IAT and driving environment for safety.

*** If you have a catalytic converter still on car, you will not be able to lower vtec bellow 5300rpm and get any gains, a TP is a must for this. Also if you have a bad plugged up cat which is very common on a FI s2k, this will make it run hot and like poop and give you some symptoms you are experiencing. I would get under the car and verify if you have one or not. IF you do, get rid of it asap and get a TP and report back. Still should dial in a better timing advance, but this wont do anything with a plugged up cat.

ihiryu

https://www.dropbox.com/s/au4ejplpez...g%202.PNG?dl=0

Okay, I configured the VTEC output back down to 6. Pretty much looking at the ignition map it made sense, in the upper RPM's it was showing ten degrees of timing, when vtec came on, it would add the 14 degrees or so, giving it a total timing of 24.

So configured the VTEC output from fourteen, back down to six, then added timing values to the map (simple math).

I left the VTEC fuel output at 14.8 or so though (since the fuel maps were pretty good, I don't really see a reason why to change it).

I also added timing down low, since I wasn't seeing knock. It also rev's a lot cleaner now.

I haven't had a chance to take it back down the road to see though.

How do you feel about timing down low? It's a bit scary to see 40 degrees or so down there to me! The BP motors run the risk of bending rods before they show knock, so seeing numbers like that scare me a little lol.

s2000Junky

Timing map looks pretty good. I don’t see any issue with where the map is showing 40 some degrees because its not in a load part of the map, its very much where the factory engine runs off the show room and there is no need to alter that with the addition of a SC, all it is at this part of the map is an additional accessory item on engine as far as load goes at best, like turning on the A/C. Did you verify if you have a Cat or not? Have you tried lowering vtec to 3500-3800 rpms? You should be able to pick up additional power in the mid range significantly if your catless. Im also concerned about possible cat melt down obstruction. If you have a cat, it will melt down, its just a matter of when. You do not what this to happen as it will send your EGT through the roof and could cause a fatal blow to the engine.

Typically if you add more timing, the motor will want more fuel, so its important to check your wideband or data logs when making some significant changes to your timing advancement, or you may be running too lean now depending on where in the rpm/load the timing change was made. Higher rpms at WOT more so.

ihiryu

Yup, she is catless. Has an oil leak from the oil return fitting, no biggie.


I have not not had the chance to lower vtec at all. Heck, I haven't even been able to drive the car yet. I've been so busy. I did play around with some cranking fuel, has some slow starts, but I believe from low voltage/dying starter. Also the IACV is dead, no matter what I adjusted the idle maps too I couldn't get it to change, so I had to clamp the throttle a little until I get it fixed. So it's almost a moot point to even play with any starting fuel if the throttle is cracked. Definitely need to get that taken care of.

I almost scared myself because it was cranking so slow that AEM wouldn't even stat sync! I ended up pushing the car, and popping the clutch on my own! Pretty fun stuff lol.

ihiryu

Finally got to drive her today. Feels pretty weak still. I'm not sure AFR's looked pretty good, knock sensor did not read any knock. Again, when vtec comes online, it becomes a monster.

I don't want to lower VTEC, because I feel like there is some issue here that I am missing. I just don't remember S2000's being so weak before VTEC. I had someone else (a friend of mine who owns a bone stock AP2), drive it, and he agrees that it just feels way weak down low.

I did a compression test today (just to be on the safe side) and compression came out pretty good, all close to 210 PSI. So engine is fresh, timing map looks good. What else could it be? My IAT's are pretty high though, and both the intake air and coolant ignition trims are at zero, so I guess maybe this car didn't get the tune finished?

s2000Junky

Yeah this can have a drastic effect. Couple that with a little parasitic loss from the blower. However I never found it to be particular noticeable, but I also ran 3500rpm vtec cross over so power "under vtec" wasn't really an issue since there was virtually nothing under vtec left, it was always right there when i rolled on the gas more then 35% throttle opening when the engine starts to see boost. Its important to sync this up. And if your running a BOV, make sure its closing soon enough or your engine wont see boost early enough at the proper time. So what is the IAT? Is the aftercooler pump working?

ihiryu

I had it running and idling for a minute yesterday, and IAT's where closer to the 230 range. I suspected the pump wasn't working, but it was working. When I started moving, IAT's dropped very, very quickly.

I'm going to add more timing before boost. I was at closer to 22-23, so the motor probably wants more timing. I'll add a bit more fuel to the map too in those areas just to safeguard it.

Once I get this figured out, I'll go ahead and lower VTEC, and blend in a little more timing to see how we do.

s2000Junky

230?! is that even possible Well Id say if that is indeed an accurate reading, that is your main problem. At idle not moving in the middle of the summer, the highest I would see is 135-140 with the shitty stock comptech pump, but once moving would lower to 110-125 average. You are in dangerous territory above 150F for detonation. When my pump stopped working I saw 152 wile cruising around and I also felt the drop in power and heard a little pinging which alerted me to the pump problem, which was a bad relay in my case. What is your after cooler set up? And how are you logging the temp?

ihiryu

I dunno, hell it could be a bad IAT sensor, it is the stock one, and it looks old lol.

It doesn't feel that hot. I'd imagine if the aftercooler is really that hot, it would hot to the touch, but it feels relatively normal. I mean it's warm, but not scalding.

That or AEM doesn't have the IAT calibration right