Speed Density on Evo ECU
 

I'm ready to give it a try to see how much driveability improves. Wondering if anyone on here has tried it yet? There's supposed benefits: improved driveability and potentially more power.

The extra power has been potentially debunked:

http://norcalmotorsports.org/users/b..._SD_111509.jpg

http://evoempire.org/index.php/topic...nsity-wno-maf/

Same AFR, same boost, same timing, no power gains. Now, if running SD allows you to run a bit more timing or boost on a given setup safely, that's yet to be determined.

Yup, everyone is always saying the MAF is such a huge restriction; obviously even at this power level it is not.

A few interesting notes:

The idle stuff makes me interested again....

I'd love to see more data on this subject, this is the best comparo I've seen so far.

JohnBradley did one and saw some power gains up top, but he was able to add timing, and there were other changes made (i.e. NOT a direct comparo):
http://forums.evolutionm.net/ecuflas...ifference.html

So I think I'm going to try it out this week/weekend.

Re: Speed Density on Evo ECU
 

I don't think there has been a single person post on EvolutionM that didn't have driveability issues on Evo 8's using the speed density posted there (9's were fine). I got fed up with it and gave up, especially after my extremely disappointing numbers at the dyno day.

The 2 2d VE maps make it pretty easy and quick to dial in, so it's not hard to give it a try if you feel like it. Acceleration enrichment and coolant temp enrichment are a lot less fun to get right though.

Re: Speed Density on Evo ECU
 

Speed Density offers improved drivability? That's a new one to me. The only reason I've ever seen to go to speed density on our setups is when you reach a point when you are out flowing the MAS.

Re: Speed Density on Evo ECU
 

^Im opposite of you.

Re: Speed Density on Evo ECU
 

Yup, that's what people have mentioned. Rock solid idle and I guess we'll just have to see. My plan is to load up a rom that should work on my car, turn the boost way down, and just do basic cruising/starting/stopping/traffic type driving and see how I like it. If it addresses some of the issues I'm trying to fix, awesome, I'll go from there. If not, test complete :)

This will cost me $0 since I already have a 3.3 bar map sensor and MAT/IAT sensor on the car :D

Re: Speed Density on Evo ECU
 

I'd say the driveability with the MAS would be better, but SD is really nice for packaging reasons. Having an aftermarket BOV venting to atmosphere is nice, as well as being able to drive if you blow off a IC coupler and don't have any tools with you.

Re: Speed Density on Evo ECU
 

That's whats nice about having a gm Maf-t right before the bolt-on tb elbow.

Re: Speed Density on Evo ECU
 

So, I did a little research today, here's my plan.

I'm going to start with the phenom out-of-the-box 96531706 rom. My car has the GM IAT sensor and evoX MAP sensor on it already so lots of the settings should work 'out of the box' but I'll be double-checking everything.

http://forums.evolutionm.net/ecuflas...hramod-v7.html
(evo8 option5 in post #2)

After some reading, apparently the big trick is getting the car to line up your current load values with its new kpa values. Seems like roughly 1:1 is a good place to start, but since JohnBradley posted this, I think I'll try it:

http://forums.evolutionm.net/7674344-post25.html
Another approach is making everything 1:1, and then foking with the MAF smoothing table:
http://forums.evolutionm.net/ecuflas...irst-test.html

I'm going to base everything and try and get back as near as possible to the tune that shane put on my car w/ the MAF, and after I get the car running and driving, I'll work on WOT fuel/timing.

Re: Speed Density on Evo ECU
 

Goodbye MAF :D

Spent a few hours converting over my ROM and trying out a few iterations based on some stuff I had seen posted online. Initial impressions: WOW! The car is so smooth. Idle is ROCK solid (albeit a bit high, gotta work on that, 1300rpm), and any stuttering/bucking I had while on the freeway before is GONE. The car is SO smooth now its amazing.

A few notes:
-It took a few iterations to get the car to start/idle correctly. It wanted to idle in the 11's and load was way high. I got one that would work ok, made a few trips around the block, and all seemed decent.
-initially I set my WGDC all to zero. No boost! I'd hit about 9-10psi and confirmed seeing AFR in the 10's under 'boost' before trying anything more. No alky on or anything yet. Baby steps.
-Made a few more iterations to the SD maps this AM on my way into work. Tried a bunch, with mixed results. Ended up going back to almost exactly what I had the night before:
http://scheides.com/misc/pics/evo/sp...y/sd-test2.JPG
-turned up boost to about 19, just keep it simple. AFR in the 10's and high 9's (I used my old afr map from my tuned rom @ DB Performance) and while it is SMOOTH as silk this new rom has lean spool completely disabled, and i don't think my previous one did (my bad).
-Got all the way to work and got CEL for fuel trims. Oops, forgot to log those, even though I had been watching AFR all the way. low/mid are -12/-12, so now I need to try and figure out what to do to fix that.
-lastly, the car wants to buck if I leave from a stop w/o revving it up to ~2000rpm. It would do this before, but I'd give it more gas and away I'd go. Now, it looks like it is leaning out as rpms drop to ~500 and then I need to feather them back to life. Not sure what's causing this, but I'm sure my messed up fuel trims have something to do with it.

Re: Speed Density on Evo ECU
 

Nice! Gonna wait till this weekend huh ;)?!?

Re: Speed Density on Evo ECU
 

sounds cool, and pretty much what everyone on link has been saying.
A PITA to dial in, but once done everyone loves it.

Re: Speed Density on Evo ECU
 

Very cool stuff! I'm jealous I can't do this kind of thing with my car. Of course, if I could I'd probably end up blowing something up!

Re: Speed Density on Evo ECU
 

^your owwdee will run speed density from the factory! You know how you can just unplug your maf and it keeps running? yea. punk.

Re: Speed Density on Evo ECU
 

So much for 'waiting till this weekend' LOL!

The big improvement since yesterday is in the fuel trims, I have them dialed into right around 0% for LTFT mid. Also leaving from a stop the car would want to stumble and die, some logging showed that load jumped into the 80 range and AFR leaned out to 18:1. Tweaked the SD MAP VE map a bit and fixed that, stays in teh 14's now as I leave from a stop and no stumbling!

Here's where I'm at:
http://scheides.com/misc/pics/evo/sp...y/sd-test4.JPG

My LTFT Low is still at -12, but I haven't let the car idle a ton. While giving my buddy a ride the other day he was semi critical of the idle, which I had left around 1200-1250 rpm. I was super happy because of how it would not dip below that at all, and he was saying he thought it really should be lower for me to say its 'solid'...anyways, I made one tweak to idle rpms (haven't touched any of the ISC Stepper tables or anything yet!) and bam, the car idles at about 900rpm, maybe 925. Logs show 900-950-1000 but the tach needle just sits dead inbetween the 800rpm and 1000rpm tick marks. Kelford cams, ported head, ported everything else, not a single dip or stall, its absolutely mindblowing!

Going to review some of my WOT logs and see where timing is at, but boost is set at 19psi now and afr is in the high 10's on my wideband. Ready to get back up to 24psi and try and get dialed into my old tune. I have yet to touch AFR, timing, injector scaling or latency values aside from translating or copying them over from my old map.

Ooh, also, the car seems jittery while its warming up, and I've noticed that at 2000-2500 rpm while cruising sometimes it feels goofy to. AFRs are around 14.5-15 so need to see what else is going on to cause this. It is very subtle once warmed up.

Re: Speed Density on Evo ECU
 

Friday update. Back up to 25psi! Its amazing how fast the car feels after its been down on power (or limped or whatever) for a few days. All of the little boost control mods v7 has to offer really make the car responsive and when its dialed in the car just rips! BBK is holding 25psi dead flat from 3800 out to 7700rpm (highest I've logged so far) with about 84% WGDC. Bryan@GST did note that he had to tweak WGDC a bit to bring boost inline with where it was before, and here's what I noticed: I needed a bit more WGDC down low during boost onset, and had to take a little bit out up top, boost was off by about 2-3%. I literally made two changes and logged a few pulls in a few different gears and its perfect again. I LOVE this ecu controlled boost setup once its dialed in!

More on topic, I have yet to touch my AFR or timing maps that shane@DB made for me (and I hope to not have to, this tune has served me VERY well this summer :D) My load up top is a bit high now, so I'm droping down the highest valve on the MAP VE table from 430 to 410 to see if I can slowly get load back to where it was before on the street. It's peaking in the 330's and tapering to ~300, before I was peaking at 280 and tapering to 250 or so. I'm also now using 1byte load vs 2byte load, so I'm focusing more on the timing values the car is running moreso than the actual load numbers I'm logging.

I had accidentally misread the EGR timing advance under cruise bit and disabled it (vs enabling it, the bit is backward, it reads 'disable EGR timing advance' 0 is enabled, 1 is disabled). I knew about this already and totally spaced it. Anyways its worth mentioning because my car drove like isht when it was cold and wanted to jerk when warmed up and cruising at low speed. As soon as I turned this back to 0 and put my EGR Timing Advance timing tables bumped up to where I had them before (bumped just slightly from stock, 6's and 8's) the car drove as it had before.

Still getting this ever so slight jerkyness when under low low load while cruising in the 2000-2700rpm range, which is a fairly widely known issue with this speed density setup and I would rate it at very mildly annoying and often not noticable...but Slo_crx1 on evoM posted up last night that he thinks he has eliminated this issue using the new tables that mrfred posted re: advanced fuel control and globally increased the values in the Asynch vs TPSDelta table (sort of a TPS tip-in type control I think). I'm going to try this out today as this is potentially a huge break through on this project.

I'm going to try these settings out, dial in my loads as mentioned above, and just bomb around for a few days and see how it goes! It's SO easy to focus on the laptop its getting to be time to just drive the car and see how it feels and just enjoy it. Once I'm happy, alky will be flipped back on and back up to 30psi!

Oh, does anyone know, can I just unplug my MAS? I'm toying with the idea of either gutting out an old MAS I have (w/ a destroyed honeycomb) or getting a 3" inlet perrin filter and just strapping it to the end of my buschur intake.

Re: Speed Density on Evo ECU
 

Yeah you can get rid of the MAS. It's not being used for anything. It won't trigger a CEL or anything as long as you have an IAT sensor somewhere else, which you do.

Re: Speed Density on Evo ECU
 

SOunds awesome, that delta tps tip in deal is only used for enrichment for a very slight second, depending on how bad your hesitation problem is that may or may not be it.
good luck.

Re: Speed Density on Evo ECU
 

How has your cold start idle been?

Re: Speed Density on Evo ECU
 

Mine started up and idled great on SD (idle was better both cold and warm on SD), but trying to take off on a cold/cool engine was a bitch.

Re: Speed Density on Evo ECU
 

Cold start has been fantastic, as well as initial cold idle and warm-up idle.

Re: Speed Density on Evo ECU
 

Monday update, the part throttle cruise either has gotten worse or I'm noticing it more. I am going to turn my async table back down to stock and see if that makes it better or if the increments I made to the EGR timing advance table make any difference either (I'll try that next).

I unplugged my stock MAS/MAF tonight w/o issue. No CEL, no stumble (did it while car was running), nadda, just plain awesome! Does anyone know if the MAF Scaling and associated tables actually do anything anymore?

Thanks a ton JohnBradley and Bryan@GST Motorsports for sharing your setups with me. JohnBradley's (Ref1, Ref2) is something to strive for, perfect fully tuned 1:1 VE tables, definite beauty to that! Bryan@GST, well, my tables look damn near identical to yours, although I did make a bump near the bottom to try and get some of my midrange load values to line up to my previous maf-based tune. However, our SD RPM VE tables are not so close, I feel like mine are globally down 15% from your or so. I have yet to idle or cruise in full open-loop but the car idled way rich and fuel trims were full -12% negative w/o setting these values in the middle of this table (1000-3000rpm) in the 67-70% region. Anyone have any idea why that might be? Ported head, cams?

I have timing very very close to where it was before and the car feels fantastic. Boost is low 24psi, right where I want it, nice and conservative. I'm nearly ready to flip the alky on except for a few problems: thanksgiving (traveling), rain, and snow in teh forcast. Sigh. :)

http://scheides.com/misc/pics/evo/sp...y/sd-test6.JPG

Re: Speed Density on Evo ECU
 

oh, I forgot! Any ideas on what to do for an intake when I delete the mas?

I'm thinking of simply bolting one of these to my standard buschur intake:
http://www.perrinperformance.com/pro...gory=3&model=2

Re: Speed Density on Evo ECU
 

How do the EGR settings play into all this? I'm a bit lost on that considering you don't even have EGR on your car.

Re: Speed Density on Evo ECU
 

You probably have a better tune now, which is why you notice the stumble more now. It was the same way for me. When it was too rich I didn't notice it, but when I got the AFR's stoich (I want to run much leaner than stoich) it got much worse. I mostly only notice it at around 50-55MPH. I don't usually go that speed, but on a new road near my house they changed the speed limit (for the 3rd time - 45, 55, 50) and it's now 50MPH.

The MAS scaling should still matter, as the way they have the SD set up is to mimic the MAS.

I wish they had the SD set up like hak has ds-map / jackal set up. My new Holset powered 1g runs so awesome. I think 1G's have the best driveability (and idle) to begin with, and they did an amazing job setting up the SD.

Re: Speed Density on Evo ECU
 

Despite actual EGR being deleted, there is a subroutine that increases timing off of your timing map while you are at cruise, basically to improve fuel mileage. If you log your car, you'll notice that the timing values while cruising will hover around 40, while the max timing values in your timing table are 38 (on a stock rom). There is a full timing table that allows you to select rpm and load points and how much timing advance you'd like this EGR timing function to add. I don't think it will automatically add 100% of the values in this table, but progressively add some and pull some as needed to keep things running nice and efficient.

On the same note, there is an actual timing table for the cold start/cold coolant temp. It modifies the stock table up to these numbers (they're all negative, right in the cruising area and 0 everywhere else), and the table that we have been messing with over the last year or so (dropped the middle values from 256 to 200, 128, 100, etc) are a reference to this table and the percentage up to which it should be used. Just more ways to tweak tweak tweak!

Anyways, I tried fulltime open-loop and it did not help the 2000-2700rpm studder/jitter problem at all. I tried afrs from 15.5 down to 12.9 w/o any difference (other than it smelled like gas a lot more LOL!). I want to elaborate on this, it is not really THAT bad, it is just a mild 'nervous' feeling the car has in these rpm ranges while cruising steadily. It is really the last thing I do not like with this speed density conversion. My AFR, timing, boost values are all perfect and the car rips on pump gas.

Time for alky :)

Re: Speed Density on Evo ECU
 

Loaded up alky/alt-map stuff last night and tested it this morning. Fuel is spot on, high 11's just perfect. Timing however, is pretty far off, 4-5°. Thankfully they were LOW, otherwise I might be crying right now :) Going to have to adjust the scaling a little to bring it up to where it should be.

I'm taking baby steps, and it is just amazing to me how much power 2° of timing adds on alky, the car just feels like it is waking up! 2-3° left to go. I'm working out what I want to do for a new intake, and still contemplating a new COP ignition setup before I throw it on the dyno for shane to dial it in.

Re: Speed Density on Evo ECU
 

Do you have some kind of freq flyer miles with shane?
I need to get in there when I get home.
Glad to hear its working out, very cool

Re: Speed Density on Evo ECU
 

I wish. I pay just as much as anyone else :) Discounts are nice, but I'd rather pay full price and know they'll be there whenever I want to go back.

Re: Speed Density on Evo ECU
 

Got alky dialed in today, car rips again! virtual dyno room puts me right back where I was, around 420whp on evoM comparator mode. I had to mess with the load scaling to get timing where it was, but seems pretty good now!

So, I have 2 pending issues:
-knock on spool-up, or tip-in. I'll try messing with the tip-in table, but I haven't logged a lean condition yet and timing seems ok, so not sure what the deal is.
-2000-2800rpm jitter. Still searching, hoping to log it and find a work-around.

Just wanna say thanks to everyone that helped me get this far, I am SO happy with the new speed density setup, it is absolutely amazing.

Re: Speed Density on Evo ECU
 

Well we've been trying to tack down this jitter problem. Basically IPW bounces back and forth when it should be more steady. Today mrfred unraveled one piece of the puzzle:


So, I'm gonna try:

<table name="MAF Pulsewidth reset (test)" category="Speed Density Tuning" address="162c" type="1D" scaling="uint16"/>

Unfortunately I'm gone till sunday night :P

More info on this subject here, we started a thread dedicated to it:
http://forums.evolutionm.net/ecuflas...ml#post7747496

Re: Speed Density on Evo ECU
 

Wow, reports are already coming in that setting this to 255 solves the jitter problem! Can't wait to try it out :)

Re: Speed Density on Evo ECU
 

Is there any reason that I should not do this to my car as soon as possible? Based on everything you've said it seems like it would cure my drivability issues and cold start idle.

Re: Speed Density on Evo ECU
 

For me to do this safely I have a wideband and have been logging logging logging my car under all driving conditions and openly accepting the fact that ultimately I could do more harm than good during this process. without a wideband, a trip to the dyno is really really necessary to get this done, and I'm sure it'd be more time than a standard tune although it isn't much more work than dialing in injectors and standard maf scaling it does take some time.

The other thing to remember is that if your volumetric efficiency (VE) changes at all, you need to brush up your fueling. If you put a few parts on and make a bit more power, you'll be running lean, as this whole system is built around specific scaling for the engine's current VE.

I'd say its worth having a wideband in the car (they're cheap now) and owning a logging cable so you could plug it in and verify all is well now and again, but I would say if shane is willing to do a tune on it I'd be willing to help anyone get converted and make sure everything's ready to rock.

Parts list:
-IAT sensor
-uprated MAP sensor, JDM/EvoX 3.3 bar or the Omni 4 bar
-wideband (LC-1 or similar)
-tactrix cable

Once I make sure all is dandy with my car I'm willing to let people check it out for themselves, I think it is absolutely worth the effort.

Re: Speed Density on Evo ECU
 

mrfred's MAF airflow reset tweak works! At cruise, at any speed (specifically 1800-2800rpm) the car drives SMOOTH AS SILK! I will be logging over the next few days to verify nothing else is changed but I'm confident that this was something that only affected airflow levels at cruise.

I'm now fully sold on speed density. This has completely transformed the car into a new level of smooth on all things that previously set the car apart from your average car that already has a smooth idle, steady cruise, and keeps everything that makes it an evo :D

Re: Speed Density on Evo ECU
 

I'll have to give it a try again then. I'm also going to give ceddy's 98-99 DSM speed density a try (ordered an openport 2.0 cable the other day), which is based on the same thing.

Re: Speed Density on Evo ECU
 

Check back here this week, there's a change that mrfred gave us to try that might actually work better to accomplish the above issue w/o affecting some of the accel enrichment stuff (which the original hack may or may not have affected, but better safe than sorry). I'll post my findings :)

Re: Speed Density on Evo ECU
 

http://forums.evolutionm.net/7753333-post44.html

fix#2:

Put fix#1 back to 205 (or leave it stock if you haven't done it yet) and set fix#2 to 0.

fix#1 was SOOO SMOOTH it left my car feeling like a caddie! I was initially so impressed, I was blinded by the fact that what this fix did was actually make the car lethargic under 160load. It's too bad, because it was so nice :D Fix#2 brings back quick response and leaves the car nice and smooth, probably the best solution for 99% of everyone that would want to try this and not touch any other tables.

Here's an excerpt from mrfred about what the two fixes do:

I'm going to run on fix#2 for a few days, see how I like it, and go from there. Might try a combo of the two or maybe dig deeper, but for your basic bang/buck speed density setup, fix#2 (Scaling Factor for Transition Load=0) is IMHO the way to go.

Re: Speed Density on Evo ECU
 

Got to drive this car last night with the #2 fix on it. Felt very good! I had ridden with scheides just before the speed density set-up and this is a vast improvement. It had a rock solid idle and cruising seemed nice.

Re: Speed Density on Evo ECU
 

Looks like I gotta order another GM 3-bar MAP sensor (robbed it off my 2G for my Holset-powered 1G that's running speed density) so I can give my SD rom another try with this change.

Re: Speed Density on Evo ECU
 

Do it, you will like it :) I ordered a new filter to delete my MAF today from perrin. It has a 3.125" inlet and is 95%+ the surface area of the old one but will bolt straight to the existing 3" intake pipe already on the car. I've had the MAF unplugged for a week or so now, no need for it anymore :)

http://scheides.com/misc/pics/evo/sp...125-vs-4.5.jpg