Hey guys,

Decided to go SD. More for future mods than where the car sits now (built 2.4, but stock turbo/cams/etc .. just bolt ons)

I've tuned a handful of things on SD before, but never an EVO. I'm using this Tephra map: Option 3 94171715 (v7 + Mods + Speed Density Omni 4 Bar)

I'm using the Omni 4.4 obviously, and the GM IAT installed in a custom IC pipe I made (next to battery). I have the IAT wired into the MAF (red/blue and black) and that option switched in the ROM (set as 03 instead of 0E)

And all that appears to be working fine. I have no CEL's and I think I'm getting the right readings in evoscan for the iat. Entered some code in an XML but I'm not sure I did it right Though I'm not overly worried about that right now.


Car runs... revs up etc. But in order to bring STFT's back to about 0, I had to adjust my SD RPM VE map to much, much higher values than I would have thought I'd need:

For example the first few values starting at 500 rpms go like this:

159
162
165

etc.

(edit: attached a pic I had taken along the way of tweaking this.. also shows VE calibration table which I tweaked to in theory get my maf tune timing table to at least be close...)

I figured I'd be in the 60-70 range. But if I go lower, fuel trims go up.. keep going lower eventually it won't idle and revs up like crap (basically relying on tip in for enough fueling to rev).

I can't figure out why this is so far out of whack. I have played with the Main Fuel Map as well and it seems to have little effect on fueling.. in fact I'm not even sure which way to go with these values. Most things I've tuned on SD had a 3D VE map that you dialed in most of your fueling with. What effect do the numbers in the main fuel map have now on the SD rom? which way do I go with those values to achieve something?

Anyway, does anyone know why my VE numbers are so ridiculously high? Stock injectors, stock values in the map etc.

I'd sure appreciate any thoughts, advice, help.

-Todd

 

So I have been through the map, and can't find any reason for the silly values.. but I have just moved forward with the tune. It starts good cold, getting WOT dialed in. Load numbers make pretty good sense.. the boost the MAP is picking up seems a little low to me.. but everything is coming together. Making good power on the VD.

Seriously lost as to the numbers that are double what they should be, but they, it's running good so...

 

Could your elevation be playing a factor with your numbers?

 

Well.. good question. I set the baro to my actual baro pressure here (.79 bar or fluctuates between 11.43 and 11.63psi here). But the boost is reading pretty low... might be because I dont have evoscan setup properly for SD though... the loads its achieving seem right though - high if anything: 325-330 max tapering down to 260-270 by 6200 (the 2.4 with stock cams/turbo doesnt like to rev). This motor doesn't like timing either... but it's reading consistent 325-330 whp on the VD (IDC is 84-85% max at 11:1 afrs) - I'm new to evo's but I think that all lines up fairly well...

I'm not sure what other effects it might have...

 

Car is running strong w/ low timing. Been sneaking it up slowly.. it just really hates timing in the 3k-3500 or so area. Once above 4k, it seems to respond to timing ok. But I had to de-senitize the timing control so I'm going easy. Something with the 2.4 and probably especially the noisy piston slapping JE pistons lol....

Oh just for reference to anyone else that comes along. Changing the cam timing from 3.5 degrees advanced, to 3.5 degrees retarded- helped out the top end tremendously. Moved the power band approx 1000 rpms higher, with no noticeably negative effects down low (would be hard to tell, with a 2.4 and stock turbo its super torquey as is).

Once I get some cams, I'll get some adjustable gears and set it up correctly...

Ordered a Depo racing IC, after that and maybe some more timing.. we'll see if it will hit 340+ on the VD at 6600ft elevation.

SD is awesome btw... IMO, the 2d ve map is limiting, but overall it can be tuned to run well enough everywhere.

 

You need to change your kpa-load table first. Then go back and fine tune the RPM VE table.

https://www.evolutionm.net/forums/ec...ched-roms.html

 

As I mentioned above, I did end up scaling the table differently. Using basically a 1:1 ratio as was mentioned in those SD threads. This doesn't account for why my VE values are double what other people are seeing. My load is slightly higher than it was on a MAF, but came out pretty close which only required tweaking to my timing table.

 

If you keep the kpa-load 1:1, you have to compensate with Maf Compensation/smoothing. You cant do it all with the RPM VE table.

 

Ahh.. I thought you were referring to the weird VE numbers.. I'll start on that. It's amazing how well its dialed in with just the 2d map / few fuel table tweaks. STFT's are within 5% .. maybe 7 in a few spots... WOT is solid.... thanks

 

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