So I have been getting very conflicting reports on how well SD performs on Tephra v7.

I was about to do SD on stock ecu with a bunch of new mods, but a very well respected shop which is going to do the work has told me that they have not had one stock ecu SD car which ran correctly. They said they could do it if I want but they do not recommend it. Another shop I also spoke with does not even touch it unless its on AEM.

On the other hand I keep hearing about all these people running SD on V7 and loving it. I know AWDmotorsports in Florida does a bunch of them, I think English Racing as well, and so do a few other respected tuners on here.

So what is the truth here?

Is it the best thing since sliced bread? Or is it not that great unless you are running AEM or another ECU.

I would love to get to the bottom of this.

*Update 1 Month later

After getting a crappy tune by a shop I thought was respected I figured I might as well give SD on stock Ecu a chance since I had nowhere to go but up. It's been one week now and the car runs great. It feels just like stock.

So if your tuner tells you stock ecu speed density doesn't work, I would suggest finding another tuner if you really want SD. It works and it works well. I have not had one problem yet.

I'll chime in again over the winter.

 

I've been in an SD car that drove smoother and made more power mod for mod in comparison to my current evo at the time. I think your shop just doesn't have enough experience in setting up SD or they are trying to get you into a different system they are more comfortable with (AEM, HKS, ect...)

 

The only issue's I have ever heard of was changes in elevation. Then again Bryan from GST says he never had an issue as he'll go up into the mountains for skiing/snowboarding.

OP your in NYC. Contact E-Spec on here he does many many SD set ups in your area and always has great results from what I have seen

 

What reasons did they give you for not wanting to do it?

There are some issues, but nothing that will keep the car from running very well, if tuned properly. It appears that many people don't tune or completely understand the VE tables and that seems to be the root of many problems.

That being said, these are the only issues that I have seen, and I believe are being worked on for the next release:

1. Baro at startup:

The current SD patch in the stock ECU uses a locked baro value. For driving around and WOT tuning, this doesn't matter because maiss airflow is calculated from boost pressure and IAT. The baro sensor in the MAF was there because the Mitsu Karman maf is a volume sensor and needs baro and temp correction to get a mass airflow.

However, there are several tables in the ECU that references the baro value for things like startup, to get proper fueling. So, for example, if you have your baro locked to a value at sea level and then go for a trip up into the mountains, then when you go to restart your car, you might be getting too much fuel at startup (since baro is lower at higher elevations). This *might* prove for a slightly difficult startup. As mentioned above, some people have tested this and it was fine. But, this is what they are talking about.

SD v2.0 will include provisions to have a separate baro sensor wired in to read the baro value at startup to alleviate this issue for those that experience it.

2. Heat soaked IAT sensors may cause a lean startup after car sitting for a while:

This isn't a flaw with the stock ECU speed density per se...it can happen with any SD that doesn't account for it.

SD uses the IAT and boost pressure to calculate a mass airflow. If you are driving your car, shut it off and let it sit for 20 mins or so, depending on where you have your IAT sensor mounted, it may be susceptible to heat soaking. Basically, what this means is that the sensor will start to absorb some of the heat in the engine bay and read artifically high right when you start the car up. This will give an artifically lower mass airflow calculation to the ECU and thus a little less fueling for a few seconds (roughly 20-30 seconds in my experience). So, you might experience a rough idle or stumble/stalling in this case.

Again, I believe SD 2.0 will include some code to account for this. The IAT can simply be locked to a value a configurable amount below the measured value when coolant temps are in a certain range or something to that effect.

And again, some people say this is not a problem for them. It really matter where your sensor is, etc, etc.



But, as far as overall drivability and WOT tuning, ECU SD performs flawlessly and in most cases, especially for highly modified cars with big turbos, aggressive cams, etc, it will run much smoother than the stock MAF for several reasons. Also, it removes the MAF as a restiction and allows running a bigger, smoother intake pipe. So, drivability and power should be up.

If you want more information, just read up in the ECUFlash subforum. I, as well as many others that have run and are running ECU SD, are there and can provide any more info.

 

^^^Definitely some good info right there...I would like to go SD soon but would like to learn more about it first...Just like the OP said there seem to be more shops pop up saying they are not a big fan of SD or don't tune SD cars at all...but that may be due to there inexperience with it...

 

im also interested in going SD because drivability is huge for me. What about the dredded 2000 rpm stutter? has that issue been fixed??

 

Yes it has.

 

i would really love to have SD with ecu controlled boost... that would be super sick nasty amazing.

 

I never said that. My personal evo is not currently running SD.

Elevation changes are an issue until they get Baro working with SD and is one of the reasons my personal Evo isn't running SD yet.

- Bryan

 

Yea knew they were, thought I had seen that in a post from you where you didn't see an issue traveling up to do some riding.

Sorry for the misquote

 

Thank you for your thorough reply! Hopefully something will work out.

 

My personal opinion is that until there is a separation between MAP sensor calibration and MAP VE, it will continue to be non-tuner friendly. Having to build up a base map for a simple MAP sensor calibration is a bad thing. JCSBank's original idea of separating MAP from VE was a better implementation.

The good news, the place in the code where JCSBanks patched into has enough room for other code changes to fit in without having to track down additional space. There are a couple of us that have written SD patch modifications including 3D VE tables and separate MAP sensor calibration tables. I have no idea if any are currently in progress of being tested. I personally have a completed patch that I haven't had a chance to test out at all.

Also, the startup issues are very real. I think it is a combination of IAT calibration and baro though. Really cold temps cause AFR changes when they really shouldn't, combined with the Baro issues, they cause a lot of trouble at high altitude in the winter. I'm talking 9000' and -30F here... If "mountain" to you means 4000' and "cold" is low 40s, you won't see these issues.

 

-30F? Who sees -30F in a Evo, or any car for that matter?

That's like snowcat weather lol

Even on MAF I was seeing swings with 7000f+ and 0 to 20F when the car was tuned for sea level and 50-70F

- Bryan

 

I'm interested in hearing how the testing goes on your patched ROM, definitely post up in the SD 2.0 thread

 

My car runs great with SD, but it takes time to
dial in part throttle drivability. I don't climb mountains in -30 degree weather though