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Speed Density or MAF with Link V3? Which way would you go?

GSTwithPSI

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Jan 1, 2012
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So I'm stacking my parts pile and spending hours a day just researching parts, looking for deals, and trying to decided which way I want to go with the car. For management I have decided to go with ECMlink V3, but I am really torn on weather to go with a speed density setup, or just to run a MAF. My power goals aren't really extreme (under 350hp). This is going to be my daily driver at some point, and I would like to retain some fuel economy as well as good driveability and reliability. These are definitely my primary concerns over making tons of power, although the car definitely will not be stock. I have a set of RC PR2 750 injectors that are going in and the turbo is just a big 16G. The rest of my mod list pretty much follows suit and isn't anything drastic. I'm reading good things about speed density, and it seems like many people are making big power on SD setups. I was leaning toward a 2G maf or and EVO maf setup just because I am under the impression this setup is a little more on the economy side of the house but will still suit my power goals (and will be a bit easier to tune), but I really can't say since I have have zero hands on experience with SD. In addition to economy, good driveability and reliability, I would also like to be able to go with an option that can be fairly easy to tune with. Although I know this is a factor which involves many other factors, please rate how you think going one way or another will effect the difficulty to tune that specific setup. If someone could help me out and point me in the right direction on which way to go with this that would be awesome. If you need a more complete mod list that I intend (as I haven't yet purchased all of the parts for the build) to use for this car please let me know, and I'll post one up. Thanks in advance for any input.

Here's a link to more info on the car: click

img00002201109201825.jpg
 
Last edited:

Brunoboy

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Apr 25, 2008
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San Bruno,CA Home of SFO
when i had my vr4, i went from a 2g maf to SD with link v3. I would never go back to a maf.
 

jmorri15

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Jul 11, 2009
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Kemp, TX
i have sd and thats the way to go
 

rdomeck

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Jun 1, 2011
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Indianapolis, In.
I am currently running SD and I will be switching to a GM MAF before I continue to drive my car. Mainly because I don't have the time to turn the car as it takes a lot more to get them to run correctly for a D.D. I have no doubt that SD makes a little more power, but for a daily driver I would much rather loose 5-10 horsepower and have it more drivable. Most of the guys I have talked to said that I should go back to a MAF for a D.D. Just my .02 cents worth.
 

turbowop

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Apr 29, 2001
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Yakima, WA
For what it's worth, I got better fuel mileage when 1051 used a 2gMaf before I went SD. I'm not sure why, possibly something to do with my lack of tuning experience when I first installed and tuned it on SD, but cruising AFR's are normal. With a 2gMaf, the car would get 28mpg on a nice easy 2hr cruise to Seattle. Now it's probably around 24mpg or so. It really doesn't matter to me since I don't put many miles on the car per year. Perhaps if I used a different SD conversion like Link, my mileage would improve, I dunno.
 

Andy_S

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Jan 30, 2007
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Shithole Wisconsin
Its all in the VE map. The more time you take to tune the VE map correctly, the better your results will be compared to a maf.
 

WaRrIoRs16

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Mar 23, 2008
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Ferndale, WA
Link offers very easy tools such as SD VE Adjust(CombinedFT) to help dial in closed loop operation.
 

ghostinthevr4

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Jun 11, 2008
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Fresno, Califonia
I was at a cross road just like you with a decision of SD or 2g maf. I did a rebuild and was wondering which way to break in the motor, maf or SD. I'm also running an HX-40 I fired the car up the 1st time with speed density, I skiped the maf altogether my setup fitment was easier without it. It fired up first try no problems, if you decide to run SD just start reading through the ECMlink wiki.

Also there a guide in the SD intergration portion of the forum, a member came up with a guide on how to start your car and how to tune SD without a maf. I suggest reading it until you get the concept, it might seem a lil intimidating but once you start using it you'll start to pick it up. I was a lil intimidated in the beginning to but decided to dive in, I'm glad I did I love the SD but I have a big turbo so it only made since to go with SD.
 

GSTwithPSI

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Thanks very much to everyone for all the input so far. I am pretty familiar with how SD works, I just don't have any hands on experience with it, and definitely appreciate the input from those who do. One thing I found really interesting about SD is how most people can take a VE table from someone with comparable mods, tweak it a little and have an end product that is making great power with very little work. I mean, whats better than using someones else's table who may have spent countless hours on a dyno, tuning, tweaking, comparing logs, making adjustments, and doing whatever else in order to optimize their tune? It's like your are getting everything they invested for free as long as they will share information with you. I feel like with SD there are so many ways to NOT start from scratch by using info from those who have already done lots of leg work. Not only that, but I know there are guys out there who just by looking at your VE table can do a pretty good job pointing out where and why your tune may me flawed. The more and more I read, the more SD sounds like a good deal. I am still very attracted to the simplicity and the plug and play option a 2G MAF would offer though, and know many people are making great numbers with this setup. If do decide to go SD, I think I will just get the sensor package ECMtuning offers. Is there something better in the realm of SD in regards to certain sensors and hardware compared to what ECMtuning offers? What are you guys running on your SD setups? Thanks.
 

ghostinthevr4

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Smart move on getting the bundle pack, it'll make everything plug and play once you install the sensors. I already had a gm IAT sensor you can find them on fox body camaros in the junk yard, but I purchased the cable and the 4 bar omni from ECMLink.
 

WaRrIoRs16

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Mar 23, 2008
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Ferndale, WA
I too went with the SD bundle pack from ECMlink. Its everything you need and the sensors are new and for sure compatible.
 

LIV4PSI

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Go speed density and don't look back.
 

GSTwithPSI

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Hey guys thanks again for all the input. Looks like SD FTW. I have decided to go with a SD setup, most likely just the ECMlink bundle package unless anyone can give me a reason not to. I have a few questions: For you guys running SD, how was your experience tuning your setup? Are the majority of you guys just doing street tunes, or getting some actual dyno time? I'm sure you all have wideband setups correct? Also did you start with someone else's VE table, or are a lot of you guys starting from scratch just running the SD VE adjustment tool? And are you guys fine tuning your SD setups in conjunction with a MAF?
 

LIV4PSI

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I can't answer all of your questions, but people who use speed density don't use the MAF. It is strictly MAP based. A wideband is needed to tune with as well, or at least to do it right. AEM UEGOs aren't expensive, snatch one up.
 

WaRrIoRs16

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I didn't use a MAF at all during my setup due to the availability of inputs to the ecu. My MAP sensor is on my Baro input and my IAT sensor was on the IAT input, so a Mitsu MAF wouldn't have worked. A GM MAF would have been no different then starting fresh with SD.
 

GSTwithPSI

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Quoting LIV4PSI:
I can't answer all of your questions, but people who use speed density don't use the MAF. It is strictly MAP based. A wideband is needed to tune with as well, or at least to do it right. AEM UEGOs aren't expensive, snatch one up.



Some people do use a MAF in conjunction with their SD setups as a means to dial in their VE table. A MAF can be used in conjunction with SD, but because the stock MAF uses the intake air temp input to the ECU, you have to disable speed density's use of the air temperature sensor for airflow calculation. Since that is the case, I was just curious if using a MAF to dial in your tune was worth while, and if anyone has even tried this? It sounds like I pretty much have my answer though, and most of you guys probably started fresh, or with someone else's VE table and never touched a MAF (which is pretty much the point of SD) after converting to SD.
 

mikus

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Aurora IL
^ You've got it right actually, LINK V3 allows use of a MAF in conjunction with SD sensors IAT and MAP, to create a baseline VE table for your car. That's a pretty handy feature I think

Now this part's off memory so please fact check me --- but, I don't think there's enough ECU inputs to pull this off well on a 1G ECU + Mitsu MAF. A MAFT doesn't make use of one MAF side input (IAT?), freeing up that line to run all 3 sensors. So MAFT is actually well suited for this approach. You'll have to get creative with wiring to get this together. Notes here
 

WaRrIoRs16

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Isn't there tuning involved when using a MAFT system? I have only used a GM MAF with ecmlink, so I don't know about how you set up the translator. But if you have to tune the MAFT, might as well just skip it and tune the SD off the base VE table IMHO.
 

GSTwithPSI

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^ Yeah I definitely see what your saying. You would still have to set up your MAF correctly and get it reading accurately before you can even use it to help you make your SD VE table any better. I guess the whole idea with behind running a MAF in conjunction with SD is just to give you another way to check or improve your tune. I was just curious how many people actually do this, and I'm getting the feeling nobody probably does because of the limited ECU inputs and the extra work involved. PS thanks Mikus for that link above outlining the ECU inputs, very helpful. If you are interested in the MAFT config with SD, there is a basic setup/outline of what to do here: click
 
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