Speed Density eliminates MAS??

[1cleanreddsm]

Ok, so I did a some research reading about speed density but none has really answered my question. So my question is,

"Does ECMlink with SD eliminate the need to have a MAS?"

Since both functions similarly, vise versa, then I'm assuming having Speed Density would eliminate the need for a MAS, but correct me if wrong, I'm planning to get ECM but wonder if its worth getting SD, and my HP goal is around 400-450ish thus a 2G maf would suffice.

Thanks in advance

-Jari

 

[LiquidX]

Yes it eliminates the MAS and replaces that system with an IAT and MAP sensor. It's easier to just setup a MAF that's already made for the the vehicle but there is no more restriction with SD nor will boost leaks have that same issues with bogging and running rich/lean.

 

[xyexz]

Not trying to hijack this thread but instead of making a new one I'll ask my related question to this (would probably benefit OP as well), I read somewhere (can't recall where) that you still need to start out with a MAF when initially tuning an ECMLink DSM because it uses the data logged from the MAF to do some sort of initial map creation for the SD, is that correct (or really needed)?

 

[1cleanreddsm]

Not trying to hijack this thread but instead of making a new one I'll ask my related question to this (would probably benefit OP as well), I read somewhere (can't recall where) that you still need to start out with a MAF when initially tuning an ECMLink DSM because it uses the data logged from the MAF to do some sort of initial map creation for the SD, is that correct (or really needed)?

I thought ECM gives you an basic MAP for backup in case your battery dies somehow. So I don't think you need a MAF for intial start up.

But thanks for the reply certianly cleared my confusion.

 

[LiquidX]

I thought ECM gives you an basic MAP for backup in case your battery dies somehow. So I don't think you need a MAF for intial start up.

Please explain what that means. MAP = Manifold Absolute Pressure (sensor). Also it's only v3 that has the internal battery so when power is lost from the ECU you no longer need to reload your tune.

It's easier to set up your VE table from a tuned MAF. It isn't required though as you can make your VE table from scratch.

 

[xyexz]

I don't think OP meant MAP as in the sensor but what some refer to fuel MAP tune MAP etc... a MAP of data.

I didn't know about the internal battery stuff in all my reading about ECMLink, good to know that, looks like I'll be purchasing ECMLink v3 full.

Thanks for the info regarding VE and doing initial tune with or without a MAF.

 

[1cleanreddsm]

I don't think OP meant MAP as in the sensor but what some refer to fuel MAP tune MAP etc... a MAP of data.
I didn't know about the internal battery stuff in all my reading about ECMLink, good to know that, looks like I'll be purchasing ECMLink v3 full.

Thanks for the info regarding VE and doing initial tune with or without a MAF.

^^ Yea, what he said
It's good to know they have internally batteries too.

 

[aba60620]

OP,
I have been running speed density on my car for a little over a year now. I have never used a MAF for tuning, so I don't know all of the differences between tuning the two, but YOU DO NOT NEED A MAF TO SETUP SPEED DENSITY. If it's the route you want to go, this will tell you how to tune speed density with out a MAF on a 1g. ECMTuning User Support Forums I found it pretty easy to figure out, without any prior tuning knowledge. You need to have an account with dsmlink to access their forum.

 

[1cleanreddsm]

Yea, thanks. My question has already been answered and resolved and I have read through some of the ECMlink pages.

 

[Jacob hoke]

Sorry this thread is really old but I know if I start one people will say I should have googled it or search and I have. However Im not getting a very clear understanding of how speed density works and if its better or not I have a 1g mas and was going to go 2g which is better then I read to just spend the extra $40 for and evo 8 mas and I understood why however why would someone choose SD over the conventional MAFs set up and I plan to go bigger one day so to me why not purchase the better of the 3 first and save some cash in the long run

 

[blktalon3]

SD and a maf are just 2 different ways measure the air coming into the engine. A map sensor measures pressure from your intake manifold a maf sensor measures it before it goes into the turbo. Some reasons people switch to SD is you can vent your blow off valve and boost leaks won't affect your tune, they will affect the performance of you car still so they are still bad.

 

[Jacob hoke]

So basically the only perk to SD is boost leaks won't disrupt the tune as much however if the system has no leaks then using mafs is just as good? Would a mafs setup be as flexible with the cold air intake as SD is thank you BTW for the reply kinda at a point in my build were I'm floating

 

[AdR]

So basically the only perk to SD is boost leaks won't disrupt the tune as much however if the system has no leaks then using mafs is just as good? Would a mafs setup be as flexible with the cold air intake as SD is thank you BTW for the reply kinda at a point in my build were I'm floating

Not quite. There are a couple of benefits.

1. MAF is way better than MAP/SD for tuning any vehicle as it has much better resolution than its counterpart. That's the primary reason why manufacturers use it over SD as it makes passing emissions that much easier. The only problem is that MAF on our cars require you to put a restriction in front of your intake path to be able to measure airflow (honeycomb and resistors) due to the fact it requires laminal flow and the only way to straighten airflow before the resistor is by using that honeycomb structure. SD on the other part removes that restriction improving airflow to your turbo.

That being said, our MAFs can flow about 52lb/min which should be fine for most people as most 20G or similar upgrades don't flow that much. If need be an Evo MAF can flow more.

2. With MAF you should run your DV or Blow off Valve in recirculating mode. As MAF measures flow, it calculates the amount of air coming into the intake charge and if you dump any of the air right after the MAF then the mixture will be screwed and the car won't run as good as it should .


For intake you'll need one that can accommodate the MAF and has recirculating provisions. There's no one size fits all intake system. You'll have to decide what you want and get the intake that fits your needs. To answer your question, no the MAF intake is not as flexible in terms of piping and location compared to an SD intake.

PS: In all honesty I cannot see not bogging with boost leaks as a benefit. That only refrains you from noticing an issue and overreving your turbo to be able to compensate the fact you're loosing boost pressure. That's a recipe for a broken turbo if you ask me. Think about it this way, if you had rod knock would you want the engine to mask your issue and continue running without any indication you have a problem to just let it get worse until there's no saving it? I highly doubt it.

 

[Geeb]

2. With MAF you should run your DV or Blow off Valve in recirculating mode. As MAF measures flow, it calculates the amount of air coming into the intake charge and if you dump any of the air right after the MAF then the mixture will be screwed and the car won't run as good as it should

Unless you do a gm maf installed before the bov, then you can do atmospheric vent because it calculates before it even gets to the bov, is that correct?

My goal is 600ish, so s.d is probably my best bet right?


AdR you're one of the only people I saw write that you're pro maf as opposed to sd.. But I'm no tuner so what you say makes sense its gotta be easier, my tuner charges 100$ more for s.d tunes than maf tunes..

Is that because you have to start from scratch?

He said he def says he thinks I should go s.d though, and he's super busy so I'm sure that's not just because it's more expensive
..

 

[AdR]

Unless you do a gm maf installed before the bov, then you can do atmospheric vent because it calculates before it even gets to the bov, is that correct?

The other way around. If you put the GM MAF AFTER the turbo/bov, sure! It's all about placement after the moment air can be lost (or expelled by the bov). Our MAF type cannot be placed as a post-turbo setup but a GM MAF can, making calculations based on the flow and temperature that goes after the turbo. In my opinion a post turbo MAF is way better as it's calculating the airflow, temperature, etc right as it's going into the intake stream since those are the actual conditions and not calculated conditions as a pre-turbo maf system.

 

[94awdcoupe]

fellow on evom made 600whp blowing through the evo 8 maf.. it was mounted just before bend at throttle body. the turbo was a side mount 35r size turbo. it was mounted were the airflow meter normally is. they didnt get the memo you cant use karmann maf in blow through. there were pics posted at the time. he didnt report any problems. it was a well sorted looking engine compartment.

 

[AdR]

My goal is 600ish, so s.d is probably my best bet right?


AdR you're one of the only people I saw write that you're pro maf as opposed to sd.. But I'm no tuner so what you say makes sense its gotta be easier, my tuner charges 100$ more for s.d tunes than maf tunes..

Is that because you have to start from scratch?

He said he def says he thinks I should go s.d though, and he's super busy so I'm sure that's not just because it's more expensive
..

I am not really pro MAF nor against it. It just depends on the scenario and power goals. A high hp setup will benefit from SD and it might suffer slightly of drivability issues but if properly set shouldn't be a big deal. Most people don't really notice the differences at all or just live with them and don't mind them. I do prefer MAF for daily use and relatively low power goals. If I ever go for +400whp mark, I'd definitely switch to SD but I've seen 600whp cars on MAF without any issue.

He's charging you more because SD takes more time to properly set and tune. I'd also suggest it by your power goals as you will easily outflow most maf setups. I don't think he just wants to force you to SD for no reason.

 

[bastarddsm]

Got a link to it? Not that I don't believe you, but the baro in these mafs are only 1bar....Shouldn't be plug and play. The karman frequency is a function of strouhal number and relatively unknown affected by density, so how would it detect the mass?