Opinion, MAF vs SD tune.

**2000dreambird** · 08-04-2012, 12:24 PM

Right now im running on a SD tune... what is the better way to run in your opinion?

**2000dreambird** · 08-05-2012, 03:07 PM

no one?

**Firebirdjones** · 08-05-2012, 03:39 PM

Haven't heard of too many people here running SD tunes but I know it's popular among certain crowds.

I for one switched to an SD tune on both my 6.0 blazer and my wifes 2000 camaro SS. My first attempt was my wifes camaro at Frosts suggestion (great tuner on this site) and I instantly loved it over the MAF. So as soon as I had time I also switched over the blazer.

It's really up to each individual. For me, not liking electronic devices all that much, it was a way to eliminate one more troublesome electronic device from the car

In the end I enjoyed the crisp throttle response and rock solid stable idle as added benefits

Keep in mind I had already tuned the car with the MAF, and still found better driveability after I removed it.

Talk to your local tuners, or Frost on the board here and get more opinions, as I'm not sure many here have tried it.

**SuperSSguy** · 08-05-2012, 05:57 PM

Originally Posted by Firebirdjones

Haven't heard of too many people here running SD tunes but I know it's popular among certain crowds.

I for one switched to an SD tune on both my 6.0 blazer and my wifes 2000 camaro SS. My first attempt was my wifes camaro at Frosts suggestion (great tuner on this site) and I instantly loved it over the MAF. So as soon as I had time I also switched over the blazer.

It's really up to each individual. For me, not liking electronic devices all that much, it was a way to eliminate one more troublesome electronic device from the car

In the end I enjoyed the crisp throttle response and rock solid stable idle as added benefits

Keep in mind I had already tuned the car with the MAF, and still found better driveability after I removed it.

Talk to your local tuners, or Frost on the board here and get more opinions, as I'm not sure many here have tried it.

whats SD?

**Firebirdjones** · 08-05-2012, 06:22 PM

Speed Density.

**SuperSSguy** · 08-05-2012, 11:29 PM

^So this involves physically removing the MAF and/or deleting it by way of a tune?

**pajeff02** · 08-06-2012, 03:15 AM

Yep, the MAF is removed and the error reporting codes are tuned out. The car then runs off the MAP sensor to calculate airflow into the engine. Technically, the MAF is not a restriction until the 500 h.p. mark and with it you do get more precise airflow reporting to the PCM so long as the MAF has not been altered and the heating wires are kept clean. In the event of a MAF failure, the PCM reverts to speed density to keep the car running.

**Smittro** · 08-06-2012, 06:34 AM

SD= less electronics, easier to tune, bach fire injectors becomes an option, more reliable,

smaller less confusing tables. etc,etc.

No down side really. imho

Many, many people run SD tunes and it's seems to be becoming more and more popular for those reasons.

OBD2 "Limp mode" should not be confused with a real SD tune either.

OBD1 cars are SD ECM's and "chips" become a quick reliable way of adding power to N/A cars.

I'm using the Mega squirt II for twin spools which is an SD stand alone ECM. average Joe can tune it.

WIth my setup I can simply burn a tune to a zip chip and plug it into my display for a quick tune change.

No need to drag out a laptop every time I want to change my tune, just plug and play and done.

**2000dreambird** · 08-06-2012, 11:17 AM

The reason i went SD is because the MAF was a bottleneck for my intake. Also my tune guy recommended it. I putting 525RWHP down to the ground. The MAF was working fine but he also said that around the 500 HP mark you really want to go SD.

What is Limp mode? It might be a newbie question but i only build them, i don't tune them.

**pajeff02** · 08-06-2012, 01:10 PM

Good clarification, Steven. The limp mode and actual speed density are not exactly the same.

**Smittro** · 08-06-2012, 01:29 PM

Originally Posted by 2000dreambird

The reason i went SD is because the MAF was a bottleneck for my intake. Also my tune guy recommended it. I putting 525RWHP down to the ground. The MAF was working fine but he also said that around the 500 HP mark you really want to go SD.

What is Limp mode? It might be a newbie question but i only build them, i don't tune them.

Originally Posted by pajeff02

Good clarification, Steven. The limp mode and actual speed density are not exactly the same.

Limp mode.. Both Obd1, obd1.5 and obd2 have this feature. In the event of an engine malfunction, and or an electronics malfuntion, the PCM or ECM reverts to a basic set of variables so that the engine may run enough to "limp" it home or repaired ect. It is a very noticable power loss or reduced power characteristic. In limp mode there maybe reduced capability to rev, reduced fueling, loss of top end etc. It's designed to protect your engine and drive train.

I'm a novice, for a more exact and detailed explanation you'd need to speak to a professional tuner such as Frost (Steve is one of our sponsors) or another professional tuner.

**SuperSSguy** · 08-07-2012, 12:02 AM

Originally Posted by pajeff02

Yep, the MAF is removed and the error reporting codes are tuned out. The car then runs off the MAP sensor to calculate airflow into the engine. Technically, the MAF is not a restriction until the 500 h.p. mark and with it you do get more precise airflow reporting to the PCM so long as the MAF has not been altered and the heating wires are kept clean. In the event of a MAF failure, the PCM reverts to speed density to keep the car running.

Whats the MAP stand for?....

**pajeff02** · 08-07-2012, 02:31 AM

Manifold Air Pressure -- it is a sensor installed at the rear of the intake.

**Smittro** · 08-07-2012, 03:16 AM

Also known as the Manifold Absolute Pressure sensor. In a nut shell it's used by the PCM or ECM to calculate manifold air flow rate/density to determine an engines proper fuel rate or stoichiometry.

**ls1camino** · 08-07-2012, 03:16 AM

I love my Speed Density Tune for all the reasons mentioned already. Frost is a great tuner for this, and he highly recommends it to anyone.

**SuperSSguy** · 08-07-2012, 11:13 PM

^^ Thanks again guys...so many acronyms

**0rion** · 08-08-2012, 07:12 AM

it's a personal preference thing.......I went SD on mine a few years ago just because the car ran better and had better throttle response in SD. At 525HP I would think you're in the same boat.....your car should run better in SD. That being said I know people running boost with a MAF and have no problems.....it's just preference. I normally tell people that unless they're modded fairly heavy just to keep the MAF.

**Smittro** · 08-08-2012, 09:55 AM

I can also agree with Orion.. Many folks keep their MAF system without issue.

My boost engine is a gen-I LQ1 and has some different engine componets than the MAF LQ1's..

Gen-1 LQ1s' are all SD engines and don't have things like cam sensors, only have one o2 sensor, etc,

and teh SD engines specifically used in manual applications use an in block crank sensor with a center crank reluctance.

Gen-II LQ1s' are all MAF engines and the LQ1 community has been boosting them without issue for some time now.

Even the 500+hp club LQ1s' are usually spooled MAF motors.

But for ease of use for the non-professional tuner, I vote SD.