MAF vs Speed Density

**00blacktransam112** · 01-19-2010, 07:52 AM

What is the advantage of a speed density tune over a MAF?

**Mr. Luos** · 01-19-2010, 08:02 AM

In my opinion (I am NOT a tuner)...there is not much of an advantage either way.
A properly tuned car should make the same power regardless of tune.

The ONE advantage of an SD tune is if you have maxxed out your MAF.

I stick with a MAF tune myself....as I travel from 5000 DA's to 15000 DA's some days in the summer.

**0rion** · 01-19-2010, 11:13 AM

I'm moving this to the computer/tuning area.

I've ran both SD and MAF tunes on my car. Seems like the car had a fewer little BS issues running in SD but probably not anything that I couldn't have tuned out using the MAF. I definitely prefer the way my car runs with the SD tune over how it ran with the MAF.

**shady milkman** · 01-19-2010, 02:56 PM

you deleted my post ?

**0rion** · 01-19-2010, 03:16 PM

Originally Posted by shady milkman

you deleted my post ?

yes, because telling someone to search isn't a good post. The time it took you to type that out you could've offered up some useful info.

**Frost** · 01-20-2010, 06:15 AM

Originally Posted by Mr. Luos

....

I stick with a MAF tune myself....as I travel from 5000 DA's to 15000 DA's some days in the summer.

If your SD setup is properly calibrated this is a non-issue; SD is based entirely around a pressure sensor.

For GenIII cars, SD makes life easier and more driveable with large cams. The thing folks like most is that you get very very snappy throttle response when compared to the MAF. If you think your throttle response is good and you run a MAF, you haven't tried SD yet.

**SOMbitch** · 01-21-2010, 04:31 PM

That would be the MAP sensor........

**El Toro Loco** · 01-21-2010, 06:22 PM

Originally Posted by Frost

If your SD setup is properly calibrated this is a non-issue; SD is based entirely around a pressure sensor.

For GenIII cars, SD makes life easier and more driveable with large cams. The thing folks like most is that you get very very snappy throttle response when compared to the MAF. If you think your throttle response is good and you run a MAF, you haven't tried SD yet.

heard some guys from around here where im from say that there cars runs like it did when it was stock, and a couple of them are running ms4 cams, it doesnt sound as raddicle either.

**Frost** · 01-22-2010, 06:17 AM

The MS4 is a very agree-able "large cam". I typically see better driveability from then than other smaller mega-popular grinds like the torquer cams (230-233 intake dur and 112LSA's). They are softer down low than a grind like that, but it's to be expected. They do indeed seem to run very well in SD cars.

**00blacktransam112** · 01-22-2010, 09:40 AM

what is the cost of converting to SD? would it make sense for a bolt on car or would the $$$ be better spent elsewhere?

**SOMbitch** · 01-22-2010, 10:05 AM

Originally Posted by Frost

The MS4 is a very agree-able "large cam". I typically see better driveability from then than other smaller mega-popular grinds like the torquer cams (230-233 intake dur and 112LSA's). They are softer down low than a grind like that, but it's to be expected. They do indeed seem to run very well in SD cars.

You are not the first one I have heard say this and I have always wondered why???

My medium 230/234 cam sucks at cold start up and always knocks off if I don't feather the gas. Once shes rolling though it has GREAT manners and never gives me any problems. I had my tuner tweak the cold start tables once but it's still not that great.

He is 90 miles away so it's not that easy to have him work on it some more.....

**0rion** · 01-22-2010, 10:07 AM

Originally Posted by 00blacktransam112

what is the cost of converting to SD? would it make sense for a bolt on car or would the $$$ be better spent elsewhere?

converting to SD is nothing more than having someone tune the ve table so you're basically looking at a tune. There's more to it than that but that's the short version. My opinion, and it's just my opinion, is that you'll be fine on the MAF. Even after a cam running on the MAF is a viable option for most cams. I would even go as far to say that most tuners will give you a better MAF tune than they would a SD tune just do to the time involved. I'm not saying they're cheaping out or not doing the tune correctly.....there's just less time invested to do a MAF tune than there is for a good SD tune.

**SOMbitch** · 01-22-2010, 10:24 AM

^^^^ I agree wth this if you are not F/I or a balls to the wall build there is usually not much benefit.....

**El Toro Loco** · 01-25-2010, 10:13 PM

IS IT generally more expensive fo rthe sd tune due to the time involved in it.

**Frost** · 01-26-2010, 01:23 PM

Originally Posted by SOMbitch

^^^^ I agree wth this if you are not F/I or a balls to the wall build there is usually not much benefit.....

SD has 'snappiness' that the MAF will NEVER touch though, and some people prefer that.

Originally Posted by El Toro Loco

IS IT generally more expensive fo rthe sd tune due to the time involved in it.

Depends on your tuner, though it SHOULD be cheaper. If your tuner is being thorough, he is calibrating the VE and then the MAF. If you have stock internals, the need for VE tuning is mostly negated, but otherwise... it should be less work for the tuner as he otherwise would have to tune the VE and then the MAF, rather than just VE. Having said that, there are a lot of hacks out there, so just be aware.

**00blacktransam112** · 01-26-2010, 01:36 PM

so what is the difference between a 2 and 3 bar SD?

**tep98ws6** · 01-26-2010, 01:40 PM

Very good info guys. I am on the wall deciding if I want to do MAF or SD ...but leaning towards SD.

Originally Posted by SOMbitch

You are not the first one I have heard say this and I have always wondered why???

My medium 230/234 cam sucks at cold start up and always knocks off if I don't feather the gas. Once shes rolling though it has GREAT manners and never gives me any problems. I had my tuner tweak the cold start tables once but it's still not that great.

He is 90 miles away so it's not that easy to have him work on it some more.....

Mine does the same exact thing w/ a 231/231

**Hi-Po** · 01-26-2010, 01:48 PM

Originally Posted by 00blacktransam112

so what is the difference between a 2 and 3 bar SD?

Copied/pasted from HPtunerforum.

1 Bar Map(Manifold Air Pressure)=reads up to atmospheric pressure or ~105kpa, used for Naturally Aspirated Vehicles

2 Bar Map=reads 14.7psi+atmospheric pressure=~210kpa used for Forced induction vehicles up to 14.7psi of boost

3 Bar Map=reads 29.4psi+atmospheric pressure=~315kpa used for Forced induction vehicles up to 29.4psi of boost.

I still really like my SD tune. I will probably run a SD tune on my next build as well.

**Knight** · 01-26-2010, 01:50 PM

pretty true. I had the sd tune on mine for about $600 if i remember right, but i had just fininshed building the car (see 99ws6 in new member intros for mod list) and needed a dyno and computer tune anyways. wont really help much on a stock car but when your a hp freak like some of us you end up doing it.