02silverbulletZ28

i see others running without a maf with a speed density tune, what are the benefits of this? and when should it be considered?

97camaro383

iTrader: (31)

Id like some info on this also!

JakeFusion

iTrader: (7)

Really big cams or lots of airflow that max out the stock MAF... which is good to about 475rwhp or so. It can be pushed a bit higher, but it starts to peg after that and should be replaced once you cross about 520rwhp with either SD or an LS3 slot-type MAF for better resolution.

SD can help with really large cams. As long as you don't drive from say Denver in winter to Miami in summer, the tune won't be affected.

Werewolf SS

iTrader: (3)

The concept that SD doesn't like elevation or temp changes is frankly a myth.
Any properly tuned SD setup will have no issue being driven from the mountains to death valley. SD is Speed Density. It is calculated based on the Manifold Absolute Pressure (MAP) and the Density of air (Intake Air Temp) to calculate the fueling requirements. As you ascend or descend in terrain or as temp rises or lowers the density of air changes which is measured by the temperature of the intake air temp sensor. The system then references that temp with what it is seeing from the MAP sensor and uses the two values to calculate fueling for the engine, if the system is closed loop then it ref's the o2 sensors for any deviation if there is any.

For reference I am running SD only and I live in central florida. Temp's change quickly in the winter it was 80 the other day and before that was down in the 30's. It rained one day with high humidity and no humidity the next and I have no issues with driving nor any change in fueling patterns when doing so and I drive 50 miles a day.

But it really comes down to preference in a stock environment. Some like SD because it provides crisp and more responsive throttle. Others like MAF because if they change anything on the car with an SD tune they would have to recalculate the VE tables as they are static numbers and the maf is a constant changing number (though it to must be adjusted if you want to do things properly).

As Jake said once you get up in power though the MAF reaches a limitation. Tuners can compensate and get around this to an effect but going to a larger MAF is usually preferred (instead of raping the table after it hits it's max.) or going the SD route especially in Blown applications. Not to say Blown cars can't use MAF my buddies T/A is running a S/C at 7psi and he runs MAF still.

So again, mostly a matter of preference. But I'll leave you with an interesting fact. Holden over in Australia released an LS vehicle that was SD only from the factory. And they have to maintain a standard warranty so if the system was so unable to handle altitude or temp changes you would think they'd stay away from it.

danieloneil01

What table do you adjust for fueling based on IAT in hptuners? Because mine was tuned and if the IAT gets above 90* the car will run extremely lean. My VE is spot on when the car isn't heat soaked.

98TransAmWs-6

iTrader: (11)

My car is SD and I have yet to have any issues. I did it mostly because I wanted there to be no restriction in the intake track and a SD tune was cheaper than getting a 100mm MAF and getting it tuned.

Y87bird00

iTrader: (6)

What did you use to physically delete the sensor from the intake?

98TransAmWs-6

iTrader: (11)

This. It's a 4" wide and 6" long silicone tube that goes from the lid straight to the TB. It fits around my FTP 104 lid and NW 102 TB nicely.

ramairetransam

iTrader: (18)

i was fine when running 6 lbs but once i was making 10-11 lbs no way. It wouldnt even get a good idle with a brand new gm 85 mm maf. So out the maf came and its so much nicer to drive now . I wish i had did away with the maf from the start .

It would have cost me more for the tune but i went through a few mafs with i sucked up a little rain water .

02silverbulletZ28

where did you get the silicone coupling at? im looking at doing a MS4 cam or btr N/A cam and a good set of heads, with a set up like that should i go with deleting the maf? would i benefit by deleting the maf instead of upgrading it?

mchicia1

iTrader: (5)

Based on my data logs, SD is a bit more inconsistent than the maf. I had my tune dead nuts on once. Went to the track a few weeks later, and I was 5-10% lean at WOT. That was the day I swore off SD. Unless you data log, you won't know if your tune is off.

I never have issues with the maf, it's always within 1% of where I left it.

If you are doing it for flow/trying to gain HP, do yourself a favor and convert to the ls3 card style maf in a 4" tube.

I would only consider SD if the maf PCM limit has been reached. The great thing about the ls3 maf is that it lowers frequency, so it gives you more head room if you're boosted.

I would even run a 50% scaled tune before I would go SD.

98TransAmWs-6

iTrader: (11)

I got it off ebay from a seller called "Potz performance". But any silicone coupler that is 6" long will work as long as the inlet size is the same or close to your lid and intake. I am of the opinion you will benefit by going SD but others may not be. Throttle response is quicker with SD. Aftermarket MAFs suck and are a pain in the *** to tune for. I personally feel the benefits outweigh everything else. Whether you should do it or not is really up to you.

Fullen

iTrader: (9)

Good info. I'll be going SD since I'm putting a Super Vic/4150 setup on mine.

02silverbulletZ28

thanks everyone a lot of good info, im going to talk to my tuner depending on how money goes i may get my car tuned before i get my heads and cam if funds dont allow me to get them soon, if i did get my car tuned before heads and cam would i benefit at with deleting the maf without any bigger mods?

02silverbulletZ28

thanks everyone a lot of good info, im going to talk to my tuner depending on how money goes i may get my car tuned before i get my heads and cam if funds dont allow me to get them soon, if i did get my car tuned before heads and cam would i benefit at with deleting the maf without any bigger mods?

Werewolf SS

iTrader: (3)

It's going to cost you to get tuned and then down the road you'll swap H/C and have to pay to get retuned. Why not wait and save that money towards your heads and cam first?

I enjoy SD personally, it gives the car a more crisp throttle response but as you've seen so far it's highly subjective to taste. You may not like it, or you may love it. If your tuner is doing a through job he'll setup both the SD and MAF tables. Drive with the Maf and see how you like it for say a week. Unplug the MAF sensor and the car will default into SD mode (it'll throw a Check engine light unless tuner disables it) and you can see if you like SD mode better, drive it a week and then decide.

Just let the tuner know you want to try both modes first so they're aware.

"MAC"

iTrader: (1)

I would ask the tuner if he charges a retune not all tuners do. Mine doesn't

02silverbulletZ28

the only reason i was thinking about getting it tuned is if i do not get heads and cam soon i do run my car at the track and a lot of guys down there have told me a tune does a lot even on a stock car, im just trying to get my car to run the best it can even with the little bit i have done to it. im trying to get a lot of bills paid off now so i will have more money to spend on it later and buy a house so thats a little more important to me then heads and cam at the moment, how much do most tuners charge for a dyno tune? theres a few tuners up my way im just trying to find the best for ls cars

mchicia1

iTrader: (5)

If you wanna go card style ls3 maf, this 4" pipe from spectre makes it really easy


Then you just need the card maf (can get on ebay for like $20 or new for $70) and the wiring harness adapter for $25.