Thule

since i bougth a 90mm NW TB along with my FAST 90mm intake, i found it a little bit odd to dont change the 72mm orginal maf out for a wider one (more like the TB)

i bougth a c6 corvette maf, and harness from casper electronics,

i have seen some members here talk about that 85mm mafs dont do nothing, hp vise,

so i ask, what is the truth?!? was i wasting my money, or is it better for me to have the 85mm Tb on my H/C/I motor?

Specialized

iTrader: (15)

Well, the truth is probably that the 72mm maf could allow as much flow as the 85 unless you're spraying. The 90mm tb allows for more crisp lean-in than the smaller stock style tb. Also- flows more overall. But I dont think the MAF would be nearly as much restriction as the tb/intake is.

99NMB

iTrader: (7)

the after market mafs are useless unless your making over 450 horses on the motor.

killerinparadise

iTrader: (2)

A MAFless tune would eliminate any restrictions that the MAF would or would not create. I do agree with you, I think the stock MAF would slow\block any extra air that you get with a bigger T/B

ringram

+1 dump the maf altogether you know it makes sense.

Most of the big bhp setups run speed density. PatrickG etc..

ae13291

iTrader: (8)

im running the ls6 85mm maf works just fine its great

99blancoSS

iTrader: (115)

All depends on where you live and how often you drive the car. SD isnt a cure all or magic potion. Your telling it what to do and what to expect.

Rain, humidity, cold.. changing environmental conditions ... MAF's have a definate use. some big overlap cams can trick a MAF but I think even thats been taken care of with LPE's 4" MAF...


I'm stepping up the the z06 MAf as well but my tuner said he didnt see any restrictions in the numbers..

the_merv

iTrader: (88)

I have the 85mm..no problems, runs great.

ringram

Old wives tails. Whats the IAT sensor for!? Whats the MAP sensor for?

If your SD tune wanders then its because its not tuned properly. The MAF hides a bad tune, thats why people like it!

99blancoSS

iTrader: (115)

Its not the tune wandering its the environmental conditions. ECU cant compensate when you've already set the variables. I have never ad an issue with the MAF and dont see a need for SD. It might have it's definate uses but in a daily driven street cars its just another flavor of the week fad IMO. In a dedicated race car its a different story as well as with FI applications but the 100mm MAF from LPE might even resolve those issues.

Let me ask you, if all you need is an SD tune then why is GM using the MAF?
Why dont they just load it up from the factory with and SD tune and call it a day? Why spend all the money they did on the system if it was so easy to have a car running great with an SD tune?

SD might have a good use but on this board it's tossed around like an ice cream flavor of the week. Just like cams around here.

Galen

iTrader: (3)

I'm not a SD fan, but by your reasoning, why did GM go SD tune on the HSV Monaros? I mean, if the MAF was better, wouldn't the have kept it on their high horsepower Holdens in Australia? Maybe weather conditions don't change down under.

Galen

Galen

IFRYRCE

iTrader: (3)

Use the 85mm. The advantage to the 85mm isn't in flow. It's in tuning. The MAF flow tables GM has in the trucks utilizing the 85mm MAF are very accurate, almost spot-on. This means that whatever A/F ratio you command is going to be that much closer to what you actually get. Those truck tables will work with any of the black plastic 85mms, as well.

Now, some people will argue that that's useless because you could just use a WB02 and fudge your numbers until you're getting what you want for your ratio, but I personally like to command a ratio and have it be. No need to screw with anything if you don't have to. HOWEVER, if you don't tune your own car, I'd say screw it, it's your tuner's problem. As far as HP, there's no number that I know of where the F-body unit becomes a restriction and the 85mm isn't. Neither of them supports more HP than the other because they both utilize the same table, with the same start and end point, just with different values between.

I agree with Blanco on SD. It's good for race cars. I'd rather have a MAF in FI, too, but that becomes a bit difficult, so I'd say SD for that, too. Other then those two, there is no reason to ditch the MAF.

Galen, I don't think the question should be why did they use a SD tune on one Holden. The question should be, why didn't they use a SD tune on every single other performance (and otherwise, far as I know) LSX car.

RevGTO

iTrader: (12)

How do you tune for that? Can you copy/paste the flow tables from the truck to the LS1 operating systems?

ringram

So why are there ECT/IAT/MAP charge blending etc, etc tables in the ECM then? I suppose they don't deal with varying conditions? Maybe they are there as decoration

Why does GM use the MAF, hmm, because its easy and it self adjusts for changes over the life of the engine, SD doesnt, because SD is a map of efficiency at each load point. New mod, new VE = updated SD.

Why does Chrysler use SD for its over 2 million Hemi's in production in the US. Oh yeah I forgot because SD doesn't adjust for climate or varying conditions.

Sorry dude, not trying to wind you up, just want the facts to be facts.

IFRYRCE

iTrader: (3)

I believe you can, if you have both of the tables. I was using two seperate computers, so I just typed in each number myself. Took all of five minutes, no big deal. Jimmyblue has made a great excel spreadsheet with all the MAF tables on it, I have it saved and can email you it if you'd like.

What?

I understand what you said about GM, but you lost me at Chrysler.

helicoil

iTrader: (104)

Exactly, all these LS1 super tuners must not get under the hoods of alot of late model cars. Honda and Chrysler have been MAF-less for decades. They run just fine in changing climates.

Not a thing wrong with a speed density tune done properly.

PowerShift408

iTrader: (44)

There's a difference though. Hondas and Chryslers are designed w/o a MAF. Our cars are designed to use a MAF sensor.

I agree with the above post though, the only times I could see SD being a viable option are in race-only or forced induction situations.

Just food for thought though, the C5-R race cars used a MAF as well. If it's good enough for their all motor application, it's damn sure good enough for mine.