mafs to speed density

[Wasted Income]

Originally Posted by Jon01

It's failed to tune the VE table but once that's completed it's re-enabled and tuned.

I just find that I can get them to run so nice with the MAF failed, that I ditch it alltogether

[jorgensensc]

Thanks for the link. That was great reading.
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[Wasted Income]

Lol, I love how the MAF vs SD debate is kinda like "blondes vs brunettes", "pepsi vs. coke", "tastes great vs less filling", or even..."chevy vs ford". Lots of passionate opinions, but really no wrong or right answer. Whatever suits you best.

Originally Posted by BR3W CITY

Wasted- you had me staring at the gauges as to what my intake temps were all yesterday.

Well? What did you find?

For reference, here's where I have mine mounted. Works great. And...omg, look ma, no MAF!

[Jon01]

I'd SD your truck vs MAF in a heartbeat. Centri/turbo apps are much better suited to SD tunes than N/A stuff IMO as they overcome changes in elevation/temp as soon as they climb into boost.

[Wasted Income]

Originally Posted by Jon01

I'd SD your truck vs MAF in a heartbeat. Centri/turbo apps are much better suited to SD tunes than N/A stuff IMO as they overcome changes in elevation/temp as soon as they climb into boost.

I'm still not sold that a MAF is needed or even "better" for an N/A application. I have empirical data (from other LS swaps I've built) that it's not.

You're probably also going to hate that I never run narrowband O2s either

I built and tuned my brother's LSx Monte Carlo SS in Illinois, and it's running door to door with procharged C6 corvettes down in the heat of Texas. Tuned open loop, speed density, and the tune hasn't been touched since I gave it back to him.

I also tuned my N/A LSx jet boat OLSD. Ran perfect in all conditions. Would it have run "better" in certain conditions with O2s and a MAF? Maybe, but my money is that it wouldn't have been enough to notice.

Plus, it cleans up the look a ton.

[Jon01]

MAF's are there for redundancy and simplicity.
OEM's produce millions of vehicles that see all sorts of climates, they have to run fantastic in Alaska and down by the equator without tune changes. That's why they have them.

I don't care what you do with your car. I run 1 narrowband and 1 wideband in my junk while tuning and replace it with another narrowband once done monkeying with the tune. Only reason is that WB NGK sensors are spendy otherwise it'd WB all the time.

[prostreet1967]

Originally Posted by jorgensensc

So if there are advantages to running speed density, what are the disadvantages? Obviously GM decided to go with MAF over Speed density for some reason.
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well in my turbo setup i will be running SD.
and BTW Ford switched to SD on the eco boost engines.

[Super73]

Originally Posted by Wasted Income

The biggest disadvantage in my opinion is that once the tune is dialed in, if you change anything (air filter type or routing, exhaust, cam, heads, etc) it will need a retune of the VE table.

You will also need to retune WOT setting even with a MAF if changes are made. WOT puts you in open loop which uses a Power Enrichment multiplier against you VE table. IE puts you in SD. I know you know this, but mentioning it for others.

In addition, if you keep narrow bands (which I personally don't but do in most customers cars) they will self correct your ltrims to keep your closed loop AFR for gas at 14.7 or what ever you have set as you stoich in the tune (they really shoot for lambda, so if you adjust stoich in the tune for E85 they will shoot for stoich).

Originally Posted by Custom 68

If they are turbo or other FI I would say SD.

Nothing wrong with SD in an NA set up. Have fun getting a big cam to idle well when there is a lot of overlap and reversion.

Originally Posted by BR3W CITY

I also weigh in, that MAF is nice when you do long road trips through multiple types of drastically different temp and density air, technically giving you the most "accurate" tables for the input its given.

If narrow bands are still enabled, they are what controls ltrims and shooting for stoich. Yes they base it off the VE table and the MAF can be set to increase resolution in between KPA and RPM cells since the VE averages between transitions. But the fact that PCM learns to adjust for LTrims (with in reason) if you VE table is well tuned, through out all the KPA and RPM settings, there is little to no need for a MAF.

Originally Posted by Wasted Income

You're probably also going to hate that I never run narrowband O2s

I am sure you have dealt with a faulty O2 sensor. Man it sure can mess your world up when the left or right bank goes haywire and the PCM tries averaging the two banks off bad data. You won't find a narrow band in my stuff.
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[BR3W CITY]

Hey wasted;

with the weather in the 50s to low 60's, I was getting anywhere from 79 (right away) up to 115-120, when it warmed up into the 70's, I saw anywhere from 90-135*...maybe a tiny bit higher sitting in traffic.

The interesting thing with looking at it how freaking erratic it is. I would get those 20-30* temp swings back and forth (we had REALLY weird weather tho). Obviously I'm not driving with HPT plugged in, but I'd be interested to see what it's seeing.

Moreover, you make me just want to put a turbo on and stop having this discussion lfmao.

[Wasted Income]

Originally Posted by prostreet1967

and BTW Ford switched to SD on the eco boost engines.

Good info...I did not know that. Interesting.

Originally Posted by Super73

I am sure you have dealt with a faulty O2 sensor. Man it sure can mess your world up when the left or right bank goes haywire and the PCM tries averaging the two banks off bad data. You won't find a narrow band in my stuff.

Yep....I've even had a goofy wideband controller screw me up. Back in the day, I had an Innovate LC1, and it randomly reprogrammed itself to something other than gasoline...alcohol I believe, since every time I flashed it, it ran worse and worse, lol. Was so pig rich...god, my eyes still burn.

Originally Posted by BR3W CITY

The interesting thing with looking at it how freaking erratic it is. I would get those 20-30* temp swings back and forth (we had REALLY weird weather tho). Obviously I'm not driving with HPT plugged in, but I'd be interested to see what it's seeing.

Moreover, you make me just want to put a turbo on and stop having this discussion lfmao.

Good info. I'm willing to bet that your big 20-30 degree temp swings may have been when the electric fan kicks on. I've seen that before in my logs....just blows a ton of heat under the hood (when sitting in traffic for instance) and causes IATs to spike up for a bit.

Beware of the boost route...it's an addictive and slippery slope my friend

[thotfulspot]

The turbo looks nice in there. Too bad I've got to much to do before I could afford that.
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[Super73]

I sure don't care for innovates stuff. Lc-1's have given me nothing but problems. I take an AEM Uego over an lc1 any day of the week.

What gets me is the people that have zero first hand experience tuning that pipe in with what is better. I am not saying sd is bettter in all areas, but for what I do and my customers, sd is the better option. How many of us drive from say negative 2500 elevation to 5000' regularly. And if we do, who says your tuner got those areas right on the maf tqble to begin with.
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[Wasted Income]

Originally Posted by Super73

I sure don't care for innovates stuff. Lc-1's have given me nothing but problems. I take an AEM Uego over an lc1 any day of the week.

Agreed. Not a huge fan of Innovate junk. I got an LM1 after the LC1 and it was better, but still needed to be sent back twice for repair.

I also have an AEM Uego now, and it's definitely awesome

[bubba353z]

I made the mistake of buying a 92 Camaro with SD, and when I put a hotter engine in it I could never get it tuned right.

Yes it was more my fault than the car's, but if your not experienced it could be a frustrating experience. I was ready to go to a FAST XFI system, but got rid of the car instead....

[Wasted Income]

A 92 TPI car?

That's not a very good comparison with a custom operating system 0411 based setup.

If you have to burn chips....it's not tuning. It's guessing, lol.

[bubba353z]

I

Originally Posted by Wasted Income

A 92 TPI car?

That's not a very good comparison with a custom operating system 0411 based setup.

If you have to burn chips....it's not tuning. It's guessing, lol.

The point was that if you don't know how to tune SD then a MAF may be a better choice. I thought I was going to hit the limit of the MAF, but I doubt I was even close.

I wound up with a Moates emulator and was able to tune in real time with a laptop and wideband O2 system. By that time though, I was sick of the car and wanted it gone.

It made almost 300 rwhp with a pig rich tune - I figured there was another 30-50 in the tune, if I could have found it.

[thotfulspot]

Originally Posted by Super73

I sure don't care for innovates stuff. Lc-1's have given me nothing but problems. I take an AEM Uego over an lc1 any day of the week.

What gets me is the people that have zero first hand experience tuning that pipe in with what is better. I am not saying sd is bettter in all areas, but for what I do and my customers, sd is the better option. How many of us drive from say negative 2500 elevation to 5000' regularly. And if we do, who says your tuner got those areas right on the maf tqble to begin with.
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Interesting to hear about the altitude. I'm going to be living at 7000' and ranging from Arizona desert to Colorado mountains.
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[themb2g]

Originally Posted by Wasted Income

Lol, I love how the MAF vs SD debate is kinda like "blondes vs brunettes", "pepsi vs. coke", "tastes great vs less filling", or even..."chevy vs ford". Lots of passionate opinions, but really no wrong or right answer. Whatever suits you best.



Well? What did you find?

For reference, here's where I have mine mounted. Works great. And...omg, look ma, no MAF!

Wasted - Do you know the part # for that sensor you have circled? Also, where did you get the plug and what port in the ECM does it go to? Do i just put it into an empty port and tune it to recognize whichever one it is?

[themb2g]

Also, do you think that the front fuel rail connector you have wuold go over the LSXRT manifold and 92mm throttle body?

[Wasted Income]

Originally Posted by themb2g

Wasted - Do you know the part # for that sensor you have circled? Also, where did you get the plug and what port in the ECM does it go to? Do i just put it into an empty port and tune it to recognize whichever one it is?

Sensor and pigtail.
http://www.diyautotune.com/catalog/g...tail-p-62.html

It gets wired to the IAT wires that are part of the MAF connector. I don't have a schematic in front of me to tell you exactly which ones. In the past, I've just cut off the maf connector and wired right to the 2 wires there. If you do that, the ECM will recognize it as IAT, and no recalibration is necessary.

Originally Posted by themb2g

Also, do you think that the front fuel rail connector you have wuold go over the LSXRT manifold and 92mm throttle body?

It could go over the hood if I wanted, since i made it myself Mine is looped up kinda high, because i made it before the throttle cable and bracket were on, and I wanted to make sure it would clear. Been too lazy to go back and shorten the hose.

It's just -6 braided hose for the crossover to the regulator....make it any length you want, and route it any way you want.

Also, themb2g....what vacuum booster is that? My hydroboost is a huge POS, and looking to possibly go back to vacuum.

[themb2g]

Thanks Wasted, your info helps a lot. The brake master/booster/proportioning valve all came from LMC or Brothers. I cant remember now. I cant tell you how well it works yet though as I havent ran the truck since installation of it.

[C10_ustacould]

I have a N/A 5.3L/4L60E with a GM hot cam that has been tuned locally. I am having trouble with locating my MAF sensor due to a change in accessory brackets, the Holley brackets put the power steering reservoir where the MAF used to be. I moved it towards the drivers fender to account for this and it did not react well, so for now it is located directly on the TB which works but looks horrible. I talked to my tuner and he said he can rescale it to adjust for the move, but all of this makes me more curious about ditching the MAF all together and swapping to SD. There are many differing opinions in this thread though, so I guess I need to read up some more. The only reason I'd be doing it is to make the air intake cleaner and easier to reconfigure if needed. I'm trying to clean up the look of my installation so I'd like to know more about the pro/con for using SD as well as the advantages of wide band vs narrow band O2s. Is there a single book I can read to answer these questions?

[themb2g]

My MAF was on the TB from the start. I cant say very much on MAF vs SD as i just got my truck running so i havent been able to measure performance.

[Super73]

No book, but lots of info on HPtuners forums.
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[thotfulspot]

Have you looked at the air cleaners with the MAF built in by Street and Performance?

http://www.hotrodlane.cc/
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