: Going MAFLess?



N0DIH
01-10-07, 10:37 AM
Is there anyone else here with an LT1 that has gone to a MAFLess tune?

I did my own, and have not regretted it once since I went. My MAF sits in my toolbox now. My BLM's are so much more stable now than they ever were with the MAF and stock VE Tables.

It is common downunder to ditch the MAF, here in the US tuners seem to like to keep it. Mainly if you do another mod without a MAF, you likley need to go back and retune the VE tables. It isn't a biggie, but I do like the flexability in the air intake now and that I can run my ride without the intake elbow if I want to and no adverse effects whatsoever (save IAT location).

Car is much more stable at high ambient temps, no power dropoff when it is 90+ and I am in heavy traffic. Ever get that soggy feel? Gone. No issues with the MAF being a restriction at anytime. WOT power is best you can get it. Tuners in Australia have worked hard at trying to prove the MAF isn't a problem when tuned properly compared to the same car with a tuned properly MAFLess (aka, Speed Density) tune. The MAFLess tune was always faster in the 1/4 mile.

Me? I just like to play with it! Even got my split BLM's pretty much dialed out, it is very stable now and even.

bigbluebrougham
01-16-07, 12:38 PM
Is there anyone else here with an LT1 that has gone to a MAFLess tune?

I did my own, and have not regretted it once since I went. My MAF sits in my toolbox now. My BLM's are so much more stable now than they ever were with the MAF and stock VE Tables.

It is common downunder to ditch the MAF, here in the US tuners seem to like to keep it. Mainly if you do another mod without a MAF, you likley need to go back and retune the VE tables. It isn't a biggie, but I do like the flexability in the air intake now and that I can run my ride without the intake elbow if I want to and no adverse effects whatsoever (save IAT location).

Car is much more stable at high ambient temps, no power dropoff when it is 90+ and I am in heavy traffic. Ever get that soggy feel? Gone. No issues with the MAF being a restriction at anytime. WOT power is best you can get it. Tuners in Australia have worked hard at trying to prove the MAF isn't a problem when tuned properly compared to the same car with a tuned properly MAFLess (aka, Speed Density) tune. The MAFLess tune was always faster in the 1/4 mile.

Me? I just like to play with it! Even got my split BLM's pretty much dialed out, it is very stable now and even.

I would like to try it. If you say it works better and you don;t have adverse effects, I would love to try it. I should have my software this week. (Tunercat). I should also have my cable this week too. I will let you know.

BBB

N0DIH
01-16-07, 08:38 PM
First make sure you have a dialed in tune. If you are stock, I can help a lot with that. I haven't messed with radial cammed engines or loose converters yet.....

caddycruiser
01-17-07, 02:03 PM
I'm still planning on getting some more info from you on this and other general tuning matters, as soon as I ever pick up a cable and/or other software (from playing around a bit, I guess the free TunerProRT is still worthwhile enough).

My '95 "base" FWB is just begging for a better shift pattern and feel, and whatever other little helpers it can get to improve general performance computer-wise.

Essentially, whatever the best tune you've done for your own car, but made to work with a 2:93 rear.

BCs71
01-17-07, 02:29 PM
Essentially, whatever the best tune you've done for your own car, but made to work with a 2:93 rear.


I would suggest lowering the fan turn-on temp for your primary fan in addition to whatever NODIH modifies his program (like 2.93 gears) to accomodate your car since he has the primary mechanical fan on his.
Lowering fan temps is one of the most beneficial reasons to alter the stock PCM tune.

bigbluebrougham
01-17-07, 02:47 PM
First make sure you have a dialed in tune. If you are stock, I can help a lot with that. I haven't messed with radial cammed engines or loose converters yet.....

I am essentially stock, with the exception of freer flowing exhaust. I am looking to get a RAISS intake and 1.6 rockers and better valve springs in the near future, but have none of that now. I have the 2.93 gears and am looking to get better shift patterns and bassically what you have done to yours. The big upgrades are a long time a comin'.

BBB

caddycruiser
01-17-07, 03:19 PM
I would suggest lowering the fan turn-on temp for your primary fan in addition to whatever NODIH modifies his program (like 2.93 gears) to accomodate your car since he has the primary mechanical fan on his.
Lowering fan temps is one of the most beneficial reasons to alter the stock PCM tune.

Good point. Everything he has described about his tune seems dead on, it's just trying to get that same thing adapted to work with the 2:93 and the electric fans.

N0DIH
01-17-07, 03:50 PM
Yup, I can do 2.93's with a similar program that I have, only I have 3.42's. Mine is somewhat based on the V4P package, as it is intended to be in more of a power mode most of the time, due to the expectation of up to a 7000# trailer. But it sure makes a great running, very responsive car.

We have to consider that we might be able to redline at 5800-5900 fairly safe (so I am told), but I don't shift there, I found my car is actually slower when I try to shift near redline. I find that I am faster at 5400 rpm shift points. But if you have more cam like BCs71, likely you can gain some by shifting higher rpms.

My tune is pretty solid for trans. I like it a lot, and anytime you blip the throttle, you are 90% of the time in the gear that you would want to be in. It is nice to be able to nail the gas and you have instant great acceleration, no lag time for shifts, no delays, no waiting for the engine to rev and downshift for acceleration.


Good point. Everything he has described about his tune seems dead on, it's just trying to get that same thing adapted to work with the 2:93 and the electric fans.

Which I have never needed any fan temp changes, the mech fan keeps the primary coolant temps very stable, in the 85-92C range, in most any weather. With the dual electrics, the temps are allowed to run to where they go until it hits the 220F or so upper temp limit for fan 1. Easy tweaks.

caddycruiser
01-17-07, 05:12 PM
That sounds terrific, just like in our emails, and as soon as I get a cable, I will get back in touch with you...aside of everything, I think just the basic tuning of the car is what I dislike most. Give me V4P-like improved, mafless, etc., and all to mesh properly with the 2:93s and fans, and that would be terrific.

Not to get too off topic regards to tuning, but with your MAF now removed (I want to do the same with mine), how does your air intake setup work as far as that small gap? I only wonder, because stock I guess just any short tubing piece would be fine, but a lot of aftermarket setups seem to depend on the MAF as a bit of a mounting fixture.

And, though I forgot now, would I be able to do this with the TunerProRT or would Tunercat be a necessity...basically just flashing from one program to a new?

N0DIH
01-17-07, 11:47 PM
I have a 1 foot or so piece of PVC painted black and a Vortec 350/454 K&N Filter on it ($49 or so at Walmart). It has maybe a little more surface area than the stock filter, which can't hurt. I think most K&N or the like cone filters are actually smaller than stock. No gaps at all.

TunerPro should work, but I have never flashed with it, if it even can. WinFlash can flash for you and is free for 30 days at tunercat.com, and is only $20 if you buy it. Then use TunerProRT to tune, and WinFlash to flash.

caddycruiser
01-18-07, 12:50 AM
I have a 1 foot or so piece of PVC painted black and a Vortec 350/454 K&N Filter on it ($49 or so at Walmart). It has maybe a little more surface area than the stock filter, which can't hurt. I think most K&N or the like cone filters are actually smaller than stock. No gaps at all.

TunerPro should work, but I have never flashed with it, if it even can. WinFlash can flash for you and is free for 30 days at tunercat.com, and is only $20 if you buy it. Then use TunerProRT to tune, and WinFlash to flash.

Sounds great--I emailed you with essentially the same stuff I talked about here.

The other question is, I think mentioned before, but would you also still need me to first give you the stock file from my '95, or did you already have one?

caddycruiser
01-18-07, 12:53 PM
Something else I just thought of, particularly with the MAFLESS deal.

For quite some time, I've been thinking of different air intake setups and weighing the pros and cons of each, and am still most interested in an "all in front" setup that basically eliminates all tubes and baffles and is a direct air shot right into the TB. Not saying for sure that's what I'd do, as a lot of people have had the same results with a basic cheap pipe, etc. to the side, but it does bring up an interesting question.

When you do one of these setups, the MAF gets moved to right in front of the TB and then the filter in front of that. For the majority, most just install these things as is on their MAF'd cars, and never have an issue--just much better breathing--and no tuning whatsoever. A few, though, have run into issues because of the excess new air being let in, with backfiring, etc. and had to have air/fuel mixtures touched up just a tad to fix it.

SO, long story short, if in theory you were to do the same kind of setup--essentially filter off TB--WITHOUT a MAF, would there be any new issues and/or would that require additional custom tuning work to get right?

BCs71
01-18-07, 02:14 PM
SO, long story short, if in theory you were to do the same kind of setup--essentially filter off TB--WITHOUT a MAF, would there be any new issues and/or would that require additional custom tuning work to get right?

IMO, if I were to consider going speed density (MAFless), I would be sure to have all my mods completed and then take extensive logging data to know exactly what my car is doing. The data would then let me know if all other engine components and sensors are running properly. After all necessary sensors are running properly, I would then get the program tweaked to remove the MAF.

I like having my MAF though as peace of mind that any changes in mods or sensor degredation should be compensated for by the MAF since everything was designed to work that way from the factory and its engineers, a bunch of guys way smarter than I am.
Admittedly, though, I am not the most educated on tuning and what all benefits and drawbacks there are to going speed density.

BCs71
01-18-07, 02:18 PM
We have to consider that we might be able to redline at 5800-5900 fairly safe (so I am told), but I don't shift there, I found my car is actually slower when I try to shift near redline. I find that I am faster at 5400 rpm shift points. But if you have more cam like BCs71, likely you can gain some by shifting higher rpms.
More cam does help, but also the stock valve springs float for just about everyone I know of anywhere above 5300rpms (depends on age, rocker tolerances, etc.). So aftermarket springs would easily allow 5800rpms with the stock cam. Of course, this would only be used anyway at WOT.

caddycruiser
01-18-07, 03:15 PM
Good points. I still do worry about going without the MAF, but only feel more confident because N0DIH has apparently had such great success without his in a higher mileage car.

Something tells me still to keep it, but I at least want to try a tune from him without first. At the same time, wondering what other issues can come up without it being there...just like you mentioned.

caddycruiser
01-18-07, 04:07 PM
And to continue that thought, as said in some threads on the SS board, no-MAF cars (i.e. speed density) tend to be best for power and speed in a lot of cases, but they just can't compensate for random changes surround environment and air, etc. It can basically only depend on and use whatever programming has been done and that's it.

N0DIH can probably say a lot more, though, as he has had great success with it.

All I really know myself is that I've yet to be dissatisfied with the year round feel and performance of either of our OEM Mafless cars--the '93 FWB and '92 Roadie--so, aside from other clear performance differences, I want to try it on the '95, which has left me wanting in a lot of ways that are clearly due to tuning.

Here's some questionable threads, albeit made up by people who never actually had the correct tuning:

http://impalassforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=34;t=000558#000011
http://impalassforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=34;t=002196#000001

N0DIH
01-18-07, 07:04 PM
The key is good VE table tuning. If that is wrong, it will never be right. People like to move the IAT, all that does is shift the VE Table indirectly. AFAIK it doesn't matter where the IAT is, as long as the VE Tables are set right it will always be fine. Cadillac 4.5/4.9L PFI cars have the IAT in the intake manifold.

Most cars have a poorly setup VE table. It is set to the 5-13% low everywhere (lean) in the table. So for it to be a dead on 128 BLM, it MUST use the MAF as a correction OR ditch the MAF and correct the VE. The VE tables are used always, some believe that they are not used with a MAF, I have proved beyond the shadow of a doubt, they are used 24/7.

When people dis the idea of not using the MAF, they likely are saying they don't know enough about it to tune for it. It DOES take more work to tune, but I feel it is very rewarding to do. And my BLM's are so stable it amazing. I only see it go lower in BLM under slight throttle decel. Which honestly isn't a big deal, but when I have time to fuss I work on it.

I have been narrowing down split BLM's too. I have almost no splits now. (this is where the left and right bank are one rich and one lean)

As for springs, mine will rev to 5900, but it just isn't making as much power there. Maybe it will make more with new springs, but with stock it doesn't give me indications of float, but just doesn't make the power that it does at 5400 rpm. It is like I passed the peak power of the cam or heads and power is going down.

Those 2 links on Impala SS forum are showing how little people know about MAFLess tuning. I would never go back given a choice.

Myths of MAFLess tuning by N0DIH:

1. It makes the car more sensitive to changes: FALSE! It might be a narrower range before you should retune, but hardly makes it sensitive. You add headers to it, you will see BLM's move off into the lean range. But with stock VE tables and a MAF vs tuned and MAFLess going with headers, or cam, you will be very close to the same hosed up BLM's.

2. You need a dyno to tune for MAFLess: FALSE! You need a tool like VEMaster and some time to run some datalogs. You WILL need a custom PCM tune to dial out DFCO and PE Mode for a while, or be prepared to do a lot of manual editing of the datalog before you run it through VEMaster.

3. You have problems with VEMaster and Split BLM's: TRUE. If you study your datalogs and see split BLM's, VE Master will not fix it. It will likely be worse with it. Work carefully with your Idle and Off Idle Individual Fuel Trims to dial out the splits and then return some new datalogs to VEMaster. I use VEMaster up to 5500 (max it goes to) and let my VE Tables be as correct as possible, then PE mode when kicked in will be accurate for the amount of fuel multiplier it is going to give. THIS is where you need dyno tuning. But any car, MAF or MAFLess needs this for peak power production.

4. Car won't run without a MAF: FALSE. It will, but it must be disconnected prior to turning on the ignition. It needs to fault out first, you will be now running strictly on SD mode, but with a fault and ugly VE Tables. Key is not to run it with a BAD MAF, either good or none.

5. Moving the IAT helps power: FALSE. It hoses up the VE tables. Moving it will offset the VE Table range. So keep it where it is when you tune. If you move it, fine, move it and then tune. You toss all the calibration off when you move things around after a proper tune.

6. MAF is a restriction: TRUE. ANYTHING is a restriction. But not always much of one. But honestly, the mid range of my car feels better without and mine is 90% stock as delivered from GM. Do expect some top end. MAF's aren't terribly fast reading, the air in the MAF is not the air in the cyls, it takes time. The MAP reads what is in the cyls, as it is a depression, so the air in the cyl at the time the intake valve is open is what the MAP sees, the MAF is seeing measuring the air when it is quite a large distance away, probably 2-3 rpms, quite possibly more.

6. MAF's are a bandaid to weak factory tuning: IMHO, yes. I think it is a EPA requirement, as nothing today doesn't have a MAF, can't prove it though. It allows the car to adapt to users playing with things and putting on K&N's and such, or even cams and exhausts. It gives an additional correction factor. Proper tuning removes the need for it. But, if you do a major change, more power is seen by a proper MAFLess tune than leaving the MAF there and letting it do the corrections.

7. MAFLess cars are faster in the 1/4 mile: According to my sources down under, always. From tuners who have tuned as best they can MAFLess, then install the MAF back in, the car ALWAYS slows with the MAF in place. Numerous people have done it.

IMHO it is one less thing to break, one less thing in my intake tract, it is sweet to have it missing. I won't go back.....

caddycruiser
01-18-07, 08:24 PM
Exactly what I thought, and what I wanted to show from those Impala SS links--a lot of people talk against it, but have also never tried it themselves.

That said, and again, I'm more than up for you working your magic with mine in the coming months, and willing to pay for it.

BCs71
01-26-07, 05:59 PM
Here's some MAF-less LT1 info from a guy in a local F-body group that I am a part of. He is a very studious engineering grad and could probably elaborate on this more.

http://www.drinknet.net/~kdrinkwater/buttercup/maf.html

FYI

N0DIH
01-27-07, 12:04 PM
From what I have read, I agree with him. Proper tuning and MAFLess is very rewarding. Even without it still runs fine, you would be hard pressed to prove that it really runs different with vs without the MAF. Tuned it runs better, definately more precise, my BLM's statistically are very very solid and close. +/- 3.5 or so for ALL conditions. And I am narrowing it down more. And the split BLM's are all gone (that is not something MAFLess helps/hurts), I have been carefully working on them too. Split BLM's if you are wondering is when one bank of the engine is lean while one is rich. The computer compensates, but there isn't VE tables on one side or the other to tweak.

caddycruiser
02-16-07, 01:13 PM
Just to bring this thread up to date a little more, after LOTS of back and fourth emails between me and N0DIH (mainly because of my non-stop questioning:rolleyes: ), he's been working his magic on a new MAFless tune for my '95.

Still waiting on my cable to send him the correct current program from the car, but can't wait to see what his extremely attractive Fleetwood V4P/Vette tuning will do to the current slosh tune--both in trans shift modifications and other things to eradicate the use of the MAF. Hopefully, all turns out well, and I can experience the same thing he's been doing with his own '94.

Very, very nice to have an actual Fleetwood guy in the know about ALL of it, as well, and over and beyond willing to help and answer any question:thumbsup:

caddycruiser
03-06-07, 10:10 PM
Well, finally got all set up and read and sent my current stock PCM file to N0DIH early this past weekend...now just chomping at the bit to get his custom tune for me and get rid of that MAF! Really even more curious now that I just did my K&N intake and noticed a bit of a difference with that.

Can't wait to get it ALL in order...:)

N0DIH
03-08-07, 09:42 AM
I am itching to get out to a chassis dyno soon and dyno my car:

Stock
Tuned MAF
Tuned MAFLess

and see how my tuning does.

BCs71
03-08-07, 02:50 PM
I am itching to get out to a chassis dyno soon and dyno my car:

Stock
Tuned MAF
Tuned MAFLess

and see how my tuning does.


BaD Bodies is planning to hit the dyno in April as a group for a discount...
No set plans yet but it is in the works. FYI

N0DIH
03-08-07, 04:55 PM
Keep me posted!

caddycruiser
04-08-07, 12:08 AM
Just another bit of an update.

I've had a tune from N0DIH for a little time now, both one to run currently with the MAF and another to run so I can datalog and get information needed to program the MAF out. Still haven't had the time to do the latter, but regardless, liking the new improvements from N0DIH even with the MAF.

With his combo of V4P Fleetwood and Vette specs, nothing huge, but my overall power delivery seems to have gone from soft to authoritative. Shifts are spaced out more appropriately, are no longer just soft slips from gear to gear, and it just feels both more responsive under typical acceleration and if you plant it more while cruising--not as dead as before.

Still a lot of other fine adjustments to make, probably, but N0DIH knows what he's doing for sure, and I appreciate it in the biggest sense--can't wait to keep seeing what he can do, once I get some Datalogging down, the MAF out, and other things touched up.

N0DIH: Essentially just emailed you the same thing at your work address, so we'll chat again whenever. Thanks for the immense help so far;)

caddycruiser
04-30-07, 06:44 PM
Yet again, another PCM update from N0DIH, and whew it's yet again a whole new monster.

Even sharper shifts, and placed so to make acceleration (particularly from a stop) very authoritative, AND at least initially, my gas mileage seems to have gone up a tad as well--it'll take more driving to really see.

STILL haven't gotten around to doing the datalogging and starting on getting rid of the MAF, which is the main topic of this whole thread, but getting there eventually...