I am looking at installing a procharger set up on my car over the winter. What are the pros and cons of going with a maf set up vs. a speed density set up? Modifications are in my signature. thanks

 

I would do a map system, possibly off of EBL flash. Code59 can do it as well with 730 ecm. Both are easy to do and cheaper than aftermarket

Else talk to tequilaboy and visit blowerworks.net. Ask about their custom large maf for blow through maf applications. Factory maf wont cut it on a n/a 383, let alone a boosted one

 

When I got my car dyno tuned, I was told that if I did supercharge it, that it would be easier to tune if I kept it a MAF set up. What should I see better power/ drivability with, a MAP set up or the MAF with the blowerworks aftermarket MAF sensor?

 

It depends on if your exceeding the mafs 255gps limit, my vote is tune with stock or ebl p4 as well, Rbob Rocks

 

would that be MAF or MAP? I don't really have any knowledge in tuning.

 

The ebl P4 is map, you can rework your harness and use a 3 bar map.

 

If the tune is good, map will be just as driveable as maf but it may take a little longer to tune. More time spent detailing the driving spots.

It doesnt take too long to rough in a ve table to get car moving, but it will take many logs to slowly dial it in as far as idle/cold startand various part throttle positions and then ofcourse wot with boost. Good thing is a blower is more linear with boost vs rpm, so the tune is easier than say a turbo that spools quickly

Other thing you could do but id recommend against is an FMU. It references boost pressure and greatly increases fuel pressure to make injectors spray more. Thats how it gets extra fuel. You will need to experiment with different ratios of pressure rise per boost rise to find the fueling requirements. It also taxes the fuel pump as high pressure greatly increases load on the pump and it will decrease capacity. Your combo should be stout on boost and a single in tank walbro pump may approach its limits early with a high pressure fmu.

 

Well I just plan on taking it to be dyno tuned. Even going that route, would I still be better off with a map set up? If so, all that I would have to do would be convert to a speed density harness and computer with a map prom inside of it?

 

Yeah repin harness to 730 ecm. There are tech articles for that

Then need to add a 2-3 bar map and remove maf obviously. Install code $59, or buy EBL flash. Most shops will not have experience with those amd code 59 needs configured for v8's first before using and then some work to get running right with a base file you kinda have to create. EBL likely will have base files like stock L98 that you can adjust for your setup.

If you do either of these i would suggest you do it without the blower on to dial it in first

 

You could do both with a more advanced ECM like a Megasquirt.

For idle and part throttle MAF typically allows for slightly better running especially if you have an aftermarket cam. In those areas airflow vary's greately, but manifold pressure doesn't which translates to loss of resolution.

In boost, or extremely hard decel it's good to have a MAP sensor for various special case routines.

I don't have mine setup hybrid at the moment, but that's a plan in the future.

-- Joe

 

What all is involved in changing to the megasquirt system? Would that prove more effective than the factory maf or map set ups? Also, if the mass air flow set ups have better idle and part throttle drivability and are easier to tune, what advantages do the map set ups have? Thanks again for all the help.

 

Don't get caught up in that debate. Arguing about changes in weather, and which is better is a lot like arguing about batch vs sequential. It is so overrated it isn't even funny, and you won't even really see or feel the differences anyway. Some engines like to run richer than others, so a MAF leaning out the air/fuel for correction is not always a good thing. I would go with the EBL and never look back. Target your idle, part throttle and wot throttle air/fuel and see what your engine likes, dial in your spark, then dial in your accel enrichment by watching your wideband as closely as possible when you stab it, and adjust it in your tune keeping O2 correction as close to 0 as possible as you accelerate...

 

Yup i could put you in maf cars or map cars and you wouldnt beable to tell a difference.

 

What is involved is some wiring changes.

I prefer a MAP setup on a boosted car, however a hybrid MAP/MAF setup is even better for the reasons I pointed out earlier.

None of the stock stuff can autotune or provide real closed loop from wideband 02 feedback. The stock stuff, even the EBL, uses general target AFR constants rather than actual AFR tables.


It's not a dabate. It's like comparing a Commodore vic 20 to a brand new HP with Windows 8. Despite how many patches and code changes people attempt to make, add on boards and emulators, it's still a 30 year old computer. I can't comprehend why anyone would recommend running older, slower, less featured technology unless they are Amish.


-- Joe

 

It may be old but it works well enough to get job done. Lol how much more you need? And i dont feel confident in wideband closed loop, especially at wot. I'd rather have a constant set fuel delivery. Dont need a sensor failure or some other hiccup making drastic changes to fueling under boost.

 

I don't know about you, but I've nevet met an engine that wanted a constant AFR throughout the entire operating range.

I do understand the sensor failure causing issues.

How much more do I need? I needed more than the '730 could provide even with all the patches. And while some of the added features to EBL seemed cool, they were beyond dwarfed by everything else aftermarket and I wanted realtime tuning which I've come used to in the past decade.

One thing that I really like, which I'm sure you have no use for, is the fact that I can run ANY combination of sensors that I want. All I need to do is select from a dropdown what the sensor is (toyta, nissan, whatever). Defining a new one is quite simple too. You can run a dizzy, dis, whatever you want. Try that with a '730.



-- Joe

 

Code $59 has a 3d afr table. Its not a constant air fuel number

You can program idle to be lean like 15-16:1 and cruise to be 14:1 heavy throttle 13's:1 and wot 10-12's dependin on the motor lol seems nice but i never used it.
Only big issue i had is lack of timing table resolution for rpms above 4800 in code $59 but i think super aujp has extended tables

I never had a need for fancy features but i have simple tastes lol. Its definately the cheapest option out for boost. Next would be ebl or megasquirt. I do hear great things about megasquirt tho

 

You all make some good points.
Something to keep in mind is that the intake sensor (MAF or MAP) doesn't determine the AFR. It is a combo of things including the sensing device. If using closed loop then it is the O2 sensor that does this. With a NBO2 any AFR other than stoich is a guess no matter what ECM is used.

With big cams I like using alphaN along with MAP. MAFs used to be expensive and less reliable so I learned to not use them. Old habits die hard.

I like the Vic 20 vs Windows 8 comparison. What is my 1995 chevy truck ECM..........a i286x? It can control a 4L80E/4L60E, read a map (I run a 2Bar), run a MAF (dimented's code), does sensor error checking (MS doesn't), has unused inputs&outs (water/alky) control. Can do real time ALDL updates with NVRAM installed ($100).
Maybe better than a i286x?

 

I'd say your '95 PCM is quite a bit more advanced than a stock thirdgen '165 or '730.

MS (ms2extra, ms3extra) doesn't have diag codes like the OEM stuff when a sensor fails, it simply has some basic routines that determine an out of range or inop sensor and set a hard value. For example, an IAT sensor will default to 70*f if the MS determines is not working properly.

The MAP + Alpha N is a good idea. The infiniti and ford MAF's are kind of cheap now though. An MS can read a 0-5v infiniti, ford MAF or a frequency based LSx MAF.

I have mine running off a regular GM 2-bar right now, but I'm going to add a MAF and run hybrid. Probably switch to MAP at > 100kpa, while off boost use the MAF for my airflow calcs. Even though I absolutely hate the OE MAF stuff, I was never ever able to get minor throttle transitions on either $8D and $58 to be as smooth as I could with $6E.

Most of the guys with manuals that like to "buck" under low load (i.e, parking lots) are running MAP. A well detailed low-load MAF tune fixes those problems.

Given the choice if you could only pick ONE, I'd say MAP. But it's 2013 and we have choices

-- Joe

 

If the 730 had the transmission ckts it would be better than the 427 ECM due to more available I/O.
If I couldn't modify assemble code I would run an MSII. I wouldn't run old GM ECM with hardware mods that is still tuned using mostly GM over complicated tables that few understand fully.

MAF is good by all means. I agree that it responds to airflow changes quickly.

It suprises me that after all these years that MS hasn't done more work on error codes ans SES light.

 

Yeah. I was somewhat surprised their was no basic code reporting, but I guess all they care about is LIMP functionality when a sensor goes AWOL.

MS1 and MS2 also don't have a VSS input by default, although adding one in the code took all of 10 minutes. MS3 fully supports VSS.

-- Joe

 

My friend and ls tuner has done a trex cam in a 4.8 truck. Idled at near 4" vacuum lol ran fine. T56, twin turbos, never had an issue with map only tune.

It can be done. I was actually happy with my latest 401 build, and how 730 map handled it with 3 bar map. 245cc heads, 246 deg cam, lower air speed and 115 lb injectors. Actually idled well

My concern with maf is with big cams and lots of intake reversion, i have heard its hard to get fueling accurate. Define big cam tho, my maf didnt have a problem with a fairly high overlap cam but certainly not a race only setup. I happen to love maf tuning 165 with $6e, i find it easy and enjoyable lol

 

That is one reason I like the MS systems. It is open and configurable. Try that with an old 80s / 90s ECM with hardware add ons. You are still stuck with what GM did or what the person selling it did for hardware and software changes. Suppose you want to add progressive N2O which any ECM should support. MS is no problem. Won't happen in a GM ECM with stock code or GM ECM with hardware add ons that doesn't have the code to support it. Water/alky, wastegate control, etc. The list goes on.

The MS is more advanced. The only downfall is the architecture choices made over the past years. I would have rather seen the I/O connector being expanded instead of costly add on boards. I don't think extra I/O is an add on. It is desperately needed. Control for E-trans is needed, not an add-on. Start adding up these add on costs and the MS is rather expensive.

 

Couldn't agree more. The MS3 has the trans support and extra I/O, but the price point is very high. I'm using the Microsquirt MODULE (MS2) which I wired up into an old '165 case. I have enough I/O for what I'm doing, with the following unused:

10: CAN communications H
12: CAN communications L
14: VR tach signal no.2 (+) input
17: SpareADC1 0-5V analogue input or digital output
18: 0-5V Flex fuel input
19: Opto tacho in(+)
20: FIDLE mid current ground out
23: VR tach signal no.1 (+) input

If I need to control more things I'd have to add an IO extender inside the case which ties into the CPU lines on the J10 connector.

I think I have maybe $310-320 into it.

http://members.cisdi.com/~anesthes/p...om/megasquirt/


-- Joe