turbo ranger

['93BajaSport]

A speed density system would be nice although harder to tune.

Why do you think a speed density system is harder to tune?

 

[RacinNdrummin]

Speed density is easier to tune than MAF is, especially when you have MS and Megalogviewer. Under boost, speed density is more reliable because your basing your tune off of manifold pressure not calculated airflow. Plus there is the benefit of having NO restriction in the intake tract, any maf is a restriction.

 

[turbo cat]

actually its kinda an opinion some will actually tell yoyu that using a tuner like sct or tweecer is easier to tune a turbo car rather than a programable speed density and some prefer the speed density and say it makes it so much easier. It all depends on the setup however and the person tuning the ecu. A maf isnt always an restriction i dont know where you read that from. There are cars that are putting down 1000+hp with pulling thru a MAF because if you need it theres always going to be a big enough MAF out there. My lil tiny ass oem MAF on my exploder wasnt a restriction on my tinyh ass T3 as even on the dyno I logged 5lbs of manifold pressure at 2000 until redline. I have also pulled enough air thru the mAF for that same tiny T3 to push 15+ psi inot the manifold at 4000+rpm. The MAF bore is about 50-55mm about the same size as the inducer to the turbo. MAF as a restriction is a myth becasue even if you have a MAF that becomes a restriction it can always be replaced with a bigger MAF.

 

[michael_cope]

Ok speed density or systems with a map sensor like aftermarket efi systems are easier to tune IF you go that route. But with Factory EEC systems are tuned best with a maff. Most ford pcm do not have programing capability's when their are old enough to have speed density.

 

[turbo cat]

exactly and depending on the ecu and wether it be eec4 or eec5 most guys who have been in the tuning game for along time will say to stick with the ford ecu to tune the setup unless your power breaks a certaint point. Not to mention stand alone speed denstiys are batch fire ecus unlike his 2000 eecv ecu which is sequential efi which can make for a little better drivability /economical. With soem of the SCT stuff you can roll the car on the dyno and make a few pulls and have the car dialed in quickly. SOme stand alones take a little while to get everything right. In a few instances there were a few guys on different setups where the car loss power after going witha system like megasquirt. These guys were also not beginers in the tuning game. It all varys you cant really say this way is better or that it all reallly depends upon hundreds of varriables.

 

[michael_cope]

Standalone's can take time to set up with maybe paying the price. I had a friend eat an engine on a lighting with a mustang wolf system in it, on the dyno. No Good

 

['93BajaSport]

Okay, you guys are twisting the argument around and comparing apples to oranges. Yeah a factory ECU will be easier to start with when it already has a good, working factory baseline program. If it just happens to be a mass air system, that does not qualify the statement that "MAF is easier than SD."

Also, there are multiple standalone systems with a sequential injection option; even MegaSquirt has one on the horizon. However, Ford uses it more for low-load emissions and fuel economy than anything. In racing applications it can be useful when trying to tune idle and low load with huge injectors because the opening and closing times don't stack up, but everywhere else, bank-to-bank injection does not lose much to sequential.

Most ford pcm do not have programing capability's when their are old enough to have speed density.

Ford actually used a form of mass air metering before implementing speed density. The EEC-IV in the '83 turbo GT had a vane air meter which measured volume and temperature to calculate air mass. It, as well as the SD 5.0 Mustang EEC-IV and many others are tuner compatible. Flash rewriting didn't come around until the '90s, but generally speaking, it can be chipped/tuned if it has a J3 port.

 

[rurouni20xx]

maf is better than speed density because you are using the ACTUAL airflow thru the motor not a sample w/ a reading and a guesstimate table. thats why ford went to this along w/ the other manufacturers cuz its more accurate. im going to do the megasquirt ems w/ maf cabability, the wolf system has been proven to be unstable hence the fried engine. the reason the maf has to be on the side b4 the throttlebody and not in front of the compressor is because after air goes thru the compressor/intercooler and plumbing the airflow going into the engine is dif and lower than what is sucked into the compressor. by measuring what goes into the engine rather than what is being sucked in you have the actual measurement of air going into the engine that needs to have the fuel calibrated. not higher speed air going into the compressor and tuning for that which richens or leans according to compressor speed, not actual air inlet speed.

 

[RacinNdrummin]

MAF is not better than speed density for anything but a better idle, and that goes out the window when the sensor gets dirty. The MAF sensor is NOT measuring actual airflow, it is calculating airflow based off of resistors in the sensor itself, it is no more accurate than using engine vaccum to determine load characteristics.

The accuracy lies in the load tables themselves and how well they are tuned to the corresponding info coming in. If you plan to use MS with a maf sensor, your limiting yourself in that sense, because it is going to be a pain in the ass to tune under boost, all for absolutely No gain.

Also, it is worse to have a MAF meter on the pressurised side of the intake tract, MAF meters calculate air flow by using resistors and its harder for the Meter to read correctly (unless you tune the tables for it). Having a decent sized meter before the compressor housing measures the Airflow going into the engine more accurately than a meter after it.

And as far as the whole "compressor speed" richening and leaning things out, your out to lunch there dude, it does nothing of the sort.

 

[michael_cope]

Ok we may be getting off track, ya it cool and ya their is lots of different ways of doing it. just matters on your ck book and your knowledge or who you know. but other then that it cool to see what other people have done and get now ideas. So thanks for looking and lets get off the maff or map thing

 

[rurouni20xx]

whatever makes you sleep at night, ive seen the dyno results on the two setups that was used as an example why the maf has to be on the t/b side. enuff of that, i want more pics of this setup and how everything went plz...

 

[RacinNdrummin]

whatever makes you sleep at night, ive seen the dyno results on the two setups that was used as an example why the maf has to be on the t/b side. enuff of that, i want more pics of this setup and how everything went plz...

Oh yeah, post up the dyno results then.....



On another note, its good to see another 4.0 turbo setup out there, Im interested in seeing some updated pics as well.

 

[rurouni20xx]

lost access to them when i moved from pa back to la. i have excerpts from my books tho stating why it the maf has to be there and in as much of a straightline as possible to reduce turbulence not in bends etc, plus why performance mafs have screens to reduce turbulence and correct the reading. they are from a dyno tuning manual that explains just about everything required for tuning stock ecus/installing standalones/performance fuel injection. i like this guys setup its dif there are a few things i would do dif but if i seen the whole picture maybe i could get a better opinion of what im looking at. overall excellent setup, clean install and good job.