Do you really need a 'tune' or is it bs

a91what

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most aftermarket systems utilize speed density

on a street car, a maf is preferred

Look at OEM. There ain't no SD systems in OEM that I know of, all maf, at least since the 1990's (which are antiques)

ask yourself why

I'm pretty certain that if OEM's could save a $20 MAF and still provide the good NVH, fuel mileage, drivability, and reliability they would most definitely run the "simpler" SD system. $20 saved is a generality. If they built 300,000 cars all the same with SD (no maf), for a savings of $20 each, that's a savings of $6,000,000. I'm certain that if an automotive manufacturer was given the opportunity to save $6M, they'd do it. But $20 is a VERY general figure to throw out there, I would venture to guess it'd be much more substantial once you figure in the wiring, ecu, intake piping, airbox, and a bunch of other things that benefit the maf system and the sensor itself.

Actually this subject reminds me that I need to order some parts, doing a T4M0 94-95 GT computer in my 93 coupe 4 cylinder so I can run a slot MAF with it (turbo). The VAM system works ok but it's very limited and CRUDE.
I have cars never touched in my driveway that are speed density from the factory.. including my EcoBoost f150 they simply used air temp and map along with throttle mapping to reverse calculate the air mass. Works excellent and is the reason a properly tuned speed density setup works perfectly. Lately the oem have been moving away from maf
 
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Habu135

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Recently installed a stock style intake which LMR just released. Car immediately began surging at idle. Brought it to a local tuner today and the new intake had caused the car to run rich at idle. Tuner did his thing and pulled fuel all along the rpm range. Car added 12 hp and 10 tq. Yes, tuning works.

BTW, car is stock bottom end with Trick Flow Stage 1 upper kit and a fresh valve job.
 

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96pushrod

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Recently installed a stock style intake which LMR just released. Car immediately began surging at idle. Brought it to a local tuner today and the new intake had caused the car to run rich at idle. Tuner did his thing and pulled fuel all along the rpm range. Car added 12 hp and 10 tq. Yes, tuning works.

BTW, car is stock bottom end with Trick Flow Stage 1 upper kit and a fresh valve job.
What else was changed when you had it tuned last? Of the two runs, the fueling for the richer pull didn’t seem rich to the point where it would rob much hp. Unless that didn’t show the worst pull.
 

General karthief

wonder how much it would cost to ship you a pair
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Recently installed a stock style intake which LMR just released. Car immediately began surging at idle. Brought it to a local tuner today and the new intake had caused the car to run rich at idle. Tuner did his thing and pulled fuel all along the rpm range. Car added 12 hp and 10 tq. Yes, tuning works.

BTW, car is stock bottom end with Trick Flow Stage 1 upper kit and a fresh valve job.
What engine are you talking about?
I didn't know lmr sold a 'replacement ' intake for a 5.0 push rod engine.
 

Noobz347

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The surging idle can come from crappy airflow over the sensor too. Re-clocking or changing routing or even a screen can change this. Tuning wise; You can 'smooth' the sensor inputs.
 

Habu135

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The surging idle can come from crappy airflow over the sensor too. Re-clocking or changing routing or even a screen can change this. Tuning wise; You can 'smooth' the sensor inputs.
Exactly. I have an aftermarket BBK MAF. The car had been tuned with a 3" ID intake tube and open element air filter. If you look at photos of my car you'll see that. I swapped over to a stock style intake box and the outlet of the box is a smaller ID than the inlet side of the MAF. Apparently that caused some kind of velocity issue for the MAF and the car was highly rich.

I'll ad that the car dyno'd at 299/301 with that setup. Since then I had a valve job done and installed the new LMR stock intake box, but the idle surging didnt occur until I installed the intake box. Now, it's possible that the compression was raised slightly as a result of the valve job head milling, but I do believe the intake is good for a few hp. I was not told that my heads were milled at all. Overall I was surprised I gained 12/10.
 
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2000xp8

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Recently installed a stock style intake which LMR just released. Car immediately began surging at idle. Brought it to a local tuner today and the new intake had caused the car to run rich at idle. Tuner did his thing and pulled fuel all along the rpm range. Car added 12 hp and 10 tq. Yes, tuning works.

BTW, car is stock bottom end with Trick Flow Stage 1 upper kit and a fresh valve job.
Unless i'm missing something, i fail to see where the tuning was of value here.
You needed it tuned to run the stock air box that was put on 750,000 mustangs?

Sounds like you could have just run a better meter and been fine.

The valve job alone is typically worth 10-15rwhp by itself.
 

Noobz347

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Unless i'm missing something, i fail to see where the tuning was of value here.
You needed it tuned to run the stock air box that was put on 750,000 mustangs?

Sounds like you could have just run a better meter and been fine.

The valve job alone is typically worth 10-15rwhp by itself.


Eh... We both know there are a hundred different things that can cause this. I'm with you though. I also believe that this particular surge issue probably should have been resolved mechanically.

There are plenty of instances where digital tuning is used to 'mask' mechanical issues. That's not necessarily a problem so long as the overall AFR is repeatable and reliable.

One surging idle issue, in particular, that is massively easier to address with electronic tuning vs. mechanical means is with a PD blower setup that has no bypass. I always thought it was, "The Nature of the Beast" on those combos until I saw it smoothed out over a remote tune.
 

Habu135

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Eh... We both know there are a hundred different things that can cause this. I'm with you though. I also believe that this particular surge issue probably should have been resolved mechanically.

There are plenty of instances where digital tuning is used to 'mask' mechanical issues. That's not necessarily a problem so long as the overall AFR is repeatable and reliable.

One surging idle issue, in particular, that is massively easier to address with electronic tuning vs. mechanical means is with a PD blower setup that has no bypass. I always thought it was, "The Nature of the Beast" on those combos until I saw it smoothed out over a remote tune.
Rather than accept my explanation you two search for any explanation that fits your narrative that tunes are pointless. Maybe, just maybe the tune resolved the surging idle problem as I explained that it did. Good grief.
 

Habu135

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Unless i'm missing something, i fail to see where the tuning was of value here.
You needed it tuned to run the stock air box that was put on 750,000 mustangs?

Sounds like you could have just run a better meter and been fine.

The valve job alone is typically worth 10-15rwhp by itself.
You clearly didn't read the part I wrote about air velocity through the MAF and how it was altered due to the new air box. But by all means flame away.
 

Noobz347

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Rather than accept my explanation you two search for any explanation that fits your narrative that tunes are pointless. Maybe, just maybe the tune resolved the surging idle problem as I explained that it did. Good grief.


I think you fail to see the point of the discussion.

You can ask these guys (any of them): I don't argue [against] digital tuning. It though, like everything else, has its place. The point I was trying to make is about how common it is for some tuners to use those tools to mask mechanical issues.

If you refer back to the title, it's the topic of the discussion. :p
 
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Habu135

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I think you fail to see the point of the discussion.

You can ask these guys (any of them): I don't argue [against] digital tuning. It though, like everything else, has its place. The point I was trying to make is about how common it is for some tuners to use those tools to mask mechanical issues.

If you refer back to the title, it's the topic of the discussion. :p
Asked and answered.
 

Noobz347

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You may also be missing one other piece of background:

2000xp8 and I, have been bantering about this for more than 15 years. I'm the Pro tuning side and xp8 is Con tuning side (historically).
 

Habu135

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...and to be clear: I don't think that your solution was 'incorrect'. It's just not the only means.
Timing set at 10 degrees
Fuel pressure set at 38psi
Idle at 950-1000
New IAC and O2 sensors

Car ran great idled perfectly prior to the new air box. Surged after. How come? A/F showed pig rich. Tuned to pull A/F back down. Problem solved. What logical and reasonable alternative was there?