Currently doing a swap with Holley Sniper dual intake on a stock LS3. E38 ECM.
In theory, could I run just one MAF in one of the intake tubes?
Then just multiply the MAF curve with x2?
I will have 450g/s at 6000Hz, instead of 12000Hz.
This must be the same as running a very big intake tube and just tune for it?
(This is off course assuming that both banks pull the same amount of air)
Am I completely rambling here, or could this work?
That's making the assumption that there will always be the same amount of airflow in both tubes, which is not correct.
Why even use a MAF at all?
Why do it at all?Originally Posted by blindsquirrel
Just tune it SD…. Run 3 tubes then
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You mean, like, why do anything, give away all your stuff and go live in a cave?
Like, what are the benefits to trying to make that work on a stock ls3?
The benefit is that there is no MAF sensor and makes one less thing to worry about.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I was hoping to get more constructive answer.
I prefer to use the MAF for tuning as its a a "finer" instrument.
I got a balance tube between the plenums to even out the balance (mostly effective at idle).
I believe that you learn a lot when playing with stuff like this, intake is a preparation for twin turbos to come, but for the next season I will be using intake only.
Then I would like to keep the MAF, without buying a another MAF and a module to run dual MAFs.
My thesis should be more or less the same..
Mostly for fun and to learn.
It will be twin turbos later and SD, but for this season I would like to keep the MAF.
It's not a finer instrument once you split the airflow in two and then only measure one half of it. Not only are you cutting the resolution in half, there is no way in hell that flow will be equal through two separate, non-identical paths.
If you're thinking 'well then I'll just make them exactly identical!' - they won't be. Not even an OEM could engineer that solution. That's why engines that use two intakes/throttle bodies are either pure speed density or are built from the start with two MAFs and are essentially, from the powertrain control view, two separate engines that happen to share a common crankshaft.
You a right on the resolution part!
Do you think running of MAP will affect the tip in/throttle response differently, compared to running MAF? With dual TBs the MAP readings will change quick.
I think MAF should be smoother on this part.
BR Marcus
My truck has better driveability, better fuel economy, and makes more power by failing the MAF. I think you're ascribing magical qualities to that sensor that it really does not deserve.
Seems that I need to do some comparsion testing! Do you keep the MAF in place for the IAT sensor?
It showed the same benefits either way, but I've since removed it altogether and added a standalone IAT.
I was referring to dual throttle bodies on sock ls3, not tuning in SD.
*** offtopic
I apologize already with this very offtopic question but why it is so (in your case)?
*** /offtopic
For the OP (original poster): just don't use MAF at all as suggested in this thread.
Especially with modified intakes, as in your case, the MAF may be very unstable at low throttle openings because airflow is not always steady enough. Check my old post from 10 years ago:
https://forum.hptuners.com/showthrea...S3-A6-Corvette
In many cases with retrofitting stock LS engines to old muscle cars MAF doesn't always have steady enough airflow. It's the same with, say, some C6 Corvettes with aftermarket CAI's. There's just too much turbulence for the MAF and the end-result is bucking.
Interestingly, I had today a C6 with A&A Vortech kit and with MAF it was bucking, but this is not common with that kit. I don't know why this car did it, but after going SD bucking was gone. So MAF turbulence was indeed the root problem.
Again, I would suggest going with SD with your setup.
Again, don't do that and go SD instead.
Now, going with single MAF for dual TB does actually work fairly well, but this case in the link below I had to do it because of very limited PCM capabilities for this particular setup:
https://forum.hptuners.com/showthrea...ed-Gen-V-Viper
No idea! MAF & VE were each properly tuned separately but everything worked better with MAF failed, even when it still had the stock intake tube & MAF in place.
Actually they are not split into two separate engines. My G35s VQ35HR and my M56S VK56VD both shared an open plenum and the MAFs readings were combined by the ECU. The airflow total is then used by the ECU for fuel and load reference. At very low throttle and idle the throttle bodies were often not in sync with one open slightly more than the other.
Last edited by Fast4.7; 10-07-2022 at 05:04 PM.
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