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-   -   How did GM/Magnuson tune m62 3400 (http://www.grandamgt.com/forum/showthread.php?t=91134)

00redse 04-15-2017 10:19 PM

How did GM/Magnuson tune m62 3400
 
I searched but couldn't find an answer

How did the original m62 3400 guys cars read boost and add fuel? Weren't they available as a dealer add on with a CARB sticker and all?

Pardon me if this is a silly question. My knowledge of the subject is mostly limited to the 2.4 and the m45 s/c kit. I know they just got a 2 bar map sensor and bigger injectors with a reflash.

So is/was there a reflash for the m62 3.4 setups?

I have a turbo 3400 which was boosted/tuned before I bought it. It runs well, but I'm looking into my options for changes with future upgrades. I will have hptuners available to me.

Advice and knowledge appreciated.

O1GAGT 04-16-2017 08:42 PM

They used a rising rate fuel pressure, which mounted on the top of the fuel pressure regulator.

https://www.google.com/search?q=3400...tm_QMVhPxQG7M:

00redse 04-17-2017 12:09 PM

Thanks.

So it's good for low boost only, PCM isn't reading boost.

Nice move gm. lol (At least the 2.4 s/c kit let the pcm read boost)

So, from my understanding, removing the MAF forces the car to run in Speed Density mode, right?
And it also makes the tranny shift super hard and at full line pressure which is bad.

What else happens when you delete the MAF?

Seems like if it's just the trans issue, then a 5 speed swapped car could just run w/o MAF and fake a 2 Bar MAP sensor with HPTuners. But this seems too simple (not that the 5 speed swap is "simple"), so what am I missing, or not taking into account?

O1GAGT 04-18-2017 04:39 PM

There is a way to add a 2 bar map with a DHP Tuner and Tiny Tuner software. I don't think it is an option with HP Tuners. I personally wouldn't run the car without a MAF.

As a side note, I read one of the PCM's from a supercharged concept car that had the 4T65e swap. The only changes were for the transmission, fueling, spark, ect were stock.

00redse 04-18-2017 05:12 PM

Quote:

Originally Posted by O1GAGT (Post 1266428)
There is a way to add a 2 bar map with a DHP Tuner and Tiny Tuner software. I don't think it is an option with HP Tuners. I personally wouldn't run the car without a MAF.

As a side note, I read one of the PCM's from a supercharged concept car that had the 4T65e swap. The only changes were for the transmission, fueling, spark, ect were stock.

I'm pretty sure HPTuners will let you fake a 2 bar MAP on the 3400. I know it can on the 4cyl.

And I understand most want to keep the MAF, but other than upping the trans pressure, what's the ACTUAL effects of removing it?
The upside is it running in speed density mode and using the map to adjust fuel for boost if you scale the map values for a 2 bar.

Cool about the concept car. Which one was it? I was at the Barrett-Jackson Auction when they auctioned off a bunch of the GM concepts. Did you keep the file? I don't doubt that the tune was the same. Most of the time to run low boost, you don't need a bunch done. Case in point the m62/3400 not having anything changed. Just the fpr.
But to run higher boost, that concept car would need a way to read boost and adjust. Not just spray and pray. Sure you can just dump a bunch of fuel in when you add boost, but that's not ideal.

AaronGTR 04-23-2017 10:44 AM

Quote:

Originally Posted by 00redse (Post 1266425)
Thanks.

So it's good for low boost only, PCM isn't reading boost.

Nice move gm. lol (At least the 2.4 s/c kit let the pcm read boost)

So, from my understanding, removing the MAF forces the car to run in Speed Density mode, right?
And it also makes the tranny shift super hard and at full line pressure which is bad.

What else happens when you delete the MAF?

Seems like if it's just the trans issue, then a 5 speed swapped car could just run w/o MAF and fake a 2 Bar MAP sensor with HPTuners. But this seems too simple (not that the 5 speed swap is "simple"), so what am I missing, or not taking into account?

Yeah, the kit only ran 5 psi in stock form, and they only added a fuel pressure modifier to add extra fuel under boost. And GM had nothing to do it. :duh: They didn't design the kit, it was all Magnacharger and there was no partnership involved. They didn't design the car to be boosted from the factory, so why should it be their fault? The 2.4L kit was designed for GM performance parts by GM (not Magnacharger, it just used an Eaton blower), so of course it was going to have better integration.

Anyway, removing the MAF sensor is not a good idea on these cars. They are not designed to run normally in speed/density mode, and doing so is just asking for problems. There is no need to eliminate the MAF anyway, so why would you want to? It still reads the amount of air coming in, so it still adds fuel. The MAF is in fact the primary fuel enrichment device. There is a way to add a 2 bar MAP to the car with a tuner though. Mine is running one right now. The only advantage to this is that by knowing if it's in boost or not, the PCM can reference different points on the VE table, which is the base fuel map the car works off of before making changes based on MAF sensor input. The stock VE table goes up to 140 kPa (about 6 psi of boost), but atmospheric pressure is about 100 kPa normally. Since the car is NA from the factory, everything in the table from 100-140 kPa is the same. They had no boost to tune for, so did not do any VE tuning up there. If you added boost, you could add a 2 bar map to reference those upper points on the map, but without extensive tuning to figure out the VE, it won't do you any good. You can't just guess at it. It takes a lot of money and dyno time. Easiest thing to do when adding boost is get bigger injectors, and tune the MAF table to add fuel.

00redse 04-25-2017 08:52 AM

Thanks.

Good info, and duly noted.


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