Thanks Orr, we must think alike!

Literally just posted that I'm thinking of keeping it fully stock except the injectors will be 80lbs and the turbos. The OEM cam and ECM should need very little tuning besides under boost which I'm assuming is easy with the 2 bar map sensor? I want to use the 2 bar bc i won't be more than 12 psi prob ever and more around 8 for the street with no intercooler and just j
Run the NA meth kit I have for boost.

 

Yep, and that ratio will change site to site.

Right, which is why I brought up MS. WOrks on SBC, LSx, LTx, Fox body, bikes, airplanes, boats, everything.


For a stock LSx sure, use a stock ecm.

But the thread title was twin turbo 5.3 LS.. That aint stock

-- Joe

 

Lol turbo doesnt change the motor tune tho. Bore stroke heads cam changes tune up.

 

Huh?

Boost spark retard
Boost fuel adder
MAT vs boost spark retard


Stock LS1 PCM doesn't have any of that.

-- Joe

 

Stock motor. You can use stock file lol no changes to motor tune tables like fuel and timing except for boosted areas. A new system will not have a good base file like that.
Just slapping on turbos doesnt change how the engine drives starts and idles to a point. Lol all he is doing is possibly mild cam and adding snails. Copy over tables from 5.3 stock file into the 2-3 bar op system and its damn near ready to go.

And yes stock pcm lsx stuff has those features just have to get the 2-3 bar map operating system

 

I think we are mixing things up.

When we say "Stock ecm" I mean a stock LSx ECM using stock software with just calibration changes.

If you are loading a custom operating system on it, that's not stock.

I wasn't aware that the stock software supported 2-3 bar, boost, etc, but now that I realize you are talking about custom code sure. Just like folks do when they load Sy-ty code on a '730 ECM.

Do you have a link to this special OS ? Is it just modified stock software or written from scratch?

-- Joe

 

Theres many different operating systems for stock lsx pcms. Many different vehicles and engines they came with

Its not special its just stock but with 2 or 3 bar map. Same crap thats in stock file so its not exactly like sy ty code in 730's. But even that is gm stock code in a sense so again not sure what the big deal is? Its oem and its cheaper than aftermarket

 

Read on hptuners site.
http://www.hptuners.com/help/vcm_edi...ters_gm_os.htm

 

Sounds interesting. Can I run it on my 2012 6.0 ?


So what is the total cost for the ECM, Operating System, and tuning software?

-- Joe

 

Is it a 58x ring? May need to converter box but heard issues with them

Hptuners comes with like 8 credits for operating systems. Unlock the pcm vin. Each credit is like 50$ and 2 are needed for basic pcms. 2-3 bar may be an additional credit. I am not sure.
Hptuners is 499 for basic and 650 for the log box which allows 4 inputs i think, mainly used for external wideband logging. I didnt get that but wish i did. I now plan on getting an external standalone logger for the car

 

I'm not sure what my 2012 is.

So it looks like an ECM is about $75 on ebay, $499 for the hp tuners. Not terrible, but a few hundred dollars more than my megasquirt.

I guess it depends on what your goals are. For a stock vehicle like you said, maybe that would be easier on someone who isn't much of a tuner.

-- Joe

 

Or for those electrically challenged ppl like myself who dont wanna assemble circuit boards haha i can wire harnesses but dont wanna do ecms

 

I don't blame you. I wouldn't assemble a MS2 either.

-- Joe

 

whats the deal with the face book page called "mega squirt sucks" you guys seen that?

 

My megasquirt works great, no problem with it. I have a friend who runs a 58 tooth motor in his go using the converter box. Works good.

 

Yep. They were a bunch of clowns that got sour over the Megasquirt licensing.

Some started Free EMS.

Others backed a competing system called VEMS. Vems was produced because people complained about the MS licensing and bug sin early MS1.

VEMS was originally open source, but is now closed source.

-- Joe

 

Yes, this thread us about the OEM 5.3 LS GM ECM and using HP tuners to hack it, unlock it and custom tune to my liking. Looking to make 500-550hp with 8psi on stock motor. Cam and heads and easily in 600hp range. The appeal of all this is 500-550hp for less than 4k and idles like a new truck and acts just like one before boost. I figure highway mileage will be in the 25-30mpg.

I'm still have no idea how to tune the OEM system or how to swap the 2bar system in but I will hopefully soon. The 5.3 motor with its 9.5:1 can take boost and still run on pump gas compared to the higher compression LS1 etc. Pulling the motor apart is Def an option but once u start u can't stop and costs a small fortune in the end. If I pulled the motor I would do full teardown, new bearings, rings, rod bolts, maybe pistons, ARP studs, head porting etc and all new gaskets. I'm gona leave it alone and have some fun with it.

I started getting some of the small parts to get to work. Got some set back motor mounts, egr and evap block off plates, tq converter adapter spacer, oil level delete plug to convert to oil temp sensor. New aftermarket fuel rails. Gona get the 80lbs injectors soon.

Going to swap out the 105 amp alt and OEM starter for new 130 amp and gear reduction Starter. Then it's going to get new idler and tensioner and belt. One of the spark plug wires fell apart so thats on thr list but gona wait till I get the turbo headers to figure out placement/routing. Once I get the LS6 valve springs and a cheap spring compressor the motor is basically done. Besides lots of cleaning and paint.

What can I use for the throttle and TV cables? Im looking for a lokar bracket so I Can reuse my lokar cables. Do you guys recommend replacing any sensors now that the motor is accessible like cam position etc?

 

Got the harness all thinned out and in the process of taping it back up. I deleted all the VSS wires since I run a gps speedo. But I couldn't find a definitive answer on this...

Red connector pin 33, TCC brake signal wire. PCM is looking for 12v all the time until the brake is pressed and looses the 12v signal so the PCM knows the brake has been pushed. Can someone please explain this further? I don't believe I need this as my converter is lockup but runs off a standalone lockup kit and I don't have cruise control. So what purpose does this have now? I left it in just in case but I don't want to connect it and run the wire if I don't need too. I don't see the reason why the PCM would need to know since I run a non electronic 2004r with TV cable.

Got the block and accessories painted and the adjustable motor mounts attached. I also recieved my 60lb LS1 Bosch fuel injectors from FIC with the wire adapters, as well as the billet LS1 fuel rails (need to make custom mounts for them to work. Also got the torque converter adapter, and all my sensor adapters/block off plates.

What would u guys do about the OEM sensors? Mainly crank position, cam position, watertemp? Would u leave the OEM ones in or replace now while the engine is out?

Turbo up and forward headers are on the way!


I also don't think the truck oil pan is going to work... ugh. Might have to spend like $380 on a holley fbody oil pan kit. So much for cheap.

 

If sensors are good no need to replace

 

Well idk if they are good lol. Guy says it ran good and i had a video of it running. I was just wondering if a cheap replacement would be better than the old OEM ones.

 

WEll guys I got the harness pretty much banged out. I rewired and de-pinned and got it on the engine then got to hacking and soldering as i'm mounting the ECM on the pass side firewall. I cut off the MAF (everything is telling me to go SD tune) but now I need to wire and mount in an IAT sensor. Ugh

Fabbed up some fuel rail mounts for the driver side… ugh that was annoying. Still need to do the pass side. I also am looking at plugging the rear brake booster port on the intake… I don't need it since I run a hydroboost. Any ideas?

I received the new gates serpentine belt, tensioner pulley, idler pulley for the 130amp alt, placed the order for the 130amp alt, and gear reduction starter. I think I'm going to have to pay the $65 for the lokar LS1 throttle cable. ugh.

Side note is that the turbo up/forward headers arrived and they clear everything! They look real nice for $160.

 

Hey Guys,

Might be reconsidering my twin setup for a single. running exhaust on the driver side looks like ti would be a PITA!

What do you guys think would be a good single turbo for 550-800 fwhp on the 5.3L? Im thinking of one of these.

T76
76mm compressor
.80 A/R
4" inlet and 2.5" oulet (would like a 3" outlet)
76.71mm inducer
102.36 exducer

Exhaust T4 flange
.96 A/R
3" Vband
74.5mm inducer
65 or 68mm exducer

3" downpipe seems pretty small though... but would be nice to run a 3" catback again lol. Otherwise looking at 4" downpipe and 4" catback. Looking for quick spooling... since Im running the truck intake and stock 5.3 truck motor It wont be pulling higher than 5500rpms. I run a 2400 stall converter as well.