Megasquirt and LS swap.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

hopefulbull

Junior Member
Joined
Oct 10, 2021
Posts
12
Reaction score
4
Location
Fenton mo
First Name
Mike
Truck Year
1986
Truck Model
K20
Engine Size
350
I have been cruising around for a few days searching the board, but I can't seem to fund any info. I'm planning LS swap into an 86 k20. I *** thinking of going with Megasquirt for the ECU. It seems like everyone is using the stock ECU, but they are also using the tranny that can from the donor. That will not work because we're like manuals in our family. The plan is also to keep the SM465 that is in the truck now. There is my ideas but not much of a plan.

Will the donor ECU from an auto tranny work in my manual swap?

If the donor ECU is a no go what are options that others have had success with?

If you have some megasquirt info (wiring diagram, basic tune, ect.) Please feel free to share.
 

CalSgt

Full Access Member
Joined
Oct 3, 2021
Posts
1,517
Reaction score
3,209
Location
CA
First Name
Casey
Truck Year
1980
Truck Model
Chevy K-10 Custom Deluxe
Engine Size
350
I have been cruising around for a few days searching the board, but I can't seem to fund any info. I'm planning LS swap into an 86 k20. I *** thinking of going with Megasquirt for the ECU. It seems like everyone is using the stock ECU, but they are also using the tranny that can from the donor. That will not work because we're like manuals in our family. The plan is also to keep the SM465 that is in the truck now. There is my ideas but not much of a plan.

Will the donor ECU from an auto tranny work in my manual swap?

If the donor ECU is a no go what are options that others have had success with?

If you have some megasquirt info (wiring diagram, basic tune, ect.) Please feel free to share.
Not what you are asking but I'm gonna say it anyway...

Megasquirt is for hotrodders that are either going to pay for someone else to do it or guys who are all in dedicated to educating themselves about the tuning and build of EFI setups. However many guys download their tunes through "tune studio" which is on the MS tuning forum, i suspect a stock tune for an LS is probably easy to find on there.

My understanding with factory ECM's is having them hacked to disable VATS is a possible requirement and if it is designed for an "E-needs" tranny it will want an "E" tranny hooked up for it to to run.

The Holley ECU & harness kits are ridiculously simple albeit expensive but are worth every penny.

My dad built a mega squirt setup for his '56 with TPI and dedicated months on end researching programming, what sensors to run, tuning, AFR values and gauges, input values to trigger functions etc. The car ran and sounded great but no person other than him could have ever figured out what he had done to get it to that point.

He decided to get a holley terminator and harness to make it simple, hooked it up in an afternoon and the thing fired instantly. Matter of fact he was using a remote to bump the motor over with a plug out making sure his timing was on, well he forgot to disconnect the coil and that sucker took off the instant he hit the button before he had ever attempted to start it.
 

Camar068

Supporting Member
Supporting Member
Joined
Feb 5, 2014
Posts
4,157
Reaction score
3,015
Location
Kentucky
First Name
David
Truck Year
1986
Truck Model
K10/LM7 5.3/4L60e/np208/3.73/32"
Engine Size
10 yrs Air Force
I have been cruising around for a few days searching the board, but I can't seem to fund any info. I'm planning LS swap into an 86 k20. I *** thinking of going with Megasquirt for the ECU. It seems like everyone is using the stock ECU, but they are also using the tranny that can from the donor. That will not work because we're like manuals in our family. The plan is also to keep the SM465 that is in the truck now. There is my ideas but not much of a plan.

Will the donor ECU from an auto tranny work in my manual swap?

If the donor ECU is a no go what are options that others have had success with?

If you have some megasquirt info (wiring diagram, basic tune, ect.) Please feel free to share.

keep searching the web. I believe with you having a manual it will actually be a bit easier than with an auto. Don't hold me to it, but I think it's only a switch here and there.
 

dusterdude

Full Access Member
Joined
Oct 7, 2020
Posts
324
Reaction score
338
Location
US
First Name
mark
Truck Year
1985
Truck Model
gmc c15
Engine Size
305
Look on youtube,there are boatloads of videos on how to hack the 0411 ecm
 

yevgenievich

Full Access Member
Joined
Mar 1, 2014
Posts
4,789
Reaction score
3,327
Location
Texas
First Name
Viktor
Truck Year
sad
Truck Model
very sad
Engine Size
less sad
No problem with running a manual on stock ecu
 

hopefulbull

Junior Member
Joined
Oct 10, 2021
Posts
12
Reaction score
4
Location
Fenton mo
First Name
Mike
Truck Year
1986
Truck Model
K20
Engine Size
350
So even if the donor is an auto I can still use the stock ECU with no codes? That would be great. We're are not looking to do performance stuff, but we're wanting it to work correctly. So far the only LS swaps I could fund that were done using a manual they also changed the ECU to something like a holly dominator.

Thanks for the numbers on the ECU that should help me dig up more options using the stock ECU. If anybody has links to info in this direction feel free to post.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,190
Reaction score
5,088
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
So even if the donor is an auto I can still use the stock ECU with no codes? That would be great. We're are not looking to do performance stuff, but we're wanting it to work correctly. So far the only LS swaps I could fund that were done using a manual they also changed the ECU to something like a holly dominator.

Thanks for the numbers on the ECU that should help me dig up more options using the stock ECU. If anybody has links to info in this direction feel free to post.
Lots and lots of guys that do it with a manual. You can actually just do a manual trans segment swap from a corvette or F-body OS. Or even just run an entire 5.3/manual OS from an F-body.

You can get an OBDXPro VT tool for $60 and then do all of your programming and tuning using TunerPro and PCMHammer/PCMLogger or LSDroid(which are all free software).

Loading your desired OS into TunerPro and removing VATS and shutting off the rear O2 sensor codes is super easy. Modifying the tune for VE's and timing is a bit more involved, but not too bad.
 

hopefulbull

Junior Member
Joined
Oct 10, 2021
Posts
12
Reaction score
4
Location
Fenton mo
First Name
Mike
Truck Year
1986
Truck Model
K20
Engine Size
350
So I have been watching a ton of videos on how to use ls droid, and different tuner software packages. Really ls droid and a stock manual trans file will do everything we want to do. Thanks for the info on the ECU numbers. That *** the key that unlocked my searches.
 

wlwarnke

Full Access Member
Joined
Sep 14, 2021
Posts
132
Reaction score
183
Location
Helotes, TX
First Name
William
Truck Year
1983
Truck Model
K5
Engine Size
5.7
VATS is the only thing that will stop the engine from running.

If you don’t have the Tranny it’s programmed for, it will set codes.

When you get VATS disabled, just have them (or you) disable any codes you don’t need, such as auto trans, rear O2, AC pressure, etc.

I wasn’t aware that there were free option when it comes to making changes to the PCM nowadays. I personally use HPTuners. Wasn’t free but wasn’t horrible either. I’ve made my initial investment back by setting up and tuning friends and friends of friends engine/Tranny/ Gears/ and cam swaps.
 

Forum statistics

Threads
42,123
Posts
909,582
Members
33,614
Latest member
BryantRiverRat
Top