L31 into an '86 Regal Limited V8

[nova_rookie]

Fundamentally, what you are asking can be done but would be very tedious and time consuming. It would be much simpler to keep your existing Regal harness intact as much as possible and just try to control the engine and transmission with the Vortec harness. If you get rid of the unnecessary stuff (stuff already performed by you existing harness) in the Vortec harness you only need those connections specified here http://lt1swap.com/1999_vortec_5.7/index.htm

In reality, all the new power connections are really only two connections to your existing electrical system-- either HOT ALL THE TIME (BATT) or HOT DURING START/RUN. The HOT DURING START/RUN can be obtained through the Regal's ignition circuit by use of a relay.

Mike

 

[ATL Regal]

Fundamentally, what you are asking can be done but would be very tedious and time consuming. It would be much simpler to keep your existing Regal harness intact as much as possible and just try to control the engine and transmission with the Vortec harness. If you get rid of the unnecessary stuff (stuff already performed by you existing harness) in the Vortec harness you only need those connections specified here http://lt1swap.com/1999_vortec_5.7/index.htm

In reality, all the new power connections are really only two connections to your existing electrical system-- either HOT ALL THE TIME (BATT) or HOT DURING START/RUN. The HOT DURING START/RUN can be obtained through the Regal's ignition circuit by use of a relay.

Mike

OK, maybe I should have made this clear at the start of this thread, but the Regal's engine harness has been modified also.

About 2004 I had a crate long block 307 installed, same exact engine as it was before but the smog pump was deleted and some other things that had to do w/ emissions.

"(stuff already performed by you existing harness)"
The Vortec has a different a/c compressor, the only way I can see using the existing harness for A/C is if I was to use the a/c compressor from the 307, which is still practically new, I bought it shortly before the 307 started giving me problems, but I wouldn't know how to mount it. Would it be a direct replacement in place of the Vortec a/c compressor?

Same thing with the cruise control, how would I connect a harness designed to control cruise control in an '86 Regal to the cruise control on a '97 Vortec 5.7L?

 

[ATL Regal]

Fundamentally, what you are asking can be done but would be very tedious and time consuming. It would be much simpler to keep your existing Regal harness intact as much as possible and just try to control the engine and transmission with the Vortec harness.

What exactly are you referring to when you say "can be done but would be very tedious and time consuming"?
And why would it be any more tedious & time consuming than what they did at LT1SWAP.COM?

How is what I'm asking about any different than what you're telling me?
Everything under the hood is from the Vortec, all accessories, all wiring, all plumbing, computer, etc, everything except power steering gearbox and brake booster.

I thought it would be easier to just have the Vortec harness & computer control the engine, trans, and all accessories then feed power and gauges through the firewall (or cut them @ the C100 and connect the wires to the existing regal's firewall connector)

If you get rid of the unnecessary stuff (stuff already performed by you existing harness) in the Vortec harness you only need those connections specified here http://lt1swap.com/1999_vortec_5.7/index.htm

What is this "unnecessary stuff" you're referring to? I mocked the harness on the engine before I put it in the car and every connector/plug had a corresponding place for it to go, except the O2 sensors.
I want it to run closed loop.

In reality, all the new power connections are really only two connections to your existing electrical system-- either HOT ALL THE TIME (BATT) or HOT DURING START/RUN. The HOT DURING START/RUN can be obtained through the Regal's ignition circuit by use of a relay.

Mike

I don't understand that bolded part.

 

[nova_rookie]

ATL Regal,

As far as power goes, you only need pwr from the battery and an ignition/run source. To get power from an ignition/run source, the easiest thing to do is to find one wire in your Regal harness that is hot in start and run. This will likely be the wire to the original coil. You just need to make sure there is 12V there under these conditions, ignition switch in start and run. You use this wire to pick up a relay (due to the downstream loads you may actually need two relays) which supplies all the HOT/RUN circuits in the Vortec harness. You only need one wire other than a battery feed from the Regal to do this.

As for the other wires:
1) run the Vortec tach wire to your tach
2) run the VSS speedo to a new electronic speedo which you will have to buy; there are other ways to do this but this is the best
3) you will have to run the serial cable to an OBDII plug, there is also a +12V source in the plug (shown in the drawing above, and some grounds)
4) I would recommend that you incorporate the starter circuit in the Vortec harness, it needs to run through the neutral safety switch (I will draw this later). There is a swich in the transmission which makes this easier to keep in the Vortec harness

I will provide my drawings as I do this, perhaps they will help.

Mike

 

[nova_rookie]

ATL Regal,

You stated:

"What is this "unnecessary stuff" you're referring to? I mocked the harness on the engine before I put it in the car and every connector/plug had a corresponding place for it to go, except the O2 sensors.
I want it to run closed loop."

This is the stuff I deleted in the Vortec harness:
1) rear O2 sensors
2) recirc door motor control- this wire runs to C200, and controls air flow into passenger compartment
3) VSS to radio
4) VSS to anti-lock brakes
5) evap cannister purge
6) evap cannister vent
7) EGR valve- your headers don't have tube to supply exhaust gases anyway
#8 transmission gear indication wires to C200
9) air condition wiring- I Have a Vintage air system and will wire it separately (I kept plugs for compressor)
a- compressor clutch
b- compressor cycling
c- compress high press cutout
d- compress low press cutout
10) htr solenoid valve
11) oil pressure switch- I have a oil pressure gauge which came with its own sensor; I need to make sure the oil pressure switch does not send a signal to cut the engine off on low oil pressure
12) hood light
13) starter wiring- I will be adding this wiring back but routed differently (need to tie into existing ignition and trans neutral safety switch)
14) backup light wiring- I will add this back from the transmission range switch

Mike

 

[RUDE DOG]

ATL Regal,

As far as power goes, you only need pwr from the battery and an ignition/run source. To get power from an ignition/run source, the easiest thing to do is to find one wire in your Regal harness that is hot in start and run. This will likely be the wire to the original coil. You just need to make sure there is 12V there under these conditions, ignition switch in start and run. You use this wire to pick up a relay (due to the downstream loads you may actually need two relays) which supplies all the HOT/RUN circuits in the Vortec harness. You only need one wire other than a battery feed from the Regal to do this.

As for the other wires:
1) run the Vortec tach wire to your tach
2) run the VSS speedo to a new electronic speedo which you will have to buy; there are other ways to do this but this is the best
3) you will have to run the serial cable to an OBDII plug, there is also a +12V source in the plug (shown in the drawing above, and some grounds)
4) I would recommend that you incorporate the starter circuit in the Vortec harness, it needs to run through the neutral safety switch (I will draw this later). There is a swich in the transmission which makes this easier to keep in the Vortec harness

I will provide my drawings as I do this, perhaps they will help.

Mike

Thats a very good way to connect the power to injectors,coil,,, with a relay with the direct power from battery, although you can also make connection to the alternator like racetronix hot wire kits that give you that direct current with a fuse of course.

 

[RUDE DOG]

Ive done plenty of LT1 and have built my own harnesses, but a lot of my stuff is missing and or gone. I know I still have an LT1 harness I built 10 years ago but have to look for it and do some checking into how different I wired that one in comparison to a vortec 350. I kept everything simple on my harness if i find it ill show you guys what im talking about.

 

[ATL Regal]

What is I/P harness?

 

[nova_rookie]

What is I/P harness?

It is a wire harness in the passenger compartment, probably stands for Instrument Panel.

Mike

 

[ATL Regal]

What's this pipe attached to the driver's side exhaust manifold?



Here's where it attached to the intake..