Build Thread: '99 C2 996 LS1 Swap
#226
Rennlist Member
Thread Starter
They make fittings that u can slip into the flexible hose if u cut off the aluminum section. U just slip it in and clamp the metal rings down. I had to use a repair union in one of my lines. I could have converted it to a standard ac fitting. One of the rings broke so i used s hose clamp.
Wow. Just read this whole thread!
Very nice!
I' love seeing these swaps, brings my two worlds together., Camaro's and Carrera's
Did the LS swap in my 70 Camaro, worth every single penny and frustration. the swap is 8 years old now and has 23,000 reliable miles on it and has seen 19 states.
this is intriguing. I hope u keep and continue to hot rod. love me some outlaw.....
Very nice!
I' love seeing these swaps, brings my two worlds together., Camaro's and Carrera's
Did the LS swap in my 70 Camaro, worth every single penny and frustration. the swap is 8 years old now and has 23,000 reliable miles on it and has seen 19 states.
this is intriguing. I hope u keep and continue to hot rod. love me some outlaw.....
I'll keep hot rodding for sure. Hoping to start taking my 996 LS1 to a few HDPE and Autocross events this summer. I just need some AC, this cabin is HOT!
plumber 452-is the system charged and do you have the porsche small alternator wire connected ?I don't know the dme logic but do know the climate control must see engine running which is the alternator wire and the dme needs a signal from the low pressure a/c sensor/switch that there is 25 psi or so in the system .
Ditto here, thanks for sharing this! Excellent info here on Rennlist, it's great!
#227
which alternator wire ?B would probably work .Quick check -is the instrument cluster battery idiot light on when key on engine not started ? and off with engine running ?
If yes on above then another simple test would be to probe the wire from the climate control to the dme -with engine on and ac engaged you should see a pwm voltage -that would prove climate control is calling for a/c .
If yes on above then another simple test would be to probe the wire from the climate control to the dme -with engine on and ac engaged you should see a pwm voltage -that would prove climate control is calling for a/c .
#228
Nordschleife Master
#229
Plumber452 -you probably know this but need to push auto button on climate control to engage a/c .I am assuming compressor is good since you had to run to fill system .Don't know how you are engaging fans but with a/c on low speed fan should be engaged .
#230
Rennlist Member
Thread Starter
Looking at the AC system and radiator fans.
Found the AC trigger wire in the engine bay, I had tucked it into the harness sheathing. Green wire with yellow stripe.
I also found the Porsche high side AC hose. I’m going to attempt to have a local AC shop make me a custom hose. If not I might cut and TIG weld.
I found the #12 pin blue wire on the top X51 plug. This had 12v signal with ign on. This is not routed to the alternator but I don’t have a battery light on the dash.
I do, however, have a CEL which is likely from the tach not working. I believe the DME needs a crank signal from the LS engine to work the tach and allow the DME to trigger the radiator fans. I have the P car water temp sensor in the LS1 head. I also have new radiator fans and resistors installed. I jumped each relay and confirmed all 4 fan speeds work in the relay module (2 hi and 2 lo). Other 996.1 LS swap guys say their fans work via the sensor but mine do not appear to be working when the engine is hot. The gauge does read lower than the LS sensor shows on the Holley Terminator X readout. I recall the 996 fan kick on temps being somewhat high and others have ran wires from their LS standalone harness to bypass the P car relays. I might have to give this a try to activate my fans and control the kick on temps myself.
I’m looking for advice on where to splice into the chassis wiring with my tach signal. I have a tach converter box to convert 24x signal to 58x essentially.
Found the AC trigger wire in the engine bay, I had tucked it into the harness sheathing. Green wire with yellow stripe.
I also found the Porsche high side AC hose. I’m going to attempt to have a local AC shop make me a custom hose. If not I might cut and TIG weld.
I found the #12 pin blue wire on the top X51 plug. This had 12v signal with ign on. This is not routed to the alternator but I don’t have a battery light on the dash.
I do, however, have a CEL which is likely from the tach not working. I believe the DME needs a crank signal from the LS engine to work the tach and allow the DME to trigger the radiator fans. I have the P car water temp sensor in the LS1 head. I also have new radiator fans and resistors installed. I jumped each relay and confirmed all 4 fan speeds work in the relay module (2 hi and 2 lo). Other 996.1 LS swap guys say their fans work via the sensor but mine do not appear to be working when the engine is hot. The gauge does read lower than the LS sensor shows on the Holley Terminator X readout. I recall the 996 fan kick on temps being somewhat high and others have ran wires from their LS standalone harness to bypass the P car relays. I might have to give this a try to activate my fans and control the kick on temps myself.
I’m looking for advice on where to splice into the chassis wiring with my tach signal. I have a tach converter box to convert 24x signal to 58x essentially.
#231
The blue wire needs to be connected to the alternator -if gm alternator would be the l terminal .( best to verify terminals by your specific model ) .This will make dash light function and also enable abs and climate control .
Pins 35 and 36at dme activate fans ye/gn wires .35 is low 36 is high .They ground the fan relays for activation .No need to bypass relays .The engine speed sensor is a white wire to pin 78 at dme .
Pins 35 and 36at dme activate fans ye/gn wires .35 is low 36 is high .They ground the fan relays for activation .No need to bypass relays .The engine speed sensor is a white wire to pin 78 at dme .
#232
With limited knowledge of how the dme is programmed it would seem prudent to have the terminator control fans and fuel .I don't know what the dme will do once it has a run signal and no other sensors input .It could be a recipe to turn it into a random cel generator and limit functions .I don't know if a/c will work or not .Others have reported it will - I am skeptical - it would be good to find someone who has done it successfully .Bypassing the dme for a/c with a functioning climate control is not hard .
#233
Rennlist Member
Thread Starter
Originally Posted by dcdrechsel;[url=tel:18203825
18203825[/url]]The blue wire needs to be connected to the alternator -if gm alternator would be the l terminal .( best to verify terminals by your specific model ) .This will make dash light function and also enable abs and climate control .
Pins 35 and 36at dme activate fans ye/gn wires .35 is low 36 is high .They ground the fan relays for activation .No need to bypass relays .The engine speed sensor is a white wire to pin 78 at dme .
Pins 35 and 36at dme activate fans ye/gn wires .35 is low 36 is high .They ground the fan relays for activation .No need to bypass relays .The engine speed sensor is a white wire to pin 78 at dme .
For fans, the Holley Terminator X send ground signal to activate fans also. Seems I could just tie those two signal wires (high and low) to pins 35 and 36 at the DME and control fan kick on temps via Holley software.
I’ll wire in the tach signal converter and send to pin 78. I’m feeling under the weather but will do this when I’m up to it. Thank you again!
Originally Posted by dcdrechsel;[url=tel:18204162
18204162[/url]]With limited knowledge of how the dme is programmed it would seem prudent to have the terminator control fans and fuel .I don't know what the dme will do once it has a run signal and no other sensors input .It could be a recipe to turn it into a random cel generator and limit functions .I don't know if a/c will work or not .Others have reported it will - I am skeptical - it would be good to find someone who has done it successfully .Bypassing the dme for a/c with a functioning climate control is not hard .
#234
RL Community Team
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Rennlist Member
#235
Rennlist Member
Thread Starter
Originally Posted by TexSquirrel;[url=tel:18204673
18204673[/url]]You have a Tip?!
I guess I’d missed that.
I thought no one had LS swapped a Tiptronic before.
Maybe I’m thinking about the 944 LS swaps.
As far as I know there are no 944 automatic LS swaps.
I think I’d prefer a tip with a 996 LS swap.
I guess I’d missed that.
I thought no one had LS swapped a Tiptronic before.
Maybe I’m thinking about the 944 LS swaps.
As far as I know there are no 944 automatic LS swaps.
I think I’d prefer a tip with a 996 LS swap.
#236
The alternator light does not appear to be working .Key on engine off light should be illuminated .With key on - the blue wire will have 12 volts and when connected to the proper alternator terminal will be grounded and turn the light on . .With engine running the alternator terminal will turn 12 volt positive and light will go out . That wire is also the engine run signal for abs operation and climate control .
The easy button for the fans is to just home the relay activation wires to the terminator .
The easy button for the fans is to just home the relay activation wires to the terminator .
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gtxracer (06-20-2022)
#237
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Thread Starter
Whew. I finally got around to wiring up the cooling fans to the Terminator X controls and the tach. This wasn’t all that bad, but I wanted to make it a clean install. I bought a metri pack 150 4 pin connector and used the power tap plug on the Terminator X harness for power and ground to the converter box since this plug is right next to where the tach converter box will live. The fan wiring was straightforward and easy. Should’ve done that long ago.
I tapped into the 78 pin on the DME but no tach movement on the gauge cluster. Weird. So I take the blue wire with white stripe and go directly to pin 78, bypassing the converter box. Nothing. I check power and ground, good to go. Still scratching my head on this one.
I’m waiting for Improved Racing to restock their oil coolers. I’ll be putting their largest cooler at the back of the car with a cutout for cooling. This, combined with an inline thermostat and ceramic coating on the exhaust, should lower temps while racing to normal levels.
I also ordered some small bullet mufflers to splice into the exhaust to take it down a few decibels. Although the existing mufflers are big, it’s a little too much for every day driving. I bought double wall stainless tips to give it a bit more flash and a refined look.
I’ll be measuring line lengths for the AC setup at the same time. I’m slow to get stuff done right now due to the move and work building up - but I’m gaining some momentum finally.
I tapped into the 78 pin on the DME but no tach movement on the gauge cluster. Weird. So I take the blue wire with white stripe and go directly to pin 78, bypassing the converter box. Nothing. I check power and ground, good to go. Still scratching my head on this one.
I’m waiting for Improved Racing to restock their oil coolers. I’ll be putting their largest cooler at the back of the car with a cutout for cooling. This, combined with an inline thermostat and ceramic coating on the exhaust, should lower temps while racing to normal levels.
I also ordered some small bullet mufflers to splice into the exhaust to take it down a few decibels. Although the existing mufflers are big, it’s a little too much for every day driving. I bought double wall stainless tips to give it a bit more flash and a refined look.
I’ll be measuring line lengths for the AC setup at the same time. I’m slow to get stuff done right now due to the move and work building up - but I’m gaining some momentum finally.
Last edited by gtxracer; 07-22-2022 at 01:08 PM.
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#238
Pin 80 (vi/gn ) is the tach signal to the instrument cluster and several other subsystems .I connected my tack converter to this and works fine .Don't know what you would need to do to use pin 78 -
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gtxracer (07-22-2022)
#239
Rennlist Member
Thread Starter
Originally Posted by dcdrechsel;[url=tel:18262125
18262125]Pin 80 (vi/gn ) is the tach signal to the instrument cluster and several other subsystems .I connected my tack converter to this and works fine .Don't know what you would need to do to use pin 78 -
edit: I got it. Switch 7 on the converter box needs to be ON for anything under 14 volts. The supply is 12v from the Terminator X. Tach works and it is accurate! Woohoo! I’ll wrap this up and start the exhaust and AC work finally.
Last edited by gtxracer; 07-26-2022 at 01:52 AM.
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#240
Race Car
Any ideas 180 headers fit with the Dailey or Aviaid dry sump setups ? Whats the tubing diameter ?
Dailey
https://www.drysumpsolutions.com/pro...ge/ls-race-pan
Aviaid - specifically C mount with a 4 stage pump. I would prefer the Dailey for cost but it requires a line for each scavenge on the sump to the pump... Lot going on.
https://aviaid.com/shopsite_sc/store...e-systems.html
Dailey
https://www.drysumpsolutions.com/pro...ge/ls-race-pan
Aviaid - specifically C mount with a 4 stage pump. I would prefer the Dailey for cost but it requires a line for each scavenge on the sump to the pump... Lot going on.
https://aviaid.com/shopsite_sc/store...e-systems.html