2001 Porsche 996 Cabriolet LS2 Conversion
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Thanks, I found this diagram on Pirate4X4.com and kind of had questioned the flow myself. That is why I am posting this stuff up here to figure things out and share with others!!!!
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Some one please post in if I am looking at things *** backwards?????
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That makes sense now, I thought your cooling system was plumbed backwards. I did not think about your driveshaft path!!!
Last edited by 4LUX; 12-07-2014 at 09:49 AM.
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Not a lot that has taken place on the project. I have my LS2 block and SRP pistons at the machine shop getting honed to match the 4.005 pistons. And they will fit the rings and check the line bore on the block. Also will look to drop my crank off this evening to get micro polished and waiting for the rods to come in, so I can have them balanced with the crank and pistons. Ordered my bearings and plan on starting to get the inside of the car taken apart to start the wiring process.
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I have been working 60+ hour a week for the past few weeks, but have taken 12/23 - 1/4 off. So I had received some more parts, that I had been waiting on. The rods, cam, valve springs and bearings.
So with the parts in, I had to start doing some work. Decided to do the trunion upgrade today. I do not have a press, so the vise had to work.
So here is the finished product, you can really see the difference from stock to upgrade in the following photo.
So with the parts in, I had to start doing some work. Decided to do the trunion upgrade today. I do not have a press, so the vise had to work.
So here is the finished product, you can really see the difference from stock to upgrade in the following photo.
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I worked on things today, got the interior pulled out. Now I am the only one that I have seen that has done this conversion on a convertible. You can see in this photo that things are a little tight in the back seat with the top and roll over protection system. I will not be cutting a access panel like Fierofly did on his coupe.
I also do not have the room in the quarter panel areas that the coupes do, so I think the GM ECU will be mounted under the passenger seat.
In this photo you can see one of the Porsche computers is mounted under the drivers side seat.
I also do not have the room in the quarter panel areas that the coupes do, so I think the GM ECU will be mounted under the passenger seat.
In this photo you can see one of the Porsche computers is mounted under the drivers side seat.
#51
can't believe i missed this thread. going to be great. I too was fantasizing about a porsche swap and didn't know about the gearing issue. Sounds like you have good resources and will come up with some solution.
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Well, tomorrow will be the last day of my time off work. Monday, I will be back to working 60+ hours per week. I managed to get a few things done during the holidays. Got my block back from the machine shop, they got things up sized on the bore to 4.005". And my crank, pistons and rods are at another machine shop getting balanced. I managed to get my block cleaned up inside, it was really rough cast and needed some attention. I also took on the task of porting my stock LS2 intake, managed to get it looking pretty good. And I also started porting my "243" heads. Maybe next weekend I can get my long block stuck together. I did some major research on building my stand alone wiring harness for the LS2, converted to 58X with a E38 PCM. I will post up some pictures of the ported intake and heads tomorrow.
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It has been a little while since I last posted any progress. I have been working to much and studying for my Beer Judge Certification Program Exam. My other hobby is Home Brewing Beer!!! And it takes up a lot of my spare time, brewing for contests and other events. Well, I managed to get all my parts from the machine shop and have been working on porting my heads and intake. I have also been spending a lot of time researching and prepping to build my own standalone harness for my LS2. With this convertible 996 I do not have the room behind the seats for the ECM, that the coupe guys do. My harness is going to be close to 15 feet long. I plan on putting the ECM under the passenger seat. And I will be using the E38 ECM, beings I converted the LS2 over to 58X, from 24X. So the Porsche tack can direct read the signal.
So This evening I managed to get my Porsche Oil Pressure sender and Porsche Temp Sensor mounted. I looked through Fierofly's thread and pulled up that he used a M14X1.5 tap to tap his extra temp port in his LS head. So I drilled the existing hole with a 31/64" drill bit and taped it with a M14X1.5 tap. I decided to mount my Oil Pressure Sensor in a different location compared to a few of the other 996 build. So I picked up a billet aluminum oil block off plate and drilled and taped it with the 31/64 drill bit and M14X1.5 tap. As the Porsche Temp and Oil Sensors are the same size. The Photo below is the finished product.
So This evening I managed to get my Porsche Oil Pressure sender and Porsche Temp Sensor mounted. I looked through Fierofly's thread and pulled up that he used a M14X1.5 tap to tap his extra temp port in his LS head. So I drilled the existing hole with a 31/64" drill bit and taped it with a M14X1.5 tap. I decided to mount my Oil Pressure Sensor in a different location compared to a few of the other 996 build. So I picked up a billet aluminum oil block off plate and drilled and taped it with the 31/64 drill bit and M14X1.5 tap. As the Porsche Temp and Oil Sensors are the same size. The Photo below is the finished product.
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I will take my chances and use the GTO pan. It makes sense with the rear engine configuration. Oil pick up is in the rear of the car and the filter is easy to access. I have already planned the exhaust system out to work with this oil pan. And if it does not work, a few hundred dollars and I will change to a corvette oil pan.
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It has been awhile since I have updated things. Been too busy at work and studying for my Beer judge Certification Test. But I have been doing a little work. Planned out the fuel line plumbing and bought the parts, see photo below.
Plus I have been working on wiring up the Porsche sensors and re-plumbing the cooling system to fit the engine mount. See pics below.
I have removed all the stock wiring out of the engine compartment and have thinned it down to the sensor wires needed to runn the stock Porsche dash.
Removed all the Porsche wiring for O2, Hall Sensors, injectors, Cam Sensors, ect. Kept the Oil Pressure, Oil Temp & Level, Coolant Temp, Crank Sensor, Starter, Alt, AC, Hood Latch and engine compartment cooling fan.
I am having PSI build me a stand alone harness for the LS. I was planning on doing my own, but just do not have the time. At first I was looking at locating the ECM under the passenger seat. Beings The convert does not have the room that the coupes do. But after doing some measuring and talking with Renegade Hybrids, I have decided to located the ECM behind the roll over protection mounting bars. It is going to be a tight fit with the convert top folding down in that same area. Pretty much will be 20 pounds of **** in a 10 pound sack. My Beer Judge test is this weekend, so I should be able to get back working on things in the next few weeks!!!
Plus I have been working on wiring up the Porsche sensors and re-plumbing the cooling system to fit the engine mount. See pics below.
I have removed all the stock wiring out of the engine compartment and have thinned it down to the sensor wires needed to runn the stock Porsche dash.
Removed all the Porsche wiring for O2, Hall Sensors, injectors, Cam Sensors, ect. Kept the Oil Pressure, Oil Temp & Level, Coolant Temp, Crank Sensor, Starter, Alt, AC, Hood Latch and engine compartment cooling fan.
I am having PSI build me a stand alone harness for the LS. I was planning on doing my own, but just do not have the time. At first I was looking at locating the ECM under the passenger seat. Beings The convert does not have the room that the coupes do. But after doing some measuring and talking with Renegade Hybrids, I have decided to located the ECM behind the roll over protection mounting bars. It is going to be a tight fit with the convert top folding down in that same area. Pretty much will be 20 pounds of **** in a 10 pound sack. My Beer Judge test is this weekend, so I should be able to get back working on things in the next few weeks!!!
Last edited by 4LUX; 06-16-2015 at 02:52 PM.
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So I have been working on my wiring for the conversion. I have spent a few hours pouring through the Bentley wiring diagrams and think I have came up with an easy way to let the E38 GM ECM control the Porsche cooling fans with out completely re-wiring or adding any additional relay system on the standalone side. In the attached mark up I would cut the Fan 1 (-) and Fan 2 (-) from the Porsche DME and connect the E38 Fan 1 (-) and Fan 2 (-) to them. I will also add a GM pressure switch on the AC line, so the E38 can control the fans for the AC condenser cooling. Please make some comments, so I can see if I am headed in the right direction.
The following is what RH tells you to do to wire the Cooling Fans??? I really do not like some of the ways they are wiring things, with the splitting low and high fan control between the Porsche DME and GM ECM.
Radiator Fans- There are several options for controlling the Porsche radiator fans. The simplest option is to allow the Porsche computer to control the fans. While it is tempting, modern cars rely heavily on the cooling fans to maintain temperature, so you want the most reliable system possible. Given how upset the Porsche computer is that the engine has been removed etc, we would generally prefer not to rely on it for critical operations. Our preference is to allow the GM cooling fan relay to control the Porsche fans. The Porsche fan relays are setup to be controlled by a ground connection instead of a positive one. To control the fans the Porsche fan relay control wire needs to be independently controlled. There are two ways to create a “ground” based fan control signal. One option is to use the GM fan relay to trigger a 2nd relay which switches the output to ground instead of positive. The 2nd relay just connects the chassis ground to the output terminal when activated, so it becomes an on/off ground source commanded by the original GM relay. As an alternative, if you are up to it you can also rewire the GM fan relay base wiring to have the same effect. That would allow you to skip having the 2nd relay in the loop. Basically you go to the GM fan relay wiring and substitute a ground wire for the input power wire that feeds relay output. Then when activated it will connect the ground instead of the positive as it was originally. As far as how to connect them, we typically leave the low side of the fans connected to Porsche control, so they will turn on with a/c request etc. The triggers for the two Porsche high speed relays are buddied together, so we just take the newly established GM fan relay “ground” wire and connect it to command the two Porsche high speed fan relays. Relatively simple and effective.
The following is what RH tells you to do to wire the Cooling Fans??? I really do not like some of the ways they are wiring things, with the splitting low and high fan control between the Porsche DME and GM ECM.
Radiator Fans- There are several options for controlling the Porsche radiator fans. The simplest option is to allow the Porsche computer to control the fans. While it is tempting, modern cars rely heavily on the cooling fans to maintain temperature, so you want the most reliable system possible. Given how upset the Porsche computer is that the engine has been removed etc, we would generally prefer not to rely on it for critical operations. Our preference is to allow the GM cooling fan relay to control the Porsche fans. The Porsche fan relays are setup to be controlled by a ground connection instead of a positive one. To control the fans the Porsche fan relay control wire needs to be independently controlled. There are two ways to create a “ground” based fan control signal. One option is to use the GM fan relay to trigger a 2nd relay which switches the output to ground instead of positive. The 2nd relay just connects the chassis ground to the output terminal when activated, so it becomes an on/off ground source commanded by the original GM relay. As an alternative, if you are up to it you can also rewire the GM fan relay base wiring to have the same effect. That would allow you to skip having the 2nd relay in the loop. Basically you go to the GM fan relay wiring and substitute a ground wire for the input power wire that feeds relay output. Then when activated it will connect the ground instead of the positive as it was originally. As far as how to connect them, we typically leave the low side of the fans connected to Porsche control, so they will turn on with a/c request etc. The triggers for the two Porsche high speed relays are buddied together, so we just take the newly established GM fan relay “ground” wire and connect it to command the two Porsche high speed fan relays. Relatively simple and effective.
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The drawing I did is of the existing Porsche wiring set up. All I plan on doing is cutting the two (-) fan control wires from the Porsche DME and connecting them to the two (-) control wires from the GM ECM. I really do not see how a picture would help one to understand. The two Porsche fan control wires run from the DME to the relay/fuse box under the dash. I will cut them back by the DME, which is where the GM ECM will be mounted also. Pretty straight forward....