Lsx Rubi

I would eliminate the X pipe in the exhaust it'll give a smoother more exotic sounding exhaust note .

gtxracer

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Thank you! I will take videos for sure.

Thanks! I have since taken it out after finding this out from research - I appreciate the input!

gtxracer

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180 degree headers are nearly finished with design, waiting for quotes and doing a few more checks with the actual car and LS1 to ensure fitment. Under-pan tube connection will either be a flange or a spring retainer setup. Leaning toward spring retainers for space limitations and easy of removal.

gtxracer

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The last update on had on the car itself involved mounting the water pump. To finish it out, I mounted a 20AN swivel for the water neck and converted both heater hoses to 12AN for simplicity. Some people cap these and route lines over the 996 coolant tubes but I am not a fan of that method. To each his own.

I also removed the stamped tube with a couple smacks with a deadblow and pressed in a 20AN male piece from CBM Motorsports. Very nice piece, as is the 20AN swivel (amazon special). In the pics, the 20AN CBM piece is not pressed in yet, I had to take .010" off the diameter and I also used 609 Loctite meant for press fits for a good final seal and peace of mind. I also used ARP hardware as the pump has to come off any time the engine needs dropped since the motor mount plates attach to the heads and the WP is in the way of two bolts.

I also took a M16 to 1/8 NPT adapter and drilled and tapped the NPT side to M14 for the sensors. I believe the pitch is 1.5, but I can't recall exactly. I used the port on the side of the water pump for this adapter. This is for the Porsche coolant sensor. I retained all Porsche sensors and all GM sensors and will run both redundantly. I am still working on the 996 oil level/temp sensor, that's the last one to be used. I believe I can swap out the looooong 996 dual use temp/level sensor for the same sensor used on the coolant as the plugs are the same.

All the AN fittings are not necessary if you want more of a budget coolant setup. I just don't like spring clamps and some of the other methods. It's all preference.

Some pics of the water pump:









The heater hoses attach underneath the car to these 7/8" lines. More on how I'm converting these later, I am still getting those fittings made. They're designed and ready for lathe work but I haven't gotten to it yet.



Left side coolant line, or driver's side and where I cut it for the AN20 fitting (orange mark)


Right side or driver's side cut mark, just before it bent. I am using a 45 degree fitting on this side so I wanted it tight to the body. Again, this is preference, and a simple bead roller and some typical coolant hoses could be made to work here - but will look gross to me! Haha Again, preference.



Every single line has a redundancy of clamps holding them in place under the car. Never seen so many line clamps but they are very well done. I yanked the lines out and cut them. I am hoping to weld them this week so I can finish out the last part of the build!

The pup wouldn't move so here's my GSD in all her glory. Love this dog!

gtxracer

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The LS1 still need the LS6 PCV update. This is about $100 and well worth it. Much better system, especially with aftermarket valve covers. I still need a catch can but overall this is much better. In order to convert an early LS1, you have to knock down one of the bosses inside the valley.

I had to mask the entire valley and it took a while. This mostly worked! haha







Done. LS6 PCV on an early LS1.



Unfortunately, this also meant the LS1 steam port lines would not work now. They were already smashed slightly with the Fast 92 intake. So, more AN lines! I bought this kit off eBay specifically for the Fast intakes and it worked well. I think the accessories on my LS1 are worth more than the LS1 itself...

Link: https://www.ebay.com/itm/FAST-102-92...K/132107718315

In these pics you'll also see I made some aluminum fuel rail brackets to hold the LS3 injectors to the Holley rail and Fast intake. These did not exist until I designed them and it was a pain to make it work. Holley claimed the brackets were LS3 to Fast compatible but that is not true at all. Oh well.

You'll also see the Holley Terminator X fuel injector harness since I started wiring. I also final plumbed the rest of the fuel system on the engine with the crossover tubes, fuel pressure gauge, and some other goodies. I am using a Lokar LS1 bracket and cable, more on that later. I used all new hardware too since I was missing bolts.

gtxracer

iTrader: (1)

I mounted a short version of the LS oil pressure sensor to a tower I got off ebay. The sensor is part number 12616646 and has the same M16x1.5 thread as the tall unit. The 996 sensor is M14x1.5 so I had to drill and tap in the side of the tower.

Tower link: https://www.ebay.com/itm/29336551218...m=293365512189

Sensor Link:


Onto the Tiptronic to manual conversion...

Here's the fittings I designed to convert the entire system to 3AN. I still need to make 2 more fittings, but they're in the hopper now for lathe work. I'm using 3AN braided PTFE line from Pegasus.

Clutch master to 3AN:



I grabbed a used brake master cylinder from a 6MT car off ebay for $30 and yanked off the reservoir. Did the same to the master cylinder that was still in the car after sucking out the brake fluid to avoid a mess. The difference in reservoirs is the 6MT has this port drilled with a push to connect fitting for 8mm (or 5/16") push-in style plastic line. I bought the line off ebay for cheap and designed a new version with 3AN on the side. I'll take more pics of these fittings later on.



Added the clutch pedal. This was kind of a pain in the ***. You do NOT need to take the dash apart, don't let the Porsche gurus lie to you! hah!

There's a bolt that holds in the brake pedal. You'll need to remove the 10mm nut on one side and then turn the head head of the bolt CCW because there are threads right after the hex head that hold in the other side of the assembly. No idea why they did this but it's suuuuuper fun laying upside down for a while to do this. Everything bolts up easily. You'll need M6 bolts for the master cylinder to mount (2 at 40mm long) and some M6 nuts (4 with flange) for the pedal to finish mounting. I bought the pedal off ebay for pretty cheap with the master attached.





Next is the fuel system. No matter what 996 you have, you'll want to read this page and the DIY no cutting required FAQ listed there:

https://stuttgartmuscle.com/pages/fuel-system

Since mine is a return style, I followed this guide (listed in above link):
https://cdn.shopify.com/s/files/1/00...999-2001.pdf?1

996 fuel filter vs Corvette filter and regulator combo.



Sorry for the picture quality, I have about 14" to work with including my body under the car and it's a challenge to get a good pic of this whole setup. Easy to do though! Man, I need a lift....

Corvette regulator/filter takes place of the 996 filter

gtxracer

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As for the throttle pedal, since I'm DBC I'm reusing the 996 pedal BUT I'm not using this funky cantilever deal for the actual cable that runs to the throttle body. There's a TPS sensor that runs off another cable so that must stay. I believe it also helps run the cruise control, so I'll want that.



I'm using the Lokar LS1 throttle cable mount and 120" throttle cable. Links below-

This cable kit is for a Ford, you just take off the carb linkage and add a cable end. Easy.

Brackets for intake:

I'm mounting the clevis end to the 996 pedal using a single shear bolt that I'll likely epoxy into place. More info on this when I finalize it, but that's the plan. Orange mark is where the bolt should be. The throw on the 92mm DBC throttle body is about 1.8" so the travel at the pedal needs to be between 1.8 and 2.0 inches BUT I want it to bottom out at the same time I reach WOT to make sure I am not putting the cable into too much tension.



I'm shoving both the braided clutch line and throttle cable through the same pass-through hole as the transaxle shift cable and e-brake cable. It's getting crowded but I have a plan to make it all fit nice and snug.



I believe this gets the thread up to date - hoping to have another next weekend. Thanks to all that watch the progress!

gtxracer

iTrader: (1)

Finally more updates. Been very busy but can focus on the 996 again now.

Welded the coolant tubes to the 20an bungs. I haven't welded aluminum in a couple years so I used the TIG at work. Ugly, but sealed and good to go.



I mentioned swapping the brake master cylinder reservoir and this fitting is the key. Instead of using a separate reservoir, I wanted to tie into the factory Porsche reservoir and share the fluid. It's a push to connect type fitting, 8mm diameter and .800" long IIRC. I designed this 3AN conversion fitting and asked one of my guys to turn it on the lathe. They take only about 90 min to make one and I take....not 90 minutes. Maybe 9 hours? Hah!

17-4 SS and worked beautifully



Plumbed with SS braided PTFE hose and fittings from Pegasus Racing. Also used a bulkhead fitting to pass it through the firewall. I'll grab more pics of all the clutch work but essentially the clutch master is remote from the reservoir and is mounted with the fluid input exposed through the second firewall where the pedals are mounted.



This is another fitting from Pegasus Racing. It's designed for the fuel systems and brake systems but it's the same flare as the other systems. I had to ask one of my machinists to turn back the hex because it wouldn't seat the flare in stock length. M12x1.0 thread for this, into the factory 996 clutch slave cylinder.

Link to fitting: https://www.pegasusautoracing.com/pr...asp?RecID=5935



The plan for the throttle cable...this is nearly complete. I drilled, tapped, and epoxied this 10-32 1.5" long set screw into the pedal for a single shear mount. More on this later when I wrap it up.



Last, but most importantly, I mounted the LS1 for the first time in the 996. Big milestone considering all the work that had to be done just to get it here. Converting the car to 6MT was the hardest part to figure out but I believe we're there. I'm sure I'll be chasing a few of the Porsche chimes and electrical errors for a little while but I can start driving it as soon as I route a few more lines and get the electrics configured. I need to finish up a few details with the fuel lines, final cut the clutch line length, route all of these lines to their final placement in the engine bay, then drop the motor and send off a few of these aluminum pieces to anodizing while I cut back a few more pieces of body panels. Right now, the water pump just barely won't squeeze in there. I also need to drop the pan, install the ICT double bolt oil pickup clamp, and inspect the bottom end one last time. I am also hoping to order the exhaust headers in the next two weeks once I design the 996 engine bay in CAD and verify all the fitment. I'll also design the muffler hangers and finish the remaining exhaust components very soon too.

Quick note: The FAST 92 intake tilts UP more than a LS6 or other GM intake. Therefore I have to cut into the trunk/spoiler. The actuated wing will be disabled until I can figure out another method to mount the motor and lines.

Anyway, the LS1 is mounted!





Close fitment, the OEM crossmember will go right behind the adapter...

gtxracer

iTrader: (1)

Whew. Been plowing through the little stuff on the 996 LS1 swap. Had to drop the engine and route all the wiring, clean up some little stuff, and adapt the Porsche vacuum and vent lines to barbs. It takes a while to get all that wrapped up but the end product is well worth it. I don't want to worry about lines coming off during a track day or autocross event after I get everything tidied up.


Conversion fittings, ¾ to 7/8 and ¾ to ¾; a few other brass fittings for vent lines and vacuum:


Hot tip – buy the 7/8 180 degree silicone hose adapter, cut the ends off, and use the ends for your 7/8 to ¾ conversion. Of course, you’ll have to find the barbed reducers that don’t exist for some reason….which is why I had to make them! The heater lines on the Porsche are over .800, these 7/8 silicone tubes slip over due to the size differences. Clamp over the hard lines, push in adapters, run your lines to the water pump, done.


Had to swap the straight 12an fitting for a 45 and also swap the straight 10an to NPT for a 45. Everything clears and runs perfectly through the engine bay now.


Also mounted the remote oil filter and lines, tucked up tight to the body next to the alternator. Temporary filter since I’ll run some cheap synthetic oil and filter for the first 500 miles then swap to Amsoil.



I still have the Fast 92 on there, it was confirmed the black and gray are the same but the 102 is a bit longer and will never fit. I am going to have to get a bit more creative to make this 92 fit. It's staying!

Chop chop. Someone's crying as they're seeing this...



Had to cut out more trunk for ease of working on the new powerplant. Much better. I’ll move the latch to a better position too.


A lot more updates coming...

gtxracer

iTrader: (1)

I had to figure out the wiring for the NSS bypass or Park Switch. The Tiptronic switch was in good shape so I yanked it off the Tip for a quick diagnostic and found the last two pins in the top row can be jumped to simulate "in park" so there's a super fancy paperclip jumping the connector under the car right now. If anyone needs a picture of this, let me know.

As for the rest of the wiring, I have the original M96 engine wiring harness. I kept this as some of the wires were cut/broken/rough and it needed to be replaced for the most part. I thinned out the harness (cue more crying) and wrapped and finished it to make it look as factory as possible. It matches the Holley Terminator X harness so everything looks great! I have to extend a few sensor wires and the starter wiring for final fitment but otherwise it's a great way to clean up the engine bay and keep it looking OEM.

Mess


Finished product


I also made a nice little bracket to repurpose the positive terminal lug for the engine bay from the original Porsche harness. It’s a high quality piece so I wanted to put it back in. I mounted it upside down to keep it out of the way of dipstick.

Bracket holding said terminal:


Hard to see, but it mounts under the coil pack. It can also mount over it.


FYI, if you use a Terminator X, you will love it AND you'll need to buy an 4 pin alternator wiring harness to excite the alternator. This should plug into the power plug on the Terminator X harness, IIRC. Here's a link:
https://www.holley.com/products/acce.../parts/197-400

The Terminator X was very easy to setup. I'm a little bummed I can't see the GM oil pressure sensor but perhaps I'm not seeing it in the software yet. Maybe I can see it on my laptop, we'll see. It's a breeze to get it going though and I am happy to ditch the Porsche Tiptronic DME. I am going to keep the Porsche M96 DME as I believe it runs the ABS system and also runs a few systems through it such as the starter. I'm sure I could bypass it but won't until I know what systems are totally affected.

gtxracer

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The 180 degree headers have been ordered. I should see the first set in about 3 weeks. I threw on the bumper to measure for exhaust outlets, muffler placement, etc.. I think the Spintech mufflers should sound pretty good!

Maybe I should paint or coat the pan after all…


I threw in a new AGM Oreilly's battery and it CRANKS! No fuel pressure but it turns over great. I need to verify a few things, such as oil pressure and fuel pump operation before firing. I have some freebie LS truck exhaust manifolds on there for now.

Nearing the end of the electric steering conversion. I used RSR fittings since I didn't have time to make my own. They're a nice set for only $90. I also bought new Porsche O-rings made from organic unicorn toenails for too much money. I'm using PTFE 6AN lines and fittings (5/16 ID) for pressure with 6AN rubber hoses for return (3/8 ID). I have bought some nice bulkhead fittings and will run the lines near the brake master and pass through the firewall. Easy peezy.

Placement of the new pump. Way too tall. Bracket not really usable. I don’t want to drill down into the area it’s sitting on, that’s the fuel tank. More on how I mount this later on!



New bracket I drew up:


Cut on the Langmuir baby plasma cnc and bent:


I drew up this bracket. It needs a couple tweaks but came out great for a first draft. These TRW pumps are from a Vauxhall Astra and is the same pump as the Porsche GT3 cup pumps....but costs 1/10 of the price. As soon as I feel like sitting on my side for another 3 hours putting in the bolt on the rack that holds the fittings, I'll have this wrapped up.

Mega extension to reach said bolt, which stripped, but I got it out:


RSR Fittings and new SS bolt: Rebel S Racing (RSR) Steering Rack Fittings for elec. Pump – John James Racing


To do list is much shorter now:
Find lack of fuel pressure culprit and fix
Shift cables were wrong end type for transaxle end; too large, need earlier smaller versions or convert to heims
Fill and bleed coolant
Fill and bleed brakes
Bleed clutch
Tweak throttle cable; Only opens 75%
Mount Terminator ECU
Run Terminator lines permanently and route through interior
Reassemble interior
Tweak clutch pedal; it’s slightly out of position
Fab intake tube and tap for MAT sensor
Fab/buy PCV catch can
Hookup Porsche oil pressure sensor; extend wiring harness
Extend starter wire
Rework starter to alternator positive cable; route in cleaner fashion
Add 1 more block to chassis ground
Clean up wiring routes through car
Reassemble rest of the rear end of the car; crossmembers, sway bar, bumper, etc.
Final cut/fit of engine lid area
Test Drive!

gtxracer

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Forgot to update this. Been a while!

Car starts and runs. Have to jump the fuel pump relay to get the pump to operate. Holds 58psi no problem. I need to find the correct wire in the loom to supply with 12v switched for relay to click over with the key. I have the starter wire ran and everything works as it should. Had to hookup a Holley 5v alternator trigger wire to the GM alt so it would charge the battery. New AGM battery from Oreilly's has been awesome for sitting then starting suddenly after weeks.

COVID shut down most of the midwest so the shop that was building the headers took a hit and had to close its doors for a while. They started cutting and bending tube this week so I should see the first set of headers in a couple weeks at most. I'm beyond stoked because I didn't think it would happen during this crazy pandemic nonsense where we think small business will survive 4 months of quarantine.

I will NOT be using SpinTech mufflers. I stumbled across an outdated webpage called Dr. Gas. The mufflers looked very similar to SpinTech but have some differences. I call them up and speak to the owner and original designer of the "Boom Tubes" and the SpinTech design. Evidently, he came up with that design and SpinTech and NASCAR ripped it off after the intellectual property rights expired, which I believe is 5 years. He now has a new shop setup in Utah and I'll be sourcing my mufflers through him. They should sound amazing and give the perfect tone. They're essentially built for this type of exhaust and scavenging specifically.

I had to redesign the exhaust headers a few times to meet all the bend criteria and fitment requirements. The exhaust now has expanded joints underneath that are offset so the headers are now a left and a right side. At this time, not using springs or other means to hold the halves together but that may change after the first prototype. I have a few people that will be running this exhaust in the 996 or 997 LS swap so I will have the headers, mufflers, and even clamps and mounts designed and ready for a bolt in LS swap exhaust system for Porsche 996 and 997 cars. Pretty neat.

Anyway, that's what I'm waiting on. I made a booty fab exhaust but refuse to drive it. It's annoyingly loud. I still need to bleed the clutch system and figure out why my clutch pedal spring seems to be backwards. I also need to bleed the cooling system. The electric steering is pretty much set up and ready for final painting, wiring, and final tightening and bleeding. It's basically there, just needs a little more finishing, but I'm waiting for the exhaust and I need to finish the backhalf of my TJ before continuing.

Smoked myself out of the garage upon startup but it was a fantastic feeling-

gtxracer

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Sorry for the delays, I've been swamped. First set of headers are bent and tacked up. This set is going to the east coast for fitment on a few 997s and a 996.2. The second set will go to me to fit to my 996.1 and verify fitment before we produce the other sets. I've ordered my Dr. Gas mufflers and will be getting the 180 degree bends and turndown tips soon.



Anyone have a good source for stainless steel turndowns?

gtxracer

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Here's a few more shots. I should have the next set in my hands in a week or two and can finish it up completely for sound clips and test drive.























Check out Chavis Performance and Engineering, he's swapped over a dozen of the 996 and 997 cars including the world's first 997.2. He offers plug and play CANBUS harnesses and is the cleanest install I've seen. These are his motor mounts, very well done.

gtxracer

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Here's a video of the headers in a LS7 swapped 997 belonging to TJ Kenny:

G Atsma

That is one hairy sounding Porsche! That exhaust note totally disguises, to the unknowing, the type of power motivating that beast!

merim123

iTrader: (11)

Saw your headers in the fB Porsche swap page. Great design!

gtxracer

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Thank you He loves that car, I believe someone bought it right after these videos were taken I'm super happy with the exhaust note, hopefully mine is similar with the mufflers I've chosen (Dr. Gas).

Thank you very much

gtxracer

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I finally drove my LS1 swapped 996 for the first time. My alternator isn't charging, I think it took a dive after the first few startups. After I replace that and do some finish work, it'll be ready for it's first long drive to start racking up 500 miles to break in the clutch. After that and an oil change, it will be time to really start tuning this little LS1 and finish up the intake ducting, sensor placement, dash light and gauge fine tuning, and start some body and interior work. Of course, I'll put up a ton of videos for the exhaust sounds

A buddy of mine that LSx swaps 911s regularly, Tyler at Chavis Performance and Engineering, took these pics of my headers installed on a LS3. Enjoy!

SwapStang

This is a swap I've been looking into for a LONG time now. Really want a unique platform and making the enthusiasts upset would be well worth it. How are you finding the gear ratios for the LS1 motor? Are they pretty decent? I did some quick math and on a stock 996.1 I thought 6th gear would be aroud 2700-2800 ish at 70mph. That sound about right? I have to admit that's about the only thing really making me hesitate on this right now. It's winter in New England and I've found 2 of these at a pretty good deal. Both 996.1 one is a C4 one is RWD. If you could weigh in on either of those choices I'd appreciate that too. I hear a lot of people ditch the front axle anyways. Thanks and the car looks awesome!