996 ls2 swap

I�m not the greatest with build threads so this will probably miss quite a bit, but here�s my attempt with stuffing an LS2 into a 99 996. Reason for doing the swap is 2 fold, reliability and power. Ever since I picked up this car in May of 2015, I�ve really enjoyed driving it but always hated that thought in the back of my mind that said �you�re on borrowed time.� I get that the general consensus here is that these motors are fairly stout if they are cared for (which mine was�very) but once you go out on the track, all bets are off. I have very little interest in potentially dumping 7-10K in replacing this lump of an engine, so I decided that if I could sell it for my asking price, I would swap in an LS based motor instead. As luck would have it, my m96 sold within 2 weeks and is currently powering a 996 in Canada. I figured that the sale of my engine would fund at least 80% of the parts needed to do the swap and I was pretty close. Labor excluded, I�m fairly even at the moment. Quick note for anyone looking to do this in the future with the Renegade Hybrids kit: if you have the means to fabricate your own engine plates, do that! The Kennedy adaptor that mates the engine/trans together is good quality (and one of the 2 kits ultimately available right now) so everyone seems to go that route. RH has a reputation for vague information (or at least that was my impression) and slippery time lines and so far that�s mostly true. I will say that they always pick up the phone and do their best to help so I cant really complain. water pump hits the engine mount plate bolts and needs to be spaced out 3/4" (so F body accessories are needed) The main thing I didn�t like about the RH engine plate (besides price) is how the water pump needs to be spaced and interference with the TB. I�m using an LS2 so we had to trim just a bit to get it to clear. Also, the bolt holes didn�t really line up so we had to enlarge those as well. Overall, bolting in the LS2 motor once the rear chassis gets notched out was pretty simple. There is tons of room in the engine bay with the LS motor so getting to each vital component will be much easier than the m96 ever was. I�m losing all Porsche wiring (wont be using Porsche gauges) so I wont be doing any of the tach, oil pressure or water temp integrations that I�ve seen other people do. The AIM dash will take care of all that. just a mock up with a spare boxster dash to see how it would look. Think I'll go back to the 996 dash. I ordered the kit on December 15th and got it in my hands February 13th. Drivetrain went in this weekend. Fuel lines are ran, water pipes need to be finished and wiring harness needs to be installed. assuming no major issues come up, should have this thing fired up and ready to run for my first event in april. Exhaust work looks to be the most complicated item on the list so far...

Looking forward to following this.

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Me too! Been awaiting updates from Hoovie on his but he hasn't done much with it maybe because of winter in Kansas. . Could you tell us how much you got for your M96 engine and how many miles were on it?

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I got 7K for the engine. I'd say it was fair considering the engine was rebuilt with new rod bearings, new AOS, freshly machined heads, new gaskets, new chain guides and new tensioners (along with a host of other things). It had 118K miles on it, but after the rebuild, it was fresh as can be without replacing pistons/rods.

Nice. Super nice. If there�s one thing I think would make a stock 996 perfect, it would be an LS2.

Is this a street build, track build, or both?

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both. street car at first. something that can be driven to the track if need be.

I bought my roller 2000c2 to put an ls motor in, but i fixed the motor for a couple hundred $. Im just gonna drive it for the summer and save some money. i dont think i can get near your money for mine used. It has almost 200k with a repaired oil pan but has a newish ln ims. My plan is a 8k rpm l33. Should be fairly easy to do with the right parts. Im hoping to keep some of the high reving charateristics of the porsche motors. Do u have any pics of the mounting plate by itself? I have a mill so i can probably figure it out with a decent pic. Also, why not go electric water pump and r u using an eletric ps pump?

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I'm not a big fan of electric water pumps for a few reasons. they are fine for street/drag strip but arent always the most capable for 20 min road course abuse. The typical electric pump is something like 20-30gpm (or less) while a mechanical pump goes to 70-80gpm at higher RPM. Also, the meziere pumps protrude even farther than the mechanical ones. I plan to use an MR-S electric steering pump with custom lines, but that'll be the last thing on the list.

That flywheel is hot **** (literally, I love it). As for the water pump, skip f-body and go LS3+ and use a 3/4" spacer. The pulley is MUCH smaller than the fbody so you don't have to cut so much out of the car.

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thats actually exactly what I did (based on your thread). I was just posting that since Renegade told me I could use the ls3 water pump without any interference and thats not even remotely true. I had to pull the waterpump off to try and get some better heater core fitting on there to clear the chassis.

Thx for the wp info. So does spacing the wp mess up the alignment with the rest of the pulleys or do the spacers put it in alignment and help clear the bolts because it looks like a different fastener would fix the interference issue. Also r u going to run an ac compressor?

seeing that crossbar get hacked just makes me nervous. Are you planning on adding any additional strengthening back on?

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it doesnt mess up alignment so much as it forces you to use F body accessories to push everything out 3/4". You wouldnt be able to use the ls3 water pump without spacers even if you used completely flat bolt heads. Without bolts, the WP still hits the crossmember on the engine. I will not be running AC initially, maybe later on, but I doubt it. we'll add something I'm sure, but to be honest, it really isnt as bad as it looks (strength wise). There are plenty of people who run it this way without any issues with 500+hp.

I like the concept, if you are not going back with a Porsche engine. The LS engines are powerful and relatively simplistic. The problem I have with the swap is the electricals. There is nothing even remotely close to a plug and play setup.

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in my experience, even when you get something thats "plug and play" it still requires work. I'll admit, adapting the porsche gauges didnt sound like fun (plus my cluster was on its way out) so I'm happy giving up the OBC functionality in exchange for an AIM dash. makes things much simpler. Other than gauges, there is really little complexity in wiring.

Please document here what parts from the various kits work as advertised and which don't. Are you running an external oil cooler? Looks like you have an AN fitting welded to the pan

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I'm only using 2 parts of the "kit" and both require close attention to work. The KEP flywheel/clutch/adaptor is a great piece but I would recommend getting the 996.2 "L" version of the pressure plate (specify that with RH and they'll know what you mean) and update your pivot ball/release fork to the 997 parts TSB (if you still have the 996.1 short pivot ball style). this way there wont be any confusion. there are 2 different stack height pressure plates and depending on what year trans you have will determine what RH sends you. Alternatively, you can just specify that you upgraded your clutch hardware on the bellhousing side to 997 and save yourself the heartache. the RH engine mount kit just needs to be drilled out a little to gain better alignment when bolting onto the head. Not a big deal. You can also dremel down certain parts if your TB hits the plate (mine did). this is not necessarily an issue for everyone. Other than that, its fairly good and works as intended or at least to keep the motor in. We'll see how it does under some abuse. I'm running an external oil cooler tilton pump with -8 lines running the length of the car. I was doing this with the m96 to cool the oil so I'm just tapping the oil pan and hooking up the lines. This was the best way I found to integrate an oil cooler for the M96, kept temps roughly 20-30* cooler on the track.

What's your plan for the AIM dash? Are you running a newer ECU and able to get everything off of the CAN or are you going to have to plumb in sensors everywhere?

Do u have a pic of the engine mounting plate off the ls motor. Maybe because i have not pulled a porsche motor i cant visualise how it bolts into the mounts. You r right about RH, they r very helpful on the phone but very secretive with their tech.

Does this help?

Yes it does, thx, just need to source those motor mounts.

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I'm using the e38 ecu so its compatible with CAN. I should be able to pull data from the ecu and run pressure/temp sensors separately. RH sells all their parts a la carte, I think I remember just the plate being something like $250. If my math is right, the difference between KEP clutch/adapter kit and the engine hardware from RH was something like $1200 or $1300 (which seems high for what you get)...but they are the only game in town for what they offer.

You Tube just a teaser of the first start up

Nice!

had some time to assist with the progress. Engine wiring harness is now complete and only missing a few finishing bits on the interior/chassis side. We moved on to the dash and made a little mount for it. Exhaust is being worked on and cooling system all wrapped up. With any luck, we should be able to bleed the system and start final trouble shooting within the weeks end.

Is the pully top left fixed or a tensioner pully? Progress looks good.

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its a tensioner pulley

It looks like the swap is in its final stages now. After some initial trouble with getting the engine running properly, we were able to sort some minor issues and get it to hold idle to bleed the coolant. For anyone new to the LS2/3 engine, the MAF sensors tend to be very sensitive to minor changes. When we first started the engine, there was horrible throttle lag, poor idle with misses constantly cutting the engine off after 5 minutes of warm up. Turns out the maf sensor doesn't particularly like having the intake boot loose on the throttle body. After tightening up the headers/ intake boot and securing the air cleaner, the engine ran significantly smoother and throttle response came back to normal. Who would have known. The whole swap was done over at a good friends shop in Carol Stream IL and he's put in some serious hours to get this thing running in such a short time. Most of those hours went into the exhaust. My biggest fear was for this thing to be deafeningly loud, but 2 vibrant resonators and a set of dynomax mufflers keeps the exhaust note very reasonable (at least at idle so far). Havent had a chance to drive it at all yet, but from the outside its already quieter than the M96 was with just an AP muffler. This is using 2.5" piping all the way from the header back. since I'm not running any factory Porsche gauges, I elected not to keep the Porsche ECU. Cant quite say if that made the wiring any easier, but it definitely made cutting wires a less stressful job. Here it is almost ready for interior panels to go back in. my beloved switches. I got a lot of slack for asking for these. manual rad fan switch, electric oil pump for front mounted oil cooler and power steering switch pie cuts. Lots of them. all the bends were too tight to get mandrel bends to line up so Adam spent centuries mocking up/welding this beauty. Worth it. still need some rubber hangers to avoid chassis smacking. my crown jewel. I initially thought the AIM dash would greatly simplify the wiring, but running 15 feet of CAN lines to the front from the engine bay took some doing (3 sets total). At the end, hooking up 5 wires total was pretty simple though After running the engine for 10 minutes we realized there was one small coolant leak coming from the steam vent to coolant overflow connection and once hard coolant line was slipping from its clamp. Otherwise, there were no additional leaks. I'll post the idle video here once its uploaded to youtube for anyone interested in hearing the exhaust. Thats all for now. Last on the docket is power steering. I have all the parts (I hope I have enough line), just need to run everything up front.

You Tube

Congrats - nice progress? Re: Carol Stream, IL, are you local to Chicagoland?

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I actually live in Lakeview, so really local.

Is there emissions inspection in that area? Assuming this is a street car, I’m curious about your plan to comply without the Porsche ECU. I don’t know the details of your state’s test, but several attempts in my state were abandoned after failing to make the car compliant. Not saying it’s impossible, just would like to hear the details of someone that has successfully accomplished it.

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good question. Most of IL is OB2 emissions plug in testing but some has no emissions at all. Right now, the car would fail due to mismatching vins and no mileage reading so the plan is to figure out how to register the car in a zero emissions county.

Most of the aftermarket ls harnesses have obd2 plugs built into them. U just have to extend them so u can mount it in the factory spot. On my friends ls miata he sent the computer out and they burned the cars vin into it. His car passes nc emisions and inspection. I can get the shop name if u need it. The guys tune also unfu*ked the crappy efi-live tune that original vendor put on it.

Jeeper- that’s good to hear. I would like to know more about the shop that made it possible, and where he sent the ECU. Thanks.

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interesting, but wouldnt it still show 2008 Corvette, or whatever car the e38 ECU came out of? I think in IL, it has to match year make and model along with the VIN. Still interested in pursuing this though...

http://www.team208motorsports.com/contact.html i guess call them and see what they can do.

We've been making some progress at the shop. Most of the loose ends have been tied up so car is now running and driving. Cooling system was surprisingly easy to bleed. On the street, I'm seeing temps between 176* and 185*. With the GM ecu controlling the fans, temps go from 194* (when the ecu turns them on) to 190 in a matter of seconds. I'm pretty happy with that. Right now, I have a front mounted oil cooler that sits in front of the driver radiator and it manages oil temp for street driving fairly well. Grant it, it was 45 degrees out so it didnt have a very difficult job. My guess, I'll have to add another cooler in order to properly regulate oil temps. But this will do for now. It's not all smooth sailing, however. We've been battling Map codes, bank1,2 rich codes and at least one trip to limp mode. We had to try 3 different map sensors before being able to drive for any extended period without low map sensor voltage codes (p0107), car still felt lively with plenty of power. Adam (shop owner) seems to think were out of the woods for the MAP issue, I however remain skeptical. Intake fabrication is also complete (a potential change may also be required in the future). IAT's seem to hover around 10* over ambient but once the car stops moving, those temps climb sky high. The rich codes will unfortunately require a tune. I'm lost when it comes to HP Tuners so I'll a local pro handle that part of it. Last piece that went on was power steering. I've read mixed reviews for how people like the car with manual vs assisted steering and let me tell you, power steering is infinitely better. We drove the car with unassisted steering all of saturday. While it felt ok/manageable (much lighter than a traditional 3000lbs car with a front engine), I definitely struggled negotiating tight turns at low speeds. Even at speed, you notice more bump steer and really have to have decent effort to control the car. The MR2 pump is perfect. The feel now is less then it was with the porsche mechanical pump, but in my opinion, its perfect. We wired the controls to a switch so power steering can be turned off at anytime. I've been taking my car to Adam at Midwest Auto for years. He's worked on every project I've ever had. To say he wasn't a fan of the 996 from the beginning is an understatement. We've talked about doing this swap since early 2015 and now, since he's had the chance to really understand the dynamics behind doing this sort of project, hes changed his view (perhaps more than somewhat). So much so, that the new shop project was delivered last week with a fresh ls3 instead of using the 110 degree elbow that places the intake right at the edge of the pumper/deck lid, we used this tight radius to offset the TB. just enough clearance to fit all the intake piping and keep things cool-ish steering pump mounted nice and low. I lost a little trunk space but gained functionality. I can live with that trade off. A dyno tune is scheduled for Thursday morning. We have roughly 30-40 miles on the set up now and nothing has broken yet so I'm somewhat confident the dyno will go smoothly. I'll report back with the conclusion.

Seems like it's getting pretty toasty just driving around town but looking forward to seeing how it cools on track. Thanks for the update keep em coming

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not at all actually, the 194 temp I was referring to was while sitting still. Thats the highest I've seen the temps climb. While cruising, it hovers between 176 and 182.

How is the balance of the car compared to having the Porsche engine in there?

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hard to answer that for now. Around town, no change. I have noticed that it lost some weight so it brakes better, but I havent thrown it around a corner yet so cant tell how it really behaves. I'll have it corner balanced before I take it to the track in a few weeks but I suspect a bit more understeer early corner entry and a bit more oversteer on throttle corner exit...just a guess for now.

I should add that the real winner for now is drive-ability. The M96 always had a smooth power delivery but was completely gutless under 4K RPM. Cruising around in low RPM's was somewhat of a chore. The Ls2 is just as smooth, if not even smoother and the power delivery makes this car do everything at an exponentially lower effort. 4th gear at 40mph, just tap the gas slightly and you're at 60. You have acceleration in any gear, no bogging, no more lugging the engine at 2000 RPM. it just pulls right through. This is obviously to be expected with an engine that produces 400ft/lbs but the feeling is something you have to experience to truly appreciate. I think this is the biggest reward for completing this swap. The car feels the same. The connection to the road is still porsche, but its just that much more alive now. Having driven a modified 996 turbo, I prefer this set up.

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No question that a 996.1 3.4 has to be rev�d to the max to be fast and it doesn�t have much of a torque feel. A 996.2 3.6 makes some noticeable improvement there. So I can imagine the LS is way better.

Careful, once you get spoiled by that big v8 flexibility nothing else will feel good enough.

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Thats for sure. Car made some impressive power putting down 370whp and 380tq. Only downside is something others have noted that completed the swap, not enough gearing. Really strange how the car used to struggle to accelerate in 5th and 6th gear before...now, I can keep it in 5th taking on ramps at 30mph and just cruise to 60-70mph without even thinking about it. I'll be taking a 600 mile road trip up to Ann Arbor this weekend so this will be the real test of reliability. So far, she hasnt given me any signs of struggle

I got so used to driving my V8s under 2k rpm (and having more than brisk accel even there) that 3k felt like straining. With stock gearing, even going to a larger OD tire in back you're going to want a 7th gear. I doubt it's worth the cost or effort to make another trans work or change out the gearing you'll just have to band-aid with tire OD and live with it.

There is a company that makes taller final drive ratios for the trans. Unfortunately I can't remember the name, but I think Renegade knows them.

Albins has a 3.00 ring and pinion -which is about right( stock is 3.42) .The gears are $ 2932.00 plus bearings and labor .Probably a $4,500 to 5,000 solution .I am leaning toward bigger tires .

I also remembered, Retro Sport is the Albins distributor in North America. Not an inexpensive solution, but what is for these cars! For a 'money no object' conversion: https://retro-sport.com/porsche-gear...6-ring-pinions

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Theres no way a final drive conversion is worth the effort. I'll eventually move on to a bigger tire, maybe 285/35, but that won't make much off a change. The highway RPM aren't great, but its doable and she still gets 21-24mpg so it is what it is. I've got about 400 miles on the swap at this point. My concerns for the warmer weather will be oil cooling. While the water cooling is more than sufficient, oil temps are slightly concerning. I don't know how guys run this without an oil cooler. I watched oil temps climb to 220F without the front cooler activated with 38F ambient outside and all this while moving 90mph. Once I have the oil cooler on, temps stabilize between 180-195F depending on RPM. My oil cooler gets great air flow but I'm concerned there just isn't enough surface area to manage the heat from the 6.0. I'll just have to add another cooler on the passenger side duct location.

I personally would want the oil temp up and over 212 degrees to boil out condensate. 220-240 would be right by me.. Cooling the oil does relieve the heat load on the water some, but get it up over 212 to over the milky mess.. Ken

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I agree with keeping the oil to around 220 F to 240 F .

So I'm finishing my 600+ miles trip from Ann Arbor, Michigan driving along 355 north, get off on North Ave and right before the toll (on the off ramp) I feel a violent shimmy in the steering wheel followed up by a loud clunk. I stop the car and check to see what I broke. Turns out, my road trip could have ended with a trip to the ER or even worse, morgue. The bolt from the Rennline bump steer kit, the one that uses a mono ball to replace the factory tie rod ball joint, snapped in half. The tie rod fell into the wheel and I lost all steering. Lucky for me this happened at 10-15mph and not 85mph that I was doing moments earlier. This happened after driving 285 miles for the day. I got a 7 mile tow to my shop. I must have used up all my luck last night. Still dont know if the knuckle took any damage, doesnt look like the wheel suffered at all but we'll see once its all off.

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WOW!!! could have been catastrophic for sure Glad it wasn't! How'd the car feel/perform otherwise? From the sound of it, everything was good - until it wasn't...

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yeah, that could have been the shortest lived swapped car ever. Other than this horrific experience, the car drove flawlessly (engine wise). not a single hick up the whole trip.

Dang. Glad it was painless and didn�t cause any damage.

That is downright scary ! Glad the outcome was just a tow .Rennline needs to do a root cause analysis on why it broke .

Congrats on getting this on the road!!!! I really like the throttle body relocation. I ran 18" 996 turbo (wb) wheels and tires. The gearing was still a little high, but nothing ridiculous for the LS and fuel mileage at highway speeds.

Something had to put it in a bind to cause that. I believe those are the black ones that they source through ERP. Were all of your bolts torqued and painted?

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Are you talking about the bolt itself? I�m no Bolt expert, but whenever I see a shiny bolt, think �cheap.� Any way to determine what the quality/grade is?

Just got a chance to look. Those aren’t the ERP. Not sure on them.

so found the cause of the broken bolt. looks like the insert piece to the knuckle (the ones that press on to the bottom and stay with the kuckle) were not used when these tie rods were installed. I looked at my old factory tie rods, the ones that came off the car, and noticed these pieces were still on the tie rods. I'm gonna try to find an image of the pieces I'm referring to since I'm not sure that my explanation is clear enough. What is clear is that this was not Rennline's fault. Tom from Rennline was very helpful and courteous. For anyone looking to install a bump steer kit, make sure to leave the factory spacer looking things on the knuckle, if they come out with the tie rod, make sure to remove them and place them back on the bottom of the knuckle...

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Thank man, your original thread was a huge help/inspiration for this

Great info. That makes perfect sense. I just bought 4 of those cones to go with a used set of front and rear bumpsteer's I sold. FYI, a ~6mm punch works great for getting those cones out. Not sure why the smaller size punches don't work as well but the larger ones make it really easy.

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curious where you bought those separately, link?

I had a chance recently to put the car on scales. Total weight was 3050 without me in it (full tank of gas). For reference, it was 3130 on these same scales with the m96 last I had it corner balanced. The weight distribution is way off now, something like 40-60 front to back and cross weight is 44% (which is fairly bad). I'm debating if I wanna upgrade the shocks prior to full corner balancing again. No track time yet, but I can comment on its overall handling characteristics somewhat: a bit more understeer and slightly more twichy now. I can feel the higher CG in the rear while on an on-ramp at 70mph (interstate on ramp) where as before it would feel a bit more planted. The front still has a somewhat floating feel which is exaggerated when under full throttle. Traction is amazing however!

So overall the car is 80 lbs lighter, but the weight distribution is more biased toward the rear. From your description, engine cg is further back and higher in the chassis. Is my understanding correct? Maybe the car would benefit from adding some weight in the frunk??

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that pretty much sums it up. I may be incorrect with my facts, but I remember reading that the 991 received some improved handling characteristics from moving the engine toward the front 1" (from the 997). If this is indeed true, it would make sense how moving the engine 2" back and CG up would create handful. Can't imagine its anything a good corner balance cant solve...

have you relocated the battery or anything else yet? looking forward to seeing how it survives on track

so figured I'd do an update. Been driving the car since early April without a single issue (besides the little tie rod incident). Just got back from a 1500 mile trip from Chicago to KY, TN, SC and back (through the smokey mountains). Car performed flawlessly. Sadly, havent had any time to take it on the track, but after driving it through 110* heat in Louisville on the 4th, I dont think I'll run into any issues. Something else to note, I've been tracking gas mileage (as miles driven is my only way to tell how much fuel I have left). Average hwy mpg has come out to 24mpg. City driving obviously brings that figure into the low teens at times, but consistent 90mph cruise can net 22-24mpg. I'm happy with that.

Good to hear. So it�s just like any other 996 except it has more power? Like a 996tt but no lag and more power?

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lol in a nutshell, yeah. behaves just like a regular 996 but has enough power to do anything you want. No strange noises, no worries

Aw heck, wish I woulda known you were passing through- I just did the Tail Of The Dragon a few weeks ago and was seriously contemplating a trip back over the long weekend. Do me keep posted if you plan a return visit as I�d love to check this thing out. And thanks for keeping this thread updated as it further documents one option for anyone that experiences an M96 failure.