V8 Conversion
 

Hey guys, I'm just starting to work on a Boxster V8 conversion and I thought I'd share my build with you. My name is Vlad, and I'm a 27 year old Mechanical EIT from Toronto, Canada. This is my first Porsche and first car build, so please bear with me. If this is something you are interested, please also check out BoxsterLS376's build. His thread has been an amazing resource, and it's one of the reasons I started my project. Hopefully I will have some unique content to offer, as I am doing this on a budget. I'm currently unemployed, so every penny counts here.

PS you can also follow this buil on my blog at rollingshell.com or instagram at PorscheLSX

http://rollingshell.com/wp-content/u...91-600x399.jpg

Hi Vlad
Looking forward to learning more about your build! Thanks for the shout out :) Care to lay out the basic details of the build for us?
Good luck!
J
"BoxsterLS376"

Hey, pretty much the plan is to get an L33 truck engine in there. I will have to buy a whole bunch of car parts to make it fit first. The car that I bought was pretty gutted, so there will also be a lot of work on that end as well. Most of the interior is missing and half of the wiring has been cut. I will do my best to bring this car to street legal condition, but it will probably end up looking like more of a track car. I wil post a whole bunch of content sometime this week so you guys can see exactly what I'm working with.

PS I forgot to mention in the intro, the car is a 2000 Boxster S roller

The first thing that I bought was an engine. Jalopnik had a gret guide on how to build an LS engine on a budget, so I decided to go that route. I first picked up an LM4 aluminum block from a 2004 Envoy XL. The guy at the scrap yard said that it was tested and had great compression, so I couldn't pass it up for the price.

http://rollingshell.com/wp-content/u...17-600x450.jpg

I spent the following week tearing it apart and cleaning. The engine looked good, but it did have some rust. I managed to snap a couple of exhaust manifold bolts which was a major pain (you can see more pics on the blog)

http://rollingshell.com/wp-content/u...23-600x450.jpg

I got a whole bunch of NPT fittings from my dad and put together a leakdown tester to see how good the engine internals were. To my surprise it pretty much had 0 compression. You could hear the air rushing out pretty much everywhere. At this point I decided to take off the heads and clean up the valves to see if that would solve the problem.

http://i.imgur.com/2WNAC1B.jpg?1

http://i.imgur.com/yMkyF1D.jpg?2

At this point I'm really considering abandoning the drive by wire setup and going with a throttle cable. Staff at Renegade told me that its easier to use DBW since you just plug in some wires, but it doesn't seem to be the case. Most people use LS3 crate engines for their swap with respective throttle bodies, ECUs, and harnesses. In my case I got a truck engine which I'm trying to convert to a car engine. This pretty much leaves me with one option: an overpriced C5 Corvette TB, harness, ECU, TAC module and pedal, unless I want to make some Frankenstein setup of mixed parts. Personally I don't have enough experience with wiring to do that, and even the tuning guys told me to go with cable throttle. I guess I'll sleep on it tonight and see how I feel tomorrow morning. Meanwhile does anyone have any pictures of how the old Boxsters had the cable throttle routed?

Maybe try ********************************************.com

Yeah I was actually on it today, for some reason they omit a few throttle parts in their diagram, but I awas able to figure it out with a little bit of google searching

I took the heads apart and as expected the valve faces and seats were pretty gunked up and pitted, not to mention all the crap and leaves that were in the cylinders. Since I didn’t have money to get the valves recut, I decided to lap them. Most people are against this, but this is a budget build, so screw it. I used a hand drill and a little piece of air hose to do the job. Again, most people advise against this, but there was way too much pitting to do it by hand.

Here are some pictures of my car. It took me a while to find a good one actually. I posted several wanted posts on Kijiji, and signed up for notifications on eBay and every major city on Craigslist. A few things came up here and there in the States, but nothing really worth the drive and hassle of importing it to Canada. After a couple of months of searching I found this best. I actually bought it from one of the guys on this forum. Had to drive to Ottawa to pick it up, but it was worth it. It looks pretty bare in the pics, but thats actually how I wanted it. I'm pretty much trying to make a street legal track car.

Looks good man - keep up the good work!

Are you keeping the interior stripped? My vote is yes, but it's your car. It looks like you're missing everything but the dash anyway.

Well, I haven't bought any interior bits from you yet ;) .Yes I plan on keeping it mostly stripped. I'm making RS style door cards, and some sort of custom aluminum floor panels.

I did another leak-down test after lapping the valves. This time the results were better, but pretty inconsistent. The leakage numbers were between 5 and 25%, and you could clearly hear the air escaping past the piston rings. I decided that continuing forward would cost me much more than what I paid for the engine, so it went back to the scrap yard for a refund.

For the next engine I spent a little more and got an L33 aluminum block. These came with 799 heads, which are pretty much the same as the ones that came on LS6 Corvette engine, minus the sodium filled valves. It was a little overpriced at $1200 CAD, but I couldnt afford to sit around waiting for a good deal. The engine looked pretty clean, and only had 80,000 miles.

My buddy purchased a soda blaster for his business, which came very handy for cleaning the engine. Definetely not a fun process, but it's worth it. If you are planning on doing this, make sure you do in in a ventilated booth or outside. Lab goggles are also a must!

Before:

After:

Blasted engine block:

A bunch of parts I purchased from itsnotanova. Have to make this thing street legal.

I had a little downtime waiting on parts, so I made these RS style door cards. You can see more pics of the process on the blog.

Hey guys! Not much to update this week as I’m pretty much waiting on 90% of the parts to finish this build. I’m getting everything shipped to the same location in Buffalo to save on border fees. Once my engine mount kit is here, the build should really pick up.

Here are some pictures of my electric power steering conversion. There is no room in the engine bay to run a belt pump, so this conversion is a must! I am using a Vauxhal Astra power steering pump that I purchased from UK. I believe this is the same model pump as Porsche uses in their GT3 cars. The pump itself was pretty cheap, but it’s the shipping that killed me. The pump fits perfectly in the front trunk, on the opposite side of the brake master cylinder. This is a good location, since it won’t take up your trunk space, and its excellent for wiring.

Things you will need:

• Vauxhall power steering pump. MR2 pump is also a popular choice.
• 8 gauge wire. Not too much, about 2-3 feet, depending on how much cable came with your pump.
• 2 x 8 gauge lugs to hook up the pump to ground and battery
• 16 gauge wire. Buy a decent amount. This wire will be used to run the ignition signal to the pump.
• -6 AN power steering hose. I used Russell 632620. Either way you go, make sure to get high pressure rated power steering hose. The power steering system pressure goes as high as 2500 psi.
• -6 AN Fittings. Russell 620421, 620401, and 648060. The first two are for steering rack side, and the third one is for pump outlet.
• Custom Porsche steering rack to -6 AN fittings. I’m still not sure what to do about this one. GSR offers a set, but they are way too expensive. I might source a manufacturer in China and make a whole bunch if there’s interest. I also made drawings for these if anyone needs them. Just email me!
• Grommets for the power steering hose holes
• 80A circuit breaker
• Basic crimper or solder
• Custom pump bracket

-The 8 gauge wires will go directly to the battery and ground. Put the 80A circuit breaker on the power wire.

-There are three other small wires, but I don’t think the brown/white one is used for anything. You need +12 in the other two wires in order for the pump to run. The best way to do this is to wire the black one to the ignition wire, and the blue/white one the alternator dash light. This will ensure that the pump is on only when the alternator is running. You can also wire one of these to a switch, should you need to turn off your power steering. I used a relay in my setup just to keep the power steering pump separate from the rest of the car wiring.

-You will need to figure out a way to hook up the -6 AN return line to the power steering pump. The easiest way to do this is to cut the stainless housing and stretch out the core until it slides over, and then use a hose clamp. This is a low pressure return, so it shouldn’t be a problem.
-You will need a custom mounting bracket for the pump. I just got nylon working on my 3D printer, so hopefully I can make something with that.

You can see more pictures here. They are not great, but I will update them once the pump pump is in.

I love your door panels!

Thanks! Trying to keep the interior as clean as possible. Now only if Rennline would throw me a bone and hook me up with their floor boards, that would be epic haha

Just got off the phone with Renegade, and I got some bad news. They had some issues with the flywheel, so they are currently in the process of redesign. I was told that the prototype is nearing completion, but it will be at least a couple of weeks until it's ready for production. Not really sure what I should tackle now... I got 8 packages waiting for pickup in Buffalo, but there's no point in driving down without the kit. I guess I'll take the time off to get serious with my job search.

If you plan on doing this through Renegade, do yourself a favour and order the kit as early as possible. I placed an order at the end of January and I'm still waiting.

Here's a rundown of things that need to be done:

• Pick up the packages from Buffalo. This includes:
  -Low profile LS2 oil pan to improve ground clearance
  -C5 Corvette engine mounts
  -Wevo Boxster S transmission mounts
  -Oil pressure sensors and relocation hardware. Once the intake is flipped 180 degrees, it will not clear the oil pressure sensor.
  -LS1 fuel filter/regulator. The LS1/LS6 fuel rails don't have a return line, so the regulator is located on the filter.
  -Engine parts: gaskets, head bolts, harmonic balancer bolt, intake bolts, remote thermostat housing, LS4 harmonic balancer. There's not enough clearance for a regular harmonic balancer, so you will have to purchase an LS4 unit.
  -A whole bunch of fitting and lines
• Engine. Still waiting on that kit from Renegade. I might just make my own reinforcement plate and weld that in while I'm waiting.
• Wiring. Still looking for LS1 harness and ECU. The harness will need some work to get rid of the unnecessary bits. On the Porsche side, I'm probably just going to make my own harness. It only needs a couple of sensors, so there's no point in ruining a good one. I might just buy an ECU plug from itsnotanova to make things easier. If you need some parts for your build, he's the man!
• Throttle pedal. I just purchased a cable throttle pedal from an early Boxster. Still gotta figure out how to route it to the engine. I'm looking into purchasing a Mr. Gasket universal bell crank to match the pedal travel to the LS1 TB.
• Brakes. I need to replace all the brake lines and one hard line. I'm thinking about buying a Copper Nickel coil and replacing the hardline myself. Currently designing a tube straightener. I also have to fix the vacuum lines.
• Electric power steering. I pretty much have this one figure out, just have to cut the lines and put everything together. I'm thinking about leaving this one for last in case I have to relocate some stuff. I do still need -6 AN fittings that go into the steering rack. If you have a machine shop, please get in touch with me.
• Interior. The interior will remain mostly stripped, except for the custom door cards. I will most likely get some Rennline stuff for pedals and floor. I'm still looking for some nice budget racing seats.
• Suspension. I think I will keep the stock suspension until I have the car on the road. The rear struts are fairly new, but the front ones are looking pretty rough. Once I have the money, I will probably get a set of PSS9s.

This is all I have for now. Thanks for following guys, and sorry about the lack of updates.
Vlad

Awesome, man! And I agree, those door cards are sweet. Gonna store that pic away for the day when this car retires from DD work and becomes just for crazy fun.

There’s still no word on the status of the mounting kit, so I guess for now I just have to suck it up and wait. Today I started cutting the engine compartment to make clearance for the engine. It was a lot harder than I thought, the sheet metal is reinforced and having the car on jack stands does not provide enough room. I found it was easier to first drill out all the tack welds on the reinforcements to detach them from the actual sheet metal. This makes cutting and bending away the metal much easier. There was quite a bit of water in the enclosed compartment, which got me a little worried, but thankfully there was no rust.

Today I only had enough time to do a rough cut on the left side, but hopefully tomorrow I can finish it up if I can find my rotary tools. I also plan on making a reinforcement brace to replace all the missing sheet metal and also make relocation bracket for the e-brake.

Looking good man! Yeah this part is a PITA but once you get into it, it becomes clearer. What are you using to cut with? I used an electric cutter/grinder with a 4.5" wheel on it, although I had the car on a lift so I could easily stand under it etc. so I know being on jack stands does not make it easier!

Do yourself a favor and go get a fiberglass welding blanket too if you don't already have one, lots of sparks fly towards the interior. Also will be valuable when welding~ The carpet and insulation on the interior is where most of your fires will start because they glue the foam directly to the body. I tried to remove a bunch and was wasting more time doing that then I did welding - just weld small section, put out fire, weld small section, put out fire :D

Good luck!
J

Hey John,

Thanks! I started with a small rotary tool, but then realised that it was getting me nowhere so I switched to a 4.5" angle grinder. My dad hooked me up with a nice wheel, so it was slicing like butter. Its a little difficult to manoeuvre with the car on the ground, so I will definitely have to finish up with a rotary tool.

My car is as stripped as it gets so I don't really have to worry about the dust or fires :)

Finally done cutting! This was a huge pain in the butt. I wouldn't suggest attempting this without a good rotary tool and angle grinder. Tomorrow I have to pick up some steel to make a brace.

Looking good Vlad!!

Hey guys,

I just spoke to Renegade yesterday, the kit should be on its way next week! I also started fabricating the reinforcement plate to replace all that metal that I cut out, but I have no pictures to show you. I probably won't be welding it in until I get weld-thru primer and good aerosol 2K primer. I might also get some seam sealer to seal the welds and keep the moisture out. There was a whole bunch of water inside the body when I was cutting it up, so just want to make sure the reinforcement plate doesn't rust.

Since it's been a little slow lately, I decided to run up the total for my build up to this point. You can find the updated BOM here. This does not include everything, I still need: seats, brake lines, starter, alternator, belt, power steering fittings, headlights, water pump, water hoses, and whatever else I'm forgetting.

Awesome thread.

What was the issue with the renegade flywheel?

I never really got a straight answer. From what I understand there was nothing really "wrong" with it, they just updated the design to make it more maintenance friendly.

interesting... if you dont mind, shoot me a picture of it when you receive it so that I can compare it to mine.

No problem. I should have it on Wednesday

The kit finally arrived and this morning I was able pick up all my parts from the Niagara Falls mailbox. In total 21 packages! Had to pay $150 to the mailbox facility in storage fees while I way waiting on the delayed Renegade Hybrids kit and an additional $460 in border taxes.

There are still a few little things that I will have to buy as I go, but the majority of parts are here. Tomorrow I will begin on the motor assembly and possibly fit the renegade kit to see where everything goes.

My first impressions of the Renegade kit are mixed. The packaging was horrible! The boxes looked like they've been reused about a dozen times, and two of them had holes the size of a grown mans fist. I just hope that nothing fell out in transit. The overall quality looks pretty good, the welds look nice and the paint finish is excellent. All the hardware came in one huge bag with no labels or instructions. I feel like I will have to spend some time figuring out which bolts go where.

The Kennedy Engineering bits look amazing. You can tell that a lot of care went into the design and machining of their parts. Their kit also comes with an installation manual, but I haven't had a chance to look through it.

Hey guys,

Sorry for the lack of updates recently. Last week I put together the engine and tranny. I am using a low profile LS2/LS3 oil pan for ground clearance. At 4.75", this is the thinnest OEM wet sump pan available. I had to get a new o-ring (blue) for the pickup tube, which cost a whoppig $14 from the dealership. I believe all LS pans are interchangeable, so there was no trouble there.


I am also using an LS1 intake manifold. The intake is rotated 180 degrees for clearance. I've heard of issues with the oil pressure sensor getting in the way with LS3 engines, but mine seems to be ok. Nonetheless, I plan on mounting both GM and Porsche oil pressure sensors on a 4 AN line remotely (I will make a post on this with a complete parts list when I'm done).


The Kennedy engineering adapter and flywheel look amazing. The adapter plate was slightly damaged during shipping, but it was nothing serious. The kit comes complete with hardware and instructions. I didn't purchase the optional KEP clutch, so I had to buy the pressure plate bolts myself. These are longer than the OEM Porsche bolts, so please give KEP a call to find what size you need.


I was told that the Boxster S clutch will work for a 5.3L swap, but Kennedy Engineering suggested that I upgrade to a sprung hub disk. The new flywheel is no longer a dual mass design, hence a rigid disk might be a bit too harsh. The KEP clutch is amazing, but its close to $1000, so I had to downgrade to a SPEC Stage 2 clutch for $650. As I was putting everything together, I realized that I was actually sent a rigid disk. The online store where I had made the purchase admitted their mistake and offered me a full refund. I decided to give SPEC a call directly to see if I could just make swap with them instead of shipping everything back to the store. They told me that the Boxster clutch normally only comes rigid, but they could make a sprung disk for me free of charge if I just paid for shipping. I guess for now I'll just bolt up the tranny without the clutch to see how everything fits together.


I used a pallet jack to line up the transmission to the engine. This is pretty easy if you have the right equipment, but I would still suggest an extra set of helping hands.


The Renegade Hybrids kit wasn't so straight forward. All the hardware that comes with the kit is mixed in one ziplock bag. It's not that big of a deal, but it still takes a while to figure out which bolt goes where. I was short a few washers, a harmonic balancer spacer, and a belt pulley. Either these parts were never put in, or they fell out the massive hole in the box during shipping (Steve promised me that the replacements would be on the way shortly). The Wevo transmission mounts which you must purchase separately come with a the bolt and washer for the stock setup. I replaced mine with a 75mm bolt and ground down the square protrusion on the washer.


I had no issues with the rest of the Renegade kit except for clearance around the oil pan. I opened up the bolt holes a bit to allow for some extra clearance.

Today I finally managed to bolt in the engine for the first time. This was a very frustrating experience, especially trying to do this on my own using a set of stands and a pallet jack. At first I thought I could just roll the whole assembly in together and just bolt it all in inside. I played around with it for a few hours and failed miserably. There's just too many things to get in the way and too many holes to line up in one shot.


I partially disassembled the engine mounts and tried fitting everything piece by piece. This was still a huge pain in the butt, but at least I managed to put it all together. The clearance seems to be pretty good, and I don't expect to be doing much more cutting. I am a little more concerned about the air intake situation since there's only 6.75" of space between the manifold opening and the firewall.


The way it is now, the engine is slightly tilted towards the front. I may have to add some spacers to the engine or transmission mounts to level it out.

Good to know. I opted for the unsprung "STAGE - 3 !!!!!" clutch. I wasn't aware that they would able to spring it for me. I might have to give this some thought if the solid disc is truly unbearable. I've driven many crappy cars in my day, the bar is pretty high. :)

http://986forum.com/forums/uploads01...1433267705.jpg

This * 10!

Don't get me wrong, I love what Renegade has done and I never would have thought this was even possible without their pioneering, but they could have taken the 4 weeks they were waiting for the new Kennedy parts to draft up a simple step-by-step manual. Something like this would surely prevent many otherwise preventable phone calls to the shop in Las Vegas.

Wait, I was supposed to get a balancer spacer? If so, chalk mine up as missing as well.

Also, did you get a belt tensioner with your kit? I have no idea how the belts are supposed to be routed or what tensioner to use. :(

Also, the bolts supplied for the front lateral cross member were waaay too short. IIRC, the kit came with two M12x65 bolts. There were maybe two threads protruding above the mount with these bolts. I had to use a pair of M12x80s instead. A parts list / bill of material would have been REALLY helpful through all this.


Whenever my wife questions my justification for this early 40th b'day gift I bought for myself last month, I'll show her your comments here. An additional post about how "dangerous" and "unsafe" you felt would also help tremendously in my cause. :)

http://986forum.com/forums/uploads01...1433267687.jpg

I love hearing updates. Keep 'em coming! Personally, I'm keeping my project on the down-low until I'm closer to completion. However, I think we are both pretty close in regards of progress at this moment. I'm sure I'll be coming to you with more questions in the near future.

-Andy

Yeah I think that was supposed to be there

I was referring to the tensioner as a pulley. I'm not sure if I can use it since I'm only running an alternator, but I haven't really looked into the belt stuff yet

Yes, I also found my bolts were way too short. I'll have to get some longer ones. So M12x80 works well? The bolts that came with Wevo mounts are M12x95. Do you think they will be too long?

Haha safety always comes first! Tell your wife "Don't be a fool, use the right tool!"

Hey Andy, btw is your engine sitting flat? Mine is tilted towards the front and I'm not sure why. Could you please measure your engine mounts height when you get a chance? I didn't use the mounts recommended by Renegade, but they are all supposed to be OEM corvette height. Mine are from Jahns Fabworks

Today I tested an early 986 Boxster throttle cable to see how it would work with the engine. From what I’ve read on other blogs, the cable is too short and the pedal travel only gives you about 60% throttle. The only alternative is to run a drive by wire setup, which requires some fabrication to mount the GM pedal and a lot of money to buy the whole setup. I would have to get a C5 corvette ECU, harness, TAC module, and pedal. This setup is about $800 used if you can actually find it. I was able to find a cable and pedal setup from an early 986 Boxster for $50, so I decided to give it a try first (these are rare, but believe some pre 99 models came with cable throttle).

There are no mounts on the new chassis for the cable, but it’s easy enough to bolt on. The cable is perfect length and you get about 90% throttle without any modifications. If you grind down the pedal stop you can go up to about 95%, which I am happy with. I will have to figure out a custom throttle cable bracket, but that’s pretty much it. The other issue is the space for intake hoses, but that's a whole other project.

Don't quote me on that, but M12x80 or 85 sounds like what I wound up using.


I'm using the stock transmission mounts. I butchered up the original trans mount brackets to use as a spacer between the cross member and the bolt. The round hole on the cross member was ground out to a square'ish hole to hold the OE mount in place while torquing. I know the color quality is off, but it's otherwise difficult to get a picture of the high gloss pieces in a dirty engine bay.

Also, note my two LEFT frame rails that I was given my kit. :(

http://986forum.com/forums/uploads01...1433334873.jpg

I unfortunately have not mocked my engine up yet. I'm making my own custom pedestal mounts with a different poly isolator. The placement of the C5 mount is awful and creates all sorts of fitment / clearance issues. I am instead making a mount that will go directly to the front Renegade cross member, eliminating the left / right rails that otherwise interfere with the exhaust and starter. I'll probably start fabbing those up this weekend.