802Projects.com

LS2 RX-7

Top of PagePart List DownloadBeginning the Swap
Motor SpecificsEngine AccessoriesWiring
Finishing the swapHID RetrofitInterior Work
Paint Job

While my dream car has always been a 3000gt vr4, I've always liked the style of the 3rd generation FD rx7. After a lot of saving I decided to buy one and ls swap it. This section of my website I've dedicated to documenting the build. I'll try to cover everything from buying the car to swapping it.

Is the Rx7 the right car for you?

(Warning this may offend some owners! :P )

The cars are tiny inside. I thought being only 5'11 I'd have plenty of room, but I don't. My head will rub the ceiling if I sit up straight. My knees are close to the bottom of the steering wheel. The people who say they are 6'something and drive one must be very uncomfortable. It is true the non-sunroof model will have more headroom (maybe 3/4"). I wish I had the luxury of sitting in one before buying it because if I did, I probably would have held off for one without a sunroof

The factory paint sucks. Unless it is a low mileage car that has rarely been exposed to the sun; it probably has clear coat pealing. They also used as light of coat as possible in the engine bay. You can literally rub it off with your finger. They also have no undercoating underneath.

The interiors are cheesy. Your chances of removing anything without breaking a plastic mounting tab are slim. The chrome rings around the gauge cluster is just paint that flakes off. The vanity mirror inside the visor uses folded hard plastic as a hinge. Open/close it enough times it tears. The glovebox latch handle mechanism is made of plastic and will break off. The door pocket lids pivot point is made of plastic. They break and fall off. The dash vents crack. All the foam inside the dash climate vents deteriorates over time. You'll have it blowing out your defroster vents sooner or later. If you lean too hard on your center console, it will crack on the underside and now creak forever.

There are some overall design problems. Let's not even talk about problems tied directly to the Rotary motor. Want to pull the carpet? It's easy just pull the dash first:/ I've never seen any other vehicle where you have to remove the dash to remove the carpet. Mazda also GLUED parts of the carpet to the floor. So peal carefully. Are you ball joints bad? Well guess what, they aren't serviceable. Mazda utilizes front forged upper and lower control arms that have built in ball joints. When one goes bad you have to replace the whole arm. ($300+) The rear hatch shocks get weak over time. The rear quarter panels actually curve down behind the rear wheels. This creates a giant pocket for moisture to collect and is usually where they start to rust first. The hood latch cable is held in place by a plastic snap. Guess what that means? It means that one day it will break and you won't be able to open your hood. Guess what the exterior door handles are made out of? Cheap plastic.. One day they will snap off. The headlight covers are also held in place by cheap plastic tabs. These grow brittle and blow off. New oem headlight covers are abut $120 a side and were never revised.

It's going to be expensive! Not just the car itself but the swap parts. Even if you do all the labor yourself, plan on around 20k to do it right. Say $6k for a car, $6k for engine/tranny, $3k for subframe stuff you are already at 15k. Now start calculating the cost for a clutch/flywheel, LSD, driveshaft, exhaust, radiator etc... it will add up fast.

Now let's talk about die hard rotary fanatics HATING you

There are a lot of people out there who think the Rotary motor is what makes the rx7 an rx7. A lot of the haters don't even own one, but it's their dream car so they feel inclined to voice their opinion. "You're ruining the car" or "Go buy a Camaro" are common phrases you will hear as you begin your ls swap. I tend to ignore these people as it's a waste of time explaining. 90% of the time they won't want to hear it anyways. Just go about your way and enjoy being on the their "dark side."

So why did I decide to ls swap my car? The rotary motor can make a ton of power. But it's shelf life is limited. Even a properly built motor, you are lucky to get 70k miles out of. They also run really hot and you can toast an engine if it overheats just once. They don't get the best fuel economy either (10-15mpg). The transmissions and rear end are also not very strong once you start to upgrade the car. There are always WTB ads on the forum for these parts. The ls motor has been around for a while. Parts of cheap. They are reliable stock and even upgraded. The aftermarket industry is endless. Fuel economy is also really decent for the power level (~20mpg).

Online Forums

Below are a lot of the sites I used to help with my build. Norotors is the best site as everyone there is dedicated to swapping out the rotary motor in these cars. The forum members are really nice too as long as you don't join and start posting a ton of newb questions. Rx7club is great to buy/sell parts and research general Rx7 products such as suspension, floor mats, headlights etc.... They do make you jump through a bunch of hoops and "read" a lot of rules just to get an account setup. I find that this is probably the first forum new Rx7 owners join. So there are a lot of new members creating WTB FD rx7 ads or or posting in every other thread saying that it should be a Sticky. Nopistons.com is a forum for die hard Rotary fans. You still may want an account there if you have a bunch of Rotary parts you are trying to unload. The remaining sites are just good resource links.

Finding the right rx7

I paid $7000 for my rx7 and another $500 in shipping from Virginia. It was a complete clean title 94 rx7 with 140k miles. The motor ran but had bad coolant seals. It was rust free and accident free car. After selling the stuff I didn't need for my swap (ECU, engine wiring, engine, engine subframe, transmission, driveshaft, rear diff, stock wheels) I guess have about $5800 into my shell. You can find them cheaper if they have a salvage title or accident damage. You can also get bare shells fairly cheap. But if you have to piece together a hard to find interior, good luck. Here's a pic of my rx7 from the For Sale ad when I bought it.

Part list

It took me a while but I went through all my old email and compiled a list of everything I ended up needing to get where I'm at. The list doesn't show you some of the trial and error parts I ordered and had to return, or just kept as it wasn't worth the hassle. Hopefully this will be useful to anyone swapping theirs, or contemplating it. It's definitely an expensive project, but the one good thing about RX7's is they seem to hold their value well.

Click to Download Rx7 Swap Parts list

Beginning the Project

Here's the first picture of the car at my house. I had it trailered from Virginia to Vermont. I hooked up a battery charger and it started right up. I pulled the radiator cap and it was bubbling. The coolant seals were bad. I drove it around the house once anyways just to verify the transmission worked. Immediately after I pulled the motor.

I pulled the front and rear subframe as well. The front subframe isn't used in the swap so I sold it. With the subframes off, I could clean up and undercoat the underside of the car. This gave me something to do while I waited for swap parts to start to arrive. I also pulled the gas tank to make it easier.

I cleaned up the tail lights too. They were all dull and scratched up. I took the 3m kit to them.

IT bought a motor off eBay. It is an 06 Pontiac GTO LS2 6.0 motor with 68k miles. It came with the 6 speed T56 transmission, ECU, wiring, MAF, and DBW pedal. This cost me $5900 and I had to pick it up at our local FedEx distribution center an hour away.

For the subframe I decided to go with the Ronin/Samberg kit. This is basically the engine mounting kit that Samberg sells. RoninSpeedWorks though resells it powdercoated black. They also add in their custom engine mounts with poly bushings, and there rear subframe kit. The rear subframe allows you to mount an 8.8 Ford Explorer rear diff. This diff is bulletproof compared to the factory Mazda rear diff, and more importantly it allows you to run custom gears. I went with an 07 Explorer with 3.55 gearing. This was $400 from our local scrap yard and it came with axles. When you bolt it in the Rx7 you need a custom driveshaft, and you need to make custom axles. The axle shafts are included from Ronnin. On the wheel side end you use the stock rx7 CV's, and on the diff end you use the explorer CVs.

The Ronnin rear kit involved a brace that welds to the stock subframe. You need to level it and use a special degree gauge to make sure the diff is pointed ~2.5 degrees up. My friend welded it in for me wearing safety sandals. I bolted the front samberg subframe in to check fitment. The nice thing about this kit is that it re-uses the stock rx7 steering rack.

To finish the underside I applied some heat mat on the underside of the transmission tunnel. This will help keep the center console from warming up. I also added some above the tunnel when the time came for it. I scuffed up and painted all the heat shields too with some high heat aluminum paint.

The Motor

Now the Pontiac GTO uses a front sump oil pan. This means that the sump is in the front of the oil pan. This will not work with any of the Mazda subframe kits. The sump needs to be at the back of the oil pan so that the front of the oil pan can clear the power steering rack. I had to buy an ls1 F-body oil pan setup to correct this. This includes the pan, new dip stick tube, new pick up tube, and new baffle plate. I also purchased an ImprovedRacing oil ban baffle. This helps keep oil in the bottom of the pan when cornering hard. I sold the ls2 front sump setup on eBay. People who v8 swap Nissan 240's buy them as a rear sump won't work on their setups. I replaced my rear main seal too as that was leaking.

I went with a Monster stage 3 clutch and LW flywheel setup from Tick Performance. It was a full kit with pilot bearing and new TOB. I had to order a shim kit for it to get the slave in spec. I also got a remote bleeder kit. This makes bleeding the slave cylinder easy as you don't have to crawl under the car to do so.

With the transmission mounted to the engine, I started to mount it to the front subframe kit and realized a new problem. The ls2 headers interfered with the steering linkage.

To correct this I had to get different headers. I could have gone with some aftermarket ones, but I was trying to stick to a budget. I went with ls1 headers. They were $90 shipped off the forums. They fit tighter to the motor. When installing them I put in new plugs and wires too. The motor fit fine after that. It was really close to the lip on the firewall so I cut the lip shorter and had my friend seam weld it.

Now the stock engine bay looked pretty bad. There was oil sludge built up on it. The paint was faded almost pink in spots. It was also scratched pretty good. Not to mention I had a seam on the firewall I cut/welded. There were also some bare metal spots where I drilled out the factory radiator mounting brackets. So I decided to paint it. I used Dupli-color matte black caliper paint. I could have had it professionally painted, but I figured that would be more money plus I'd have to trailer it somewhere. I was really happy with my $20 investment. Also since I had my fenders off I cleaned up and painted the bottom inside to give them some extra protection. This is where dirt can settle and rust.

The rear part of the transmission mounts to the chassis using a special mounting bracket from Samberg. Once the engine is in place you jack up the rear of the transmission until the mount sits flush against the car. THen holes are drilled and special mounting plates go on the inside of the car. I had my friend tac them in place and I RTV'd around them to keep water out. I pulled my dash as I have other plans, but technically you wouldn't need to.

Engine Accessories

Now that the engine is in there are a lot of little things to deal with. The stock master cylinder isn't compatible with the T56 slave. It won't provide the right amount of throw. I went with a master cylinder out of a Toyota Land cruiser. It has a similar angle mounting flange like the stock one. The spread on the mounting studs differs though. One of the studs is in the right spot, just the stud isn't long enough. On the other side is just a hole without a stud and it's not in the right spot. Long story short I ended up using both Mazda Master cylinder studs. I just removed them and installed them on the Land Cruiser master cylinder. I had to drill/tap a single hole on one side. Hopefully the pics help.

The diameter of the Land cruiser master is slightly larger than the rx7 one. So where it passes through the firewall I had to enlarge the hole slightly with a die grinder. Since I'm using the stock rx7 clutch pedal assembly I needed to enlarge that slightly as well since it bolts to the inside of the firewall. Finally I had to deal with the piston bolt thing itself. This is what connects the pedal to the MC. The Land Cruiser one was too short and not the same thread pitch. I ended up cutting the rx7 one and the LC one, and welding them together. This way the pedal assembly has the right thread pitch, and the other end works right with the LC piston.

Next was the brake booster. I cleaned it up and painted it with the same matte black paint I used in the engine bay. I deleted my ABS too since it would just clutter my engine bay and I've heard bad experiences with 20+ year old abs systems. I re-used the prop valve off of the abs pump. On an RX7 the front calipers are T'd together, and the rear are T'd together. The rear T's in the back of the car. I didn't have to touch that. The front I did have to put a T in. I was able to re-use the stock line. Total cost was about $7 from my local auto parts store for a T and 3 brake line connectors. I had a scrap piece of aluminum laying around that I made a bracket to mount the prop valve below the reservoir. Now the factory brake reservoir has a hose that runs down to the clutch reservoir. Since I used a different clutch master with it's own container, I don't need this hose. So I had to cap it off on the Brake reservoir. Mazda actually has an OEM cap that can be used since the automatic transmission rx7's wouldn't have a clutch reservoir.

Since I'm still using the stock steering rack I need to hook it up to the ls2 power steering pump. To start with the power steering reservoir is too high. The hood will hit the cap and it won't close. So I had to modify the mounting bracket to lower the reservoir. The problem with doing this is that the return line on the reservoir will run straight into the ps pump feed line. I was able to heat up the nipple on the reservoir and bend it out of the way. The feed line I made myself with some AN fittings and line from SummitRacing.com. I had to use some AN fittings on the rack itself as well. All part #'s should be in the build spreadsheet.

Edit: Since driving my Rx7 I'm actually changing my steering up. For starters I had to start running a power steering cooler. In stop and go traffic it would heat up. I went with a universal one they sell at Advance Auto Parts for $20. It seems to work well. Also while the LS2 pump is the right pressure the flow seems to be too much. At higher rpms the steering is really easy to turn. It feels like you're on ice. Turn One Solutions is sending me a revised pump to try that will have the right pressure and 1.3gpm flow that the Rx7 steering rack likes to see. I'll report back on how I like it, but it won't be until the summer of 2017.

For a radiator I went with the Samberg radiator kit. It is pretty slick. It bolts to the car using factory mounting points. It comes with SAL fans, hoses, an intake filter, and a remote reservoir that bolts right to an ls block. It also has mounting points to run an A/C compressor. I painted the bottom half of the shroud black so that you wouldn't see shiny aluminum behind the bumper opening. You also need to buy/route 2 coolant hoses from the motor to the firewall. These run coolant through the heater core. Fortunately there are some 90 degree hoses that auto parts stores carry that work perfectly for this.

The intake filter in the Samberg kit ends up being really close to the Throttle body. People do run MAF's in between the two, but it's not ideal and can cause tuning problems. The specs for the factory MAF say to be at least a foot from the TB and to not be on a bend. Well both of those are not true with the Samberg kit. So I decided to run Speed density only. I mounted the IAT sensor in the intake filter itself.

With a bigger engine requires more fuel. I had to redo most of the fuel system. TO start I switched to an Aeromotive fuel pump that I hotwired. The fuel pump calls for 10gauge wiring. So I drilled the top of the fuel pump assembly and added a grommet so that I could run 10 gauge wire right to the pump. I hotwired it through a relay mounted in the spare tire well. For the fuel supply I used a corvette FPR. The corvette FPR seems like it was made for swaps. It is a filter/regulator all in one. I mounted it to the rear subframe and ran new high pressure hose. I had to use an assortment of AN fittings to adapt to the regulator. Basically one hose runs from the pump to the regulator. Then a return hose runs back to the fuel pump assembly. The other end of the regulator runs to the stock hard line underneath the car. This runs to the engine bay. From there I ran a piece of hose up to the fuel line supply on the motor.

EDIT: So I would not recommend funning the 10 gauge wire directly through a grommet down into the gas tank. I kept smelling fuel in my car. Turns out the fuel was actually being wicked up by the wiring all the way to the relay. It was dripping at the really connection down into my spare tire area! Fortunately I caught this in time. I made a short video below when I realized it was happening. I changed my setup by making studs that go through the fuel pump assembly cover. I used some stainless bolts, and nylon bushings that I got from Home Depot. The bushings fit pretty snug but to be extra safe I used some ThreeBond sealer I had laying around. It's fuel safe.

There are 2 sensors you need to re-use from the rx7 in order for the gauge cluster to work. You need to re-use the stock rx7 coolant temp sensor and oil pressure sensor. The coolant temp sensor mounts on the back passenger side of the engine. There is a dummy coolant plug you can remove and replace with the coolant sensor using a brass adaptor fitting. You can do the same thing with the oil pressure sensor using the cover cap above the oil filter. There is a cover that is held on with two 10mm bolts. You can remove it, drill/tap it, then use a 45 degree fitting to mount the stock oil pressure sensor. The 45 degree fitting is needed to keep the sensor away from the exhaust.

I wanted A/C in my rx7. Fortunately the swap is so popular that one guy on the Norotors forum (halfspec) sells A/C kits. It includes all the hard lines, the drier, and wiring. I basically had to get an ls1 F-body a/c compressor for my car to work with his kit, and a special condenser that mounts to the Samberg radiator kit. Then it was a matter of running the lines and wiring it up. I wish I took more pictures of the install but it was very straight forward. Here is a shot of the lines running out of the compressor. You need to use an ls1 F-body compressor as the ls2 compressor lines exit out the side. There is not enough room between the frame rail and compressor to use side exit lines.

The last thing to deal with besides the wiring is the transmission. The LS2 GTO shifter does stick up through the tunnel opening and into the cabin but it's way too far forward to line up with the shift boot in the center console. To make it work you need to buy an ls1 MGW short shifter. This is meant for a Camaro and on the Camaro there is a bracket that moves the shifter to the 9 o'clock position. You can just clock the bracket to the 6 o'clock position on the rx7 and it will line up perfectly with the rx7 center console. In order to use the F-body short shifter on a GTO transmission, you need to also buy the F-body shifter cup. This is about a $50 part. After installing the shifter I added a cover to keep the inside of the car sealed.

The wiring!

I decided to put the wiring on another page to keep this page from getting too cluttered. Access it here:

Rx7 Wiring Page

Finishing it up

The 3.55 Ford explorer rear end is an open diff. This means only one of the rear tires would spin. I went with an aftermarket Truetrac LSD. I had a friend install it as it involves a bearing press and using shims. He has done it a few times so I didn't want to risk messing it up myself. After I got the diff in I could take measurements for my custom driveshaft. I went with DriveShaftShop.com. I was told they have really slow turn around, but I had my shaft within 2 weeks. One thing I want to point out is the brake/fuel lines. The actual floor board needs to be indented slightly so that the lines will be able to run over the Ronnin rear end brace.

With the swap stuff mostly done I could start putting the suspension back together. I cleaned up all the control arms with a scotch bright pad and some soapy water. It made them look like new again. I bought all new wheel bearings and painted all the knuckles/dust shields/calipers. I bought some slotted rotors and bc coilovers.

The exhaust was the last big thing on my list. Since I opted to use ls1 headers there isn't exactly a bolt on exhaust I could buy. I could have bought some $1200 headers, and an $800 catback but then I would have $2k into an exhaust! Instead I had my friend waterjet me some ls1 flanges. Then I bought some pre-bent pipe, a high flow cat, and a vibrant muffler. I cut and tacked everything together by myself and then had my friend weld it. As soon as I started the car I realized it was too loud:( I changed my exhaust setup. I added a vibrant resonator and went with a FlowMaster muffler with stainless tip. This seemed to quiet it down quite a bit. I installed a rear diffuser beforehand as I wanted to make sure the exhaust exited the car in the right location.

I replaced the stock rims with some wider ones. I figured the v8 is going to need more traction and the stock rims actually rubbed on the Samberg bump steer kit I added. I went with 17x9.5" Enkei Rpf1's in the back and 17x9 in the front. I mounted some 275/40/17 BF Goodrich sport comp 2 tires in the rear and 255/40/17's in the front.

Here it sits now. I still have a few minor issues to work out and then hopefully come spring it will be off to paint.