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I thought I’d share my LFX swap project and experience here. This is another Keisler Automation LFX swap. TL;DR: The RX8 is amazing with the LFX!
Why swap?
I bought my 2005 RX-8 new off the lot in early 2006. I have really loved this car, and after 14 years of ownership I still love it. It has great balance, it is fairly lightweight, the back seats are very usable, it is completely at home on the track and occasional autocross days, and it has been a great daily driver. I see so many complaints about reliability, but mine has been very reliable. I do change coils/plugs/wires every 15k-20k miles, but there has been very little maintenance other than that. I love the rotary engine, but I've always felt this car would be perfect with another 100 or so horsepower. Mine is close to 90,000 miles now, and I decided last year that it was probably time to start looking for something new with a bit more power. I started my search with a few requirements: Around or under 3,000 lbs, good front/rear weight balance, 300+ horsepower, neutral handling with good suspension geometry, and usable back seats (I have young kids). This would need to be a daily driver that I could also take to the track and occasionally autocross. I spent quite a bit of time, considering everything from BMWs and Camaros to GT-Rs and Aston Martins. Nothing really met my requirements and had me excited. There are plenty of 2 seaters that fit the other requirements but I would only consider cars that could haul my kids. The BMW M2 seemed like a good candidate but they were heavier than I wanted, and while they are great cars I just wasn't that excited about them, especially given how much I'd have to shell out. At this point I started thinking that maybe a swap might get me what I really wanted.
Why LFX/Keisler Automation?
There are a ton of different swaps for the RX-8, with the LS swaps being the most common. I think they are a great engine, but for me the biggest downside was the additional weight up front. I love the balance of this car, and I was a bit afraid I wouldn’t be very happy with it after significantly increasing the weight up front. I did a bit of searching around and ran across www.keislerautomation.com. This looked like exactly what I wanted - 340ish horsepower, keeping the weight and front/rear weight balance nearly identical to stock. The engine is taller than the Renesis so raises the CG a bit, but not really a significant issue for me. Since this is a daily driver I was also very happy to see that I could still have air conditioning and I could keep the stock gauges. If you aren’t familiar with it, the LFX is a 3.6 liter V6 that has been used in a ton of cars, most notably the Chevy Camaro. I could keep the car I loved, but with a huge torque/horsepower boost that would actually be more reliable and get far better gas mileage (not really a priority). Also, if you haven’t seen them, Andrew’s parts are simply beautiful. I climbed under my car in the driveway the other night just to stare at the diff housing. There are cheaper swap kits for other engines, but this was exactly what I wanted. When you see his dedication to detail reflected in the parts it just makes sense.
The Process
I contacted Andrew and he was immediately super helpful. We discussed the swap and I decided to start shopping for the right car. I thought about using mine, but I’m at close to 90k miles and I thought I’d look for something in good condition with a few less miles. In late February I flew to Florida and bought a 2005 with 53k miles from another member here. It had been garaged its whole life, had Mazdaspeed front, wing, suspension, and replica Mazdaspeed skirts. It was also supercharged with the Pettit Racing stage III setup. I thought hard about whether or not to just keep the car as it was since it likely had similar peak horsepower, but as a daily driver and track toy I was definitely concerned about reliability with a boosted renesis. I was also very excited about the swap by this point. I had the car shipped to Andrew at his Colorado shop, figuring I’d fly out from Seattle with my son and drive it home when it was finished (this was before Covid-19 was in full swing). I was definitely nervous about sending a bunch of money to a stranger, as well as the car I had just purchased. I had seen enough online and talked to other people who had used Andrew for their swaps that I decided to bite the bullet and do it. It turned out that the people I had spoken with weren’t wrong. Andrew was incredible to work with. I can honestly say that I have never had better customer service anywhere in my life than I had with Andrew, both during the project and after I got the car home. Andrew worked with me to pick all of the parts and get them shipped to his shop. I was able to get an engine with 2,076 original miles out of a wrecked 2018 Cadillac XTS for $850 including freight. These engines are plentiful and cheap. I opted for the 3.45 diff, thinking that the 3.91 might be a little too short for my liking (still deciding if I want to move to the 3.91 in the future). Andrew was splitting time between his Colorado and Tennessee shops, and with Covid-19 happening I told him to take his time and not make my car a priority. He was sending me pictures of the process, and I had over 250 emails back and forth with him throughout the project. In May Andrew finished everything and worked with me to get the car shipped home to Washington. Meanwhile I was listing all of the used parts for sale and Andrew was generously handling all of the shipping and transactions.
The Car
This is what I wanted. The car fits me like an old glove, but oh god is it rowdy now! This engine pairs so nicely with the RX-8. The handling feels the same, but step on the gas and she goes!. There is torque everywhere. The tires that came on my car were old, and I couldn’t keep them from spinning all through first and second gear. I spent the first two tanks of gas roasting them on launches with a big ****-eating grin on my face. After some new shoes it definitely handles the power much better. I opted for Michelin Pilot Sport 4s in 275/35-18. The big thing for me is that in the twisties the car feels like it did before the swap, with the exception of drastically more oomph. Again, this is exactly what I wanted!
On the track
I've had the opportunity to track the car twice now since the swap, and man this car is so at home on the track. I haven’t really been able to push it on the street enough to really get the most out of it. Get it on the track and it is huge grins. It is very neutral and so predictable. I can’t give an in-depth back-to-back because it has been a lot of years since I’ve tracked my rotary RX-8, and that is a sport model while my new swapped car is a GT (a bit heavier due to the sunroof and heavy leather heated seats). It does feel very similar though, and like I said, it is very neutral and predictable. With the new engine it is also much more forgiving when I do inevitably blow a corner. The torque is increased by more than 75% over the Renesis and it just pulls hard when you ask it to.
Cons
It is too easy to drive fast! With the Renesis I can wring it out and still not be in too much trouble. If I drive the swapped car the same way it is more likely to be handcuffs than a ticket. :D
I’m not a big fan of the MV5 transmission. It works just fine, but it is definitely not as smooth as my stock RX-8 transmission was. I don’t really notice it anymore, but comparing them back to back I prefer the stock transmission.
The LFX doesn’t like to start with a low battery due to a booster circuit that gives 48 volts to the injectors. I’ve found that below around 11.9 volts it won’t give enough power to the injectors, so won’t start. That isn’t normally a problem, but I’ve got a slow drain somewhere that I haven’t spent the time to track down yet, so if I leave the car for more than 3 or 4 days I need to use a small jump box to start it. Once I track down that drain I down expect that will be an issue.
Summary
I love the RX-8 with the LFX swap. That’s it. I still love rotaries, but since getting the swapped car my original RX-8 just sits neglected. There just isn’t much reason to drive it when the swapped car is everything it is and a lot more. It is going to be hard for me to sell, having owned it more than 14 years, but at this point I’m not really seeing a reason to keep it and pay for insurance. I’m so glad I bit the bullet and went ahead with the swap. Also, again, I can’t say enough good things about working with Andrew Keisler through this whole process. He is an incredible guy that goes way above and beyond for his customers. I hope to see a whole lot more LFX RX-8s in the future!
The Ridge Motorsports Park Purchased and ready to swap One Car, Two Car, Red Car, Blue Car! Look Ma, no rotors Eye Candy Between track sessions
There’s maybe a half dozen or so Keisler conversions on here, most of them are over in the racing forum I think
Spoke to him about the trans mount brace and rear diff front subframe attachment for eliminating the PPF on a future rotary project, which he’s willing to sell separately. He also said the power steering harness fits on the factory RX8 too.
This is not making this any easier for me. I must have patience! Lol. Glad you are enjoying yours.
they do make a twin screw supercharger for this lfx engine that I THINK may fit with the stock hood. Then you have about 375 to the wheels. Hmmmmm.
Hey olddragger, we are all rooting for you to get this dream project! Don’t think I haven’t thought about a supercharger!
I don’t feel like I need it now but down the road I may consider it. I’ll wait and let you pave the way on that one.
Originally Posted by olddragger
This is not making this any easier for me. I must have patience! Lol. Glad you are enjoying yours.
they do make a twin screw supercharger for this lfx engine that I THINK may fit with the stock hood. Then you have about 375 to the wheels. Hmmmmm.
Here’s three different views from my second track day. I’m headed back again this Friday, so hoping I can find a couple of seconds. I think I do want to improve the brakes. I was running street pads (Hawk HPS), but I think I also boiled the fluid in the session where I had a passenger. Pedal went to the floor when I tried to stop in the pits. I’ll be running HP+ this time, but that might make them even hotter.
I used to run ATE Super Blue, but right now I’m using the Willwood 570, which has a higher dry boiling point. The wet boiling point on the ATE is higher I think, but this is new fluid. I haven’t tried the carbo techs.
I am talking to somebody that has Brembo big brake kit for the 8 for sale, but I don’t know if it fits with my wheels. He said the spokes on the stock wheels hit, although the barrel is large enough. He was running 19’s. I have the RPF-1s in 18x9.5 with 43mm offset. I think there is more clearance than stock but I don’t know how much is needed for them to clear. @TeamRX8, I saw some old threads with you talking about big brake kits. Any idea if the RPF1s typically provide enough clearance?
I’m Running 300TW tires right now (Pilot Sport 4), so a stickier compound would help a lot.
Originally Posted by olddragger
Put carbo techs on it, blue brake fluid, and some r compounds and it will be a beast. You will catch so many cars in the braking zones!
That particular RPF1 didn’t clear the Racing Brake caliper without a spacer. At one time they made a special version of the kit to move the caliper further inboard to clear it, but they discontinued and went back to the standard. Not sure about any other BBK, but most stuck out further. Or if Enkei ever changed the spoke curvature on the wheel. That was back in 2006-2007.
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Sweet vid! It looks smooth and not requiring much steering wheel movement. You are figuring your car out. Hp and torque really changes it ... right?
you want a big brake kit for the looks? Stock set up ( with correct fluid and pads) will do fine! Carbotechs are great pads and there is no substitute for a True track pad. Those advertised for street and track don’t really do it when you get faster. Especially when you run r compounds.
Put some Hoosiers on it ,18 inches are fine....if I remember correctly I was running 245s? (But I may be wrong..). I know they were 18’. And carbotechs, tweak the suspension for the Increased g’s you can now do and Oh Boy will you be grinning. I remember being able to turn into turn 1 at road Atlanta at 100 mph....woo hoo!,
That particular RPF1 didn’t clear the Racing Brake caliper without a spacer. At one time they made a special version of the kit to move the caliper further inboard to clear it, but they discontinued and went back to the standard. Not sure about any other BBK, but most stuck out further. Or if Enkei ever changed the spoke curvature on the wheel. That was back in 2006-2007.
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Thanks Team, sounds like it is pretty unlikely they would fit with my wheels, and I can't space them out due to clearance.
Originally Posted by olddragger
Sweet vid! It looks smooth and not requiring much steering wheel movement. You are figuring your car out. Hp and torque really changes it ... right?
you want a big brake kit for the looks? Stock set up ( with correct fluid and pads) will do fine! Carbotechs are great pads and there is no substitute for a True track pad. Those advertised for street and track don’t really do it when you get faster. Especially when you run r compounds.
Put some Hoosiers on it ,18 inches are fine....if I remember correctly I was running 245s? (But I may be wrong..). I know they were 18’. And carbotechs, tweak the suspension for the Increased g’s you can now do and Oh Boy will you be grinning. I remember being able to turn into turn 1 at road Atlanta at 100 mph....woo hoo!,
Yeah, the HP/Torque definitely change things! It is more forgiving, and I feel like it gives me some better options. In terms of the big brake kit, my main goals would be better cooling, reduced unsprung weight, a little more braking power, and quicker pad changes. Cooling is a big one. I'm running new Wilwood fluid with a dry boiling point of 570F and I am sure I'm boiling the fluid. We run 20 minute sessions once per hour and it is fine in the first and second session but then starts to get noticeably worse after that. I came in from one session where the pedal was getting very soft and after a full cool down lap the outside of my calipers were at almost 500F. Rotors were at 725F. The fluid is definitely getting well over 500. After giving them an extra hour to cool (during lunch) things were much better again. In my last session though I went to brake in a hard braking zone (from 102mph to 35mph) and had almost no brakes. I'm not sure how I managed to keep it on track but is was very close. I'm guessing I had about 30% of my braking power, and I was pumping them. When they were cool they worked really well with the Hawk HP+ pads. Definitely better than with the HPS pads. I'm on 300 TW tires (Pilot Sport 4) with 275/35's. I might try a higher boiling point fluid, like the Motul RBF 660. Andrew Keisler sells a Wilwood caliper kit with adapter that uses the stock brake rotors. That is definitely an attractive option, but I think I probably still have the same problem with my wheels not providing clearance. I thought the stock brakes would be fine, but for repeated lapping I think these calipers would be a big upgrade. https://www.keislerautomation.com/rx...nt-caliper-kit
No brakes are a lot of fun right? Woo hoo! Glad all is ok.
if I ever had a soft pedal on track I change the brake fluid... boiling it changes it and it needs to be swapped out.
hp+ pads are not really track pads....if you like hawks go with a dtc pad, but carbotechs is what we all settled on. We changed discs too for a track weekend. No one ever had any fade problems on stock calipers an super blue ate fluid...think one person was running the motel 660. Before you throw a big brake package on it , give those a try. Temps? We saw front disc temps over 800 on hard high speed braking track like road Atlanta. But we had time to cool off before the next session. Most of us were on Hoosiers too
Yeah, I definitely need to change out the fluid now, and smooth the pucker marks out of my seat! I basically had 40 minutes to cool off between each session, but after a few sessions the heat was adding up. Things were much better after the 100 minute break. ATE still sells the fluid, but not in blue anymore. Which Carbotech pads were you running on track? I'm not married to Hawk pads at all, but somebody gave me a set of the HP+ to try so I tried them out. It is definitely nice that our stock rotors are so cheap. You keep those with the Wilwood calipers Andrew sells, but not with the big brake kits. I was thinking I'd pick up some spare rotors to have ready to swap as needed. You'll be entering the hardest braking zones with quite a bit more speed with the LFX than with the Renesis, so if you weren't boiling fluid before you might start to creep closer to that line. Even more so if you go with the SC. :D
My AC compressor just died in the swapped car, so now I need to get that swapped out and recharged. The condensor was brand new, but sounds like it is best to replace that too with the metal bits the compressor has likely threw its way.
Andrew Keisler sells a Wilwood caliper kit with adapter that uses the stock brake rotors. That is definitely an attractive option, but I think I probably still have the same problem with my wheels not providing clearance. I thought the stock brakes would be fine, but for repeated lapping I think these calipers would be a big upgrade. https://www.keislerautomation.com/rx...nt-caliper-kit
I have those Wilwood calipers on my turbo 8 . I've found they cause the front rotors to overheat (over 100C higher than the rears after a cooldown lap) . With Yellowstuf pads the pads themselves disintegrated . Then I tried DTC pads up front with yellowstuff on the rear ... the fronts were ok but still getting super hot . Next up I have DTC60s all around . Hope that solves it ,but so far it's been a problem.
Thanks Brettus, good to know. Were you having issues that prompted you to upgrade to those calipers in the first place?
Originally Posted by Brettus
I have those Wilwood calipers on my turbo 8 . I've found they cause the front rotors to overheat (over 100C higher than the rears after a cooldown lap) . With Yellowstuf pads the pads themselves disintegrated . Then I tried DTC pads up front with yellowstuff on the rear ... the fronts were ok but still getting super hot . Next up I have DTC60s all around . Hope that solves it ,but so far it's been a problem.
if you have a functioning ABS system then you should run the same pad front and rear
that was all detailed out in a past thread somewhere; due to the ABS system having an electronic brake proportioning function it will override any attempt to alter proportioning via pad compound. So you might as well have something in the same proper heat range and let it do it's thing rather than fighting against it.
not familiar with that caliper setup, but that situation might have to do with how the piston area compares to the OE caliper
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Thanks Brettus, good to know. Were you having issues that prompted you to upgrade to those calipers in the first place?
There weren't any issues...lol .
It just kinda happened over time after I inherited some twin piston Wilwoods the next size down . Those had the opposite effect (rears getting too hot) . So I got rid of those and got the next size up and now the fronts get too hot.
Team:
The original setup was EBC yellowstuff front and rear . After the fronts burned up i tried with just dtc60 on the front ..... which didn't burn up but still def getting too hot . I then got DTC 60s for rear as well ... i suspect it will improve but still get hotter than ideal.
The issue is that the calipers are larger than stock so getting too much force on the front.
Edit :The actual braking power is great .... it's not too much front biased to lock up or make it skittery ...the only issue is heat . Put some wider rotors on there and they would be perfect IMO.
At road Atlanta the back straight is long... that is good to help cool the brakes but at the end of that straight there is also about a 90 degree turn... so braking from a little over 140 mph down to about 60 mph generates a lot of heat. The rest of the track it pretty demanding of the brakes also. So our brakes would get rather warm. This is when I was running a supercharged engine with just a tad over 300 rwhp and r compound tires. BUT we didn’t have back to back sessions like you. When you are on track that long .... you have to guard your brakes. Yes lap times would suffer some but that is what it takes.
we ran carbotechs xp8’s and separate rotors. I would swap rotors and pads before the track weekend. We could do it in a bout an hour, jack up to jack down. At the same time I would bleed the brakes some ....had speed bleeders which worked well. Everyone in our group would run a no brake session. Yep we wouldn’t use any brakes at all! That was fun! No one ever got a bbc and one of us won his time trial class championship with southeast NASA. We had a lot of fun.
Oh yeah, with the SC you'd definitely be seeing speeds similar to what you'd have with the LFX. Rwhp is a little bit lower with the NA LFX. I'm only running 20 minute sessions, so I am wondering how people handle it that are endurance racing (Lucky Dog, etc...). Those carbotechs are spendy, but they look like a good option. I'm probably done with track days for this year. I need to at least rebuild my calipers before next season. My dust seals are almost completely gone.
I've considered speed bleeders so many times I've lost count. Every time I'm tempted to buy them I read through the reviews and there are so many complaints of leaking that I've never pulled the trigger. Did you ever have issues with them leaking?
We all had them and no one had any leaks that I remember. I used to hook up a bled bottle to them also. That is just a hose ran through a bottle top and down into the bottle which has brake fluid in it. The hose in in the fluid so it is all sealed for the second time. Lol. Plus I didn’t get any fluid on my driveway.
just make sure you don’t cross thread them into the caliper.
when I get mine you know it will have a twin screw supercharger.........!
Seems like a lot of Andrew's swapped cars have the compressor quit and have the parasitic drain causing the no start from the few threads I have read around.
Still an awesome swap, I'm considering it currently. The K-Swap seems to be a great option as well with less labor but a bit more fab time.
Currently it seems that is was a grounding issue. These kind of bugs get figured out.
New development.....2021 may start out well for me. Stay tuned. Let’s just say I don’t count my chickens before the eggs hatch.
08-16-2020, 03:16 AM
