Engine Mounts Filled With Polyurethane

Not many solutions seem to be out there for the RX-8 in terms of alternative engine mounts. The original 2004 to 2005 version was flawed in design as they didn't last long, forcing owners to replace them somewhere between every 30,000 to 50,000 miles. In 2006, the engine mounts were revised to be much more efficient and longer lasting.
This DIY goes over how to take your engine mounts and turn them into some very nice and stiff engine mounts that you won't have to ever replace. We used Dave's engine mounts on his RX-8, which is the 2004 version, not the upgraded version. Be sure to check out this thread on RX-8 club with a nice writeup from Team RX8.

Tools & Materials

• Wooden Ruler
• Paint Thinner
• Drill and a 1/4" - 3/8" diameter drill bit
• Sharp Knife (that you don't care about getting fluid on)
• Oil Catcher
• Clothing to wear that you don't care about staining permanently
• Blow Dryer
• Canned Air
• Polyurethane base and activator (I purchased mine from McMaster-Carr and it's item #8644k11)

Process

A couple of quick notes. This write-up assumes you already have the engine mounts removed from the car. Be sure to double check them for any cracks or leaks, because doing this to a damaged mount is not advisable. Also, the polyurethane takes 48 hours to cure, so be sure to do this when you won't need to use your car for a few days.

1. Start by turning the mount upside down and removing the top rubber cover of the mount with the knife
2. After you have removed the cover, be sure to empty out as much of the fluid as possible. The fluid smells and will stain your clothes pretty good, so be careful!
3. At the center hole, you will notice a rubbery layer. Carefully cut that out with the knife, trying not to puncture all the way down and through the entire mount
4. Skip this step if you have 2004-2005 engine mounts - The upgraded engine mounts have no circular opening, so you will need to drill in the center carefully and make your own circular opening in the center
5. Once you have cut out and removed the rubber layer, you should see a honeycomb-like design inside the mount. Those pouches are what will be filled with polyurethane
6. Now drill 6-8 holes around the middle hole in the engine mount with your drill. You will feel as you are drilling down, the drill going through 3 layers. The moment you feel the 3rd layer, pull back so you do not accidentally drill through the mount.
7. Once you have made your holes, check them to be sure you drilled all the way through the hard brown layers and down to the black rubber surface. Use the canned air to clean out any excess shavings left by the drill
8. Now fill the mount with your paint thinner and clean it out as much as possible. You can use water as a first pass, or go straight to the paint thinner, whatever you feel comfortable with
9. Once it looks like all of the fluid has been cleaned out, use your blow dryer, on high setting, to dry out the inside of the mount. I held my mount upside down for about 5 minutes with the blow dryer pressed against it
10. Once the mount is completely dry inside, prop both mounts on a flat surface, with support to ensure they don't accidentally get tipped over. Remember, these mounts will be sitting wherever you place them, for 48 hours
11. Take your polyurethane base can and mix in ALL of the activator for 5 minutes. BE SURE TO DO THIS OUTSIDE as the warning says. I also thought their wooden stick was too small to stir, so I liked using a long wooden ruler instead
12. Once you have mixed everything, begin by very slowly pouring it into the center of the engine mount. Pace the pouring slowly so that everything can settle nicely and the air can escape. Switch from mount to mount if need be as well
13. After some time, you'll start to notice the polyurethane rise up from the center and the side holes. Keep filling slowly until you have a nice, flat, even surface at the top of the mount
14. Once you're done pouring, you can take the ruler and run it slowly across the top of the mount so that you can ensure it's flat. Be sure to clean up any mess around the mount because it is bound to happen!
15. After clean up, let it sit for 48 hours before placing back into your car!

Outcome

I noticed a huge difference right away when I drove my car, but then again, my passenger engine mount was collapsed previously. The throttle response was greatly increased to the point that it feels like the car is drive-by-cable. Less slop in the shifter as well I noticed, but definitely an interesting feeling being able to feel the power go to the rear tires more. Overall, it feels as though I had gotten a brand new engine put into my car, so I'm overly pleased with the results. I highly recommend this to everyone. It's very very affordable, a fun project, and easy to do with some patience! With the end result being that you will then have engine mounts that will never collapse, how could you say no? Happy Motoring!

STX VS. BSP & RMC 2nd Points Event

Today was the 2nd points event for Renegade Miata! Dave is looking to get that 1st place jacket at the end of the year from SCCA just as bad as I am, so he decided to come out for some extra seat time. We decided to switch it up a little bit this event however. Thanks to Rob (chairman of the Renegade Miata Club), he allowed Dave and I to do a test in the morning. We were going to switch cars and compare the differences in our two cars with their current build, and how well we could adapt to them. This would be a great opportunity to focus on being smooth on the course while being in another RX-8 that is setup differently. In the afternoon, we then would switch back to our own cars and see if we could beat our times in the morning! This would really allow us to critique our own cars, as well as each others and consider making changes if need be. This is the first, in hopefully many more to come, "BSP VS. STX Battle"!

Photo by Ed Savage - NoWin Photography

I decided that I will be running the rest of Renegade Miata on street tires so that my Hoosiers can stay as top notch as possible, (and to be fair for this test/battle). There are not too many differences between Dave's RX-8 and my own RX-8. The biggest differences would have to be that I have the BHR midpipe, flywheel, 4.777 rear end, very different spring rates (730 lb. and 450 lb. versus 503 lb. and 337 lb.), and 255/35 Dunlop Star Specs as opposed to 265/35 Yokohama Advan AD-08. The course was very tricky and had a very interesting rhythm to it, emphasizing heavily on being consistently smooth.

Photo by Ed Savage - NoWin Photography

The battle in the morning was interesting to say the least, where as I was enjoying Dave's car and putting down quick times, making only minor adjustments, and Dave was fighting with my car to keep it stable and put the power down when exiting the turns. I helped Dave by adjusting the shocks and playing with tire pressures, getting it down to full soft in the rear, 12 clicks from stiff in the front, and 29 PSI in the front with 30 PSI in the rear. A very different setup compared to when I run R compounds. Next event I think I may actually benefit with the rear swaybar removed, so I will try that out and see how it goes.

My fastest run in the morning was a 1'21 clean, with Dave getting a 1'19 very dirty, and then a 1'22 as his fastest. In the afternoon when we switched back, I was much more at home, and so was Dave. I was able to get down to a 1'20 clean, but with a fastest of 1'19 dirty. Dave was right behind me with a 1'20. I think we both could've gone faster if we had more practice in our own cars in the morning, but I was happy with the overall test and am looking forward to the next SCCA NER race. As always, results for Renegade Miata are located here. Thanks Dave for the test, I had a lot of fun and am looking forward to our next swap or comparison battle. Below are our fastest runs in the morning and afternoon. Until then, I will be filling my motor mounts with polyurethane because it felt AMAZING in Dave's RX-8, so stay tuned!

Springtime Coneage

NER's third points event today and what a blast it was (isn't racing always a blast?)! With my refreshed alignment (thanks to Kaizen Tuning), and flipped Hoosiers, I was ready to see what I could do. We even had a surprise visit from Alex of DSG! He came out to play today and test out his new launch control and make sure the car is running properly.
The course seemed to be relatively simple, with a tricky turn-around at the beginning. If you over-cooked that turn, you would lose a lot of time trying to recover from it. Sometimes a simple course can be refreshing, and I'm sure it was laid out in such a fashion in case it would start raining again. B Street Prepared is becoming very interesting, and each race has truly been a battle for the first place. I took first with a 48.3' clean as my fastest run, and a 48.2' was my fastest dirty run. There was definitely more time out there, but I didn't want to get greedy, so I focused on being smooth and consistent instead. The results of the event are located here.
As for the results of my alignment from Kaizen Tuning (which I can't thank enough again for fitting me into their schedule!), it was very solid and felt great. Getting more negative camber in the rear is going to be key I think however, so we're aiming to move the rear to -2.0 camber, with 0 toe, and then move the camber up in the front to possibly -2.7. In order to do all of this however, I needed to order brand new adjuster bolts, as after only 40 miles and one run on the autocross course, the adjuster bolt began to spin. Flipping the Hoosier's and bringing up the tire pressures felt great, so at least there is good news there. Hopefully my alignment won't be too far off from where I need it for next Sunday, but until then, stay tuned. Below are two videos of my fastest runs for the day.

Cars & Coffee With A Side Visit To Kaizen

Photo by Josh Hanley - Josh Hanley Photography

Early morning gathering at the Larz Anderson Auto Museum on a Saturday? Sure! I suppose I could manage that after pulling an "all nighter" installing my old rollbar for an RX-8 road racer from Pennsylvania, Francesco. Once there, I got to catch up with some friends for awhile, such as Josh (Altspace), Scott of Kaizen Tuning, Mike Lee and his beautiful M3, and others. What's always nice about the Coffee & Cars meets is that it's very casual.

Photo by Michael Lee - mike-lee.org

Unlike many other gatherings I've attended, these gatherings are low-key, with some beautiful cars, tons of photography, cool enthusiasts, and ZERO tolerance for show-offs. That being said, there is never any fear in having the Police come to an event to start giving everyone a hard time because of someone ruining it for everyone. Much respect going out to Scott for letting me park next to him for some pictures by the castle. I know people have a lot more interest in his GT-R than my RX-8, but the two cars side by side came out beautiful in the shots, especially how well the vinyl work on my car popped out. Be sure to check out the pictures thread on YuppieRacing for more pictures of everyone that attended.

Photo by Michael Lee - mike-lee.org

After hanging out for awhile, we all parted ways and I took a trip over to Kaizen Tuning to drop off Serenity for some work. After seeing the wear marks on the Hoosiers and discussing it with a few other racers last event, she is desperately in need of an alignment, having my Hoosiers flipped, and my street tires as well. Once I got to the shop, I got to speak with Malcolm, who is one of the coolest cats of the crew there at Kaizen. He is a very down-to-Earth kind of guy who you can talk to about anything. When it comes time to get down to business however, you are treated not just with respect, but professionally as a racer. If anything, he probably takes whatever motorsport you compete in just as seriously as you do; and I like that because it's hard to find that mentality these days.

Photo by Josh Hanley - Josh Hanley Photography

I'm looking forward to see the result of his work, especially to see how well she will perform on Sunday's race. Thanks again to Scott for helping me out when being in a time-crunch, and massive respect to Malcolm for taking on the task of dealing with my car and my overly particular needs. Once I get her back, I'll be filling the motor mounts with polyurethane, so look forward to updates on that, along with a nice DIY. Until then, stay tuned.

Photo by Josh Hanley - Josh Hanley Photography