Mazdaspeed 6 KSport Big Brakes! Posted on 18 Apr 19:44
Trying out K Sport's big brake kit, install and first impressions!
Trying out K Sport's big brake kit, install and first impressions!
If you've been following Chicago Car Life's social media feeds, you may have seen my RX-7 pop up a few times. I did an impromptu photo shoot with it a while back, and while it is not as in depth a shoot as I would normally want for a feature car, I wanted to get the back story of the car on the blog. I owned a couple of modified Honda Civics previous to this car, and the modding/go fast bug bit me hard. After I was forced to sell my 00 Civic for need of more doors (new little additions to the family), and my more heavily modded 92 Civic HB was stolen, I was on the hunt for the "next thing". As much as I really enjoyed the Civic's, I did not want to go back to one for fear of having another one stolen, and I was determined to have something that was a purpose built sports car. This eventually led me down the rabbit hole of RX-7's, mostly lured in by the odd yet fascinating rotary engine. The first generation FB seemed too old tech, the third generation FD seemed too complex and costly, so the FC fit the Goldilocks model perfectly, just right.
My searches turned up this TII model in Connecticut, and having an inspection I set up come back good, I decided to make the deal. It was late April, and I decided I would fly out on a one way ticket and drive the car back home to Chicago. I flew out, inspected the car (poorly I might add), drove it through some winding, sandy roads in the rolling hills of a CT suburb and I was immediately smitten, and bad. I began the long trek home with a huge grin on my face. The weather started off as a cool, gray and misty rain in Connecticut but as I crossed into NY, progressed to a heavier rain, and a fairly heavy wind. About halfway through NY, it was now a downpour with flooding in the area, and heavy winds that had put at least one truck in a ditch. A bit unforeseen, but I soldiered on. As I transitioned into Pennsylvania I had some...concerns. It had begun to snow lightly. It was at this point during a fuel stop, that I realized my tires were a summer compound, and also not at all the amount of tread the inspection said they were. Unfortunately I was dealing with somewhat worn front tires, and nearly bald rears, all summer tires. A bit worrying, but being late April I assured myself this would be a light snow that blows over quickly and I could manage. I was wrong, and hours later I would find myself crawling at a snails pace behind a plow truck in Pennsylvania high country, with very little of anything around. Snow was accumulating by several inches on the road at this point, and traction was nearly non-existent. I found the value of fog lights in the now heavy snow fall that also cut visibility dramatically. I found the value, because I didn't have any fog lights at the time, and it was like driving through a series of white curtains, hoping there was nothing to hit on the other side. Traveling at about the pace of a bicycle now, it had gotten into the wee hours of the morning and I resolved to stay overnight somewhere in OH, hoping the storm would blow over and the April morning sun would erase all evidence of it happening.
I was awakened the following morning by the familiar and at this point, horrifying sound of plow trucks clearing the motel lot. Yep, still snowing, and with over a foot on the ground I had no idea if this thing would get me home. I spent about 30 minutes trying to find a clean enough path with no incline to fight against, and managed to somehow get out of the lot and onto the interstate highway again. The snow let up and visibility was better, but the road was a slushy mess so I was still moving pretty slowly. I struggled on, and the road conditions gradually improved, and when I was greeted by sunny skies in Indiana, I knew I would make it home. I did, and having survived this journey, made my bond to this car that much stronger. It washed away any regret about the condition of the tires, or many imperfections I would later find. I just loved that it felt like nothing else I had ever owned before.
I would continue to drive it and enjoy it for the next year or so, and that would begin a second chapter of it's life... Eventually a small coolant leak that I was negligent in fixing, led to the engine running a bit too hot on a couple of occasions. I started noticing starting the car became more difficult, idling a bit more erratic, and it would stall at times. This led me to test engine compression and unfortunately the numbers weren't great. I probably could have run it for a while as it was, but I decided to pull the engine and rebuild it. I got as far as removal and tear-down, but life circumstances intervened and I had little time and no money to continue the rebuild. The car sat for two years before I could begin thinking about rebuilding it again. Of course at this point, I was now thinking it was going to need more than just a fresh engine, and project escalation began. What proceeded was several more years of amassing new parts, stock and aftermarket, upgrades wherever possible, all with the goal of building a completely refreshed and "OE plus" version of my TII FC. After seven years of sitting, I now had enough parts amassed and some time to allow me to start the process of restoring it. Everything came off the car, I removed some rust and repainted where an ABS module leaked brake fluid, new OE brake calipers went on, all of the mods in the list were almost entirely during this time, all at once. The work moved slowly, and many of the hours spent were on the engine rebuilding itself. I had gotten closer to completion, but now was faced with having to move to a new home, but the car was not ready. In a rush, I cobbled everything I stockpiled for the car onto it or in it and ended up shipping it off to Banzai Racing. It was a three quarters complete basket case when they got it, and they did an amazing job of piecing the remainder together and sorting some issues that I had not realized were there. I would get the call that it was ready, on my birthday fittingly enough. Thus began it's second chapter in life, and my second favorite road trip home in the old FC.
Since then, I have had to sort a variety of issues that have popped up along the way, mostly brought on by mistakes I had made installing the engine to the transmission. As it sits now, it is finally sorted well enough to get it tuned. I had been running it very gingerly on a base map tune for the last two years while breaking in the engine extremely slowly (it was tricky getting many miles on it for various reasons). It is due for it's dyno tuning session soon, and I will have an update in the very near future. It has been an extremely long journey for this car, but completion is near. I am now looking forward to putting it to track and autocross duty, as well as the occasional joy ride, everything I spent all the time and effort building it for.
1989 Mazda RX-7 Turbo II
13B-T engine rebuilt with new OE Mazda seals and bearings
APEXi power intake filter on custom intake
BNR Turbo stage 2
Top Speed single exit 3" turbo back exhaust
Injector Dynamics 725cc primaries and 1000cc secondaries
Deatschwerks fuel pump
APEXi dual chamber blow off valve
GM 3 bar MAP sensor
AP Engineering APEXi Power FC w/ commander
Mazdaspeed competition engine & transmission mount bushings
Mazdatrix short shifter
Ground Control coilovers
Bilstein custom valved struts and shocks
Mazdatrix DTSS delete
Infini IV front strut bar
RE Sugiyama three point rear strut bar
Custom front suspension lower tie bar
Mazdaspeed competition lower control arm bushings
Goodrigde stainless braided brake lines
OE replica front lip spoiler
Carbon Fiber sun roof
Carbon Fiber radiator panel
Mazdaspeed steering wheel and horn
Sparco racing seat
-photos and writing: Robert Sixto
I realize I left this topic hanging, and never really had a complete conclusion to this piece, so here is my updated revision on the topic:
In this installment, I will cover the major task of removing the rear subframe and differential assembly on my Mazdaspeed6. The complete removal of the rear subframe makes replacing many of the parts easier as an individual job, but even more so when replacing several of them at once.
Nothing like a box stuffed with automotive goodies!
Most of the parts being installed will be employed to replace old worn out original components. The Corksport rear differential mount, replaces the old and very worn original OE Mazda mount; a DriveShaft Shop rear passenger side axle to replace the original factory axle that had torn boots and worn joints (the driver rear has already been replaced with a DriveShaft Shop axle for the same reason); a pair of Corksport front upper control arms to replace the worn factory originals; and a Whiteline rear sway bar as an upgrade to the OE Mazda bar since everything would be apart and easy to access. Finally, some Prothane sway bar bushing brackets would eventually go in place as well, an important step with this combination of parts. More on that later. The front upper control arms from Corksport, are some great looking pieces, they offer some additional camber adjustment, and increased rigidity in the bushings they employ. Install was a snap, with no real mishaps in the process. Long term, I had noticed the adjusting bolts develop some surface rust rather quickly, but they appear to be holding up OK.
Looks so nice and pretty before install...
On to the real meat of the job, the rear subframe removal. I must credit the great resource that is this post on nemotorsport.com. It is a fantastic, step by step guide, that I used throughout the project. I moved slowly and deliberately through each and every step, which was really a necessity for a job of this scope on my first attempt. Also bear in mind, this car is now over 10 years old with over 100,000 miles on the clock and many winters worth of salted streets. The rust is plentiful! Patience is essential in avoiding any broken bolts along the way (which still ended up happening to one bolt). The how-to from the forum is really as thorough as it gets, and made the whole process relatively easy. I was able to have the subframe removed and on the ground within a few hours, even with a relatively slow and cautious pace.
After a few hours of battling rust and grimy bolts, the subframe was out!
With the entire rear end assembly removed, this was to be a good opportunity to replace the rear differential mount, the rear sway bar, and the rear passenger side axle. Since all these components are anchored to this assembly in some form, in theory at least, the install would be a breeze. It is worth noting, my H&R sport springs, which have been on the car for at least 70,000 miles and probably about 7 years now, are holding up incredibly well. The paint on the springs shows no signs of age other than dirt, and I don't see any corrosion setting in as of yet. That's no small feat for a car driven in Chicago winters with all the slush and road salt it sees annually.
You can see apparent here, lots of rust and lots of CV joint grease spattered on the assembly
Onward with the install which was easier with the entire rear subframe removed, but there were definitely challenges. Really one challenge, the passenger side axle replacement. I had not mentioned earlier, but this was actually my second attempt at replacing this same axle. A previous effort fell short when simply hammering the axle would not free it from the hub. Being pressed for time, I simply left the job for another day. So for this go around, the hammering continued, with copious amounts of fire, several rounds of PB Blaster spraying, and lots more hammering (with the help of a friend to basically tag team the damn axle!). The axle was quite stubborn, and literally moved fractions of milimeters at a time, for a long time the progress was imperceptible to the eye. The amount of hammering needed, caused the end of the axle to mushroom out so severely that I needed to grind the excess metal in order for it to clear through the hub once freed. We lost easily an hour and a half to this axle alone.
Eventually everything was removed that needed to be, and replaced with the new upgraded parts. Fitment of all the aftermarket parts was spot on, and went together with ease. I even did a bit of rust removal on the under body and sprayed on a couple coats of 3M Rubberized undercoating for both it's sound deadening and rust preventative properties. I also repeated this on the subframe, giving it a healthy coating of Rust Bullet. After all the paint and undercoat dried, the process of lifting the rear subframe back into place went ahead slowly and carefully. The theme of taking my time was once again at play, as I wanted to be sure nothing was left loose, pinched, cracked or otherwise broken in some way in the act of sandwiching everything back into the underbody of the car. Once all the work was completed, it was time for the test drive. This test would reveal a critical issue that is key to having both the Drive Shaft Shop axles and the Whiteline rear sway bar. What you might not notice in the photos above is just how close the axles sit to the sway bar, the bar essentially wraps around the axle. When you have these beefed up versions together, the clearances become almost zero, to the point where the axles will bump against the original factory sway bar brackets. Luckily the bumping merely tore a CV boot and caused no catastrophic damage. The remedy is simple, Prothane makes a universal sway bar bracket and bushing set that fits perfectly and restores factory like clearance. I have been trouble free for over 15,000 miles since.
Long term driving impressions:
I have really no complaints with almost a year and 15,000 miles of driving, everything has held up well. As for performance, nothing in my opinion took away from the performance or comfort. Little, if any, noise or vibration was created with the addition of these parts. The real performance stand out, is the Whiteline rear sway bar. I can say emphatically, that this is how it should have been delivered from the factory. The cornering grip and the way it rotates now is better than I would have imagined it could be simply from replacing the rear sway bar. I would consider this modification a must if you really want to extract the best handling from this car, even if you already have lowered and stiffened it via springs/shocks or coilovers. The customer service stand out, was definitely Drive Shaft Shop. You may have picked up on the fact that I was not aware my new sway bar would rub against the Drive Shaft Shop axles, and sure enough I tore open a CV boot as a result. A call to Drive Shaft Shop, just to price out the replacement boot and ask about how to replace it, was met with courteous and eager help from the staff. Not only that, but they even ended up sending me that replacement boot kit free of charge! I never asked for even a discount, as I took full blame for the mishap, but they made the gesture anyway. That is something that really makes an impression for me, and I would never hesitate to use their products and services in the future. Be sure to check out more Mazdaspeed 6 modifications, like my big brake upgrade!
-photos and writing: Robert Sixto
After doing some recent wrenching on the Mazdaspeed 6, it occurred to me that this thing might be turning into a bit of a project. I had just finished with an overhaul that required dropping the rear subframe all over again, thanks to a torn CV boot. That damage resulted from an ongoing heavyweight boxing match between two muscle bound components I had upgraded from stock; Drive Shaft Shop rear axles and an upgraded rear sway bar from Whiteline suspension. To break up the fight and remedy the carnage, I would not only replace the torn CV boot, but also install some lower profile sway bar bushings from Energy Suspension. For good measure, I also installed a set of Rigid Collars I ordered some time ago. In addition, I removed considerable amounts of rust, added additional rust proofing measures, and even added some extra sound deadening to the trunk along the way. Some of the damage was referenced in photographs for my past entry "The Car Life, an Irrational Bond". New CV boot went in with fresh grease, and the low profile sway bar bushings gave much needed space between the axle and the sway bar. Once finished, the rear of the car was quiet, felt tight, and most importantly the two brawny components, DSS axles and Whiteline sway bar, were living together in perfect peace and harmony. It felt and drove well, at least for a while.
So what is the threshold at which a car becomes a project? I had not really considered this question, I presumed a project car was something of a choice. You chose to buy a 20 year old car that undoubtedly needed some refreshing, or you chose to do some wild engine swap, or you chose to turn a street car into a dedicated racer, any one or all of these things happen as a choice driven by passion or some pipe dream. However, when a car becomes a project, that is something entirely different. Could this be where the Mazdaspeed 6 is now, crossing into the realm of project car organically? After repairing all of the rear end maladies, it seems the front end wanted some attention. I started experiencing some troubling drop off's in fuel pressure and power, which was traced to a failing fuel pressure relief valve. While under the hood, I also happened to notice what I thought was minor transmission fluid seepage, had become a bit heavier and in need of attention. Nothing major, a shifter pivot seal would fix it, and was relatively easy to replace.
No sooner than when I had these very parts on order, upon shutting the car down one day, I noticed that concerning sweet smell every petrolhead knows: coolant. Yep, radiator was leaking! Luckily it was caught before I lost much coolant, and I do mean lucky as the leak was actually pretty substantial. It never even ran slightly hotter than normal, so I consider myself very fortunate. The OEM radiator is one of the common types with plastic end tanks crimped to a metal cooling section, and unfortunately those two different materials will almost inevitably result in leakage with age. Sadly, the market is short on upgrade or entirely metal constructed options for the radiator on this car. Not finding anything available, and failing to get any manufacturers to entertain producing one, I opted to stick with the original equipment.
In order to access the radiator on the Mazdaspeed 6, much of the front end must come apart. The bumper, the bumper support beam (or crash beam), and the radiator support all came apart. In the process I found more rust, shocking I know. So it was a familiar process of removing rust, coating in Rust Bullet, and painting over it. Rinse, repeat. Much of the process is waiting for paint to dry, so it works out that this can be done while I wait for the new ordered parts to arrive. On a positive note, having this much apart, makes accessing the fuel pressure relief valve and the pivot shaft seal much easier. Although it does also present temptation to take on other tasks, "while I am in there", but in the interest of keeping a reasonable budget and keeping things simple, I will resist. (Front mount intercooler? Port and polish head and intake manifold? Injector seals? A resounding 'no' to all of that, project escalation will be kept at bay this time around.)
I never considered what the criteria for a car becoming a project were, but it certainly feels like the Mazdaspeed 6 has started to become one. With endless rust to remove and prevent, and a string of repairs in the last couple months, it seems to be creeping toward the realm of project, but is number of repairs the determining factor? All in all, I can not really complain, the car has lived a tough life and with it's age and mileage, some overhauling was to be expected. I suppose it speaks well of the car that this string of issues is something out of the ordinary. Maybe I am wrong, perhaps it is not a project car after all, but just typical aging car issues. I imagine time will tell, once I have everything buttoned up and running again, hopefully it stays that way for a while.
photos and writing - Robert Sixto
In my previous post, I had several parts awaiting install on the Mazdaspeed 6, including the Corksport rear engine mount. I had considered installing this mount along with the other suspension arms and differential mount that I have on hand, but reconsidered. I happened to be doing my oil change anyway, and the mount is fairly easy and accessible, so I decided to install it alone. I also figured, adding the parts in more gradual stages would better reveal which components eliminate which issue. This piecemeal approach will quickly change, as I rush to get the car prepped for an upcoming track day, fingers crossed.
The CorkSport rear motor mount has lived up to their tag line, "full of win"
I must admit, the results of the new mount were quite surprising. One of my concerns was my high flow downpipe rubbing under hard acceleration intermittently. Having replaced both the transmission and passenger side mount already, this rear motor mount was the last component that had any considerable wear on it. The install of the new rear motor mount, seems to have alleviated the issue completely. As such, I can now disclose the downpipe I have is also made by CorkSport, which I did not want to initially say, for fear of unfairly marring the reputation of the part's quality. After putting some mileage on the car with the new mount in place, I can say with complete confidence the downpipe adds great performance, but also fits perfectly. It is clear the downpipe and the rear mount were designed with the other in mind, as the clearances and tolerances are now perfect.
I can happily report that the the jerky sensation under acceleration and deceleration that plagued the car with the original factory mount, is completely resolved. With the new Corksport mount, throttle response seems considerably more immediate and smooth. The best part though; while the Corksport rear motor mount appears more aggressive and more rigid this has not translated into an increase in noise or vibration. Actually, it seems just the contrary, the vibration is considerably less than with the my worn mount. I can also say the Corksport mount transmits less vibration and noise than the CP-e mount that I have had in the past as well. I suspect a key design difference is the way the bushing wraps around the metal body of the mount, better insulating the cabin from an increase in vibration and noise. The CP-e mount, while stout indeed, differed in this regard, having metal to metal contact where the bolt sleeves meet the subframe and transmission respectively. The only thing in question for now, is the longevity of the Corksport piece, which can only be discovered with time. If everything else goes as planned, I will be putting the mount to the test on the track in the near future.
In short, the Corksport rear motor mount is a keeper! While no means a definitive comparison, I have now had experience with the OE mount, the CP-e mount and the Corksport mount. Of the three I can say the Corksport is easily the winner in my opinion. The biggest take away from this though, is how much of a weak link this component is, and how great an impact it has on the driveability of the car. It surprised me that it bears so much of the strain, even with completely new mounts all around it. For anyone that owns a Mazdaspeed6, or even it's little brother the Mazdaspeed3, this component really is a must have, and with the Corksport mount, there really is little downside in terms of noise/comfort. I am eager to see the improvement the rear differential mount brings, and will check in with details in the future. Thanks for reading!
-writing and photos: Robert Sixto
My 2006 Mazdaspeed 6 was beginning to show it's age. With over 100,000 miles on the odometer, and now over ten years old, there are several of the softer rubber bits on the car starting to soften and wear. This has presented itself in the car as a general clunky feel when driving over bumps, accelerating and turning. The components in question are the rear motor mount, the rear differential mount, the front lower control arm bushings, and even the exhaust hangers. For the mounts and exhaust hangers, I have opted to go with the Corksport made upgrades shown below.
The rear motor mount shown on the left, will be replacing a CP-e mount that has been on the car for over 60,000 miles now, which includes some heavy track use, heavy mountain road use, and just the daily stop and go traffic grind. The rear differential mount pictured on the right, will be replacing the original OE mount. Yes, I said original. That may seem crazy to anyone that knows this car, as it was singled out as one of the key weak points of the car. It is probably a fix that has been long overdue with over 100,000 miles on it now, but better late than never. Those nifty blue exhaust hangers are being employed to further tighten things along the exhaust, along with the more rigid drivetrain. I have been plagued with an intermittent rubbing of my down pipe, that seems likely to be a combination of worn mounts and exhaust hangers. Hopefully, the addition of all these upgrades eliminates the rub as well as sharpens the cars response with an overall increase in rigidity.
The final piece, is another repair that has been long overdue, the front lower control arms. These are long overdue because there was a service bulletin released by Mazda, that indicated the large bushing on the end would wear and end up sitting on the frame in a way that causes noise. That noise has been present for years, and largely ignored by me until now. Recently, the bushing wear seems to have increased to the point beyond being just noisy, but actually causing a harsh feel in the front suspension. I could have simply replaced the bushings alone on the existing arms, but in this case opted to get the entire arm. I did this firstly for ease of install and secondly to replace the aging ball joint on the other end of the arm, since it made sense to do with 100,000 miles plus. Once all these bits have made it onto the car, I will update with a review post on the end results. Thanks for watching!
-photos and writing by: Robert Sixto