If you search the web for any type of Honda gear sets you're garranteed to get plenty of results right away, but for us Toyota owners its always been tough. We've always had to rely on the guys that have done hybrid builds on the forums or the super knowledgeable guys over at Monkeywrench Racing. I have built a couple performance Toyota transaxles for myself, but most of my experience comes from Subarus. I've probably built around 50 transmissions in my time as a technician, and I also keep up with Paul Cangialosi on Youtube (GearBoxVideo). This guy has a ton of manual transmission experience and knowledge, and even has wrote a book on the topic! So I'll be sharing everything I've learned from Paul, my fellow Toyota racers, and my own personal experience here to help others decide on a path for their Toyota transaxle build.
1) Final Drive Gear
A Toyota Final Drive Gear consists of 1) the output shaft and 2) the differential ring gear. The final drive gear is essentially the gear ratio between your output-shaft and your wheels, and this ratio is largely responsible for your acceleration and top speed. Most Toyota cars have a 3.9:1FD and that equates to roughly a 145mph mechanical top speed, but in reality thats not attainable due to the speed limiter or low power output. Toyota decides on a ratio that is a perfect mix of fuel economy and acceleration, performance usually being the least of their priorities. So if you swap the 3.9FD for a 4.3, you get an instant acceleration boost and your top speed drops to about 125mph. Your cruising RPM will also increase and the MPG will drop, because now you are spinning the output shaft 4.3 times for every 1 turn of the differential. The higher the number, the quicker your acceleration. Very important.
2) Limited Slip Differential
This right here is the game changer, the one piece that belongs in every racing gearbox. You can have the most expensive build out there with carbon synchros and Kazz gears, but if you dont have an LSD youre going to spin one tire constantly and lose time. A clutch-type limited-slip-differential has a small clutch pack on the end of each axle stub, a cam and wedge blocks in the center, and some preload springs. The springs hold the clutches at a specific preload but still allows some slipage, and when you accelerate the cam forces the wedge blocks against the clutches and locks the wheels together. My personal recommendation is the Cusco Type-RS, I had one for a whole year of autocross and track duty without any issues or noise. I had forgotten how much of a necesity the LSD was untill I did the C60 swap with a open differential. Get the LSD at all costs, or you will regret it.
3) Gear Ratios
In a manual gearbox, gear ratios fill the gap between starting from a stop and doing 70mph on a highway. You cant start off in 5th or 6th gear or you will destroy the clutch from slipping it for so long, likewise you cant go any faster than 35mph in 1st gear or the engine will explode. In most Toyota transaxles the 2-3-4 gear ratios are similar, with variences in 1st and 5th(or 6th) gears based on the accompanied final drive. Lets take a look at the most common boxes below.
C50 5-speed (Yaris, xA, xB-Gen1, xD)
There are 3 versions of the C50 in US circulation that I know about:
1) The Yaris has a 33mm output shaft, all brass synchros, 3.7 final drive, and a 23 spline differential.
2) The 04-07 Scion xB has a 33mm output shaft, all brass synchros, 4.3 final drive, and a 23 spline differential.
3) The Scion xD has a 40mm output shaft, mostly brass synchros with 3rd being a bi-metal, 3.7 final drive, and a 20 spline differential.
The Scion xB 4.3 FD can be put into the Yaris box with the Cusco LSD, but I've found in this application the highway cruising RPM is rather high. The best option is to use the C59 .725 5th gear with this combination. If you don't drive it on the street, then disregard this step.
The C50-59 have what seem to be "the problem bearings" between 4th and 5th gear, and Ive seen several of these explode and cause gear damage. In every case its the bearing on the output shaft that fails, and I'm going to assume its due to a combination of the open-cage design and the thrust characteristics of helical cut gears. Conrad style bearings are not rated to handle a ton of axial load, so when you are launching or doing burnouts the output shaft bearing is getting hammered from all those forces. If your gearbox starts becoming noisy while driving, don't put off the repair or you'll need a whole new transmission instead of just bearings. You can tell these bearings by their open cage design, they are very different from the superior sealed style C60 bearings.
C52 5-speed (1980's MR2)
The C52 was one of the earliest C-Series transmissions, and this results in some road blocks when attempting to upgrade. Not only does the C52 have a completely different input shaft and 4th drive gear demensions, most of the synchronizers and gear cones are unique. All of the shift hubs in this box use the older, C-clip style dog springs instead of the newer individual coil spring/dog setup. Another issue is that 5th gear is almost useless in this gearbox due to the longer(not swapable) 4th gear, once you shift into 5th at redline there is only 700rpm left until you hit redline again. You can install an LSD, and you can use the C59 5th gear to extend your speed on the straights, but you will shill have outdated parts. I recommend buying a C56 instead since they use the same bellhousing and you get modern, better gear ratios.
C56 5-speed (Celica GT, MR2 Spyder)
This C56 seems like the best 5-speed option for sure, you pretty much get a close ratio box with a great final drive from the start. The only thing you need to do to this one is drop in the Cusco Type-RS LSD, set the preload, drop in the good C60 bearings, and seal it up using the bell-housing to suit your application. And like with the C50, if you drive this on the highway a lot get the C59 5th gear to bring down the RPM a bit.
C59 5-speed (Corolla, Matrix)
The C59 is another very common gearbox, probably the most widely used in the Toyota lineup. There are also several versions of this transaxle in circulation:
1) The 95'-02' Corolla with a 3.7 FD
2) The 03'-08' Corolla/Matrix with a 3.9 FD
3) The 09'-13' Corolla with a 4.3 FD
These transmissions have the worst ratios, and probably for fuel economy reasons. There is also a speculation that the C59 is the strongest of the group, but its likely those claims arent backed by a real motorsport comparison and are just based on the number of units that fail. To make this gearbox shine you would need the latest 4.3 FD, the Cusco LSD, and swap in the C56 4th gear.
C60 6-speed (All 2ZZ-GE cars + Lotus)
The C60 represents the pinnacle of Toyota transaxle design. It has the bigger 40mm output shaft bearing, the sealed 4th, 5th and 6th bearings, bi-metal and coated 3rd gear synchro, a 4.5 FD and 6 perfectly spaced gear ratios. You cant quite grasp how amazing this gearbox is until you drive it, this thing has a way of making a 140hp car feel fast. There are a ton of aftermarked parts for this box as well; from carbon synchros to a full fledged dog-box! The only thing this gearbox needs is the Cusco LSD, and you can run with the K-swap guys.
I hope this guide helps you plan your ideal gearbox, I've started to produce assembly method videos as well! You can always check out my Youtube channel where I've uploaded a ton of race footage showing how some of these builds perform on the street, autocross, and road course.
Here is where I'll list a bunch of the parts I know about for these transmissions, starting with the 5-speed:
1) Mfactory 4.7, 4.9, 5.1 FD (AE92)($600)
2) KAZZ 4.6 FD($1400)
3) KAZZ close ratio gearset($3100)
1) InoKinetic Carbon-lined synchros($350)
2) Jubu Racing 5.0 FD (330ftlb rating)($1900)
3) Jubu Racing/SSC Gear stronger 3-4 gear-set (265ftlb rating)($1200)
4) KAZZ 4.8FD($1300)
5) KAZZ close ratio gear-set($3400)
6) Quaife dog-gear set($6000)
6) Quaife Sequential transmission ($8000)
Thanks to the sales team at Frank Subaru, I was able to test drive the NEW Subaru Ascent today, and it was awesome! The completely new 2.4L turbo engine and re-mapped CVT work together seemlessly to provide suprisingly fast acceleration, and the suspension feels tight and nimble. If you can imagine for a second, the current Subaru Outback and a WRX were mashed into one vehicle with a 3rd row of seats....Yeah its that good. Read more about this from my post on Wheelwell.
I've been told several times by people that suspension braces "just add weight", but almost every time I install one there is some kind of a noticeable change. I don't have many braces, just what I feel are the three essentials: strut tower, front lower, and a rear lower. I also have a 4 point Autopower roll bar, and it's worth mentioning that this acts as a very large brace as well. So let's discuss the things I feel are the purposes of a brace and whether or not this UR brace meets that criteria.
1 - Reinforcing An Actual Weakness
As enthusiasts, we must strive to remain focused and not be tempted into buying every single shiny part we can. The ultimate goal should be to connect suspension pick-up points across large openings like an engine bay or trunk, and always triangulate when possible. Unfortunately for those of us modifying a Yaris, there are limited options. The strut bar is a given because of the engine bay void, and then there is a not so obvious area under the rear of the car. The rear lower brace not only reinforces the recesses of the rear axle beam primary bushings, but it also ties these points together on each side of the car. From the factory Toyota had placed two stamped steel braces here, so we know without a doubt it needs to be supported. Can you imagine the forces being applied to these bushings when cornering over 1G?! Exactly, get this one.
2 - Upgraded Hardware Included
The benefits of adding a brace that transfers suspension loads probably wouldn't last very long if it attaches using Grade 2 fasteners. A good rule of thumb is to meet or exceed the original fastener hardness, and that's exactly what UR does. The original Toyota fasteners are the recessed, mark-less 4T bolts. The 4T's are the lowest on the chart for strength classification but the UR lower brace comes with a set of stainless 18.8 fasteners. That's quite the upgrade, just be sure to put some grease on the threads before installation and torque to 20ftlbs.
3 - Construction And Fitment
Now of course when you purchase a part designed to keep chassis flex to a minimum, you shouldn't be able to bend it with your bare hands. I've seen some no-name strut tower braces that are so flimsy they bend when being leaned on, that's ridiculous. Gladly that's not how UR operates. When I did the 6-speed swap I had my engine supported by a chain that was looped around the strut bar, for 5 weeks! The rear lower bar seems to be just as strong, the welds seem to have made full penetration and the paintwork is exceptional. The fitment is great as well, I'm sure the elongated mounting holes help with that aspect.
4 - Ground Clearance
One of the biggest downfalls of installing under-braces is smashing them on speed bumps. I've ridden in peoples cars that are pretty low, and when going over those Texas-sized speed bumps you feel your teeth chatter from the impact. Not only is this super unpleasant, the next time he had his car on the lift for service all of the braces were smashed up pretty bad. The openings where the bolts are were bent over and covering parts of the bolt and some of the threads in the chassis were pulled back. Good luck removing that.
If you look at the picture above you'll notice that is not the case with the UR rear lower brace. It wraps around the rear of the fuel tank only about 1 inch lower. One could even argue this can provide an amount of protection to the fuel tank, especially since it's composite. I've driven this car over many speed bumps without a single scrape, I've had the car on a Uhaul trailer as well without issue.
I honestly don't have one negative thing to say about Ultra Racing or this brace. I've seen some videos on YouTube mentioning the weld quality or how the elongated holes are a sign of weakness. If a product does what it's intended to, doesnt fail prematurely, looks great, and has a lifetime warranty...how can anyone say its sub-par just based on the price? Exactly.
Again, it's hard for me to provide feedback on a noticeable change in performance because I have a roll bar. However, I'm sure someone without one will feel a increase in chassis rigidity after installing this brace like I did with the roll bar. Check out the install video below!
One of the most dreaded issues with the GT86 seems to be the camshaft correlation faults, with a wide range of codes from P000A to P0020 this problem can leave your FA20 feeling sluggish. Don't worry though, many others have had the same issue and it's not a mystery as to what's actually going on. The reason the ECM sets these faults is due to a discrepancy in the crankshaft and camshaft timing. This can be caused by either a faulty OCV solenoid, misaligned chain, a faulty camshaft sprocket, and sometimes the ECM.
Here you can see the VVT designations as described in the service manual. Bank 1 is always on the side with cylinder 1, so B1 is on the passenger side and B2 is on the driver side. Bank 2 Sensor A is the first sensor on B2(intake cam), and Bank 2 Sensor B is the second sensor on B2(exhaust cam). With this information, you can see our P0018 Bank 2 Sensor A code is directed at the driver side intake cam.
Step 1 - VVT Initial Position Learning Values
Whenever a new ECM is registered to an FA20 equipped car, it has no stored learning values for the VVT sprockets. Even new cars from the factory need to perform a drive cycle before the ECM can "learn" the sprocket positions. Once these values are stored there is no way to erase or reset them, small adjustments can be made over long periods of time but that's it. This is why it's very important to diagnose these issues properly the first time. If you install a new ECM before the cause of the failure is repaired, you will need to replace it again and they are not cheap. Be prepared to transfer your tune software or license to the new ECM as well.
In the image above you can see what our problem cars learning values were, and right away you can tell VVT #2(intake cam Bank 2) is out of the specified range. The VVT #1(intake cam Bank 1) looks good and so do both of the VVT Ex(exhaust cam) values. At this point we know we have a problem with the driver side intake cam sprocket timing and we will need an ECM at the end of our repair. Let's move on...
Step 2 - VVT OCV
The first part of the VVT equation is the oil control valve. This 2-wire solenoid is commanded via duty cycle by the ECM to control the VVT sprockets. The solenoid presses the button in the center of the sprocket, opening the passage and allowing oil to flow inside. The oil pressure from the engine flows through the camshaft and into the sprocket chambers, forcing the inner section (attached to cam) to "advance" in relation to the outside shell (attached to the chain). The duty cycle determines how far the solenoid opens, which performs either an advance, hold, or release action.
So you can see just how important the OCV is, so let's start by marking our problem part with a sharpie as "B2A". Swap the Bank 2 sensor A solenoid and the Bank 1 sensor A solenoids, clear the ECM memory and perform a 10-minute road test. After the road test check for any pending codes, if you now have a P0016 then you have a bad OCV and it should be replaced. However, if you have the P0018 again like us then keep reading...
Step 3 - Inspect Timing Chain
Another possible cause of the cam correlation issue is jumped chain timing, I've seen it several times already and even on new unsold cars still on the lot! You will need to drain the fluids and remove the radiator and front cover to inspect the chain. Once you get access, turn the crankshaft clockwise until the key is at 6:00 and the triangles on each sides sprockets face each other like the image above. If any mark is not aligned properly then that is probably the cause of your issue, I would recommend replacing both sprockets and the tensioner on the affected side. There is no way to tell what caused the jump, and the amount of work it takes to do this repair are the reasons for my suggestions. You will need an ECM to correct the learning values for this failure.
However if your timing is aligned properly like ours was, keep reading...
Step 4 - VVT Sprockets
You can see in the picture above that there are many small parts inside the VVT sprockets. I do not know what part fails inside these gears but 90% of the time they are the cause of cam correlation issues. After verifying your chain timing is correct in the previous step, lock the tensioners with appropriate tools then go ahead and remove the chains CAREFULLY with the marks still aligned. The chains and guides are universal so you don't have to worry about mixing them up, the tensioners however, are specific. Once the chains are off, turn each sprocket by hand and be sure the cams feel smooth an free within the unloaded range. If all 4 cams feel the same and you dont find any damaged parts, go ahead and replace BOTH the intake and exhaust sprockets on the affected side. Again, you dont want to re-do this repair in the near future so be sure to eliminate the odds of accompanied component failure. I've learned this the hard way.
Reassemble the car being sure to double check the sprocket knock-pin alignment, torque the sprocket bolts, set the timing and verify chain is in the guide grooves, tensioner bolt torque, then clean ALL of the old silicon from the cover and mating surface. Install 4 new o-rings and put down a 1mm bead of silicone on the cover, get the bolts ready and wipe the engine surface 1 last time being sure no oil is there to cause a leak. Install the cover and torque the bolts accordingly, assemble the rest of the car and fill fluids. Clear the ECM memory and run the engine to purge the cooling system, then go on another 10-minute road test. When you return to check for pending codes, the P0018 should be there waiting for you.
Step 5 - ECM
The final step in this repair is to replace the ECM. The GT86 ECM is located behind the glovebox trim on the passenger side. You will need to remove the glovebox, and the surrounding trim to access the module. It is attached to a metal bracket and two 10mm nuts hold it in place. Once you install the ECM you will need to register it to the car, this process takes 30 minutes so have the battery on a charger. Once registration is complete, go ahead and do another 10-minute road test. When you return to check for pending codes again, at this time there should be nothing.
If you decide not to replace the ECM, be prepared to reset the check engine light every two trips. Also be aware your car will be down on power since the ECM will be limiting you to about half the VVT operation. I hope this helps and don't hesitate to leave any questions in the comments or suggestions.
What is corner balancing?
Corner balancing is the process of shifting weight around in the car and adjusting corner heights to obtain a desired 50/50 cross-weight percentage, ultimately making the car perform equally in left and right turns. The weight you shift in the car is usually the battery, but can also include ballast, the fuel cell, oil accumulators, and fire system tanks. You want to place these items in areas of the car that is lighter than the rest to off-set the weight from the driver and drive-train components. Ideally, these items should be kept within the wheelbase of the car, and not placed in the far corners of the trunk or engine bay to prevent a pendulum effect. After relocating everything possible the ride heights are adjusted to create a 50/50 cross-weight percentage.
When I installed the BC Racing coilovers I decided not to do the corner balancing right away. Instead, I started with the weight reduction and testing spring rates, this way I didn't need to get re-adjustments after every change. Once I had removed a lot of weight from the car and settled on the 5k springs, I set an appointment with Bret at Yawsport for corner balancing. I also asked him to do a thorough inspection of the car to verify everything was optimized. We made the 50min drive to his shop in Ramona CA to drop off the car, and anxiously awaited his updates...
The following day I get a message that the balance was pretty far off, (maybe 3% if I remember correctly) and he is unable to correct it any further due to lack of adjustment in the rear. I'm told I need to purchase ANOTHER set of Swift springs since I was sent the 7" instead of 6". When I installed the Swift springs last year I did notice that they took up almost all of my adjustment to set the ride height, but I'm a noob and didn't think anything more of it at the time.
I emailed BC and was told to call their tech support hotline, I tell them my situation and they begin to look up the part numbers to verify I was sent the correct springs. It turns out that they did send me the correct parts listed in their catalog, and because my springs were installed we couldn't do an exchange. I'm not sure if this is a isolated problem for me because my car is much lighter than stock, or if anyone else with a Yaris and these DR's have run into any issues like this.
I told Bret to do whatever was necessary to get the car balanced, he ordered and installed the new springs and had the car balanced by the following day.
I was a bit annoyed about having to buy a second set of the same springs, and Bret gave me the appropriate "I told you so" talk in regards to testing a new set of coilovers. He had warned me plenty of times, but I wanted to test something other Yaris owners could attain easily with good results. Well, that's how it goes I guess, all is well now and It didn't cost too much to do some valuable R&D. haha.
You can see in the photo above that we are now at a 50% cross weight with a driver ballast, and everyone mentioned it was going to be a huge improvement. Bret gave me a list of improvements I can do to the car, including getting that LSD as my main priority. We talked about the future of our local SCCA region and how we can make another round of spring rate changes next year when we know more about venues.
So what are the differences?
On the drive home the car felt amazing, it was like the front and rear suspension were working together now. Before, anytime I went over dips or large bumps it felt like the back of the car would rebound off the bump pretty hard. This is the reason I had to turn the dampers down to 5 clicks to drive it on the street, but now I was able to keep it at my race setting and not get beat to death. Interesting.
Our first race after the corner balancing was the 2018 Match Tour, and I noticed right away that the car felt loose. I was struggling to hold the car composed through the slaloms, but it was easily correctable so I kept rolling with it. It wasn't until my co-driver spun the car that we made some changes, we turned the rear damping down from 16 to 12 and that seemed to solve the problem. We will continue our tuning process at the next event and refer to the results to verify we going in the right direction. You can check out the Match Tour video below:
Coilovers are an amazing tool for tuning a car's suspension, but don't think for a second that you can just install them without ever messing with them again. If you're buying coilovers to slam a car and go hard-park at meets then that's fine, but to me, that seems like a waste of such a functional product. For those that want to race you need to properly install and set preload, test-n-tune the dampers, figure out spring rates, and corner balance the car. Everything you change will affect how the car behaves, so be prepared to repeat this process as your project advances. I highly recommend you get in touch with Bret and discuss your suspension goals, and listen to what he recommends the first time so you don't have to learn the hard way like me.
Connect with me