I rode in a friend’s Ferrari (1978 308) recently and while I love how it sounds… I often can not get enough of the turbocharged sound. So if you love the sound of turbochargers doing work here you go:
Link for you RSS peeps.
It may be an older video of ours, but I love it and cannot get enough.
Update: Apparently I decided to post this exactly two years after uploading it to YouTube. Odd.
In June of 2008 I wrote an article lamenting about Rally America’s rules on sequential transmissions. Turns out they’ve caved…a bit. I was reading the rules and I stumbled over this on page 89 section 6c:
Gear Change: The use of an unassisted manual sequential gear change mechanism is allowed.
Neat! You can use a sequential given that you have direct access to the mechanical selector. That is only one step away from an electro-whathaveyou sequential with paddle controls. Although you cannot control many parts electronically (yet), as seen on page 89 section 6b:
Electronic Controls: No type or form of electronic control is permitted for the following components:
i. Suspension, steering, braking, gear change/clutch, front and rear differentials.
ii. Simple engine cut operating during a mechanically activated gear change is permitted.
So you cannot control the clutch/transmission electronically yet. But you can flat shift, which means you keep your foot planted on the gas pedal during shifts and electronically cut the engine’s power. Either way, there is hope for Rally America to become the premiere rally league in the future. Not for a while though.
I came across some intruiging information earlier on the Nissan GT-R. While this may be old news to some of you, the gist of it is that Nissan is not honoring the warranty if the transmission fails after doing launches with the VDC off, and launch control on.
The GT-R has an interesting transmission, a computer controlled dual clutch sequential. So this means that Nissan has intentionally included a feature in their car that would void the warranty when used for anything other than getting the car unstuck from mud or snow. While this can be interpreted in a lot of different ways, it brings up an interesting, although blindingly obvious point to me.
Cars break.
The real question then is why do they break? For the average person, it’s likely due to improper maintainance, or simply normal wear and tear that takes out a component that may or may not be critical to the operation of the vehicle.
However, for people like Charles and I, and most likely you as well, we drive our cars hard. We expect the engineers who designed it to allow the car to be driven at full power and aggressively by including headroom in the strength and durability of critical components. But of course, even with that, there are things that you do that wear down parts, and will eventually break them.
Luckily, things are designed so that cheaper parts that are easy to replace take the brunt of the damage, protecting the more expensive components.
Aggressive turning will wear down suspension bushings, and tires a bunch. Hard shifting is hard on the clutch and engine mounts. Rough roads are also tough on the suspension bushings, and the dampers, and sometimes rattles the interior apart.
However, it’s not too hard to exceed the limits of some of these safety components and break something more important. For example, launching the car by dumping the clutch with the engine at a high rpm is very hard on the transmission, driveshafts, differentials, axles, and related bushings. It’s not uncommon for someone to break a differential gear or axle spindle when doing hard launches like so.
Something else transmission related that is hard to avoid is synchro wear. Synchros allow you to change between gears easily, and without rev-matching. In most modern manual gearboxes, the gears are always meshed together, but spin freely on a shaft. The gear is selected by engaging a ring, which then prevents the gear from rotating, and transfers the torque into the shaft. When engaging this ring, it needs to be spinning close to the same speed as the gear, or else there will be an awesome grinding noise and you won’t be able to select the gear. It is the synchro’s job to make sure everything is spinning at the right speed. However, the synchros wear out with use. Each gear shift puts a little more wear and heat into it. If you’re using the synchros a lot to make shifts that involve large RPM changes, they overheat and warp, creating a spot that rubs more than the rest, getting hotter and wearing faster, etc. So when downshifting, try to double-clutch whenever possible to reduce wear on those synchros! I know that was an awkward and cumbersome explaination, so I’m sorry, I’ll make a dedicated transmission post someday to explain it in more detail. However, we have made a video a while back on how to double-clutch if you’re not familiar with it:
In addition to that, there are plenty of other things. Keep the interior and exterior clean to avoid rust and damage to the finish. Don’t run into stationary solid objects. All those things that you generally can’t avoid when rallying, hahaha.
Oh Look a Video!
Read the Text version here on Two Guys Rally.
A video on how to double clutch:
Read the text version here on Two Guys Rally. Youtube video. Revver video.
Performing a Heel-Toe Down Shift
Step 4 is what makes the Heel-Toe a Heel-Toe. Its name comes from the fact that the toes of the right foot and the heel of the right foot are on separate pedals. Specifically the toes (balls of the feet) are braking while the heel blips the throttle. Depending on the pedal setup of the car a Heel-Toe becomes an Inside-Outside where the Inside of the right foot brakes while the outside blips the throttle.
Steps 3 and 4, after practice, happen simultaneously. The six steps end up taking very little time to execute with practice. To make it even more complex steps 3 and 4 can also be expanded to include a Double Clutch to be easier on the transmission. Double Clutching during the Heel-Toe procedure adds 3 steps to the process:
Why Heel-Toe?
Under braking and cornering a sudden load on the drivetrain (because of a failure to match RPMs in a downshift) could cause the drive wheels to lose traction. The Heel part makes the downshift smooth while the Toe part keeps the braking pressure on. A properly executed Heel-Toe also keeps the car balanced while braking.
Keeping the drive wheels loaded with the engine’s torque will also make braking lock-ups of the drive wheels harder to do.
Just as with Double Clutching the point of a Heel-Toe is smoothness and it gets easier and easier with practice. Remember, keep it smooth and the speed will come.
Performing the Double Clutch
The hardest part of those 7 steps is figuring out how much to raise the engine revs in step 5. It all depends on how fast you’re going and your transmission’s gearing. In my WRX I’ve noticed it is about 2-2.5k RPM increase during a downshift.
Don’t worry about how quickly you’re double clutching, speed comes with practice what matters is smoothness.
Why Double Clutch?
Double clutching was once a required technique. It was used to sync the engine and transmission speed. In older cars without double clutching you were unable to shift (you even had to double clutch to up shift). However, in new transmissions synchromesh gears do most of that work. While the synchromesh gears reduce the need for double clutching, they don’t handle the large changes in speed that go with down shifts very well. Double clutching makes the downshifts smoother and saves wear on the transmission by reducing the amount of work done by the synchromesh units. So go out and practice a double clutch down shift (in a safe place), it’ll save you precious money on your transmission.
Here’s the video version: How To Double Clutch: The Video.
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