Last time we spoke about New Dash and Rear Diff oil catch can.
We dropped Project Moff off at Abbey Motorsport for a large list of work !
Firstly, cambelt and water pump change.
What did we change the cambelt ?
This engine was built back at the end of 2010. We are actually a litle overdue a cambelt change. The cambelt (or timing belt) is a rubber belt that controls the timing of your vehicle's internal combustion engine. It performs a vital function by ensuring that the crankshaft and the camshaft rotate in synchronisation. It is the ribbed belt that is placed in a specific configuration along one side of your engine to keep the crank and camshafts timed properly. Essentially, it keeps the top half of the engine (cylinder head, valves) in sync with the bottom half (crankcase, pistons).
What happens if my timing belt snaps ?
Well, that depends. There are two types of engine timing configurations: interference, and non-interference.
An interference type engine means that the valve's stroke and piston's stroke take up the same space in the cylinder, so the timing belt essentially keeps them from hitting into each other, since they do it at different times. If the timing belt snaps, they run into each other, causing bent valves (most common), cylinder head or camshaft damage, and possibly piston and cylinder wall damage. While it is possible that no damage could occur from a snapped belt on an interference engine, such a case is unlikely.
What parts were needed ?
Cambelt (we chose an HKS timing belt for its additional strength over the standard belts)
Idlers and tensioners.
Nissan N1 Water pump.
Why did we change the water pump ?
There was no other reason, than it is not much additional time to do whilst the cambelt is off. To do the water pump alone would require the cambelt to come off anyway, so made sense to do it at the same time. Then we also have peace of mind that is it new.
Fitting of Nitron suspension
We recently told you about the wordls first Nitron suspension we have been working with Nitron to develop for the R33 GTS-t Nissan Skyline.
The remote reservoirs were very neatly installed, meaning they would be easily reachable to adjust at the circuit.
The next step was to set up the geometry and corner weighting for the car.
Why is my car geometry / alignment / tracking important ?
There are many reasons, which include un-even tyre wear reduction and fuel economy improvement on road cars. Misalignment may also cause vibration that you'll feel especially in the steering wheel. Simply put, proper wheel alignment allows for safer driving.
How car you set up car alignment ?
Abbey Motorsport use the Hunter Hawkeye four-wheel alignment tool, which is renowned for its accuracy and uses a series of high-definition imaging sensors which measure 14 primary alignment angles on your vehicle. These include Camber, Caster, Thrust Line, Toe in and Toe out. The position and orientation of your wheels are compared against the vehicle manufacturers data for your vehicle, ensuring the vehicle is set up perfectly for you to drive.
How do you set up geometry for a race track ?
‘Set-up’ means adjusting all the variables on the car to make it go around the track as fast as it can. It means getting the car to feel right for the driver and making it behave properly around the corners. Car setup is part science, part art, part luck. The really annoying bit of it is the amount of variables in play make it very difficult, if not impossible to define exactly what is the solution to any particular handling problem.
In short, you adjust the Camber, Caster, Thrust Line, Toe in and Toe out of the wheels.
This is quite a big topic, so there is further reading below at the bottom of this article.
For now, we will cover what we have done. Firstly the car needs to be aligned, then it can be corner weighted. PLEASE NOTE - Once the alignment of a car has been completed, and you start playing with corner weighting, it will be necessary to re-check the alignment. All in all, it can be quite a time consuming job.
What is corner weighting / corner balance ?
In short, it is the amount your car weighs through each of the 4 corners. We cover it in more detail further below. In short
One of the most important aspects of car setup is the static weight distribution and the cross-weight percentage. Why?
Your car is really fast in right-hand turns, but understeers in left turns. If you get the car neutral in left turns, it oversteers in right turns. The situation is frustrating. You’ve tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. Even on a track with mostly right-hand turns, the problem in the left-hand turns cost a lot of time.
While several different setup parameters could have caused this situation, a likely cause is excessive cross-weight.
So, to set this up, the car is put on the scales. 1 under each wheel, and a reading taken. We are looking for an even diagonal reading (to be half the weight of the car). A car is rarely in a straight line, without other external forces changing the weight balance of the car (these can include acceleration, braking, gradient of race circuit and more).
We are happy with the end result, whic includes 80kg for the driver and 60kg of fuel.
The end result for our geometry as below, which would be more than useless on the road, and wear out the tyres in no time, but looks set to be fantastic on the circuit,
In our next part, we are going to be having the Link G4 ECU fitted, and the car will be going on the dyno, exciting times !
Below is further reading on the suspension geometry, corner weighting and more for the really nerdy ones out there ! :)
A Beginners Racing guide To Car Set-Up / Geometry
You’re trying to balance driving technique, damper rates, spring rates, camber angles, caster angles, toe angles, Ackerman (or anti-Ackerman) angles, anti-roll bar rates, brake balance, roll-centre position and height, king-pin inclination, tyre pressures and innumerable other variables to find a handling package that works.
Each of them is interconnected with the others and changing one has an impact on the others.
At this point many people give up and go for the Jeremy Clarkson approach of “POWER!” Don’t despair.
There are a few principles that can make life much easier. The first thing you need to be clear on is what you are trying to make a car do. If your car over-steers horribly in the pit-lane, who cares? It is not going to affect your lap time. Drivers regularly try to find a set-up that feels great in every corner. In reality that is as unnecessary as it is difficult. The first thing you must do when setting up a race car is figure out which corners are most important.
What happens to the car in cornering ?
This is the part of the corner from brake-point until apex. When you hit the brakes the rear tyres lighten and the front tyres gain download as the weight transfers to the front. This happens regardless of what settings you have on springs and dampers. Even if you make your suspension out of solid box-section, you still get weight transfer when you hit the brakes. As you begin to turn in (you may or may not still be on the brakes) the weight begins its transfer from inside to outside as the lateral g-loading increases.
This is the point at which the car ‘takes its set’. This is an easy way to put something that is a complex interrelation of slip angles and weight transfer. It is basically the point at which the car assumes the attitude it will remain at until the exit phase starts. The transition phase is when the driver is not adding any more turning to the steering wheel and (usually) is transitioning from brakes to throttle. At this point the car will be at maximum lateral g and will be transferring weight from front to back as the brakes are released and the throttle applied.
This is the phase where the driver will move to full throttle and start to unwind the wheel (ideally at the same time). At this point the final weight transfer to the rear is completed as full throttle is reached. The reason it’s important to analyse corners in these phases is because you’ll find totally different things causing similar car behaviour in each of the phases. Let’s take it from the engineer’s perspective; you’re waiting in the garage as the driver comes in. He gets out of the car and tells you the car ‘has too much over-steer’. That’s essentially useless unless he can understand where and thereby why…
If it is corner-entry over-steer, the cause could be brake balance or poor gear-shifting. If it is transition over-steer it could be overly hard dampers, bump-steer, roll-bars, spring rates or a simple ‘pop-off’ the brakes by the driver. If it is corner-exit over-steer it could be over-heavy spring rates or roll-bars or a leaden right foot.
So if you’re the engineer any changes you make will be as likely to make things worse as better if you don’t know where the car is doing what it is doing.
All of this looks very daunting and complicated if you don’t know one end of a spanner from the other, but it isn’t that tricky. A lot of variables are taken out of the equation if you get Sheane Cars in Co. Wicklow to do a basic set-up on the car. They’ll set camber, caster, toe, Ackermann, bump-steer, roll-centres and spring rates. That leaves the less mechanically-minded driver to play with dampers, roll-bars and brake balance.
What is oversteer ?
Oversteer happen more frequently in rear wheel drive (RWD) cars. This is when the rear end of the car tries to overtake the front of the car. Look at any of the car test videos on most TV programs.
What is understeer ?
This is when a car loses grip on the front end in a corner and continues to go straight on even though the wheels are being turned.
Understanding Corner weighting / Corner balance
One of the most important aspects of car setup is the static weight distribution and the cross-weight percentage across all 4 tyres.
Lets say, your car is really fast in right-hand turns, but understeers in left turns. If you get the car neutral in left turns, it oversteers in right turns. The situation is frustrating. You’ve tried springs, shocks, different anti-roll bars and everything in between.
While several different setup parameters could have caused this situation, a likely cause is excessive cross-weight.
In an ideal world, you would like each corner of the car to have 25% of the weight of the car, including the driver and fuel.
How is the corner weight on a car changed ?
This is done by adjusting the ride height of the car in a given corner. Think of how you would transfer weight from one foot to another. By doing this, you can make your weight of one foot weigh more on one scale to the other. This is the same of a car, only it has 4 contact patches with the ground.
How to set Static Weight Distribution:
-Check static weight before working on cross-weight.
-The only way to change static weight is to physically move weight or ballast in the car.
-To increase left-side weight, move weight as far to the left as possible.
-To increase rear weight, move weight as far back as possible.
-Move ballast first, since it's easier. Then move components like the battery or fuel cell.
-It is best to get 50 percent left-side weight when possible.
-Get the rear percentage as close to the manufacturer's specs as possible.
How to set Cross-weight:
-Once static weight percentages are set, work on cross-weight percentages.
-You cannot change the left or rear percentages by jacking weight around in the car, although this will change cross-weight.
-Changing the ride height at any corner will change the cross-weight percentage.
-If you raise the ride height at a given corner (put a turn in or add a round of wedge), the -weight on that corner will increase, as will the weight on the diagonally opposite corner. -The other two corners will lose weight.
-If you lower the ride height at a given corner, that corner will lose weight as will the diagonally opposite corner. The other two corners will gain weight. This will not change the left-side or rear weight percentages.
-To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. For example, if your initial setup is 56 percent cross-weight, and you want 50 percent cross-weight, lowering the right front or left rear corner will decrease cross-weight percentage. You could also raise the left front or right rear ride heights to do the same thing.
-It is best to make small changes at each corner, instead of a big change at one corner. This keeps the ride heights as close to ideal as possible. In the above example, to go from 56 percent to 50 percent cross-weight, try lowering the right front and the left rear one-half turn on the weight jack bolt or spring perch while raising the left front and right rear the same amount.
-Always record the cross-weights and ride heights for reference at the race track in case changes are needed.
-Measure control arm angles after each change. The angles are another way to set the suspension for the desired ride height and cross-weight percentage.
-The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal.
-Remember that changes in stagger, tyre pressures and springs will change the ride height and alter the cross-weight percentage.
Changes at the Track:
-Make small changes at the track, and make only one change at a time.
-If the car understeers or oversteers in only one direction, check the cross-weight percentage.