Posts Tagged ‘weight saving’

Robin Returns

Tuesday, August 14th, 2012

After test runs at Santa Pod the Robin hit the track at Mallory Park. With it’s suspension upgrades the grip was so good we upped the boost and timing slightly for more power. About 3 laps later the headgasket blew, it was fairly inevitable. After the Nissan Deltawing was so successful in this years Le Mans we opted to take the Robin project to the next level. The Robin already uses many similar principals to the Deltawing but until now has used a different concept for weight distribution. The whole car is coming apart again to have a massive rearward shift designed into the weight balance. The engine will get more power and better cooling. nissan deltawing at lemans

custom throttle body manifold

bike throttle bodies on our manifold for the Reliant head


Reliant Robin track day car

At Mallory Park


ensuring engine is level

Relocating the reliant enginebike throttle bodies on our manifold for the Reliant headAt Mallory Park

It’s what we do- excerpt from an article for Practical Performance Car magazine

Friday, April 27th, 2012

It’s strange that the first question people ask when they’re checking out modified cars is often ‘How much power has it got?’ It’s all well and good being able to say it’s got 400 bhp, but how much weight is that power having to shift? If the car weighs two tonnes then you’ve only got 200 bhp per tonne, which is suddenly less impressive. That’s only equal to a 100 bhp engine in a 500 kg car. The thing is if you tell people you’ve only got 100 bhp they’ll snigger and walk away. ‘Pfff, my Mom’s Corsa has got more power than that’. The conversation’s over before anyone mentions weight.


Weight goes far beyond the simple bhp/tonne figure though. Bigger engines will often produce more than enough power to compensate for their extra weight. Carrying a hoofing great engine around does nothing for the handling though. The overall weight of a car will make a huge difference to how it accelerates, brakes and turns into a corner. The distribution of the weight in the car is just as important and can be used to either tune or ruin the handling characteristics.


It’s fairly obvious that having a light car means you can accelerate and brake faster, there’s less weight to move around. But just as important is how the weight is spread out across the cars tyres. Each tyre is actually holding up a different weight. In most road cars with the engine up front, the front tyres are holding up a lot more weight than the rears. Likewise with only the driver in, the off side tyres are carrying more weight than the nearside. Amongst other things, the amount of weight (or down force) a tyre has on it will dictate how much grip it can produce, up to a point. From that you could think a heavier car could corner faster. The problem is that the cars weight also acts sideways in a corner and it takes some of the available grip of the tyre and pulls it sideways, causing the tyre to ‘scrub‘. All tyres scrub sideways when turning, it’s known as the slip angle.  Push the slip angle too far and you’re sliding, push the slide too far and you’re spinning. Heavier cars increase slip angles faster than light ones so they run out of grip faster.

To help ensure each tyre is carrying an equal load to start with, cars can be corner weighted. That involves raising the spring heights so more load goes onto the corners where there was less. Unless you have a very well balanced car the weight distribution will always be biased in one direction or another, but it helps to spread the cars weight as evenly as possible. This means each tyre is doing it’s fair share of clinging your car to the road. Corner weighting a car doesn’t necessarily move the weight distribution in the car, it just alters how the car’s suspension supports it.


Of course all that talk of spreading the weight out on the tyres is massively over simplified. There’s so many other factors influencing how the car’s suspension behaves, and all we’ve considered so far is how the weight is supported across the four corners. We should also spare a thought for where the weight is in the car. Rather than just say the car has weight, the weight distribution around the car can all be added up and said to have a centre of gravity. It’s basically the balance point for all the weight in the car. If the car was hung from a rope attached at the centre of gravity it would always be balanced. The centre of gravity also has a height within the car. The higher the centre of gravity the more a car will lean as it corners. It leans, or rolls because opposing forces act on the centre of gravity as you corner. It’s those forces you can feel when you are pushed out of your seat as the car brakes or corners. This is called weight transfer. The more it rolls during a corner the more it takes load off the inside tyres reducing the overall grip available to the car.

The centre of gravity rolls around a pivot point called its roll centre, which is set by the cars suspension pick up points. Unless you’re planning on moving the suspension pick up points the best way to reduce the amount of roll a car has is make it lighter and get the weight as low down in the car as possible. Stiffer suspension springs will resist body roll. Generally you’ll always want the softest springs possible for traction but stiff enough to stop too much weight transfer. Assuming your tyres are up to the job of transmitting the load then sometimes a bit more weight transfer in a straight line (pitch) helps push them into the road surface and get more grip. For example if you have a rear wheel drive car with the engine at the front you’ll need a bit of weight transfer to get the driving tyres to grip properly. Generally though too much weight transfer reduces grip and ruins the balance in the car, especially during cornering (roll). It’s that balance that everyone’s trying to find when they set a car up. How much weight your car has and where it’s distributed will affect how much weight transfer you have, how much work your suspension is having to do and so how hard you can push your tyres when accelerating, braking and cornering. Performance driving techniques are all developed around shifting the balance around the tyres to get the best grip for the longest time. It’s all of these factors and more that we focus on when developing a car, and it’s driver.

MX5 Hillclimb car

Friday, April 27th, 2012

We’ve been building this hillclimb car for Practical Performance Car Magazine. The full details of the build will be available to read over the next few months. PPC mag have an event called the 999 challenge. The idea is to build the best MoT passable car you can for 999 quid and carry out  a timed quarter mile and handling course. The fastest car wins. We decided to take the concept a step further and see if we could build a hill climb car for full competition still sticking to the 999 pound budget. The list of modifications is massive. We reduced the weight by about 20% which is hard going on a car that’s so light to start with. With all the weight stripped out we built a cage that not only keeps the driver safe but adds to the shells rigidity. The engine received a turbo and anti lag system including launch control and flat shift. It also features a hydrogen gas system for better combustion and a cold water spray for the intercooler. We carried out a few suspension and brake modifications and thoroughly set the cars geometry to give it perfect handling. The aerodynamics were last to be addressed and are controlled tightly by the regulations. We designed an aero package that other than the allowed rear spoiler didn’t change the cars silhouette. We achieved this with a flat underfloor, undercut splitter and a rear diffuser than uses a cut out into the rear bumper. The rear aero is fed by the exhaust gases between the spoiler and the diffuser which aid flow attachment. There’s still some fine tuning to be done but it should be an awesome package on a very tight budget

Capri Construction

Monday, November 29th, 2010

The AA Silencers Capri is finally going back together. The inside and engine bay have been painted and lots of weight taken out. There have been various changes to the oil and cooling systems plus fuel system. The Aerodynamic underfloor is ready for construction and the exhausts need finishing but it’s taking shape ready for the start of the next race season.

How to get rid of rust and make your car faster

Friday, June 11th, 2010

As AA Silencers is busy with Practical Performance Car Magazines racing efforts this year our Capri is not needed on track.  We decided this would be a good time to give it a bit of a freshen up and try to squeeze out a bit more speed. As always the main item on the agenda was weight saving but also to improve the aerodynamics and get rid of the rust that can creep in to any older car.

The solution was simple, identify any bits of the car you don’t need and cut them off, especially if there’s any rust in them. The shell has been multipointed and the cag extended and a complete new aero underfloor has been designed. There’s a huge amount of work to do but it shoudl be worth it when the car gets back on track. Here’s some pictures for the mean time




AA Silencers-gives you wiiiings

Tuesday, January 26th, 2010

The Capri has been resting over the winter but development has slowly been taking place. lighter rear brakes have been developed and some more weight has been trimmed from the shell. Wider wheels have been added and some modifications were required to get them in and still be able to turn the wheel! All of the glass bar the windscreen has now been binned in favour of plastic which again is a huge saving in weight and even the wing mirrors have shruk in the name of weight loss and better aero efficiency. The aero package has extended further than the mirrors though and the car now has a front air damn and rear wing, plus a few other cunning tweeks here and there. Now it’s time for more power so we’ve got a new engine in development which will hopefully give us an extra 100BHP or so. Fingers crossed



Monday, January 19th, 2009

2008-Capri- work began in earnest on AA Silencers next race car.

DSCF1305What was originally a 1.6 Ford Capri came in for some major work. This started by completely stripping it to a bare shell. All major areas of rust were tended to, all none structural metal was removed and a roll cage fabricated. Fibre glass wings, bonnet and tailgate were fitted and a new lightweight wiring harness was made. A new cross member was fabricated for the front to relocate suspension and steering components plus engine mounts for the new engine. An inlet manifold was fabricated from scratch to take an as yet untried inlet system combination and an ECU was sourced for the ignition. The wiring loom was made for the ECU and all necessary sensors sourced and brackets and adaptors made to fit them as required. The engine was fitted and rigged with a temporary cooling system. A dash was made and wired in to monitor everything and countless other jobs were completed to make all of these parts resemble a car and stand a chance of working. In late 2008 the key was turned and it fired in to life. All of the prototype systems functioned and the car could be driven. Although there was a huge amount of development to be done the ground work was laid for what would be a tremendous racing car.


2009- Capri- Endless development has continued with the Capri. Wheels tyres, brakes, suspension pick up points, axle and drive ratios, gearbox, differential, anew cooling system, a new lubrication system, more weight loss, aerodynamic aids, a new fuel delivery system, a new exhaust, more testing and more set up work and finally it is ready to race! Fingers crossed for the end result but hopes are high.

capri_FB           capri1_FB

September 2009- the big day has arrived, the first race for our capri. It was a 3 hour treck up to Cadwell Park near Skegness and we set up for the compulsary nights camping, BBQ and beer. 6am soon came around and the team were in full force preparing for Qualifying. The reward for their efforts was 3rd in class and no dramas with the car. It was a tremendous result from a new car at its first showing and all eyes were set on the race. Tension was high as everyone felt it was too good to be true, everyone knew there were always teething troubles and we were all waiting for them. A good start kept the car out of trouble and a super smooth pitstop jumped us up in to 2nd place. The car worked perfectly to the flag and the result was better than anyone could’ve imagined. Smiles all round on the long drive home and a thankfully short check list before the next race.

 Hammersley 1     Hammersley 2

The Capri was put to good use at the final race of the year at Snetterton.  There were many new cars entered in out class and Snetterton is an open fast circuit favouring big powered cars, so we were concerned we may be at a disadvantage. Despite being down on power to the big Jaguars, Porsches, Lotus’s and Ferrari’s we still qualified 4rd in class. A good start and hard fought opening laps brought us up to 3rd and closing on 2nd place when suspension failure led to an early end to the race. New suspenson was designed and built as the car had to run the following week at a magazine’s track day.  The car impressed and we may be running cars for the magazine ext year. Watch this space.  It was good to see several customers at the track day and is something we are hoping to build on in the new year.

hammersley 3           hammersley 4