Brake Flush is Necessary: fact or fiction?

Spring is upon us and with it comes maintenance, especially for those of you in colder climates where your cars have been in hibernation for the last few months. Most Lotus/Ariel owners perform the required maintenance, but many overlook one very important service: the Brake Flush.  This service is very important for modern vehicles with complicated ABS systems. The fluid sitting idle in the system likely holds moisture and contaminants and should be replenished.  Why?  The water will expand when it gets hot causing brake fade and poor feel/performance - especially on track.

  You may be wondering how water/moisture enters the brake fluid. It's very simple: most automotive brake fluid with the exception of DOT 5 (which is a silicone based fluid) is hygroscopic. This means it has the tendency to attract and absorb moisture from the atmosphere.

  So, how can you tell if your car needs a brake system flush? They make special test strips which can detect high levels of moisture present in the brake fluid, but I prefer the old-fashioned eyeball method, personally. Remove the brake master cylinder cap and visually inspect the condition of the fluid. Brake Fluid should be clear or with a slight yellowish-tint.  Black or dark colored dirty fluid should be changed out. You can also test it with a refractometer or a fancy electronic tester.

  My personal recommendation for street-driven cars a biennial flush (every 2 years) but if you are taking your car to the track frequently, adjust accordingly.  Sector111 recommend at least once per year for a track oriented car.  If you are racing, we suggest even more frequent flushes...we've been very happy with Motul RBF600.  

Measuring Ride Height

Setting ride height is especially important to ensure your car handles correctly. Ride height is crucial when setting up your car. Lightweight cars are very sensitive to proper set-up and the right height is a key criterion that should be managed carefully.

First, pick a spot to measure from. The best spots to measure ride height on a Lotus are from points A and B shown in the above picture. Make a mark where you measure the first time, so you can check the same exact spot each time thereafter. Being precise in your measurements matters and the little details are key.

We measure ride height with a telescoping gauge. When measuring the gauge, use a digital micrometer if possible, as this is much more precise than a ruler. Above, you'll see a picture of the front of the car, and as you can see, in this position it is very easy to access and not touch the car.

This is the point at the rear of the car where we measure. Once again, it is in a spot that is easy to check and where you're not at risk of touching the car.

This can be a long and tedious task. Be patient. Remember, details and precision matter when setting a car up for the track. We believe that the correct setup is one of the most important things you can do to ensure you have a fast car.

Here are some other tips as you plan on setting your ride height:

• Make sure tire pressures are set at your preferred track pressures
• Make sure your suspension is settled before checking anything
• Try not to touch your car after settling it
• Fill up your fuel tank so that it is full

Wide Tires Can Be Bad!

As more power is added to our cars, we naturally look for more rear traction.  Wider rubber with wider wheels becomes the natural solution.  Ensuring you have good clearance is important as you can rub many different parts on your car, including:

• Fenders
• Wheel well liners
• Wishbones
• Suspension
• Chassis

Remember your tire (maybe even you wheel!) can flex under heavy cornering loads.  This reduces your clearance so it is critical that you leave room.  

The picture above shows a Nitron race shock that has a remote reservoir attached by a hose.  This joint can come in contact with an improperly sized wheel/tire combination.  

Recently we learned that a Lotus owner knocked this hose loose and lost his shock performance at the track.  He blamed the clip that holds the hose fitting to the shock.  We've never had any failure from this design but recognize that if something rubs it - like a tire - it could come loose.  Frankly, we think properly sizing your tire is the correct solution.

Recent track testing of our ETHOS 17x9 with 245 Hoosiers revealed that we were rubbing the outside fender.  Adding ReVerie rear fender flares would resolve this completely.  We will be adding these fenders soon to test but for now, we would admonish all y'all to watch clearance when adding wider wheels or tires to your Lotus!

Wheel Offsets and You

Wheel Offset is the relationship of the wheel center line to the mounting flange of the wheel, as seen in the picture below.

Manufacturers determine offsets by taking several aspects into consideration; such as:

• Fitment - the given space of the wheel well during all conditions of wheel movement; whether that be the up and down motion of the suspension or the turning of the front wheel during steering.
• Styling - cars just look better with the wheels somewhat flush with the outer fender line of the wheel well.
• Performance - cars have a tendency to handle better with the wheels pushed out away from the center line of the vehicle.

The Lotus & Ariel have positive offset wheels with wheel bolt spacing that is unusual.  Spoke clearance from the caliper is a challenge with both of these cars as they use opposed piston calipers.  We developed many different wheels for these cars and generally have found that reducing the offset - which pushes the wheels outwards, has helped handling. Generally pushing your wheels out by 5mm works well on these cars.  

Don't strip it!

The undertray and diffuser are parts on our vehicles that need to come off a lot; whether that be for making repairs or just to check for leaks, tears etc. However, the stock undertray bolts can make this a real pain.

The stock undertray bolts are button-head alleys which can strip. The problem usually stems from improper use.  An allen head bolt starts to strip from overtighting them, or not putting the allen key all the way inside the head of the allen bolt. (This goes for all allen heads. Not just the undertray and diffusers. Allens are used alot on these cars, so pay attention that your key is all the way in when removing and be careful not to over-tighten.)  Conversely, if you do not remove your undertray much, the bolts start to seize inside the hole, due to rust.

One of the easiest ways to get them out, without drilling, is to get a cutoff wheel and cut a straight line through the head of the bolt. Use a punch and hammer, and tap the bolt in the direction to loosen it. You can try to use heat, but the undertrays are very sensitive to torches due to the material and the fact that it's so thin.

The easiest way to avoid all of this: replace the button heads with a standard hex head and add a little Anti-seize. You can purchase these bolts at any hardware store (M8-1.25x25 for both the undertray and diffuser). The only way to strip these bolts is by using the wrong size tool. Even if these do seize in the hole, they will come out with a standard wrench.
Highlighted in red are two of the bolts and where they should be replaced.

Working on these cars for as long as I have, and repeatedly seeing this issue, I started to change these bolts on any service, or, any time i had to remove the undertray or diffuser.


Here's a chart that is a great guide for torque specs.
http://www.imperialsupplies.com/pdf/A_FastenerTorqueCharts.pdf

Have you inspected your MAF lately?

Modern Fuel Injection engines require the measurement of the air into the engine.
The common Mass Air Flow sensors available include:

• Hot Wire
• Vane Type
• Hot Film
• Karmen Vortex 
• Speed Density

 The MAF found on the Lotus is of the Hot Wire type.

   Most common hot-wire MAF sensors use a platinum wire or filament heated to a prescribed, maintained temperature above ambient, located centrally in the incoming air stream. These sensors function on the electrical principle that resistance decreases with temperature. As intake air moves past the wire or film, the cooling effect causes a measurable drop in resistance, and thus lower voltage is required to maintain the prescribed temperature. The hot-wire MAF control unit is sent a reference voltage of 5V, and returns about .4V to.5V at idle and from 4.5V to 5V at full throttle. Based on a fixed data set, an accurate assumption of air mass is made. 

  However, when these sensors become contaminated, they can send false readings to the Engine Management system and cause driveability issues. 

Cleaning these sensors is quite easy and can restore performance to your engine. You will need Mass Airflow Sensor cleaner. Do not use anything other than this, as other cleaners (ie. Brake or Carb Cleaner) can leave residue on you sensor

After cleaning, you should not see any dirt and that the wires are clean.



Make Sure Your Radiator Hose is Fully Attached

One of the important issues of any engine is keeping your engine at the right temperature. One of the best ways of doing that is making sure it won’t leak!  Coolant leaks are caused by radiator failures, leaking reservoir bottles, old hoses or improperly installed hoses.  This post discusses hose related issues.


1. Check your hoses to see if they are in good shape.  Over time the stock hoses will start to crack and split, some start to swell etc. With our cars starting to get up in age, it is never a bad time to replace hoses or at least have a closer look at them. 


2. Make sure your hoses are on correctly. A lot of leaks occur at the two front hoses that bridge the hard lines, to the radiator. Generally it is caused by hoses that are incorrectly installed. This is the area where the car is drained for coolant flushes.  One of the reasons is because the hard line is so close to the crash structure, and with such little flex from the coolant hoses, it is hard to get the hose clamp in the correct position because it almost pinches the clamp against the crash structure and with the stock coolant hose being so stiff, it is hard to see where the flange on the hard line is. There is also a little movement from the hard line when trying to push the factory coolant hoses back on, which causes you to not be able to get the hose on enough of the hard line needed for a proper seal with the stiffness of the factory hoses. 

We run silicone hoses and they fit great. They are very flexible which makes it easier to put the hoses on.  They slide right over the flange and allow almost no movement from the hard line.  This lets you get the hose clamp on easier and in the correct position.  Since they are flexible, they also allow you to see exactly where the flange is and that helps make sure your clamp is in the correct position and your hoses are safe and secure.  

Single vs Double Shear Explained

We know the rear toe link joint is a weak point in the Elise/Exige - mostly with track driven cars.  There is a misconception that the toe link is weak - it is actually the joint where the stock balljoint meets the subframe.  This blog entry discusses how we reinforce the joint, with our new DSbrace and RTD2brace, by placing it into Double Shear.  

The easiest way to explain the differences between Double & Single Shear is to think of when you were a child and fighting over a stick or piece of wood with a friend.  He grabs one end, trying to pull it out of your hands, the stick starts to go back and forth, you can hear it starting to crack and then you grab the other side of the stick putting his hand in the middle of your hands. He keeps pulling as hard as he can, but you have full control and there is no more tension on the stick. His force with one arm is now dominated by the strength of your two arms. Now, replace the stick with a bolt, and you and your friends arms are metal rods. The same applies to the bolt as it would the stick. 


The strength of a Double Shear joint is effectively double of a Single Shear joint.  Here is a picture that helps illustrate the shearing actions:

Dry Sump Track Testing & More

We conducted track testing this past Sat. at Spring Mtn with the Lotus Cup racers.  We tested a few products:

1. S111-Dailey Dry Sump
2. ETHOS 16x8 & 17x9 wheels
3. DSbrace - affordable toe link brace
4. TRACKpipe - track muffler

We made a quick video to share some info:

Overall we had great results with the Dry Sump and are ready to release it to other race teams and shops.  Amazingly we ran the car with no oil coolers.  Oil temps slowly climbed over the course of the day to about 280degF.  Clearly a small cooler will be a good idea when the ambient temps are hot.  I think a laminova oil cooler will be perfect and should allow us to delete the front coolers.  We think the complexity of a Dry Sump does not lend itself to the average shade tree mechanic.  If you are interested in a solution, give us a call so we can discuss your needs.

The TRACKpipe is our new track muffler.  We've been running it for a few weeks and have shown sneak peeks of it and sound clips in recent videos like this and this.  The sound is not loud and has a great tone to it.  We think track guys are going to be pleased with the price and quality.  

The DSbrace is our new affordable toe link brace.  It uses the same components as our tried and true RTD & RTVbraces.  We eliminated the central brace and added lower cost, but still effective, brackets to place the toe link joint into double shear.  This product also bolts on with absolutely no modifications to the chassis. This kit delivers the highest joint strength of any solution we are aware of.  

The ETHOS wheels ended up coming off the car as we experienced some rubbing at the rear.  We ran 245 Hoosier A6s at race ride heights and experienced some rubbing on the outside fenders.  We took them off and installed our back up wheels/tires.  We think these will work with Lotus that are running flares.  They are perfect for their primary application: the Ariel Atom.

We recruited our good friend Dave T. to push the car hard.  He turned some of the fastest times of the day with only 211s beating his times.  This allowed us to push the car hard and see how it would perform. He turned 2min56s times on the 3.5mile config.  Overall it was a long but productive test day for our team.