Wednesday, August 31, 2016

Tuning, Testing, and More Testing

We work hard to bring new products to market for our customers, but at times, keeping an existing product on the shelf can be a challenge. Suppliers throw us curve balls ocassionally which make us re-evaluate our current approach. Such has been the case with the Lotus Cup Air Box. We originally spec'd this box in both the Katana2+ kit and our Stage 1 Tune for the Elise/Exige. We liked this air box because being an OEM piece gives us several advantages when it comes to reliability and performance. Another benefit of this air box is that it flows more air than stock but maintains a stock MAF signal since the MAF housing is unchanged.

Well, as happens sometimes (and probably more often moving forward), the Cup Box is becoming hard to source and may not available in the foreseeable future. This means we either needed to stop selling our extremely popular supercharger kit, or come up with an alternative. Our idea was to partner with our friends at K&N to see how a drop in filter in the stock air box compared to the Cup Box and OEM air filter. We do not just push things to market and call it good, we test and validate everything we sell. Being an engine part, it was especially critical to actually track test the effect of switching the K&N drop in solution.

The White Rascal (Art Car v2), already had a Larini race Exhaust Pipe, Cup Box, and Stage 1 Tune. So we needed to get a baseline number from this known good setup. We used an AiM  EVO4 for data logging, and an AEM wideband in place of the second 02 sensor to see how the air fuel ratios were doing. All testing was done at Spring Mountain on their 1.5 mile track.

To analyze the data, we picked the back straight away of the track and focused on the AFR readings between 6400 and 7700 RPM. When we ran the naturally aspirated setup the readings were as follows:
Cup Box = 13.5-12.3
K&N = 13.5-12.36
Screen shot of some of the data collected.

Since we verified our hypothesis that the K&N would flow similarly to the Cup Box, we were ready to put in the Katana with the K&N and go track test it. On the same part of the track in the same RPM range we saw the AFR go from 13.1 to 12.3. This track testing allowed us to verify the numbers but also put some miles on the car so the ECU could do some learning before the dyno test.

We dyno'd the car a few days later and made 222 WHP . The dyno operator told us his dyno is reading about 5% low vs others but we will take the 222 number. For reference, this car made 187whp on the same dyno when it had the Stage 1 package and our engineer's stock car with the same miles made 177whp. So the Katana is netting about 45 WHP vs a stock car.
Dyno Graph of Katana 

Monday, August 8, 2016

White Rascal/Art Car v2 Testing 8/4-5/16

Last week we took our shop car to the track for some testing. We had a few things on the slate to test out:

  1. Replacement caliper seals and titanium bolts
  2. Our new prototype shifter
  3. Larini valved muffler
  4. Intake and tuning changes
We headed out to our favorite test track, Spring Mountain Motor Resort. After arriving late Thursday, we drove the car around the paddock and ran an autocross course that was setup just to give the car a little shake down and put some additional miles on it before we really got to it on Friday. 

Everything went smoothly Thursday evening so early Friday morning we were on the track when it went hot at 7am. After 150 total miles were run, the track went cold and we went home for some cold ones. 


It is amazing what a good set of pads and some weight reduction does to the braking performance of this car. While braking at the end of a long straight, you appreciate the fact that the shoulder harnesses are keeping your face out of the steering wheel. There was no sign of leakage or degradation from the brakes all day. The replacement seals we have acquired come from a manufacture that is well versed in making similar products so we had no doubt they would function as advertised, but we felt that running them in 100F weather on the track was a good way to verify they were up to our standards. Shinoo had tested these seals in the car a couple of weeks ago at SMMR.  Additional heat/cold cycling stresses parts and after multiple days of track use you can see if a part will hold up.  We are happy with the results.  Expect to see these available soon. 

The new shifter is very promising. The engagement and function feels much more positive compared to the standard setup. You know which gear you are selecting and it slides into place with a gentle push from your palm or pull of your finger tips. We definitely have some changes to make but the functionality of this first version is excellent. Track testing confirmed that the action was a true upgrade.  We've had several clients try out the shifter since we installed it and everyone agrees that it is an excellent improvement.

Valved Muffler
This new Group N muffler brings the same valve technology used in the Evora system to your Elise or Exige. When the valve is closed, the car is very quiet but when open, you are presented with a wicked sound. There are several ways to activate the valve. We tested the car with the valve closed, open, and connected to the stock actuator that opens the flap in the air box. 

Intake and Tuning
This car has our de-cat and cup airbox tune on it. We decided to play with some intake changes and log the results. We used an AiM Evo4 logger and a wideband in the de-cat pipe to log several parameters including Speed, RPM, AFR, TPS, MAF, IAT, ECT, ABC, 123... We gathered some good data and are continuing work on some new things. 

Wednesday, August 3, 2016

Brake Preventative Maintenance and Caliper Rebuilding

It goes without saying that the brakes are probably the most important system in your car, but often times they seem to receive little attention (until they do not work of course!). Most people know that fresh fluid is always a good idea but often times we pull fluid from brake systems that looks like this.
Brake fluid is hygroscopic, meaning that it absorbs moisture from the air. This moisture combined with repeated heating and cooling cycles breaks down the fluid. This contaminated fluid will boil much sooner than fresh fluid and also tends to eat away at the brake system components. We recommend bleeding your brakes before every track event and doing a complete flush at least once a year Motul RBF600 is our favorite fluid and Torque RT700 is recommended for those who see extreme brake fluid temperatures.

In addition to keeping your fluid fresh, it is also necessary to realize how old some of your brake components are. Most critical are any bits made of rubber or synthetic rubbers like your stock brake lines and caliper seals. With most Lotus Elise/Exiges now at over 10 years old, replacing brake lines with stainless versions like our innovative QWKbleed lines is not a bad idea from just a safety perspective alone. There are also rubber parts inside the calipers themselves, the piston seals. These little rubber rings are the critical bit that lets you transfer force from the brake pedal to the pad. We are currently track testing our replacements to ensure they are of sufficient quality to survive track abuse. We worked with a manufacture that makes seals for many applications (including Lotus) but we strive to do our own testing and validation, especially for safety critical items.

We have also rebuilt several calipers here in the last few months and are exploring the possibility of offering it as a service. I bought some nasty black calipers for my own Elise, stripped, painted, and rebuilt them with new hardware. 

Another interesting thing we have tried is cleaning calipers cryogenically. This is similar to sand blasting, but rather than sand, frozen CO2 (dry ice) is used. You can see the results below. These calipers had 52,000 miles on them. 
Before Cyro
After Cryo
Art Car v2 caliper with Ti Bolts
  Another interesting thing we are looking at is Titanium caliper bolts. We are currently track testing these to see how they hold up but they are certainly cool looking and are worth about 0.36lbs of unsprung weight.
Ti Bolts vs Stock

Monday, August 1, 2016

Battery Tenders and You (and your sports car)

The reality for many people is that they do not get to drive their sports car every day. One of the issues that arises from lack of driving (other than self loathing) is that the battery in your pride and joy slowly drains away every day it sits idle. Lotus cars are particularly brutal on the battery as the electrical system has a rather strong drain while the car is off. When you add a light weight battery, you also decrease the amount of time the battery can sit idle before it is completely drained. This constant draining shortens battery life and puts unnecessary stress on your alternator when you do finally drive the car again. If you allow the battery to go completely flat, irreversible damage can result from chemical reactions inside the battery and the best case scenario is that battery life is severely shortened.

CTEK Smart Charger
The solution to all this doom and gloom is to use a battery tender. This sweet little device keeps the battery voltage topped up to optimal levels so it is ready to go at 100% when ever you require a little throttle therapy. We choose to carry the CTEK Smart Charger as it is a bit more sophisticated than most chargers and can really extend the useful life of your battery. Using the charger is pretty simple, you can either use the provided clips to temporarily secure it to the battery or use the provided pigtail with ring terminals. The Alfa 4C happens to have extra posts on the battery terminals that make adding charger lead a pretty simple affair.

Alfa 4C ground terminals. The positive post has a similar setup.
Note the two spare studs, perfect for trickle charger leads.

Light weight battery systems are one of the cheapest ways to shed serious pounds on your light weight car. On the Lotus Elise and Exige, our Xtender bracket and raceBATTERY will save 10 lbs on the back of the car while in the Alfa 4C our BB4Cpack will save a substantial 20 lbs of dead weight.
Light weight battery bracket for Alfa 4C