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 

KATANA26X Initial Dyno Results

We recently dyno'd KATANA2's track-oriented, evil, brother which we have been referring to as "KATANA2track." After dynoing this setup, we realized we need a new interim name. "KATANA26X" will be more appropriate because it's putting down 235hp at the rear wheels. If you calculate for 15% drivetrain loss we're looking at 270hp at the crank. A more conservative 12.5% drivetrain loss puts us at just under 265hp at the crank. The calibration needs a couple of small adjustments until we can officially give it a number. The results, so far, look great!

The KATANA26X kit is similar to the KATANA2 but adds a cold-air intake and a Larini Header & Decat. A larger fuel pump is recommended as is uprating your trans gears as we are now entering gear eating torque territory.

The dyno graph above compares the KATANA26X's rear-wheel horsepower (rwhp) and rear-wheel torque (rw lb-ft) with the KATANA2. The KATANA26X is about 20hp stronger at the rear wheels than the CARB-pending KATANA2.

This upgrade will be perfect for you track-rats looking for more power than the KATANA2. While retaining all of the driveability you've come to expect from calibrations completed by our engine calibrator Steve. We'll have it available soon...and will be sold as a track-only solution.

Katana2 Dyno Results - preCARB Results

We completed our Katana2 street & track tuning with Steve from Secant last week and took the car to the dyno to see what kind of power we are making. Our #1 goal with the Katana2 is to achieve CARB approval and get the coveted EO# so that it is a street legal solution. Peak power was not our ultimate goal, just a safe and clean solution. We know that getting CARB approval is a difficult process, but we've taken on this challenge to help us produce better product. Most importantly, we have clients who want a CARB approved kit that allows them to legally drive their Lotus on the street.

We tested our Elise on a Dynapack dyno. This dyno attaches right to the hubs and eliminates any of the issues that come from wheel/tire variation or slip in rollers, etc. The results shown above are marginally higher than what we achieved with our Katana (see chart below). The two runs shown were after a half dozen runs were completed on the car, so it is possible that the car may make a bit more power. Additionally, once the CARB testing is started, the tune may need to change to meet their tests. The final results may change so we will post up our final numbers once we achieve them.

The chart below is our original Katana dyno chart. Of course please recognize that the results are from different cars and different dynos.

Overall I am pleased that the Katana2 dyno looks nice and flat along with making a bit more power. The butt dyno confirmed this with smooth power at the track and on the street. Steve's tune feels really OE-like. You can see the dip we had in the Katana that is now tuned out. The addition of the larger airbox is helping us, but we are still limited by the use of 91 octane. Frankly, this level of power is excellent - the car feels nicely balanced. We know that the engine/transmission internals can live with this level of power. An important point to make is that these dyno numbers are taken at the hub so you should account for a 12-15% powertrain loss to compare with dyno figures usually quoted by the manufacturers. I think it is safe to say we are in the Exige S240 to S260 range of power.

Ultimately we will develop even more powerful versions of the Katana - including one that uses the latest generation of supercharger from Eaton, the TVS. Our CARB application is completed for the Katana2. We will complete the info for the KatanaTVS and submit the whole package this week. We're looking forward to hearing from CARB to get to the next level of this process...stay tuned.

Of course, if you are a current Katana client and do not care about CARB, call us, we can offer you the airbox and ECU tune to turn your Katana into a Katana2.

Katana2 Track Testing at Big Willow

We have been busy working on a new Katana package that we will be submitting for CARB approval. I stated the goal of delivering a street legal supercharger kit at the launch of the Katana and after many years of trying - we believe we have a solution. Track testing was the last part of this development. This is an excellent place to run a car at high rpms, speed and actual loads to determine how well the car is tuned. Project Nirvana Elise has been our test mule for this new kit. Tuning was conducted by our friends at Secant Vehicles. I am happy to report the Elise ran smoothly and swiftly this past weekend at Willow Springs with the Lotus Challenge Series.

We secured the services of our good friend (and recent Daytona winner!) Dave Thilenius to run the car hard on track. Nirvana was running with old R888s but Dave still managed to crank out a bunch of laps under 1:38 with the best being 1:35.94. A new GUT aero kit was also added to Nirvana since we last ran on track. We subjected the Katana2 to a total of 10 run sessions from Friday through Sunday.

Riding shotgun with Dave on a session was Steve from Secant Vehicles. Steve is a mechanical engineer with over 15 yrs of engine calibration experience. He has worked for Roush, Bosch and even Lotus Engineering in calibration positions. Steve has taken many cars & aftermarket power kits through CARB and knows the process well. He has tuned our new Katana2 kit to meet these standards. If you seen his work on the Secant Type I you can attest to the OE-like quality of his work. Steve has also developed our Atom2 tune and are very happy with their work.

I also enjoyed driving duties when we started track testing on Friday. Steve monitored the electronic equipment and data logged engine parameters as I ran through his commands; go slower, hit the rev limiter, try to detect second cam, and go faster! By the end of the day, we landed on a tune that ran wonderfully and safely on track. I had my friend Jack Fried - an accomplished LCS racer and 211 owner, drive the car late in the day. Jack has owned many of the Elise variants and has tons of track seat time in them. He was very pleased with the performance and commented that it ran even better than the Katana that was on our last Exige.

The car runs very nicely with an excellent idle and around town manners. The mornings were in the low 50s and warmed up to the high 60s. Getting a car to run well on the street AND track while still meeting emissions is a significant challenge. The car accelerates very smoothly and the second cam is hard to detect.

All out power is not our goal with the Katana2. Again our plan is to secure a CARB EO number so that our customers can run their cars on the street. The biggest difference with this kit is that we have added a new airbox. Since supercharged cars are more sensitive to intake changes than exhaust changes, we required a new tune. Our original Katana tune was tested but did not pass all the CARB required emissions tests. We are now preparing our CARB application....stay tuned for updates!