Tuesday, March 30, 2010

Transmission & LSD Install

We are installing the Jubu 3rd, 4th & Final Drives into Project Nirvana along with an OS Giken LSD & STR Clutch & Flywheel. We want to run this config at our upcoming track day at Streets

Initial disassembly has begun which includes, the left rear suspension, exhaust system including cat and removal of both CV shafts. 3 out of 4 engine mounts have to be removed as well. In order to disconnect the transmission from the engine, the starter, clutch slave cylinder and the shifter cables must be removed. We are anticipating this job will take a full 10hrs to complete from start to finish - excluding gears/LSD assembly within the transmission. Be sure to drain the transmission before removing the CVs. Don't ask us how we know. Thanks go out to Ralph@V2 for tips.

Note the 85a durometer trackMOUNTs that we have installed. We tested these nounts at the last LCS race at Buttonwillow. The car shifts fantastically. Performance was exceptional. The street driving does suffer from increased noise vibration & harshness (NVH). I suspect any OE engineers who work on NVH might faint if given a ride in Nirvana - but the race drivers will clearly be in heaven...

OS Giken LSD Feedback

One of our AutoX friends, David Smart is running at the National level with his Lotus. He is running the OS Giken LSD for the first time. He wrote me with his initial results:

Shinoo – Quick feedback from my first event with the OSG SuperLock diff. This weekend we ran the SCCA Texas National Tour in Mineral Wells. My co-driver and I went 1st and 2nd. The track was approx 1.5 miles long with a variety of course elements. The course also had a few bumpy sections which the diff handled well under 100% lock. The Torsen was notorious for allowing wheel spin in bumpy sections.

We found that the car behaved like it was equipped with an open diff on corner entry. At mid-phase and corner exit I was able to quickly transition from neutral to oversteer to get the rotation I needed. Other good news, I didn’t hear a peep out of the clutch packs all weekend.

Overall, good results!



Tuesday, March 2, 2010

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.