Sunday, November 15, 2009

Atom Tune & Dyno Results

We got the Atom back onto the K&N dyno after making all of our tweaks to the powertrain and ECU. This was the dyno that originally revealed two years ago that my stock Atom was making 260hp at the crank. We could now test it on the same dyno and find out if we made any true gains.

We've been blogging about the mechanical upgrades we have been making to my Atom. You can see these posted in previous months on this Blog. The following items were changed:
  1. Smaller pulley & belt
  2. Larger injectors
  3. Intake
  4. IC radiator - inline with original
  5. ECU Tune with 7100 redline for 91 octane
All other powertrain internals
remained the same. Our partnership with Secant was key since they are Ecotec experts with the ability to properly tune the stock ECU. This allowed significant changes to the poor tune that came with our cars. We know that many Atoms are blowing up exhaust systems - an issue incorrectly attributed to poor quality exhausts. As it turns out the EGTs were out of control and annihilating exhausts thx to the poor tune and mechanical configuration.

The Secant team was able to achieve 280hp & 241 ft-lbs of torque with this engine in their Lotus powertrain swap. This is the safe limit for a track driven, stock LSJ engine with 91 octane. People have achieved more but at the expense of powertrain reliability. I wanted to sort a package that could be run reliably, on the track, without the headache of frequent engine rebuilds.

We hoped to achieve the same power levels that Secant sorted with the Lotus. As it turns out, we nailed it. Three runs were taken at K&N and realized Horsepower of 278-281 (stock 262) & Torque of 240-248 (stock 229). This was with 91octane - we know with
race gas, more can be achieved.
A key part of the tune is the smooth power delivery from down low all the way to 7100rpm. The original tune showed a serious dip in power from 2500-3500 - this was eliminated with Secant's tune. The higher rpm limit also helps tweak out some additional power though the new tune makes more power everywhere. The car felt faster and now the dyno confirms it!

One interesting aspect of Secant's Atom tune is the changes to the lower rpm pedal progression. The original tune created a car that was very jumpy in around town driving at lower speeds. We've all had to endure slipping the clutch to get the Atom to drive smoothly at slow speed. The magic of comprehensive ECU tuning allows the tuner to 'slow down' the pedal at the low speeds and make it much easier to drive. You can also drive the car at slow speeds with no input to the accelerator - something Steve called 'Paddock Mode'. In fact we got stuck in a traffic jam where I was able to use this 'mode' to its fullest.

Contact us if you want your Atom tuned to deliver a safe level of power. We can supply all of the mechanical parts to get your Atom to run safely. And now, we have the data that shows we make real and safe power!

My friend, Jerry, the owner of K&N, invites our local car club to visit his huge facility for a yearly visit. I want to thank him and his gracious staff for the great tour of their business. K&N has a significant R&D lab that flow bench tests all their products and conducts serious MAF trials. These guys are definitely in a different league compared to their CAI competition. Naturally our intake features a K&N filter!

Thursday, November 12, 2009

gPAN - Baffled Oil Pan Testing Results

Oil starvation is one of the 3 issues that must be fixed on any track driven Lotus. This problem has spun rod bearings and/or killed pumps. Sorting it has been on our development list for a long time. Like with our fuel starvation solution, we've tried to address problem at the source - the pick up. We had originally considered the Accusump but data collected by Ralph@V2 has shown that it is not effective. Keeping the oil trapped around the pick up became the right approach for us. The gPAN is essentially a baffled oil pan that we believe will fix the issue.

To confirm the gPAN's performance, we ran our Elise with the final version on track this past weekend and collected oil pressure data. We have been working diligently to get the fitment and ease of install correct. Our Elise has been running with a gPAN for over 1 month with no leaks. We installed an AiM data logger along with an oil pressure sending unit to log our performance. The car was run on Spring Mountain at the last Lotus Challenge race and West Coast Lotus Meet. Conditions were perfect and we ran with R888 tires.

After running a few sessions, we down loaded the data. The oil pressure ran quite consistently around 50psi with 3 different drivers over several sessions. We looked at the data closer coupled with lateral g data to look for potential starvation. Turns 1 & 2 are a fast right hand and then a left hand sweeper. This is a severe area of the track that should cause serious oil starvation, but our results show a constant >50psi of oil pressure. See the graph below from this area of the track.

Based on these results, we are confident that we've sorted a good fix for the oil problem. We should have them available by the end of the year.

Wednesday, November 4, 2009

Track Surface Differences - Choosing the Right Suspension

I am amazed at how smooth the tracks (and roads) are in England. My last track day at Bedford Autodrome along with a previous visit to Brands Hatch and Donnington confirmed that conditions are much better than what we experience at many tracks and roads here in the US. I have also been to Fuji and driven on Twin Ring Motegi in Japan so know that they also enjoy smoother conditions.

Why is this important? Suspension set up. With the bumpy conditions found on various tracks and roads we run, a compliant suspension is key. Too high a spring rate will create a car that does not soak up the irregularities. Good rebound and compression adjustment becomes key as well.
To that end, we have kicked off three new spring rate packages that you can select when ordering your Nitrons. Our experience has also shown that aero plays a significant role in spring choice. Early this year, while testing Nitrons with 525/650lb springs - it became apparent that the high downforce ReVerie kit on our Exige could use some more spring. We installed 550/700 and the car ran like a dream - it sucked up the bumps and ran the curbs like never before. Nothing seemed to upset it, even on our bumpy tracks (Willow & Buttonwillow in this case).

Rebuilding shocks last week at Nitron showed me the amount of options that exist in tailoring a suspension system INSIDE the shock! Choosing the correct valving to match your spring rates is a critical part of a sorted kit. Working with Ralph@V2, some select Lotus Challenge racers and of course, Nitron UK, we will be working to refine our kits to meet our US needs. And since Nitrons can be rebuilt/revalved by us, we will be able to tweak your kits to meet your specific needs.

Tuesday, November 3, 2009

Nitron Testing at the Bedford Autodrome Track

Ralph from V2 and I were in England last week getting training at Nitron. Guy Evans, Nitron MD, was our gracious host who along with his staff, provided us the needed training to start up our Nitron North America program. This team answered our unending questions on the rebuild, revalve and upgrading of Nitrons. After an intense week of info overload, we had the chance to do some testing at the Bedford Autodrome. This former airbase is now a great facility that can be rented for testing or for training. They offer an excellent program that gets you into several awesome cars and onto the track. We ran the 3.8 mile track config. Learn more about Bedford: HERE
We brought Nitron's newly rebuilt 111R (Elise). They bought this crash damaged car and have begun making it into their newest test vehicle - the N2. It featured a roll cage, CF seats, Nitron Single Adjustable suspension, Nitron toe links, Nitron brakes and a brand new R888s on TD cast wheels.

This was the first shakedown trip for the car so we drove carefully at first (of course the rain helped). But quickly we found the car was well sorted and a fun track day companion. This picture is of Ralph working his smooth style to the max...

Driving on a new track while shifting with my left hand added to the challenge. I also had to use quite a few towels to better fit my short self into the fixed seats that were positioned for 6ft+ Guy. After my first stint in the rain, I got the chance to get settled. The second stint came after lunch with a drying track. More fun and more speed. I started getting the line down and started linking several of the corners like a track regular and began passing quite a few of the other cars. I was not 100% with my left handed shifts but that will come with more practice. Luckily, I don't have this issue in the US. 8^)