About two years ago, we decided to run a 15/17” wheel stagger for more tire selection, and in doing so, we had to install smaller front calipers (More detail on that here). The Cup brakes that our S240 came with were too big for 15” wheels. We were able to get a few 15” wheels to fit over them, but it required running some large wheel spacers. The set up we decided on were the AP Radical front calipers and the OEM 2 Pot calipers in the rear. Since the changes, the brakes never felt as good as the stock set up. The larger calipers require more fluid volume, and with the stock master cylinder, that meant the pedal had more travel and felt softer. We also noticed more ABS “ice mode”, which could be related to the change in brake bias and front to rear tire diameter.
I am thrilled to announce the return of Toyo Tires to our race program for the 2023 and 2024 seasons. I have had the pleasure of working with Toyo for many years previously, and this partnership renewal marks a commitment on both sides for shared success.
You’ve probably already seen the results online, 3rd in class (E1) and 9th overall. But what you don’t know are all of the details, the drama, the trials and tribulations and the blood, sweat, and tears that went into this past weekend. Fortunately, that’s what this blog is for…so please, read on.
This year seems to be just flying by. We last raced at the end of March, and since then the team has been busy with a wide variety of cool projects at the shop. Personally, my calendar has been filled with work, travel, and everything in between. One event in particular that transpired during this time was the official launch of the Yokohama A055 tire.
Before doing anything K-swap related to the new chassis, we started by transferring parts over from the original tub to the new one. Since this was a low mileage car, it wasn’t difficult selling the drivetrain. Timing worked out perfectly as there was another Elise in our shop needing a motor due to a failure.
It’s been over 3 years since I put the Honda K24 into our Lotus Exige and it was the first car that I made an engine harness for. Although the harness was reliable and never gave me any issues, I felt that my harness building skills have improved much since then. What I really wanted to do was get rid of all of the unused wiring and the mess under the dash.
A few months ago, we decided to register for this year’s 2021 Global Time Attack and Super Lap Battle Finals at Buttonwillow. The Exige wasn’t built for time attack, but we thought it would be a fun place to compete and see how capable the Lotus with a K-series really is; even if it is heavily outgunned in its class (because of the rule set, the car falls into Limited, a class that normally sees cars with forced induction engine setups making well over 600whp). We decided to set our own goal of a sub 1:50 lap, which may be the first naturally aspirated Elige to do so. The best time this car had done previously at Buttonwillow 13CW was a 1:51.7 on Falken RT660s.
We went into the month of August feeling excited for two reasons. First, our K24 swap was finally complete on the Lotus and after a solid shakedown at Laguna Seca in late July by Graham and Tom -- it was finally ready for wheel-to-wheel action. Second, we would have 2 race weekends take place relatively close to each other, August 1st and 2nd at Thunderhill and then August 22nd and 23rd at Sonoma.
In part two of the K24 swap, we were left waiting for the header to arrive. We ordered a Hytech 4-2-1 header specifically made for this swap, which took a little over a month to get, but was well worth the wait! It fit perfectly. Other than trimming the J-pipe to length it needs no modification to fit any muffler designed for this chassis. Once fitted, all we had to do was make an extension harness for the wideband o2 sensor.
When we left off in part one of the K24 swap, we had the engine in the car and started getting things connected. Although it seemed like it was close to being done, there was quite a bit left to do. We decided to keep the factory dual oil coolers. This may change in the future, but we wanted to make sure the temps were stable even on extremely hot days. Moving along on the track is one thing, but following closely behind another car in “dirty air” and it can get hot pretty quickly. Because these cars are known to over cool engine oil, we installed a thermostatic sandwich plate with a 200F thermostat to help maintain proper temps.
If you grew up in the 90s and were into cars, then you’ve heard of the Honda B-series engine and how amazing it was. It was the “hot rod” engine of its time and my gateway into modifying cars. The planning, researching, parts sourcing, building, and then seeing how it improved the car’s performance is what got me hooked. In the early 2000’s, Honda came out with something even better..
In Part 8, we were waiting on a driver net before we could have the tech inspection done. The Schroth net with the new quick release mechanism that we originally ordered was still undergoing testing and its availability was severely delayed. So, we went with a equally good option- Safecraft.
With a year of rebuilding and developing the Exige behind us, we were excited to begin our “winter project,” the roll cage. When the car came back from the last track event of the year (a very wet Laguna day), we gave it a good wash inside and out before getting into it. We also had to do some homework and make sure that what we build is safe and legal for the the local sanctioning bodies we plan to race with. We followed NASA’s Club Codes and Regulations handbook as a guide.
At the last two-day track day at Buttonwillow with Speed Ventures, shifting in the Exige started to get notchy. It would sometimes be difficult to get into gear, but we kept driving it. By the last session of the day, we were not able to get the car into gear after pulling off into paddock. If the engine was off, it would go into all gears, so we suspected it to be a failed clutch that was not fully disengaging...
Fuel starvation is a well known problem with this platform. It’s mostly noticeable on long left hand corners because the fuel pick up is on the left side of the tank. It’s typically not an issue if I keep the fuel tank full, but every time our got down to about 70%, it would starve. This can cause a lean condition and be harmful to the engine, especially with forced induction.
The Exige S is known for heat soaking and extremely high IATs (intake air temps). The stock intercooler is mounted on top of the hot engine and doesn’t get nearly enough airflow through the small roof scoop. It also doesn’t help that the hot air from the radiator exits in front of the windshield and makes its way into the roof. There are some things you can do to help like a larger intercooler, additional ducting from the side scoops, larger roof scoops, or adding fans to the intercooler…
This past Monday, June 24, we decided to take a team day-off to go to the track with Golden Gate Lotus Club. In addition to drives, meets, and fun outings, GGLC hosts great track & autocross events. Only three run groups, so you get SEVEN sessions! Not to mention, they always offer snacks, coffee, fruits, and sometimes even lunch!
Monday through Friday
7am to 4pm
