Trackspec's Exige S240 Project: Part 1

Why Lotus?

My first encounter with Lotus cars was when I was 18 years old and I signed up first my autocross in my 1996 Acura Integra with the Golden Gate Lotus Club (GGLC). I always thought they were “cool” looking and after going on a couple ride-alongs, I could already tell how fun it would be to drive one.

In 2010, I got a job working for a Lotus Specialty shop and my desire to own one has been growing ever since. Lightweight, bonded aluminum tub chassis, all fiberglass body, flat under side, mid-engine, high revving; the Lotus has all the traits of a purpose-built race car. Most people would agree that lightweight is key to any performance vehicle. Horsepower makes it faster in the straights, but making a car lighter makes it faster in the straights, corners, and braking. Consumables cost less because the car doesn’t need massive brakes or tires and you have an extremely exciting car to drive that can get over 30 miles a gallon of fuel economy. At 2000 lbs, you’re basically driving a street legal go-kart. And despite seeing so many in our shop at any given time, the car is very unique. How often do you see one on the road?

In September, a Storm Titanium 2008 Exige S40 was T-boned at Laguna Seca coming down Turn 9 and the car was towed to Trackspec for an assessment. The owner wanted us to create two estimates:

  1. To completely fix the car; and

  2. To fix only the mechanical damage and the car would be the “ugly Betty” of his stable.

Depending on the costs, he would decide on which option to go with, or try to sell it as-is. After discussing his options with him, I entertained the idea of purchasing it from him and in the end, we were able to work out a deal that we were both happy with.

In the paddock at Laguna Seca after the accident.

In the paddock at Laguna Seca after the accident.

The Carnage

We started off by taking the car apart to get rid of the damaged parts. In the accident, the car sustained damage to the rear clam, all the right rear suspension, right rear CV joint, right rear brake line, wheel, exhaust, tail lights, engine cover, diffuser, and some other miscellaneous parts.

Rear subframe removed and waiting for replacement parts

Rear subframe removed and waiting for replacement parts

The Rebuild

I was lucky enough to find a matching rear Exige clam in Tehachapi, CA (about 5 hours from the shop), so I woke up at 4am on a Tuesday morning, drove down to pick it up, and made it back to the shop by the afternoon. The clam was used to make molds and then stored in a shed for a few years, so it does need some minor repair and a paint job.

Stopping for gas on my way back

Stopping for gas on my way back

I found a shop on the East Coast that was parting out an Exige, so I was able to get a package deal on the rear sub frame and control arms. The rear toe links were replaced with Inokinetic’s RTD Brace.

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Extra TLC

While the car was apart, I decided to do some extra work to it before it made its way back to the track. I replaced all the ball joints, tie rod ends, and replaced the rubber bushings with spherical bearings. The car already has a quick ratio steering rack and Nitron shocks. However, I do plan on changing out to JRZ Suspension coilovers (more info on that below). I also wanted to start fresh and get the car up to date with maintenance, so I replaced the coolant, engine oil/filter, brake fluid, transmission fluid, drive belt, spark plugs, air filter, supercharger oil and inspected the intake cam for wear.

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Later, I found that the A/C system had been removed from the car. I plan to drive the car on the street (for now), so this had to go back in. After replacing the compressor, condenser, receiver dryer, and all the lines, I was able to get it working again. Not a very exciting thing to spend time and money on...

Recharging the A/C system

Recharging the A/C system

Interior

The Exige had a Bride Low Max seat which was a little too narrow for me so I sold it and the stock passenger seat. It also had an Alitech shifter, which felt nice, but took up too much interior space, especially for the seats I wanted to install. I sold the Alitech and replaced it with the Inokinetic ShiftR111. The seats that went in are carbon Tillett B6 Screamer XLs with cut edges. These are probably the largest bucket seats you will be able to fit into this car.

First Shakedown at Laguna Seca

november 18, 2018

Before the car got a chance to get repainted, I decided to put it together and have some fun with it at the track. The right rear coilover and wheel was damaged in the accident, but two fellow Lotus owners graciously let me borrow a set of wheels and Nitron 3-way coilovers. The car was a blast to drive, but very loose on corner entry and not progressive when it broke away. We should be able to dial that out with some suspension tuning after installing JRZ dampers. Considering I only drove the car for 2 sessions, I was happy to do a 1:46. My good friends Graham and Tom also took the car out for a session. Graham was able to clock a 1:44. Very impressive for the first time ever driving a Lotus- Especially one that's tail happy.

First time driving this car. Tires: RE71R Engine: Stock Suspension: Nitron 3-way

New Shoes

Front:

  • TE37 Sonic 16x8 +25 Diamond Dark Gunmetal

  • Bridgestone RE71R 205/45/16

Rear:

  • TE37 Saga 17x8.5 +40

  • Bridgestone RE71R 235/45/17

JRZ Coilover Deal

expires december 31, 2018

The Lotus LSS suspension is known to have a soft spring rate with stiff valving, making the ride harsh on the street. Contrary to belief, you can run a stiffer spring rate with better shocks and the car will be more compliant on the street and handle better on the track. For this reason, coilovers are the the best upgrade for the Lotus Elise & Exige, whether you are using the car for street driving or racing.

Over the years, we’ve worked with JRZ Suspension Engineering for different platforms and have had nothing but great experiences. While they’ve been in business for over 60 years, most people seem to think they are only focused in motorsports. Accordingly, their Motorsport Line has been very popular with serious racers. However, not many people are aware that they have also developed their RS Line, geared for those who don’t necessarily race competitively but still want great coilovers for the street or even the occasional HPDE track day.

Therefore, we’ve teamed up with JRZ to offer our Lotus customers this limited time 20/20 Deal, to really show our customers that JRZ not only has kits for everyone (street driving, HPDE, and racing), but is also about top quality products and excellent customer service.

TS+JRZ Lotus 20/20 Deal

Until the end of the December 2018, JRZ is offering 20% off their RS Line coilovers and Trackspec Autosports is offering 20% of labor to install the kits. All their kits are made to order, so custom valving and spring rates are available to fit your needs. See below for instructions on how to take advantage of this deal.

JRZ RS PRO 3

I chose to trade out the Nitrons on the Exige for JRZ’s RS PRO 3 kit. The main advantage of their RS PRO 3 kit, vs their RS ONE & RS PRO kits, is that the 3-way dampers give you the ability to adjust both high speed damping and low speed damping. Low speed compression controls movement under small bumps, braking, accelerating, and turning. High speed compression controls movement over harsh bumps, like pot holes on the street or berms on the track. Since I plan to track the Exige, and possibly eventually race it, the RS PRO 3 kit was the best choice.

I plan to have the kit installed on our Exige in time for a weekend at Buttonwillow on Dec. 22-23.

Test Day at Buttonwillow Raceway

december 22-23, 2018

Unfortunately, due to holiday shipping delays, we didn’t get the JRZs in time for this event. The bright side is, we would get a better baseline with the current suspension before switching over. On Friday before we left, I spent the morning properly setting up the car with a corner balance, alignment, and base shock settings on the 3-way shocks. I personally like to start on the softer side and work my way up. All of this information was written down on our chassis set up sheet for reference. At the end of the day, we packed up, drove straight to the track, and unloaded everything in our garage.

Day 1

In the first session out, I noticed right away that the car wasn’t as nervous in corners as it was at Laguna Seca the month before. Corner entry felt good with smooth steering inputs. I could get the car to rotate mid-corner by slightly lifting off throttle. However, too much lift, the rear end would come around quick and there was no way to catch it. The car felt stable on corner exit, but did understeer a bit with too much throttle input. I liked the balance overall, but the low speed compression damping felt a bit soft. I noticed this the most in Cotton Corners and the Esses. The car also felt unsettled and too stiff going over the berm at Bus stop and between Riverside and Phil Hill.

Throughout the day, we wrote down notes on the changes we made to the shocks and took some tire temp and pressure data for reference. Between me, Andrew, and Sean who also drove the Exige on Saturday, we got down to a low 2:01.

There is definitely some room for improvement in driving, but by the end of the day, we felt that we had the shocks dialed in the best we could. The result was significantly better than where had started off, but we felt that there was more to be desired as far as giving us the confidence to push the car harder on this notoriously bumpy track.

Also worth mentioning…due to cold weather, we decided to bring our hot pot to the track.

Day 2

On Sunday, we were only able to stay until noon which meant just 2 sessions for me. I didn’t improve my time any further, but I did feel increasingly more comfortable with the car and was able to drive it more consistently.

Tom Tang was able to take it out for 3 sessions and it was interesting to see his process for adapting to a car that he is still largely unfamiliar with (the only other time he’s ever driven a Lotus was in this Exige for 1 session at Laguna last month).

Tom spent the first session getting reacquainted with how the Exige drives and its unique handling characteristics. It was quite an adjustment, considering he had just spent all day yesterday working with our customer, Marc David, in his track-prepped E46 BMW M3. If you didn’t already know, Tom runs an excellent driver development program that leverages in-car coaching from both the driver and passenger seat (if there is one), video review, and data analysis. He was able to help bring Marc’s lap-times down from a previous PB of 2:08 to a new PB of 2:01 in just 1 day!

After session 1, Tom came in with a big smile on his face. He said he was “reminded again of just how awesomely light the Exige is” when it came to corner entry and braking. He described how he could “adjust his braking zones back by nearly a hundred feet” because of how little the car weighed. This allowed him to brake deeper into a corner than compared to other cars. However, Tom did describe some shortcomings with regard to the current setup. He felt that the Titan QR steering rack combined with a 300mm steering wheel was a bit too heavy for his preference (something we might look into changing soon). He also complained about how bumpy the Nitrons felt in comparison to the JRZ RS Pro dampers (Marc’s M3 has these) that he was driving on a day earlier. Despite these issues though, he still managed a mid 2:01.

For session 2, Tom decided to make some adjustments to his driving style to better suit that of the Exige and he was able to drop another second. He was also becoming more comfortable in the car; catching slides and getting back to throttle earlier. On his 3rd and final session, he managed a 1:59. Really impressive, considering he was still fairly new to the car and in its current state it is still a bit of a handful.

Ride along with Tom for a sub-2 minute lap around Buttonwillow CW13:

The JRZ RS PRO3s will be installed and set up for testing at Thunderhill with Ongrid Track on January 12th. We are excited about how the new shocks should do a much better job of making the Exige easier to drive at speed and look forward to continuing to develop the platform next year. See you in 2019!

JRZ Installation

Dec 27, 2018

The JRZs arrived! As always, they were very well packaged. Inside you will find your coilovers neatly laid in expanding foam underneath two foam mats with a signature of the person who hand-built and tested your set of shocks, and another signature of the person who checked off on the complete package for quality control.

The installation was straight forward using all the factory mounting brackets and hardware. Before mounting the reservoirs, I measured and adjusted the gas pressures using our Nitrogen shock filling tool. The gas pressures are set from the factory, but we decided to start out with slightly less pressure in the front dampers. Once the install was done, the ride height was set and I did an initial alignment just to put some miles on the springs to make sure they were fully settled before the corner balance and final alignment.

On the street, the suspension felt great. Even with 450/600lbs springs, almost double the rate from factory, the car still felt compliant, but much more composed.

Corner Balance & Alignment

January 9, 2019

Before starting the corner balance, I checked the ride height again to make sure it was still where I wanted. The springs didn’t settle very much, which is expected of high quality springs, but it’s always good just to make sure.

With the ride height perfectly set, measuring from the bottom of the chassis, the corner balance had a reverse wedge of 46%, which is quite a bit. We usually like to get it within less than half a percent or perfect if it makes sense. Some cars can be difficult to adjust, or they just have too much compliance in the suspension bushings and you could spend hours chasing half a percent. This isn’t always justifiable considering the labor cost to performance gain ratio. For our Exige with spherical bearings on all of the suspension pivot points, and easy to adjust perches, getting a perfect 50% cross weight was quick and easy.

With the corner balance done, final alignment, and some base shock settings, the car was ready for another test day.

Test Day at Thunderhill Raceway

January 12, 2019

The days leading up to Saturday, January 9 looked like we were going to have a rainy track day, but we got lucky and actually had some really nice weather. I was pretty excited to test out the car with the JRZ RS PRO 3 set newly installed. It had rained the night before, so the track was wet for the first two sessions, but dried up right before noon. The only problem was that anyone who went off brought mud onto the track as they came back on, making some sections slippery until it dried up. In the first session I was doing 2:27 laps and in the second session, I was around 2:15. Given the track conditions, I didn’t feel confident that the first two sessions could provide any meaningful data or feedback.

During my third session, I took a passenger out and got down to a 2:10, with some shaded areas of the track still being wet. By session four, I made some rebound and high speed compression adjustments and ran a 2:06. I was hoping to get down to a 2:04 in session five, but ended up getting stuck in too much traffic with two run groups combined for the last session of the day.

Although I did go down in spring rates compared to what was on the car before, the major difference I felt was how predictable and planted the car felt now. When the rear end wanted to come out, it was easier to catch and it was more of a progressive oversteer instead of a snap oversteer. The car was also less unsettled over big bumps and just soaked everything up. Adjustments to the shocks were easy to do without any tools or lifting of the car and each click made a noticeable difference. We definitely need more (dry) track time to really fine tune the shocks.

From how the car was the first day at Laguna Seca, to where it is now, is already a huge improvement. The development of this Exige is moving in the right direction and I’m excited to get more seat time in it to really dial it in and set some decent lap times. Just for reference, watch Graham driving the Exige the first time out at Laguna vs my session at Thunderhill this past weekend. Graham is a highly experienced driver and you can see just how nervous the car was on its old suspension.

Overall, a great day for Trackspec, friends & customers.