Friday, December 29, 2017

Exige S260 Shift Cable Damage!

We have had two S260 Exiges in the shop in the last month.  Both cars have suffered from poor shifting.  The shifts were very stiff and somewhat vague.  Even when we compared them to a bone stock '05 Elise that we have, the shift action was clearly off.  We found that each was suffering from the same issue.  It appears the factory subframe stiffener can crush the cables (one or both)during undertray installation.  

cable interference.jpg

These detailed images show the damage.  Once the cable housing has been crushed, the action of the cable is compromised and becomes very stiff.  

cable damage.jpg
undertray.jpg

We found that pushing the cables out of the way during the undertray installation could provide enough clearance.  Though the proper fix would be to move one of the cable routing brackets - which requires removing the sheer panel and drilling new holes. 

Here is another installation tip from an S260 Owner.

...When you reinstall the lower pan, remove the NACA duct so that you can reach in and pull the cables to the far left. Then push the pan up and secure it with the nearest bolt. This will hold the pan in place and not allow the cables to get pinched. If you do not do this, you actually risk tearing the sheathing on the cable.

-Eldon

Both clients opted to get our cables as the cable housing had also begun separating.  The shifting action is greatly improved now as well.

If you have a car with a factory subframe stiffener, check your cables to ensure they are not getting crushed.  If they are, give us a call and we can help get you sorted!

Thursday, December 28, 2017

Clutch Inspection & Selection

The Lotus are getting older and racking up more mileage.  Wear items like clutches have been blowing up from the early days thanks to abuse, high power, or just wearing out.  We have run various clutches over the years and have formed some opinions.  This Blog hopes to illustrate some of our findings.

FAILURE ON TRACK

At our recent track day weekend, one friend blew up his clutch.  This Elise had seen 25+ track days since the clutch was installed.  His original factory clutch lasted about the same time (25 track days).  This 190hp car was being driven by an experienced driver who enjoys his car on the road and track.  See the pictures below:

broken.jpg

This pressure plate came apart and also did some damage to the trans housing as shown below:

unnamed.jpg

INSPECTION

Clutches don't last forever as they are designed to wear out.  The more you shift the more you wear on the clutch/fly system. There is no perfect way to determine when your clutch may fail.  Peeking through the inspection area on your trans housing is certainly one way to check, but not fool proof.  You can gauge the clutch engagement point, with the pedal, as another way to determine when it is wearing out  - but even this is not perfect.  What is the solution?  

You have to physically inspect the clutch to know for sure.  So you need to determine an interval that is acceptable to you as it takes a fair amount of time to do right thoroughly.  Your interval will be based on how you drive your car.  In fact, we know of one car with well over 200k miles with a stock clutch - though this one has never been on the track or AutoX.

If you are tracking your car regularly, I would suggest that you have your clutch removed and  checked every 3 years.  If you race, then I suggest having this done every year.  The trans is something that you should consider having inspected and rebuilt at the same interval.  If you are a regular AutoXer , I would check every 2-3 years.  More frequently if you tend to dump the clutch at every start.  If you run only on the street and are easy on the clutch, then you might consider having it done at 100k miles.

SELECTION

Choosing a clutch can be hard as there are a myriad of choices.  I find that most people think they need much more clutch that they actually do.  The torque (133 ft-lbs) on a stock Lotus is quite modest - even most modified cars don't make enough power to justify aggressive clutches. 

I tend to like clutches with smooth engagement and release.  I don't like pedal effort that is too high - in fact, stock-like effort is possible.  If you have a stock Lotus or even one with modest power (<300hp), we see no need for a race clutch.  We have serviced clients cars who had overly aggressive clutches installed and are hard to drive smoothly.  These cars usually don't need the capacity of these clutches and end up have much worse driveability - especially around town.  Get a clutch with a sprung hub.  We learned the hard way that an unsprung friction plate does bad things quickly to the trans. 

The OE clutch that came with most of the lower powered cars has great feel.  The only real weakness is that the springs are held in the hub by a plastic retainer.  This plastic will fail with aggressive use and/or abuse.  The uprated TRD clutches are a good alternative for those of you who prefer to stay with OE.

Of course, we have our favorites.  I'm a fan of Organic friction material for normal applications.  Fiber Tough is another material that we have found to work very well.   Our STREETclutch can work for most of these applications.  Our HDclutch is a good alternative for cars with more power (<300hp) or regular trackday use or AutoX.  The pressure plate on these clutches offer great pedal feel with effort that is OE-like.  We installed a kit on an Evora and was surprised to find it was even lighter!

Perfect for street cars with stock levels of power.

Perfect for street cars with stock levels of power.

Good for cars driven more vigorously or with modest power increases (&lt;300hp).

Good for cars driven more vigorously or with modest power increases (<300hp).

If you drag race or dump your clutch with AutoX, then a more aggressive clutch would be better - but be prepared for other tradeoffs.  Typical tradeoffs include:

  • Much higher pedal effort
  • 'On & Off' feel or engagement
  • Lower life
  • Additional wear on trans parts

BREAK-IN PERIOD

This is often times the worst part of installing a new clutch.  The clutch and flywheel need to mate together.  Your new parts need a sympathetic break-in period of about 500 miles.  Normal stop-and-go driving is needed.  Clutch dumps or full throttle or compression braking is FORBIDDEN during this 500 mile interval!  The feel of the clutch won't be that great initially until they bed in.  After 500 miles or so, you will be able to drive more aggressively. 

Thursday, December 21, 2017

Lotus Alignment Recommendations

large.jpg

  A proper alignment is critical to the performance of your lightweight sports cars.  These cars are very sensitive and respond well to changes in the suspension setup.  These recommendations are based on experience we've gathered since 2004 with the Lotus 111 platform.  Your results may vary so we suggest you start here and tweak as your driving style demands.  

Make sure that your car's suspension components are in mechanically sound condition.  Check your ball joints, toe links, track ends, etc to ensure that nothing is worn out.  See our 60pt Prep Sheet for a great reference.  Consider our Suspension Refresh Kit if you discover worn-out parts have a higher mileage car.

Recommended settings for an Elise/Exige street/track car with R-compound tires.         

                          Front                 Rear
Ride height    125 +/- 3mm    130 +/- 3mm
Camber            -2.2°               -2.4° to -2.7°
Toe (total)       0                       3mm total toe-in


Recommended settings for a track Elise/Exige car with slick tires.

                           Front                      Rear
Ride height    120 +/- 3mm              125 +/- 3mm
Camber            -3°                             -3°
Toe (total)       0 - 1mm toe out        3mm total toe-in


Follow These Steps:

1.      Set the ride height.  

2.      Set camber.

3.      Set toe.

  • To set the camber, remove all your stock shims as well as the ABS shim. You may need to install V2arms or machine your stock steering arms to obtain optimal camber.  Remember to use thread locker on the steering arm bolts.
  • While a lower ride height is possible, we find the suspension works best at these recommended heights and the chance of scraping the bottom of your car is less.
  • Write Down All of Your Changes!  Write down your alignment settings and then note how the car performs. Write down any changes you make and record the results. This is the best way to get the car dialed in exactly how you like it.  Use our Alignment/Set-up Sheet to help keep tabs on the changes.

Wednesday, December 20, 2017

Engine Mount Trouble!

trans mount detached

We love the fact that Lotus are lightweight cars.  One reason is the minimal number and size of fasteners used on the cars.  These fasteners have a tendency to come loose and need frequent inspection.  In fact, we always like to do a visual inspection BEFORE any driving event - especially a track day.   Engine mounts are items that we recommend should be inspected before each event or ...

detached mount

In the last month, we've had two cars in for service, a '06 Elise and an '11 Exige S260 with engine mounts that were compromised thanks to fasteners that had either become loose or fallen out!  This resulted in major powertrain movement that caused collateral damage including:

  • damage to the oil pan
  • damage to subframe stiffener
  • poor shifting
  • shift cable damage
  • more
oil pan damage

We have used the 60pt Prep Sheet to help check critical areas on these cars.  Find it: HERE.  Winter is the perfect time to look over your car and get her prepped so you don't suffer any of the problems these last two car owners have had to deal with!

Tuesday, December 19, 2017

Rear Swaybar & Soft Suspension (Spring) Testing

Palomar Rear Swaybar Testing 8-20-17.jpg

We have been testing a new suspension that features a component not found on the Elise or Exige.  This innovation is a rear swaybar (anti-rollbar) that was developed by our partners in Italy, DNA Racing.   This rear swaybar allowed us to test softer springs than we typically run.  We've spent several weeks testing on the road and track.  We recruited our friend and pro-Ride & Handling Engineer, David Thilenius for set-up and tuning.  Our focus was to create a fantastic handling car for the street and occasional track use.  We were focused on delivering a flat handling car with grip and compliance, especially on rough roads and tracks.  All the work was conducted on our street legal '05 Elise.

We tested the following:

  • Spring rates:
    • 250lbs/350lbs
    • 350lbs/500lbs
    • 450lbs/600lbs
  • Valving
    • 2 different levels
  • Swaybar settings:
    • Front: 20mm bar with 5 positions
      • .78Kg/mm to 1.1Kg/mm
    • Rear: 20mm bar with 4 positions
      • .93Kg/mm to 1.235 Kg/mm

The key advantage of the rear bar is that you can run softer springs than normal.   Swaybars are used to help manage large side-to-side body movements (body roll).  Running softer springs deliver a more compliant ride and more grip.  Without a rear bar, we've had to run heavy springs in an effort to better control the car and to reduce body roll.  The downside of a rear swaybar is the added complexity and cost.   Check this reference for more details: Wikipedia

Front swaybar
Rear swaybar with 4 adjustments. &nbsp;Requires drilling one hole into the lower wishbone as shown above.

Rear swaybar with 4 adjustments.  Requires drilling one hole into the lower wishbone as shown above.

We started with 450/600 spring rates but then switched over to even softer rates than we have ever run: 350lbs front & 500lbs rear.  We completed most of our testing with Triple Adjustable dampers with our V2 valving developed by our good friend Ralph@V2 Motorsport.  This gave us a wide latitude to test.  A future blog will cover the details of the dampers and settings. 

Dave T. spent a day running our Elise on his development route through SoCal roads to dial in his tuning.  His final settings proved to be good but firm.   He also had the dampers set at almost full soft and recommended that we revalve the dampers as well as other areas to find additional compliance.   I drove the car and was impressed but wanted to take it to the West Coast Lotus Meet to really put some miles on this set-up.

wclm canyon.jpg

The West Coast Lotus Meet trip included a several-hour freeway trip to reach the location and one EPIC canyon run that took most of the second day.  The suspension felt good and performed very well as I hung with the tour leader for hours through some great but rough canyon roads.  I knew this was a nicely balanced kit BUT it was still a bit stiffer than I wanted.  It was more comfortable than the factory Sport suspension but stiffer than the factory Standard suspension.  I wanted the best of both worlds.

We had the dampers revalved to shift the curve to deliver more comfort but kept enough to make it stiff enough for the track.  We also placed the softer 250/350 springs on to help.  Dave was recruited once again to have a go.  The advantage of a professional is that you can get excellent data fairly quickly.  It took him another day of tuning to land on a setting that struck the best balance.  I took the car out onto my favorite test canyon road and was truly impressed.  The compliance and grip were what I was hoping for.  The car turns in flat and sharply.  The soft suspension soaked up the rough roads without beating me up.  

Photo Dec 16, 1 21 27 PM.jpg

Track testing was our next objective.  I decided to drive the car to Spring Mountain and softened the Rebound 5 more clicks to see the effect.  It was even better on our bump-strewn freeways.  SoCal has expansion joints that are notoriously bad and can make a Sport pack Lotus feel like a bucking bronco.  Our new suspension was perfectly comfortable yet still sporty and responsive.  My goal is to create a  useable sports car that you can take on trips and yet still strafe a canyon or run an occasional track day, not a boulevard cruiser.  

1508947577_east_b_800_labeled.png

Spring Mtn was running the East 1.6mile course.  This is a fast and smooth course but has many curbs that you can ride that can upset a less forgiving suspension.  After stiffening rebound to Dave’s road settings, I went out to do some warm-up laps and quickly realized that the car was too soft for the track.  We decided to put the swaybar onto the stiffest settings to see if that would help the wallowly response on track.  This proved to be a disaster as the car turned in quickly but understeered horribly.  I took one lap on track and exited immediately to make a change as it was almost undrivable!  It took us another few different iterations of settings on the swaybars and the dampers to get the car to my satisfaction.  I like a neutral-handling car that maintains a nice balance.  The final setting was exactly what I liked.  

I had a couple of Lotus owners drive the car to get their feedback as well.  Steve drove the car on track and was very impressed.  He has owned an Elise for 10 years and has done at least 60 track days so is very dialed into this platform.  He also has the Ohlins TTX dampers yet was very impressed with our kit.  Watch his video testimonial: Click HERE or below.

https://www.facebook.com/inokineticgroup/videos/388429991605550/

At this point, we are ready for production parts.  We placed an order with our partner and expect to see production parts by the end of Dec or early Jan'18. 

One additional configuration that we need to test is running this rear swaybar with the factory non-adjustable bar.   I'm not overly optimistic as the torsional stiffness of the factory bar may be too light - even after drilling a new hole to increase stiffness.   We try it out this coming week... (UPDATE Edit: stock front bar works.  New Blog will be posted soon)

Saturday, February 4, 2017

Evora shiftR111 Progress

The earlier S1 Evora shifter is a derivation of the '07+ Elise/Exige shifter.  As a result, it also suffers from poor feel and durability. It has the same blue plastic ball joint that has broken in Elise/Exige/211.  We are now seeing this failure in more and more Evoras, as well.  Clearly, we felt there was a real need.

We took apart an Evora shifter system to see if our shiftR111 might work.  Lotus does a nice job of integrating various requirements to really drive down the cost of a component.  This shifer housing clearly serves a few different functions.  The key was that the overall height of the shifter and the mounting points at the front would work for our shiftR111.  It appeared with a change to our hand brake brackets, we could create a shifter kit for the Evora.  So we got to work on a design.


Shown below is our design for the Evora.  We are now getting a prototype made to test fit into a car.  We remain overtly optimistic.  8^)


We have already sorted out shifter cables and our innovative ESWkit for the Evora so a shiftR111 will complete the package nicely.   

Tuesday, January 17, 2017

Carbon-lined Synchro Testing

2nd Gear synchro
We had our trans fitted with the new carbon-lined synchros from Synchrotech.  Our '05 Elise (ArtCar v2) was once again our trusty test mule.  I ran almost 150 miles at Spring Mountain on these synchros.  The shifting and specifically the downshifts were really crisp.  Road use was also good with no negative behavior or characteristics.
rebuilt and ready to go in

The trans has stock gears, clutch/fly and no LSD.  The car was also equipped with our new shiftR111 and SMOOTHoperator but no short-shift kit.  We debated internally whether or not to run a short shift kit and ultimately decided not to have it installed.  We knew that the 'feel' of these new synchros would be important and anything that might influence feel would be another variable.

We ran on the 3.6mile Fittipaldi course.  This configuration uses 2nd,3rd,4th &5th gears.  There are some really fast sections and plenty of slow 2nd gear corners - with a couple of them heavy breaking zones.  Proper heel and toe downshifts are critical on many of the corners so it was a good test of the synchros.

a fast course with plenty of shifting from high speeds/rpms

Overall the car shifted nicely.  The feel was immediate and frankly crisp.  The down shifts were great and even at times when I did not get enough of a blip, they seemed to engage really well.  I drove the car on the 'street' a bit around the shop and grounds of SMMR.  Again the shifting was nice and confirmed that it can work fine on street cars - with no negatives,

taking a slight breather between sessions

David@Synchrotech referred to synchros as the brakes for gears.  As it turns out, there are many manufacturers who use synchros of this type for 15+ years.  Our kit uses brass, carbon and construction that have been refined by Synchrotech over several generations - mostly in Honda applications.  This is especially important to us as the Honda run 9k rpm trans that are similar to our 8k rpm gearboxes.  Essentially, the carbon can deal with high speeds far better than just the brass - as found on our stock synchros.  David did change the design slightly from stock to improve performance and my testing confirms that these changes are acceptable.  If you compare them side by side with a stock set, you may see some differences.  Our trans rebuilder, Jeff@Transaxle, was also duly impressed with the kit.  His opinion was key as he rebuilds many, many gearboxes for Lotus Cup racers.

I believe they are suitable for road & track.  The stock brass synchros are the weak link in the Toyota gearbox so these bits will be very welcome and will extend the life of the gearboxes.  Of course, you still need to heel and toe your downshifts!  Yes, these will allow for faster shifts but we still suggest clients be smooth and gentle.

We are going to get production products and release these parts.  You can find them: HERE

Monday, January 9, 2017

Evora Clutch Delay Valve

Lotus decided to protect the transmission in the Evora S at the expense of the clutch. Just like with the S240 and S260 models (which we blogged about HERE), they fit a clutch delay valve in the hydraulic system. This valve delays the flow of fluid out of the clutch slave cylinder which more gently engages the clutch. This protects the transmission from shock loads, it also prematurely wears your clutch. 

We just pulled a clutch out of a 50k mile Evora S that was completely used up. If you look closely, you can see that the heads of the rivets are ground away; there was nothing left of this thing. It also damaged the flywheel and scored it badly enough that it also needs to be replaced. 

Delay valve shown
 Aggressive driving certainly plays a roll in the accelerated wear of a clutch, but slipping the clutch at every engagement really hurts life when combined with aggressive driving.

Our solution, the Evora CLUTCHline, is a piece of stainless steel braided line with the correct fittings that replaces the factory delay valve

The CLUTCHline will allow the clutch to engage as quickly as possible, preventing excessive slipping. It will also allow you to modulate the clutch in low speed situations rather than fight the delay valve. Of course if you want to do high RPM clutch dumps, you are going to put more stress on your transmission, but if you drive with some skill and care, the reliability of your transmission should not be compromised but your clutch life should be greatly extended. This is a good thing considering that a clutch replacement requires powertrain removal and takes roughly 40 hours of labor...


The lines are available on our site HERE.  It takes about 2 hrs to install it.

Monday, January 2, 2017

shiftR111 Track Testing

We brought our ArtCar v2 to SMMR and ran the 2.4mile Fangio B course. We managed to get about 100 track miles put onto her. No issues. The shiftR111 felt great. Watch the following video from inside the car showing the shiftR111 in action going up and down gears 2 through 5.

We recruited a couple of long-time Lotus owners who have run countless track miles on their Lotus cars. I wanted to get their objective opinions about our new shifter. Watch the video below:

Our next step is to confirm fitment into a stock Elise, finalize the reverse lock-out cable length and then kick off production. Yes!