Thursday, October 20, 2016

Evora Track Car Bodywork Mods

WIn our previous post we talked about an Evora track car we have here in the shop. In an effort to focus the car more for track use, it was decided to do a few modifications to the bodywork.
     The goals were:
          1) To make the clam easier and faster to remove.
          2) To improve air flow and heat extraction from the engine bay.

After looking the car over (and taking most of it apart to do the clutch replacement), we decided that rather than do a true race car quick release style of system, we keep it more simple. The basic plan was to essentially eliminate some attachments that we feel are just not needed on a track only car. We also switched out some attachment methods. For instance, in the trunk, we replaced 6 bolts with a 4 studs and nuts. There are a few advantages to this: the studs capture the shims so they don't fall out and they help align the clam when it is installed. We deleted the two in the center for simplicity.

We also had to address the things that attached the clam to the vehicle other than the fasteners. Namely the battery, coolant tank, and truck release cable.

The switch can be reached from the driver
seat or through the passenger side window.
We decided to relocate the battery to the passenger compartment behind the passenger seat. This setup has a number of advantages besides making it simpler to remove the clam. We are able to reduce weight, better weight distribution, and increase reliability with this modification. Moving the battery inside the car reduces the vibration and thermal stresses on it, it also gets a large bundle of wire out of the already crowded engine bay. Moving the battery gets weight off the rear of the car which helps with the polar moment of inertia of the vehicle. The battery switch we installed will also prevent the car from draining the battery while stored.

Nice little unit from Moroso really cleans up the
engine bay and gives a high performance look.

The coolant expansion tank was another issue we encountered as it too is attached to the clam. We looked into relocating the stock tank but opted to replace it entirely with a nice offthe-shelf unit from Moroso. This tank fit cleanly against the firewall and should last the life of the vehicle. Here again we were able to move weight off the rear of the car and increase reliability by getting rid of the stock plastic tank.

The truck release cable that runs inside the cabin to under the rear seat was the final small thing that we wanted to move to make clam removal simpler. We decided just to re-route the stock cable so it can be pulled from the rear of the vehicle. In the future, the hatch will probably be replaced with something a bit lighter and we may do away with the stock latch, but for now, this will work great.

Stock heat shield in place.
While we were at it with these modifications, we wanted to do something that would help reduce engine bay temperatures. We decided to reconfigure some of the heat management. Since this is a track only car, we do not have a trunk to keep cool, we were able to get rid of some heat shielding and do some ventilation. Lotus obviously had a tough time controlling engine bay temps with this "big" V6. Our plan was to remove all this heat shielding and ducting and allow the heat to escape out the back of the car, rather than through just a few small ducts.
Much cleaner.
We drilled several holes in the clam and also removed an access panel in the truck to vent the engine bay to the trunk area. We then removed the bumper and drilled several holes in it to vent the trunk/engine bay area to the rear of the car. Since this vehicle also has a muffler delete setup on it, we vented the floor of the trunk to give the hot air another option for exiting. We aligned the holes that we cut with the holes that were in the subframe.  These mods were inspired by the GT4 version of the car and should help lower engine bay temperatures. We also happen to think it looks pretty cool.
Deburring the edges with sand paper
is a pain but gives a finished look.

Rear bumper vent holes.
Swiss cheese.  We also painted the rear black so the orange would not show through the rear bumper holes

Luckily, the only thing this car will be
hauling is ass around the track.

The end result of all this is a car that is lighter, more reliable, and easier to work on. 

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