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Discussion Starter #1


Why?
Well, as always I am a DIY guy. I wanted the APR front and side splitters, but had a HARD time justifying $1700+ for them. I dont care about the carbon. I just wanted more surface area on the bottom of the car to improve negative pressure at high speeds, a pinch of downforce in the front at braking, and a "skid" plate to protect my freshly repaired and painted front clam. I also shaped the fenderwell panels to direct air AROUND the tires to prevent positive pressure under the tire at high speeds. So I said eff it and improved the design and made my own.

How?
Simple really, Cut the designs I like, Cut, trim, and drill the parts to use OEM fasteners and a few extras. Paint and Install. More info in a DIY if you want it.

What?
Main panels are made of 1/4" Alumalite. Its a Plastic comb core material with Aluminum bonded on each side... Very light and durable. And cheap!
Aluminum cut and bent to make the fenderwell panels/mudflaps.
8 Self Tap Screws
2 10mm bolts x40mm and nuts
14 1/8"x3/8" Aluminum Rivets
2 Cans of Krylon Satin Black
2 pieces of 1/4" Threaded rod 10" long
2 1/4" Wingnuts
Several Fender Washers
2 1/4"x1.5" Alanhead Buttonhead Bolts
4 Locking 1/4 Nuts
2 1/2" L-Brakets

Drill
Drillbit set
Jigsaw and Skillsaw
Rivet Gun
Machinery to cut and bend sheetmetal
Door Edge Trim to cap edges (Being replaced will update)
Jack

18ish Hours.

How Much?
Total cost just shy of $250 for all of it.

Skill?
Id say an overall 7/10 with a good 5/10 fabrication skill.

If anyone is interested I took a lot of pics of the front progress and could make up another DIY just say the word! Its pretty much done, the only change are some Billet Support rods in the front and a new ribber trim for the edge with a matte rubber finish.



Here are the pics from today: Custom Front and Side Elise Splitters | TheChazz.com – DOWNSHIFT-FLOORIT









 

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oh my goodness, those side sills and front are amazing. car to give me dimensions for that please?? also any way to run the front without the splitter supports, or mounted in a different fashion without drilling through the clam?
 

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Discussion Starter #3
I ran without the rods in the front the first day, the splitter will vibrate violently at high speeds. However those rods do NOT require drilling into the clam. Take a look the top corners of your grill. The rods utilize stock access holes Lotus put there to snap the corener lights. No drilling required :) The ONLY extra holes drilled into the clam were for the winglets at the botto of the fenderwells.

It can be seen here in this assembly picture indicated by the blue arrow:

I added a speednut to this hole and then an butonhead stinless bolt:

Aside from those two, it usesed all the OEM fastners indicated here:
 

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Discussion Starter #5
Worst license plate ever. Please change it.
Worst user name ever, Please change it.

MY plate, NOT yours.

Back-story, Had a heavily modified S2000 before and transferred the plates. They don't expire until DEC so I'm keeping them until then at least.
 

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I was thinking about doing something similar to my front clam with a peice of aluminum/CF ... doubling as a scrape guard but mine wouldnt stick out very much (no more than an inch) & would only be underneath (& not wrapping up the sides)

actaully looks like a pretty clean install from the pics though
 

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V EQLS IR
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Looking good, agreed about not wanting to pay for some carbon. The black really sets off the rest of the scheme nicely, such as the nose badge and the clear signals!
They don't expire until DEC so I'm keeping them until then at least.
not sure how it works down there, but here in WI you can change your plates at any time for free, you just resubmit the form (assuming you paid the $15/yr for them in the first place).

that said, i think you should keep it anyhow : )
 

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Hi Chazz,

I really like your front splitter, it looks nice without the use of CF. You just have to make sure that it does not come off at high speed. Also, good use of Alumalite. It's the perfect material for DIYers.

Concerning the skirts, if your goal is to make them effective, you will have to seal the sides to the ground in order to generate downforce. You could make something similar to this:



Good luck!
 

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If it vibrated that badly without the retainers, mthe forces are still there with the retainers so those attachment points better be stout and you better be certain the rest of the splitter isn't still bending!! Had a BEAUTIFUL splitter made for my Evora out of 1/4 in Leucite only to self destruct at about 120!!! Improperly designed, these things can wreak havoc on the car.
 

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Do you have the same problem I have with my plywood splitter? That the material is so rigid that sufficient trauma may likely rip all the fasteners out of the clam and the crash structure instead of crumpling up or splintering the splitter material?

To deal with the rigidity, I switched to 6,6 nylon fasteners to provide elasticity that I cannot get with metal fasteners.

I also did some other things such as countersink the fastener heads into the splitter so that the wood is thinner around the washers and thus more likely to splinter and crumple and save the body work in case of an off track incident. I'm still fine tuning the ideal depth of them.

edit: A fellow on the other forum says by the time you make the splitter secure enough to handle track stress, it's also secure enough to cause damage to the car in case of an incident. So, maybe I'm after an unrealistic goal here.
 

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I am suing you for IP theft! I have designed that exact front splitter 100's of times. I never built it or I would be suing for copy right infringement.

I suspect that, unless you also stole my idea for the at wind tunnel, that you can only measure by seat of the pants. The high speed vibration is a good sigh that something is going on, and I bet it is down force (or negative lift as all the books I read call it).

Can you feel a difference? If you believe most threads, you should have wild high speed overseer because you didn't add a complementary spoiler on the back to balance down force (although I suspect that you simply moved the high speed center of pressure forward a foot or so).

Long winded way of asking.

Would you do it again? Can you feel a difference at "spirited" street driving speeds?
 

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Nice job Chazz! I'm a big fan of DIY and I've been trying to find the time to make my own side skirts and front splitter, but I'm glad I waited. I can use some of your design ideas in my parts. Any concern about bottoming out the splitter and damaging the clam when the support rods transfer the force?

I was planning on making a flat splitter with slotted mounting holes. It would extend only an inch for citing driving and at the track I could slide it out another inch or two for extra down force. But I may have similar vibration issues if it is not supported correctly.
 

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Discussion Starter #15 (Edited)
I was thinking about doing something similar to my front clam with a peice of aluminum/CF ... doubling as a scrape guard but mine wouldnt stick out very much (no more than an inch) & would only be underneath (& not wrapping up the sides)

actaully looks like a pretty clean install from the pics though
The final result turned out pretty great in my opinion. I’d expect to spend $600+ to purchase something like this. as for making a scrape guard, this should work great, just be sure to support the front leading edge properly so it does not catch wind like mine did before the supports.

Hi Chazz,
I really like your front splitter, it looks nice without the use of CF. You just have to make sure that it does not come off at high speed. Also, good use of Alumalite. It's the perfect material for DIYers.

Concerning the skirts, if your goal is to make them effective, you will have to seal the sides to the ground in order to generate downforce. You could make something similar to this:
Thanks, it’s not going anywhere. I have had it up around 100mph now with no further issues, I’ll try more at a later date.

As for the skirts, they are effective as intended. You are looking at them in a different manor. I simply am using LOTUS's logic of a flat belly using positive rake to create negative pressure (Vacuum) under the car to "suck" it to the ground. More surface area=more neg pressure. Nothing dramatic I’m sure, but still increasing a stock function via aftermarket parts. At the end of the day, it defiantly accentuates the look if nothing else :D

If it vibrated that badly without the retainers, mthe forces are still there with the retainers so those attachment points better be stout and you better be certain the rest of the splitter isn't still bending!! Had a BEAUTIFUL splitter made for my Evora out of 1/4 in Leucite only to self destruct at about 120!!! Improperly designed, these things can wreak havoc on the car.
The vibration was caused by the rake of the car and splitter. Air pressure would build up between the lip of the splitter and the bottom of the clam. This would bow the front edge of the splitter down just enough to release this pressure which would allow it to snap back against the clam and repeat.

The support rods which are one way support, they only hold the splitter UP, not DOWN. If something impacts the bottom of the splitter the rods are allowed a good 3-4" of travel inside the clam to absorb any possible impact. The rods holding the splitter UP allows the aforementioned pressure to re-direct into the radiator opening rather than between the clam and splitter. This increases down force and increases cooling duct pressure.

Do you have the same problem I have with my plywood splitter? That the material is so rigid that sufficient trauma may likely rip all the fasteners out of the clam and the crash structure instead of crumpling up or splintering the splitter material?

To deal with the rigidity, I switched to 6,6 nylon fasteners to provide elasticity that I cannot get with metal fasteners.

I also did some other things such as countersink the fastener heads into the splitter so that the wood is thinner around the washers and thus more likely to splinter and crumple and save the body work in case of an off track incident. I'm still fine tuning the ideal depth of them.

edit: A fellow on the other forum says by the time you make the splitter secure enough to handle track stress, it's also secure enough to cause damage to the car in case of an incident. So, maybe I'm after an unrealistic goal here.
The material is very ridged. Not sure what would ensue from an impact. I used the OEM belly pan mounts, which would be the same locations to take an front end impact from anything else. Nylon fasteners would definatly strip/sheer away at highway speeds however. Alumalite is a hollow core design, so countersinking is not an option.

Because of the low profile of the splitter (only 1/4") chances are anything I would hit with it, I would hit with the clam regardless.


I am suing you for IP theft! I have designed that exact front splitter 100's of times. I never built it or I would be suing for copy right infringement.

I suspect that, unless you also stole my idea for the at wind tunnel, that you can only measure by seat of the pants. The high speed vibration is a good sigh that something is going on, and I bet it is down force (or negative lift as all the books I read call it).

Can you feel a difference? If you believe most threads, you should have wild high speed overseer because you didn't add a complementary spoiler on the back to balance down force (although I suspect that you simply moved the high speed center of pressure forward a foot or so).

Long winded way of asking.

Would you do it again? Can you feel a difference at "spirited" street driving speeds?
EXACT same idea? I find that unlikely! Haha

As for the wind tunnel, no; however I should probably throw out the fact I work in an AERO division, specifically the B2 Spirit :D So a few of the flows and ideas I used were generated by my experience here. Not saying its proof it works, but my ideas were not generated from thin air.

As for the drivability and "seat of pants" gauge. I have not had the car under any heavy spirited driving or excessive high speeds yet. However at around the 60+mph mark I "feel" the front hunkering down a bit. The lane to lane steering seems to be a hair more touchy. No additional wind noise to note and no new vibrations, shakes, or pulls. As for rear compensation, I personally HATE spoilers, and facing the facts though I would LOVE to track the car, due to my location and work schedule I will almost never get to attend. Therefore I will be building the car to enjoy as I can. On the streets, cruises, meets, and plenty of spirited driving.


Nice job Chazz! I'm a big fan of DIY and I've been trying to find the time to make my own side skirts and front splitter, but I'm glad I waited. I can use some of your design ideas in my parts. Any concern about bottoming out the splitter and damaging the clam when the support rods transfer the force?

I was planning on making a flat splitter with slotted mounting holes. It would extend only an inch for citing driving and at the track I could slide it out another inch or two for extra down force. But I may have similar vibration issues if it is not supported correctly.
Thanks!
As for bottoming out, as mentioned above, the rods only hold the splitter UP not DOWN. Any bottoming out, the rods will simply slide into the clam (and have 3-4" of room) so no issues there.

As for your slotted idea, Id recommend just drilling two sets of holes and swapping. The slot's that long 2-3", would create weak spots in the design. Also you need to account for the wheel well areas. Either you will have a big gap in its "forward" position, or it will hit the tires in the rear position.

In the extended version, the lip will need some form of support. I thought about just riveting two lengths of Angled Aluminum to the bottom to support the lip. However this would make the car another 1/2" lower and I am already limited on clearance. If you use the same rod design I used, really you could install and remove them in a minute or so.

Honestly for the price, just make two splitters.
 

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Gamera The Atomic Turtle
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you're one of those multi talented guys. Oh, in case you were wondering, i'm still working my way through the girl/lotus galleries....
 

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Please post pics and description of how you fastened the vertical pieces to the fenders.

I made my own front splitter out of 6061 T6 0.063". A fairly expensive material but it was what I had available. The shape is similar to yours but with more length of material beyond/in front of the clam. I struggled with how to attach the vertical pieces to the fiberglass so I just left them off. I have had two off track incidents where I ended up sliding sideways in rough grass. Both times the unsupported aluminum extending laterally from the clam dug into the plants and dirt and folded under the rest of the splitter. My fastening to the clam is about the same as yours and the clam was not damaged by the force that was sufficient to fold the aluminum.

After seeing your post, I will be buying some Alumalite this week and fabricating a new splitter and side skirts.

Thanks,

Jason Dew
 

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Discussion Starter #19
No problem!

The side vertical pieces utilize the OEM Holes that the Mudflaps were mounted to. The rear pieces I drilled for using Self Taps and Washers. I also added 1 bolt to the front of the splitter into the "lip" that extrudes in the fenderwell.
 

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Looks great I have been wanting to fab up the sides :up:
 
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