[blackthought_]

Tools needed:

• Ratchet
• Screwdriver, star shaped
• 8mm socket
• Needle nose pliers
• Plastic or metal pry tool
• T brackets - Two 3 inch and four 5 inch brackets. Got mine from Home Depot

While it would be easier to lift the car in the air or jack up the front, I did this while the car was on the ground since I don’t have a lift and the ramps that I felt may scrape the nose. Here’s the installation of the GRP splitter for my Lotus Evora GT. I’m doing this write up post install so the pictures I use will reflect this.

Underneath the front bumper there is a long rubber strip that goes the length of the bumper

There are 19 rivets that look like screws.

Honestly this was the hardest part of the install. I was expecting the screws to loosen and the rivets fall out but out of the 19 that are on there, that only happened to 2 or 3 of them. Here’s how I resolved it. Loosen the screws a bit with the screw driver, just enough to get your pry tool in it. Use the pry tool to give yourself 1/4 of an inch and use the needle nose pliers to carefully and slowly pull out the rivets.

You can move the pliers left and right until the rivets come out. Some of them will surely break. Once you get all the rivets out, it’s a piece of cake.

Now, there are 12 bolts that hold the front tray panel to the bumper. Use the 8mm socket and remove all bolts and set them aside.

(Since I couldn’t jack up my car, I used this pic of another members setup so I can see where the 12 bolts were)

Alongside the GRP splitter you will receive hex bolts that are longer than the OEM bolts (picture above) I wasn’t able to reuse the OEM bolts as they are too short. As you remove the bolts, keep in mind there is a black rubber bump stop thing that also has a bolt. Notice the positioning of the back rubber bump stop - it’s located in the hole behind the normal bolt. They are located right next to each other but a few inches apart

Now it’s time to position the splitter onto the bumper.

To help balance the splitter since it’s pretty long, I used a spare shoe box to help support one side of the splitter as I tightened the other side. I started on the furthest end of the bumper. There are 2 bolts - These bolts will use washers just like the OEM bolts. You will need to hold one side with a wrench and loosen the other side. Do this to the other side as well to secure the splitter to the bumper.

Don’t fully tighten the bolts though. You’re simply just holding the splitter in place. Note: the OEM washers also had a very mini thick washer. I discarded it as I wanted to give the bolts more thread.

Now for this part I consider optional but probably worth doing. I heard from other Lotus talk threads that if at the track and going over 120 mph the splitter can scrape the floor so one solution was to use t brackets. Two 3 inch brackets for the outside bolts and four 5 inch t brackets for the inside bolts. I painted them black beforehand so they would blend in with the splitter. The bolts go into the t brackets. You can see the locations of the t brackets in the above pic of the orange Evora. Below is my finished painted t brackets

This should theoretically give more support to the splitter. GRP also said you could drill into the bumper with more bolts but I chose not to do that based on the feedback on using the t brackets. A few members have been able to go on track with no scraping issues using this method.

Begin aligning the remaining bolt holes and tighten the remaining bolts

Have a beer and admire your work

 

[Pritchard]

epic write up! i was looking for this myself.

this needs to be in How To

 

[joshualo]

Thanks again for the instructions! This is great and your car looks beautiful in that color.

 

[blackthought_]

Thanks again for the instructions! This is great and your car looks beautiful in that color.

Thanks! Hope it helps you!

 

[joshualo]

One more question - do you still put back on the rubber strip for aero + protect your splitter, or that's a no go?

 

[blackthought_]

One more question - do you still put back on the rubber strip for aero + protect your splitter, or that's a no go?

Nope, you can’t reuse the rubber strip as you lose access to the rivet holes when you put the new splitter on

 

[Jedifar]

So I'm doing my install tomorrow since I just wrapped up my gt430 wing install.
I was decided on drilling because I do plan to track...I thought the drilling would be to mitigate the air ripping the splitter off but I wasn't aware of the scraping issue. Also not sure how the t brackets are supposed to prevent the splitter being ripped off as some claim...I get for the scraping, it would add rigidity.
I figure drilling it would be safer as a few holes are way cheaper than a new bumper.
Any thoughts?

 

[blackthought_]

So I'm doing my install tomorrow since I just wrapped up my gt430 wing install.
I was decided on drilling because I do plan to track...I thought the drilling would be to mitigate the air ripping the splitter off but I wasn't aware of the scraping issue. Also not sure how the t brackets are supposed to prevent the splitter being ripped off as some claim...I get for the scraping, it would add rigidity.
I figure drilling it would be safer as a few holes are way cheaper than a new bumper.
Any thoughts?

When I heard about the t brackets on another thread, I read that the idea was instead of having only 1 bolt at almost the edge of the splitter, the t bracket would spread the load to the front of the splitter, thus making it more stable. The individual that came up with the t bracket concept said they also tracked there car and the splitter didn’t budge using the t brackets so I took that as a good sign

 

[Jedifar]

When I heard about the t brackets on another thread, I read that the idea was instead of having only 1 bolt at almost the edge of the splitter, the t bracket would spread the load to the front of the splitter, thus making it more stable. The individual that came up with the t bracket concept said they also tracked there car and the splitter didn’t budge using the t brackets so I took that as a good sign

You know what, that makes alot of sense. I just reread Greg's response to me and it does sound like the purpose of drilling it is to add that front rigidity. So I'll be heading to home depot tmrw morning

This is what Greg told me



Those holes will need to be forward of the existing bolt locations into the chin spoiler.
What I would do is measure the depth (front of car towards back of car) of the black chin spoiler on the underside. write it down.
Mount the splitter, measure back from the leading edge on top of the splitter to the front edge of the chin spoiler and write it down.
Divide the depth of the chin spoiler by two to find the middle point, add that to the measurement from on top of the splitter for an overall depth measurement.
Measure back on the underside from the front leading edge to that point and mark it on the splitter.
Measure outward each direction about 4" and mark.
Drill a small pilot hole (approx 1/8") through the splitter and the chin spoiler.
Remove the splitter
Drill the three holes to size for the rivet nuts --these are designed to be installed into plastic and actually provide a good amount of support.
Install the rivet nuts -- Easiest to do with a long M6 bolt, washer and larger nut.
Drill spots on splitter to 1/4 / M6
Install splitter with new hardware and existing.

By adding these three additional bolt locations it reduces the the distance from the leading edge of the splitter to the closest support area.
That length without them is what allows for flex in the splitter and can cause vibration at speed. It doesnt need a lot of extra support to eliminate that vibration and this has been proven to work by a few others

 

[dogtag114]

I added two rivnuts to the front chin strap and have had it over 140mph countless times on the track since. Although I do question if it slowing me down on the straights. I also have the sho n sto plate there which doubles as a forward bumper scraper.
They were left over from the side skirts as I taped those.

 

[Jedifar]

I added two rivnuts to the front chin strap and have had it over 140mph countless times on the track since. Although I do question if it slowing me down on the straights. I also have the sho n sto plate there which doubles as a forward bumper scraper.
They were left over from the side skirts as I taped those. View attachment 1334867
View attachment 1334870
View attachment 1334871
View attachment 1334869
View attachment 1334866

Interesting, so it looks like all it needs to handle high speeds is just a more rigid front end...makes sense since its bendable aluminum. In that case, the T brackets make the most sense. For some reason, I noticed that my front bumper didn't have the rubber strip...maybe because the first owner replaced the front bumper after some damage. Anyways, the splitter is mounted and I'll be installing the brackets tomorrow. It looks great.

The reason you feel like you're getting slower on straights is because of the added aero, it'll cause drag and cause you to slow down. I installed the GT430 wing and with the front splitter, I'm hoping for some balance although it might be very rear biased given the large amount of downforce the wing will cause. Sherman said to expect 1-2 mph loss on straights, but thats with the wing...with the splitter, I imagine it'd be less given how small it is.

Also, you might want to remove cancelling the petplus subscription screenshot

 

[dogtag114]

Lol that could have been way worse

 

[bboixtc]

For some reason, I noticed that my front bumper didn't have the rubber strip...maybe because the first owner replaced the front bumper after some damage.

,

I always thought that front rubber/plastic strip was added on GT's as I never saw any 400's with them. Unless I'm mistaken.

 

[blackthought_]

Interesting, so it looks like all it needs to handle high speeds is just a more rigid front end...makes sense since its bendable aluminum. In that case, the T brackets make the most sense. For some reason, I noticed that my front bumper didn't have the rubber strip...maybe because the first owner replaced the front bumper after some damage. Anyways, the splitter is mounted and I'll be installing the brackets tomorrow. It looks great.

The reason you feel like you're getting slower on straights is because of the added aero, it'll cause drag and cause you to slow down. I installed the GT430 wing and with the front splitter, I'm hoping for some balance although it might be very rear biased given the large amount of downforce the wing will cause. Sherman said to expect 1-2 mph loss on straights, but thats with the wing...with the splitter, I imagine it'd be less given how small it is.

Also, you might want to remove cancelling the petplus subscription screenshot

Ahh your installation without the rubber strip was probably much easier than mine was. Most of my time was spent on removing those darn rivets that hold the rubber strip in place

 

[Jedifar]

,

I always thought that front rubber/plastic strip was added on GT's as I never saw any 400's with them. Unless I'm mistaken.

well that makes sense

Ahh your installation without the rubber strip was probably much easier than mine was. Most of my time was spent on removing those darn rivets that hold the rubber strip in place

Yes, install was pretty straightforward...I bought some T brackets from home depot today and they have been painted black...right now curing in the backyard.
Looked beautiful in the home depot parking lot though lol

 

[blackthought_]

well that makes sense


Yes, install was pretty straightforward...I bought some T brackets from home depot today and they have been painted black...right now curing in the backyard.
Looked beautiful in the home depot parking lot though lol

View attachment 1334904

Looks awesome!

 

[Jedifar]

Got the t brackets on....i didnt realize this earlier but I'd recommend revising the t bracket count to have all brackets 5 inches, so 6 5" inch brackets. There's plenty of room on the last bolts on the sides to have a 5 inch bracket, the 3 inch applies to the pre 400/GT splitters (unless there's a reason for the smaller brackets)....honestly could even go bigger if they exist, there's plenty of room. If I wasn't too lazy, I'd probably get another 2 to replace the smaller ones.

 

[blackthought_]

Got the t brackets on....i didnt realize this earlier but I'd recommend revising the t bracket count to have all brackets 5 inches, so 6 5" inch brackets. There's plenty of room on the last bolts on the sides to have a 5 inch bracket, the 3 inch applies to the pre 400/GT splitters (unless there's a reason for the smaller brackets)....honestly could even go bigger if they exist, there's plenty of room. If I wasn't too lazy, I'd probably get another 2 to replace the smaller ones.

Probably true. When I was installing them I didn’t notice the sides t brackets could be bigger. As long as the current setup holds on strong, I’m good with it

 

[Pritchard]

After seeing the pics from the author with the t brackets installed, I’m not sure why anyone would try anything else. With those multiple deployments they will really help distribute load, move supporting edge near to leading edge, and are very neat and tidy (from every angle except workshop floor, ofc)

if in doubt, just go screw together two bits of wood to simulate this. One plank, one sheet. Add some screws then apply weight to the edge and watch it bend and snap.
Then repeat with the t bars. I think you’ll be surprised how much extra weight you will apply to get the same result

 

[Jedifar]

Sigh...
Just came back from vir... my splitter did not do as well as I hoped. I went above 145 all day and It pulled the front 2 brackets down a considerable amount... this was even with the t brackets.
I think drilling it would've prevented this.
Or maybe I installed it wrong. The rest of the bolt up locations were fine.
Anyone know how to fix this, short of a new bumper lol?