FT-86 SpeedFactory Front Splitter - Pics + Data

[plucas]

Ride height data as asked for

[plucas]

Also since we work closely with @Wonderbar







The best part is the numbers!

The Driveway Labs V1 Diffuser increases downforce by 5% overall. This might not sound like a big gain however it does a lot for the balance of the car.

The new aero balance is 49/51 compared to 32/68. Looks like good data for those guys racing their car.

[Wonderbar]

Woo!

[Wonderbar]

So if I'm reading this correctly, slightly more downforce on the front splitter would create a perfect 50/50 aero balance?

[eric6]

Originally Posted by Wonderbar

So if I'm reading this correctly, slightly more downforce on the front splitter would create a perfect 50/50 aero balance?

The opposite actually. You are the second person to think this today so I will clarify. The bias without the Driveway Labs rear diffuser was 32% (rear), 68% (front). With the Driveway Labs rear diffuser, it brings the balance closer to neutral, 49% (rear), 51% (front). A splitter that produces more downforce will need to be offset with something else in the rear to maintain an aerodynamic balance of ~50/50.

[Wonderbar]

Originally Posted by eric6

The opposite actually. You are the second person to think this today so I will clarify. The bias without the Driveway Labs rear diffuser was 32% (rear), 68% (front). With the Driveway Labs rear diffuser, it brings the balance closer to neutral, 49% (rear), 51% (front). A splitter that produces more downforce will need to be offset with something else in the rear to maintain an aerodynamic balance of ~50/50.

Gotcha. So the addition of more underbody panels in the rear perhaps, or side splitters?

[glamcem]

Originally Posted by eric6

The opposite actually. You are the second person to think this today so I will clarify. The bias without the Driveway Labs rear diffuser was 32% (rear), 68% (front). With the Driveway Labs rear diffuser, it brings the balance closer to neutral, 49% (rear), 51% (front). A splitter that produces more downforce will need to be offset with something else in the rear to maintain an aerodynamic balance of ~50/50.

Originally Posted by Wonderbar

Gotcha. So the addition of more underbody panels in the rear perhaps, or side splitters?

at the last event I only had the front splitter I will be going to RMP tomorrow and then drive to Oregon to attend the track event on Saturday (ORP) ..I cannot wait to see how the car will feel at some high speed corners and sweepers

I will provide some videos and data as well..woot!

[JDKane527]

Originally Posted by Wonderbar

Gotcha. So the addition of more underbody panels in the rear perhaps, or side splitters?

Curious in the cfd analysis, was the assumption made that the underbody of the car was flat or was the underbody modeled?

[eric6]

Originally Posted by Wonderbar

Gotcha. So the addition of more underbody panels in the rear perhaps, or side splitters?

Possibly... you never know with aerodynamics. To summarize the results of the ride height data, it did the opposite of what Paul and I thought would happen. The drag reduction makes sense but we thought downforce would increase, not decrease (albeit it only did very slightly). We believe flow is becoming chocked at these lower vehicle levels but we didn't think that would happen until we ran the analysis.

All CFD is done on an FR-S, so if you have a BRZ with the spoiler, that increases downforce some and would probably push it to be rear biased.

Originally Posted by JDKane527

Curious in the cfd analysis, was the assumption made that the underbody of the car was flat or was the underbody modeled?

Our model was built off of blueprints. The underbody of the car, which can be viewed up a few posts, is completely flat. I know this is stated in our "technical article," but I will state it again. This is comparing a relatively accurate model of the twins to that same model with a splitter, and then with a splitter and rear diffuser. Real world results will vary from the CFD analysis. What the analysis does do is give us a good indication of what is likely happening in real world scenarios (going down the hightway, drag strip, road course, etc.)

This is the best we can do at this time. We are looking into getting a portable scanner and at that time we may model the car's underbody more accurately, but that takes a lot of time and effort. In most cases this is considered accurate enough to properly see the benefit of the devices we have tested.

[gramicci101]

Originally Posted by eric6

The opposite actually. You are the second person to think this today so I will clarify. The bias without the Driveway Labs rear diffuser was 32% (rear), 68% (front). With the Driveway Labs rear diffuser, it brings the balance closer to neutral, 49% (rear), 51% (front). A splitter that produces more downforce will need to be offset with something else in the rear to maintain an aerodynamic balance of ~50/50.

The eight vanes underneath the splitter were added to create additional downforce. Could you remove two vanes, create less downforce at the front, and equal out the balance between front and rear?

If you were driving an oval track, could you move the vanes towards one side to create additional downforce on a specific corner of the vehicle? Just curious...

[plucas]

Originally Posted by JDKane527

Curious in the cfd analysis, was the assumption made that the underbody of the car was flat or was the underbody modeled?

Originally Posted by eric6

Our model was built off of blueprints. The underbody of the car, which can be viewed up a few posts, is completely flat. I know this is stated in our "technical article," but I will state it again. This is comparing a relatively accurate model of the twins to that same model with a splitter, and then with a splitter and rear diffuser. Real world results will vary from the CFD analysis. What the analysis does do is give us a good indication of what is likely happening in real world scenarios (going down the hightway, drag strip, road course, etc.)

This is the best we can do at this time. We are looking into getting a portable scanner and at that time we may model the car's underbody more accurately, but that takes a lot of time and effort. In most cases this is considered accurate enough to properly see the benefit of the devices we have tested.

This. I do apply a surface roughness to the underbody however. This it improve the accuracy by mimicking the type flow under the car.

[eric6]

Originally Posted by gramicci101

The eight vanes underneath the splitter were added to create additional downforce. Could you remove two vanes, create less downforce at the front, and equal out the balance between front and rear?

If you were driving an oval track, could you move the vanes towards one side to create additional downforce on a specific corner of the vehicle? Just curious...

I don't want to tell you guys to ignore the number because the numbers are cool and interesting and neat to know... but this is way over thinking it. You're talking about 1% difference between front and rear bias on a computer model. Tire sizes, a piece of tape, track width, etc all effect the aerodynamics.

Yes, I would assume you can move the vanes to create a little additional downforce on a specific corner.

I think you are asking these questions from pure curiosity, which is great, I just think that some of you guys may take the data too in-depth. It is just a tool to help you properly decide what parts you would like on your car and how parts effect a standardized model that Paul and I use.

[Kwaziekeller]

After a brief discussion with @eric6, we decided I should share my experience with everyone else. I do not feel that their product "failed" or didn't perform... in fact their street splitter performs too good in certain instances I've yet to have any problems, or complaints and I'm still planning to purchase their race upgrade once it is available.

We all knew there would be one. Someone who takes the street splitter to a failure point. I feel that the rivet nuts are a great method to mount the splitter, and never had any doubt that it was secure. I have had it 100+ several times. I've had it to 115 a couple times. For some reason, I had a wild hair and pushed further. Around 125mph the splitter let go. The front 4 rivet nuts pulled through the facia/bumper cover and along with a rapid shift in airflow, the front edge of the splitter was dragging/skipping along the pavement. I gradually slowed, not wanting to decelerate rapidly and make it scrape worse, and stopped to inspect the damage. I initally thought that it pulled the bumper loose from some of the mounts and the entire nose of the car was dragging, because the splitter is pretty secure once mounted, but one look cleared up what happened. I got home, removed the splitter, took some pics and PM'ed Eric on here. I inquired about new rivet nuts (so I can repair and reattach my splitter), and explained what happened, provided pics, discussed a few things etc. One of our ideas is the possibility of installing washers on the rivet nuts before tightening them so its spreads the load over a larger area than just the "X" from the rivet nut. Also, I'm impressed with the material. It didn't chip, crack, break, or have any damage other than shaving down as it rubbed against the pavement.

Here are some pics. Notice that the middle of the splitter is worn down from dragging on the pavement until I could slow down enough that it wasn't deflecting into the pavement. Also, the middle holes appear to have been pulled straight down and tore in a bit of an X pattern. The outer holes both tore the facia/bumper cover slightly as they pulled through.








To make a long story short... I'm the guy who pushed the street splitter to a failure of mounting points. I don't consider it a failure of their product, and if anything it proves just how well it WORKS (guys have said they can stand on the splitter and it stays...). If you're into freeway runs, or prolonged runs at high speed, then wait for the race upgrade. It functions perfectly at normal speeds, and until I get new hardware... I'll be missing mine

[eric6]

Thanks to @Kwaziekeller taking the initiative to thoroughly test a product that was meant for street speeds , we are upgrading all the street front splitter hardware kits.

Each kit will include a (8) 1" OD washer that can be used to install on the top side of the bumper with the rivet-nut. This should dissipate the load and reduce the likelihood of the rivet being pulled through in high force applications.

For the early adopters, please PM me and I will do what I can to resolve this "issue." It is not technically an issue, unless you are going well above the speed limits and have no intention on purchasing the race upgrade. The race upgrade will fix this issue by tying a metal support structure to the leading edge of the splitter. The race upgrade should be ready Early-Mid August, everything is on order and currently we are waiting on vendors to fulfill the orders. Jeremy hasn't finalized the pricing but I think it will be reasonably priced for everything it includes (in my opinion of course).

On another note, Jeremy and I have discussed selling the splitter without hardware for a (much) cheaper replacements when/if the time comes. If this is necessary for anyone already, please feel free to contact myself or him and we will get this taken care of. I believe he will be adding a part number to his website soon for these people.