ProjectFT86SFTA - Flat Underbody and Rear Diffuser Recap

[@ksnax]

Great series of videos. Terrific explanations of what the intent and results end up being.

[@dominiquegreen1425]

I thoroughly enjoyed the video. It was the video I was looking for and didn’t realize it. 😄

[@VerusEngineering]

Glad you liked it!

[@captaincurd2681]

Any idea how to get around a rear torsion beam suspension ?

[@VerusEngineering]

Can you rephrase the question, I’m not sure I fully understand what you are asking.

[@christmasisawesome9348]

​@VerusEngineering I think he meant the arms. Do you make the cover curve around the arm with extra space since it moves or just make it hollow?

[@334trax2]

Very nice, I wish I could do this to my daily/track car. I have a flat skid plate under the front of car and diffuser on order. My exhaust is in the way mostly.

[@willszc6brz395]

Looks good guys! Keep up the great work

[@mississippi_721]

Great video buddy! I was planning to put a undertray or a flat floor for the car but some people have mixed opinions about it! Like they say it heats up the engine bay because the air doesn't escape and the temperature rises! And do you prefer abs plastic for flat floor? Could you give me your advice! Thanks and waiting for your response sir!

[@VerusEngineering]

This is a Time Attack car so it sees very few laps at a certain time, so this is not a big issue for a race car of this nature.

[@TorAnderson0]

Thanks for sharing your results. Very cool project. I know this project was timed limited, but I was curious on what areas of aero you might have investigated if you had more time. Some areas I was curious about: 1. Any idea how much downforce could be gained by having side splitters extend closer to the ground (maybe w/ a flexible lip ) to reduce air ingress from the sides to maintain lower pressure on the flat botttom? 2. Any idea how much downforce could be gained by having rear diffuser strakes that extend closer to the ground and/or further towards the front of the car? 3. Relative effect that rear wheel air deflectors have to reduce drag on the rear wheels and increase downforce by increasing flow between the rear axles.

[@VerusEngineering]

To be 100% honest, we have no clue as we did not test this.

[@Rubadubdub16]

Great video series on this car. I have two questions. Why aren’t your floor panels tight together. And in the underbody cad you can see that the low pressure starts to lead off in front of the rear tires, can that area implement diffusers similar to the front splitter? Thanks

[@VerusEngineering]

The area in front of the rear tires is not really something to be focused on. Large tunnels under the car can help in the rear tire region though. As far as the underbody panels go, this was a one-off kit that made my hand. If we were to make a production model, we would certainly revise this.

[@redlyne22]

Maybe I missed it, but what happened to the overall drag after installing the underbody and rear diffuser? Looks awesome btw!!! Great work.

[@VerusEngineering]

Thanks! Drag was reduced by adding the flat underbody and our rear diffuser.

[@MIMCKMedia]

Nice I want to do this with my 350z. Is it bad to cover the exhaust?

[@VerusEngineering]

In this case no, as this build has a hood exit exhaust. Regardless Time Attack cars do not see extended periods of time on track, but race cars that see extended amounts of time on track could have issues with a flat underbody unless the exhaust is vented differently.

[@MIMCKMedia]

@@VerusEngineering thanks. i think i cut out the Exhaust Layout and also do a NACA Duct in front of the Differential

[@VerusEngineering]

@@MIMCKMedia that is actually what we did for transmission cooler on this car. As long as it has airflow to the cooler and a way for the air to escape, you should be just fine.

[@MIMCKMedia]

@@VerusEngineering thank you for feedback. I'm new to build custom made aerodynamics so I try to suck as much information as possible in 🙃

[@brotherhood0075]

How did you create the model in a CFD program? Did you just make it yourself from scratch or did you end up using some kind of laser program to sketch and digitalise the shape and model of the car?

[@VerusEngineering]

We scanned the car using a 3D scanner and then created the CAD model from the scan.

[@DookeyDuke]

What program/ products did you use to put the car in cad? That would help me tremendously Im just starting a Flat bottom project and this would speed things up majorly

[@VerusEngineering]

From the scan (stl), we use Siemens NX for reverse engineering and design.

[@DookeyDuke]

Verus Engineering Thank you!Appreciate the info

[@SuperCarSweden]

Question please: The air income from the front grill to cold the engine, from where will escape?

[@VerusEngineering]

FERAS DISHLI vented hood

[@gsin7048]

Hello, beautiful explanation! What CFD software do you use?

[@VerusEngineering]

We have used ANSYS, but this was done in OpenFOAM.

[@gsin7048]

Verus Engineering awesome thankyou, compare to flow design, ansys and openFoam which do you think is more user friendly and accurate? :D

[@VerusEngineering]

@@gsin7048 Both are equally as accurate. ANSYS is more user-friendly.

[@Wynkyn]

Can you tell us the panel specs as well as a supplier if possible? When i google “Alumalite” a product page with this description came up: ‘Alumalite is a strong, aluminum composite panel with a high-density corrugated polyallomer (CPA) core’ - is this the correct product? Thanks for any help you can give!

[@VerusEngineering]

Unfortunately, we cannot give out our supplier, but yes, that sounds correct. If you shoot us an email we can source you a sheet, but shipping is expensive due to the size of the sheet.

[@GP-fc7jv]

How does it handle heat with the pipes covered up

[@VerusEngineering]

This is a time attack car, so that is a non-issue. It only sees the track a handful of laps at a time.

[@TropicalDepression138]

will you be offering this flat bottom kit for sale or any info on how to replicate? I would love to have this for my 86!

[@VerusEngineering]

Unfortunately, no current plans. We can have a one-off made for you if you would like, but it would be too difficult to make a production piece out of this. Something to keep in mind is that this car has a hood exit exhaust. This means that there is no exhaust piping to worry about on the underneath side of the car. We can certainly do it, but it will not be a bolt-on kit and would take modification on your end to get it to work.

[@TaylorPhase]

why not just use a rear wheel spat too?

[@VerusEngineering]

From our CFD we found the widebody rear bumper caused a good amount of drag, so this was the best solution for the problem. This build was also on a limited budget, so we could only do so much.

[@GP-fc7jv]

I’m wondering if it would get better gas mileage

[@VerusEngineering]

Yes, flat underbodies can increase fuel economy due to decreased drag.

[@MsOMGwtfnoOb]

What's are the parts used and where on your website I can buy it

[@VerusEngineering]

This was a one-off project but the Rear Diffuser is out production unit, so that is available. The underbody is alumalite that we sourced locally and we have the alumalite bungs. If your interested in certain aspect please shoot us an email. [e-mail]

[@CountChokcula]

plzzzz open a vent somewhere on that thing. Im scared its going to melt a hole somewhere

[@VerusEngineering]

It is a time attack car. It only sees the track a few laps at a time. It never had any overheating issues.

[@frederickcook87]

What’s your front and rear ride height?

[@VerusEngineering]

We have run simulations at various different ride heights and Jeremy has switched up the suspension on the car as of recently, so we are still playing with it to get the car sorted.

[@samuelsklar3061]

what cfd software do you use?

[@VerusEngineering]

This was done using Ansys Fluent.

[@grips2k845]

Did you guys have any transmission/diff/oil cooling issues?

[@VerusEngineering]

The owner did not. This is a time attack car, so it only sees a few laps at a time, so this was not a big issue to worry about.