Lol, yeah, getting to break **** for a living has it's perks.


Some reference material for you guys. Good info from Simon McBeath

[img]https://www.rx7club.com/attachment.php?attachmentid=367255&stc=1&d=1258411 870img]

 

 

 

 

http://www.racecar-engineering.com/a...explained.html

 

I also have a good article about the relationship of rear diffusers and rear wings. Can't seem to find it. Once I do I will post it.

But here go another source.

http://www.accessscience.com/popup.a...260&name=print

 

Adam,

Good post!

Though, I already read most of those articals from racecar engineering, but really good stuff, as they always have!

I too will be making under body aero-effects on my FD in the next year, I hope to be able to get to a wind tunnel as well, as my cousin is one of the head aeronautical engineers for honda and could help me with that one .

-J

 

Holy crap, afgmoto1978 thats a great article! I really do think that there is a benefit to some degree to run a fully paneled underbody. I am really interested to see how Atomic rex's underbody kit turns out. A couple fd owners I have met were running large adjustable front lips at track events with great success, so I would think adding to that with a flat underbody and rear diffuser could really reap some good performance gains.

 

LOL, I knew Adam would hop in on this thread and regulate.

Has the issue of exhausting radiant heat from the engine/ turbos via the transmission tunnel been discussed?

P.S. Adam, when you get access to the wind tunnel, I want to be there to measure modified body (your car) vs stock bodied (my car)

 

what about cooling the tranny, diff, getting heat from the exhaust out.... there are a number of serious problems to solve when you box in the underbelly... though id love to do it as well

 

That's Sequence garage's old s14. cctcc gt winner 2007. Awesome article.

 

previous page...

 

^I doubt that is enough for street use.

 

^^Would you care to expand on this statement?

 

Extended periods of the car being stationary at stop lights and stop and go traffic. Which would lend itself to somehow integrating a fan system in the tranny tunnel to help expel trapped heat.

Personally, this should be left to racers and fanatical track day enthusiast.

 

AtomicRex, do you plan on selling a ful underbody diffuser to the public once your design is complete? I wouldnt mind picking one up, as well as that center exit exhaust setup ( realize Id have to run a fuel cell).

 

Briefly, but ideally you would do a properly vented hood and possibly quarter panels. This in turn affects the air flow over the top of the car. Interestingly, if done right it will improve overall downforce at the front and back by creating a boundary layer of slower air at the surface of the car. This creates more drag though. But as far as downforce is concerned this is what you want, high air velocity at the bottom of the car and slower air velocity at the top of the car.

With the above in mind wing position is pretty critical. Ideally you would integrate it with regard to the rear diffuser air flow, but that would require a wind tunnel or a lot of track testing to accurately pinpoint that location at the desired air velocity (mph). To be safe though you would just put the wing at a high enough position that it has clean air throughout.

Also something to be aware of is the sensitivity of the car to pitch, roll and yaw when you have underbody aero on the car. Rules aside, ride height is pretty critical, especially when pitch and to a lesser extent yaw is involved. Extreme example, LMP & Le mans prototypes flipping, those where caused when the pitch or yaw of the car was high enough to cause the car to be a wing. Or the reverse effect where you lose all underbody downforce when the front splitter touches the ground which stops airflow to the bottom. Note, this would only happen with a splitter that has no step to it or the ride height is low enough and coilovers are at a soft enough setting to induce this condition. Springs and dampers become a key player to optimizing aero.


That is probably a nugatory unfortunately good buddy. Getting access to the Windtunnel in the first place will be a challenge. Hopefully by next year the building shutdown won’t be as tight is it is this year. With that said, weekends are out, so that leaves only a few hours in the evening on a weekday to do it. Not a lot of time. Setup time would be the most time consuming. You’re more than welcome to be present to help though. The plan is to have the car fully equipped with all the aero pieces I will be making for the car and then remove parts one by one to see how it has an overall effect on the car.

 

 

afgmoto explained it for me. It would be hard IMO to evacuate all the heat in a low speed, stop/go scenario. Instrumented testing should prove that out.

 

afgmoto1978,

Thanks for taking me to school! good read..

 

You are more than welcome to get in touch about this. It is quite a big kit, so I would look for an alternative method of transport.

The kit is fully available for sale now

Do you want to give me a call, or email me regarding this?

 

Great reading!

 

I'm all in for helping out, you know that.

let me know when you need me.

 

So am I correct in thinking this system would in essence be:

-A flat underbody (with some amount of rake, and vents)
-2 pumps/lines/coolers for diff and tranny
-Tranny tunnel heat shroud
-And a new exhaust system that exists the rear which is ceramic coated to cut down on radiant heat

I'm interested to know more cause i've been wanting something like this for years

 

You are correct in your assumptions thus far

Do you want to drop me an email with your thoughts...and I will answer them