Evil Smile

alot of great information on these two pages. but here is a stupid question from me. do you guys even achieve speeds at which you would generate enough aeroforces to make any difference?

dinko

read the whole thread

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Evil Smile &raquo;</TD></TR><TR><TD CLASS="quote">alot of great information on these two pages. but here is a stupid question from me. do you guys even achieve speeds at which you would generate enough aeroforces to make any difference?</TD></TR></TABLE>

I'm a n00b just like ^^. I understand most of the guys that are gonna be buying this are hardcore track fiends, but you might just get one or two customers that don't really track their car and buy it only because they think it looks "sick" and it will be something nobody has. there's always people like that because it's cool to have something nobody has; something FRESH!

What type of handling characteristics would be improved upon with this product given that you're using it at high speeds on the road course?

bosco500

Read this article, it explains the theory. How much it helps depends on many factors, including car weight, car length/width, speed, etc. It wont work the same on any two cars unless they are absolutely identical. You have to make a rational decision just like anything else.

http://www.symscape.com/blog/secrets_of_diffusers

RPM

iTrader: (2)

Mold is complete! I'll see if I can snap a few pictures for you guys. I am hoping the prototype can be complete by Friday.

mlrmotorsports

what is the ETA on this?

JDM EJ2

Now how is that price looking... The $575 in the beginning sounded good but if its more than $800 I'm probably out. My bad, I just can't justify spending that much money on a part that (for me) is purely cosmetic.

RPM

iTrader: (2)

I swung by Phil Denny's shop yesterday to discuss aerodynamic systems. He is the owner of PRD Engineering and the previous crew chief for Mario Andretti when they were running the Lotus 77,78, 79, and 80 F1 racing cars.

Phil has amassed a tremendous amount of information on what aero packages work and don't work and how to implement them in a racing environment. We discussed rear diffuser, flat bottom, and front splitter/diffuser design. He definitely provided some new ideas how to implement an aero package in a racing environment.

PS- He had a lot of good things to say about the diffuser.
PPS- I just wanted to share the story.

Cheers!

moss

Just a stupid question - but what is the likelihood of air being trapped between the underbody and diffuser? It almost looks like theres a huge gap where the diffuser mounts that would trap air.

mormonboy

wow. that is amazing. let me know when you've got a few sets made. ill pick one up to test for you!

Johnny Mac

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mormonboy &raquo;</TD></TR><TR><TD CLASS="quote">wow. that is amazing. let me know when you've got a few sets made. ill pick one up to test for you! </TD></TR></TABLE>

I think he has more perspective testers than he knows what to do with. That is, unless you have a full-scale wind tunnel at your disposal.

RPM

iTrader: (2)

The prototype is complete. I will be cutting off the flashing material and testing the part for the next couple of days. I will be evaluating the flexibility/stiffness of the part.

The prototype is produced with one layer of 12k fiber and one layer of 3k using a black tinted resin.

Nova_Dust

I am always interested in the aerodynamic aspect of a race vehicle. I thought about cutting half of my rear bumper (6th gen hatch) to reduce drag and possibly do a sheet metal version of what you have designed/made.

Dry carbon product has always been expensive and this is a pretty big piece (28x23"). I personally think $575 is not cheap (dollar value wise) but for what you are getting with that $575, it is somewhat reasonable.

I think with aerodynamic, money has to be spent wisely because a wrong move in this department will not only make the car go slower, but also handle poorly as well.

powerneedy

im still hangin in there for pics and info

RPM

iTrader: (2)

Update:

I have produced two prototypes so far. Because we are vacuum bagging the part I am getting an impression of the vacuum bag on the backside of the diffuser. The backside of the diffuser is non functional, so the only downside is that the back side of the diffuser is not cosmetically appealing. The functional side of the diffuser has a mirror finish. I am using a black tinted epoxy resin which will not yellow over time.

The reason for the delay is because we had to develop a proprietary method of vacuum bagging the part so I don't get an impression of the vacuum bag on the backside of the diffuser. I owe you guys pictures, I will try to have them up ASAP.

MAFDARK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RPM &raquo;</TD></TR><TR><TD CLASS="quote">
Update:

I have produced two prototypes so far. Because we are vacuum bagging the part I am getting an impression of the vacuum bag on the backside of the diffuser. The backside of the diffuser is non functional, so the only downside is that the back side of the diffuser is not cosmetically appealing. The functional side of the diffuser has a mirror finish. I am using a black tinted epoxy resin which will not yellow over time.

The reason for the delay is because we had to develop a proprietary method of vacuum bagging the part so I don't get an impression of the vacuum bag on the backside of the diffuser. I owe you guys pictures, I will try to have them up ASAP.</TD></TR></TABLE>

I'll take an "ugly" one.
Function over form for me

Nova_Dust

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MAFDARK &raquo;</TD></TR><TR><TD CLASS="quote">

I'll take an "ugly" one.
Function over form for me </TD></TR></TABLE>

Ditto that.

RPM

iTrader: (2)

I'm actually running the ugly diffuser. I should have a nice one finished by today. I will snap a few pictures.

bigsyke

I can "test" this product for you.

And Im going to take a shot in the dark, but;

Arent most F1 race cars barely scraping the ground, which in turn highly limits the ammount of air going below the vehicle? Our economy cars even with full coilovers still allow a great deal of air to flow underneath the car. My understanding was if the resistance on the top of the car was Higher, than the resistance on the bottom of the car, you create lift. The shape of a car is pretty much like an aircraft wing, and by allowing air to move faster underneath there becomes upward expanding pressures on the belly of the vehicle. Would a more effective approach be to eliminate 90% of the air splitting downwards underneath the FRONT of the car (front diffuser/splitter), and have a mid-body diffuser to expell the rest of the static air the car is passing over out of the side of the vehicle?

I understand diffusers direct and stabilize flow, but isnt the damage already done way before the rear diffuser comes into play? Again, a mild stab in dark, without protection.


Modified by bigsyke at 3:33 PM 6/17/2008


Modified by bigsyke at 1:44 PM 6/23/2008

RPM

iTrader: (2)

Note, we are using aerospace grade materials and processes. We have also developed a proprietary method of vacuum bagging which produces a nice finish on both sides of the diffuser. We are using a black tinted epoxy resin which will not yellow over time.


Here are some photos of the process:

We have just laid up the pre preg carbon fiber on the mold:




Here are the parts right out of the autoclave:




This is the finished product. Note, I still have to cut off the flashing:

NTCustoms

you are correct about damage being done before the diffuser, but you must understand the cars that are going to be using a truly effective diffuser will have a full undertray to get rid of the damage before it hits the diffuser.

Nova_Dust

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bigsyke &raquo;</TD></TR><TR><TD CLASS="quote">I can "test" this product for you.

And Im going to take a shot in the dark, but;

Arent most F1 race cars barely scraping the ground, which in turn highly limits the ammount of air going below the vehicle? Our economy cars even with full coilovers still allow a great deal of air to flow underneath the car. My understanding was if the resistance on the top of the car was Higher, than the resistance on the bottom of the car, you create lift. The shape of a car is pretty much like an inverted aircraft wing, and by allowing air to move faster underneath there becomes upward expanding pressures on the belly of the vehicle. Would a more effective approach be to eliminate 90% of the air splitting downwards underneath the FRONT of the car (front diffuser/splitter), and have a mid-body diffuser to expell the rest of the static air the car is passing over out of the side of the vehicle?

I understand diffusers direct and stabilize flow, but isnt the damage already done way before the rear diffuser comes into play? Again, a mild stab in dark, without protection.


Modified by bigsyke at 3:33 PM 6/17/2008</TD></TR></TABLE>

I am also thinking that by adding the rear diffuser, you extend the overall "length" of the underside so air travels in a longer distance than before, closing the travelling distance versus the top to reduce the lifting effect.

(air travels in a shorter distance creates higher pressure which equals to lift right?)

But I do agree to eliminate the amount of air entering in the front is the first thing anyone should do. Cover the front wheels and go as low as possible, like NASCAR, would be the first step in my opinion.

NTCustoms

Nova_Dust, think of it this way: faster air=less pressure, slower air=more pressure.
that being said, you don't exactly increase the length of the underside by adding the diffuser. a diffuser is suppose to be an escape for air traveling under the body, hence why they call it a diffuser. since a true diffuser is attached to an undertray, which would be perfectly flat, air can only exit faster through the diffuser. faster air exiting under the car = less lift

kb58

Without back-to-back track testing or use of a windtunnel, it's just a pretty part. If you guys are really serious you'll wait for some data, else it's nothing but guesswork. There's can be an enormous difference between good workmanship and good engineering. Aerodynamicists get paid a lot for a reason and fabrication is but a small part of the development process.

Spend the bling money if you want, but without testing, it's no different than those "race" wings everyone sells.

sirlaughsalot

RPM, could it be possible for you to do a bit more specific design on each of these cars?

If I was to purchase this, I would want for it to fit flush, not stick out of the rear (unless it was the width of my car, which would probably improve efficiency even more), and get rid of any kind of gappage it has.

Please do a Version 2.0 on this...Car specific all the way bro!

RPM

iTrader: (2)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kb58 &raquo;</TD></TR><TR><TD CLASS="quote">Without back-to-back track testing or use of a windtunnel, it's just a pretty part. If you guys are really serious you'll wait for some data, else it's nothing but guesswork. There's can be an enormous difference between good workmanship and good engineering. Aerodynamicists get paid a lot for a reason and fabrication is but a small part of the development process.

Spend the bling money if you want, but without testing, it's no different than those "race" wings everyone sells.</TD></TR></TABLE>

When you put a wing on your car what type of testing do you do to ensure the wing is optimized for your car? How do you know if you are using the correct sized wing, too much chord, too little chord, high enough, placed far enough back, large enough end plates, angle of attack, etc., etc. You may have a really good designed wing but it may not be fully optimized for your car.

Same concept with this diffuser. It works, no question about it. But to fully optimize it for your setup you will need to play around with different settings. If you slap on this diffuser and placed it at the correct angle with the leading edge lined up with the floor of the car, the diffuser is effective at extracting underbody airflow behind the vehicle and you will see positive results. Is it fully optimized, no. To fully optimize it you will need to clean up the air before the diffuser.