Stock, splitter, splitter with full undertray, stock lip off differences.....

[RAAMaudio]

During tuning runs I have had my car with the listed setups up to 120+, 130 on the track...two days ago I made a run to 120 without the stock lip under the bumper and it was a bit unstable but not too bad, I have made runs to that speed with it on and it was much better. With just a splitter it was some time ago and do not recall any improvements.

With the TR splitter modified to have a full undertray there is a remarkable difference in stability at speed and rowing up through the gears it is just more planted, less darting around when going over groves in the road or when boost kicks in hard, once into third gear that is but even second feels a bit better and seems to hook up more(EFR turbo tuning, not full power yet but around 260 right no, have had it to 280)

I am going to design an aluminum extension to mount to the bottom and extend it out 2-3" for track days.

 

[Siestarider]

I have been wondering about these aero effects. Great report. Are you referring to testing an air dam extension to further clean up air under the body?

 

[RAAMaudio]

The rear mount for the undertray is also a 2 point brace and a bit of an inverted wickerbill to release the air from the tray.

First version.

The manager of the Ford race shop at MMP took a good look at my car on a lift and loved what I had done including the purposely built in upside down wickerbill.

But, he recommended I put in a duct or two to help pull air out of the engine bay and I decided to do it this way as it will help with the heat of the turbo outlet, manifold, etc.....there is enough room in the area for lots of air to escape.

I need to add more width to the wickerbill under there but not go real low unless I design some channels to flow the air to the outside of the car behind the wheels or if room like on the race Vette I had with a bent huge NACA duct design undertray to flow the air towards them to cool the brakes and still blow it out under the car, 50 hours on a wind tunnel was put into that undertray(not by me!)

I wanted to mimic it on this car but not enough room to do it well.



Pics a bit blurry but a better overall perspective.

After some street miles and 80 or so laps at MMP.

 

[RAAMaudio]

I just want to make some quick release extensions that stick out from the bottom of the splitter forward of the car to make it more effective.

BUT, I need to also consider a real wing and have been going to at least sand off the back side of the rear "grill" to let air out or go nuts and angle the bottom of the tire well and build a big real diffuser which has less drag, lower CG, less obvious on the street....and then....

There is little gain with the stock spoiler, adding a wickerbill would likely be worse due to the openings in the unit, they need smoothed and sealed first according to the race shop manager that used to run the Audi race shop and worked with world class aerodynamics experts. Even then little gain would be had from it.

One thing to remember, the aftermarket is full of racy looking but performance degrading products, want to really make improvements, spend your time and money wisely

 

[RAAMaudio]

SAD day, sold the lift, gone to a new owner, sold the hose and to much trouble to take it with us but I will get one again when ready, best tool I ever had by far

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I felt the car only needed a 2 point brace so I made one that does three things and out of scrap parts and low weight.

The Ford race shop manager agreed, said that would do what I needed.

I will however, later down the road, test 4 and 6 points, others as well on the chassis, if they make the car faster they stay, if the same they go, make it slower due just adding weight and wasting money, long gone!!!

I never take any advice as 100% have to act on it, personal bias, experience, ego, etc....all play a part in how we do things so I always want to find out for myself what really works.

My biggest issue is logging things, old school here, still have to learn new tricks

 

[OEFvet11]

Little changes can the biggest differences in the world of proper aero. Like the under tray so far.

 

[WhiteFords]

Nice work there! This is an inspiring idea.

What kind of material are you using for the undertray?

 

[WhiteFords]

You have some serious rubber on that car. What is your rolling stock setup?

 

[Original J-Pat]

I know you have alot of questions to answer but ever though of any of the other splitters on the market???

 

[RAAMaudio]

TR was about all that was made when I got it, none of the others really inspire me that much and I already built it and can easily mod it to work better so likely just keeping it.

The material I used for the under tray is Alumalite, 6mm version, a sign industry product I buy for just over $100 for a 4x8 sheet, it is very strong and light, no need to spend the money on CF

The tires may look a bit wider than they are due to wide angle lens, just thought of that.
225/45/15 Toyo RA1 on Konig Dial In 15x9 wheels.
I can fit 225 Hoosiers, which are more like a 240 or 245 wide, in the front but not the rear of the car.
Later when I start running TT events again I am considering A7 Hoosiers in 225 front, 205 rear, as they are extra wide tires.
I am also considering the Maxxis RC-1 for my next track tires, 245 front, 225 rear, they are very reasonably priced and I read great things about them.

 

[RAAMaudio]

My car is rather dirty underneath as I had to drive through road construction so after we get moved I will detail it top to bottom and underneath as really do not like working on dirty cars

 

[the duke]

Posting to remind myself to look through this later. I think I can offer some ideas to help.

 

[Peterson]

Pulling this from the dead haha. Any way you can upload those photos again? Did you ever make a matching diffuser,

 

[RAAMaudio]

Sorry, cannot upload them at this time but I might be able to forward them to your email account and you would be free to post them if so.

rick@raamaudio.com

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Did not get around to doing a diffuser as so little room to work aerodynamically it would mostly be cosmetic and I seldom do cosmetic mods. Weight is the enemy of all things performance, always will be so I only add what makes the car faster(why I only built a simple two point brace, none others needed, take money away from real performance mods and make the car slower) Even if a bit of perceived change it might not be an advantage and nobody actually provides real test data, for a reason.

Back on track, If not for a very big investment of time in building a secure storage system in the tire well and somewhat below it in one place, three areas sealed from each other, battery, pump and tank for the MW injection system. It would take a complete rework as well as have even less room to fit everything to have the proper angle on the diffuser, which in general need to be curved, just just a flat angle though those can still do well. Basically just out the tire well and start from scratch.

Or build one sticking way out the back of the car though still best to start at the rear axle.

 

[Peterson]

Sorry, cannot upload them at this time but I might be able to forward them to your email account and you would be free to post them if so.

rick@raamaudio.com

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Did not get around to doing a diffuser as so little room to work aerodynamically it would mostly be cosmetic and I seldom do cosmetic mods. Weight is the enemy of all things performance, always will be so I only add what makes the car faster(why I only built a simple two point brace, none others needed, take money away from real performance mods and make the car slower) Even if a bit of perceived change it might not be an advantage and nobody actually provides real test data, for a reason.

Back on track, If not for a very big investment of time in building a secure storage system in the tire well and somewhat below it in one place, three areas sealed from each other, battery, pump and tank for the MW injection system. It would take a complete rework as well as have even less room to fit everything to have the proper angle on the diffuser, which in general need to be curved, just just a flat angle though those can still do well. Basically just out the tire well and start from scratch.

Or build one sticking way out the back of the car though still best to start at the rear axle.

So I take it you’re not a fan of the Verus Engineering Diffuser?

Yes with how low the spare tire holder sits, it would be pretty hard to get a good angle on the diffuser. I think if anything, it would be good to seal up the rear bumper cover under the car, as it looks like a big air catch all underneath. Or perhaps jus remove the fake grill in the rear bumper cover.

907thpeterson@gmail.com

 

[RAAMaudio]

I have not paid much attention to this car in a long time, mine has not been on the road in nearly two years, blown head gasket, no good place to work on it though I will just get busy this spring and fix it with an engine swap.

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Just looked, better than I thought in the forward and middle sections, falls in favor once get to the parts sticking out down low, connected up on top would work better though not 100% on that as have not done one for this particular vehicle.

Also the flat upper section could be quite a bit longer thus much more effective.

Started out pretty cool, ended up with to much form over function.

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"the unit is strong and light; and very capable of increasing rear end grip on this chassis!
Utilizing state-of-the-art analysis software during the R&D process, we were able to extract more performance for the given build volume; increasing downforce generated and drag reduced from the addition of the rear diffuser.
During the design process; we utilized in-house scan data. This resulted in a product that features a near OEM fit and finish.
The rear diffuser was designed for owners looking for function and form."

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Where is the data?

How is it balanced with the front aero stock or added on as well?

I tend to drive all out on track at the very limit all the time so I ask a lot of the parts I choose to run.

If this does help it will only be a small amount at higher speeds, to little to do much else and could upset the balance depending on the rest of the setup of the car.

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IT MIGHT be better than it looks and MIGHT be worth spending the money on but not to likely, sorry.

A huge percentage of "performance parts" are not really for performance, they are for profit making, sad but true so I would ask them to provide hard data to show just what this does or an endorsement from somebody that has the real world experience to give an unbiased review of it in actual use.

 

[RAAMaudio]

I am not an engineer by education and maybe not much of one in general so most of what I know I learn from studying the wisdom of those that do and lots of trial and error over the decades and always willing to admit when I just do not know.

 

[shouldbeasy]

I have not paid much attention to this car in a long time, mine has not been on the road in nearly two years, blown head gasket, no good place to work on it though I will just get busy this spring and fix it with an engine swap.

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Just looked, better than I thought in the forward and middle sections, falls in favor once get to the parts sticking out down low, connected up on top would work better though not 100% on that as have not done one for this particular vehicle.

Also the flat upper section could be quite a bit longer thus much more effective.

There is a section which is vertical, behind the axle, which helps to stop the air, this diffuser is relying on having the air mostly streamlined to the rear end, it's going to be turbulent around the axle (needs room to move) but it bridges the gap from the back of the axle to the outside of the rear bumper.

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Where is the data?

Actual data is hard to establish without a proper wind tunnel - time attack cars have crazy aero and it's all done by previous experience and imitating what other (winners) do. That being said, there are pictures of what appears to be computer modeled wind simulations around a Fiesta on their webpage.

How is it balanced with the front aero stock or added on as well?

I have a front plate so that helps my air flow but I found the rear end 'floaty' at high speeds prior to installing the Versus rear diffuser.


Just objectively looking at the underside of the car there is a large void behind the rear axle and providing a transition for the air to out of the bumper cover and not allowing it to circle under is how I see it. I plan on removing the air under my engine plate with ducts, half the battle is limiting what air is allowed under the car (splitter) and the other part is what you do with it once its there. I want to remove it from under the engine (and shoot it out the top via hood vents) and whatever else is under the car I hope is smoothed out by the diffuser.

 

[Peterson]

@RAAMaudio. Any chance on those pictures again? Just need a starting point for the under tray splitter

 

[shouldbeasy]

@RAAMaudio. Any chance on those pictures again? Just need a starting point for the under tray splitter

There are two support braces which go from the engine cradle to the unibody rails - I'd suggest using them and working forward.