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This is a diffuser on a time attack highly modified Impreza. The builder wanted a deep diffuser and it apparently works. I thought that some of it may be possible on a track dedicated S2000 with sufficient modifications to the trunk. There are two videos/interviews below the picture/
the way he talked about it sounded like smaller tunnels would still work better
I'm more impressed with the whole chain drive thing for the front wheels
The height does seem excessive, although several top time attack cars have very tall diffusers. In F1 and LMP the diffuser size is limited by the rules. In F1 I believe they are limited to starting 175mm in front of the rear axle centerline with a maximum height of 175mm. Both increases in 2017 from 2016. Time attack seems to be more of an unlimited class with teams working with aerodynamicists, although with limited budgets. Even so, they claim huge improvements from reworking their aero.
There is nearly unlimited rear downforce available with a rear wing. The forces from most here seem so low they are mounted on sheet metal panels and their drag is negligible. The problem is getting downforce more toward the front of the car. With the diffuser, the low-pressure area is just in front of the diffuser. In this car, it is clear the entire suspension is in the diffuser with the low-pressure area in front. It makes me wonder if an S2000 diffuser could start in front of the rear suspension.
Andrew Brilliant says that the big improvements are often focused on the cooling airflow, an area that doesn't seem to get a lot of attention.
The height does seem excessive, although several top time attack cars have very tall diffusers. In F1 and LMP the diffuser size is limited by the rules. In F1 I believe they are limited to starting 175mm in front of the rear axle centerline with a maximum height of 175mm. Both increases in 2017 from 2016. Time attack seems to be more of an unlimited class with teams working with aerodynamicists, although with limited budgets. Even so, they claim huge improvements from reworking their aero.
There is nearly unlimited rear downforce available with a rear wing. The forces from most here seem so low they are mounted on sheet metal panels and their drag is negligible. The problem is getting downforce more toward the front of the car. With the diffuser, the low-pressure area is just in front of the diffuser. In this car, it is clear the entire suspension is in the diffuser with the low-pressure area in front. It makes me wonder if an S2000 diffuser could start in front of the rear suspension.
Andrew Brilliant says that the big improvements are often focused on the cooling airflow, an area that doesn't seem to get a lot of attention.
I hear what you're saying, I guess I didn't word what I meant to say clearly. I wasn't trying to say that smaller tunnels are better, more that smaller tunnels would have been more efficient in this case cause of all the stuff thats in the way with the giant tunnels on this car. at least thats how I understand it based on that interview and my very limited aero knowledge.
cooling airflow makes sense. most street cars are designed to vent underneath the car, and all that hot air under the hood is just pushing up. doing some proper ducting and hood venting can go a long way to reducing lift. S2000 is prolly one of the easier cars to do it on just cause of how much space there is between the nose of the car and where the engine actually starts. still nowhere near as easy as bolting on a splitter and a wing though...
In supercharged and turbocharged cars, whether the compressor itself or ducting to an FMIC it can be crowded. Even NA there is the air intake.
But the diffuser issue is getting the low-pressure area further forward and with a lower pressure. If the low-pressure area was in front of the rear axle, it would allow more downforce from the rear wing.
AFAIK, the Wehrlein crash at Monaco provided the best view of a 2017 F1 diffuser.
I guess I didn't consider FI... I guess with a turbo setup, you can get a kit that puts the turbo besides the engine instead of in front of it, kinda like the Top Fuel TA car. With an SC car, depends which kit you go with, could still be done with some compromises. but you're still not in bad of shape as most other cars where you have a foot or less from the front of the engine to the bumper reinforcement. NA is easy to sold, just ditch the OEM intake for an aftermarket one or make your own.
F1 bottom is so simple, haha... but you gotta limit them somehow when budgets are pretty much unlimited...
I don't think the Top Fuel car has run for a few years now. By 2015 the diffuser had gotten larger. What made the one at the top of this thread interesting was that it extended past the rear suspension.
It was a very popular time attack car when it was running...a very sharp effort with extensive aero, lots of power. They had access to an aerodynamicist, and have a comprehensive cooling solution. Their cooling solution is even wilder than it seems. The intercooler vents through the hood, but the radiator appears to vent under the car. You can see it nearly flat feeding from a shared plenum with the intercooler but exiting below.
12-05-2017, 04:20 PM
Interesting Time Attack Diffuser
