Chasing the F-Wing: How Spoon Sports USA Beat the FWD Unlimited Record

by Mike Kojima

Last week at the annual 2015 GTA Super Lap Battle at Buttonwillow Raceway, Chris Rado's long standing FWD Unlimited Time Attack Record was shattered by Dai Yoshihara driving the Spoon Sports USA Honda Civic to a blistering lap time of 1:45.585 seconds to Rado's 1:46.730 set in 2010.

GTA's Superlap Battle held  on Buttonwillow Raceways configuration 13 clockwise has global acceptance as being the lap time record standard for North American time attack. Likewise Rado's five year old record has been the longest standing record in North American Time Attack history, a holy grail that many considered to be unbeatable by anyone other than Rado himself.

The record was set by the Scion Racing F-Wing TC, one of the most radical, expensive and high tech time attack cars ever constructed.  With 1200 hp, an innovative drivetrain and ground breaking Aerodynamics, the F-Wing hit speeds thought to be impossible for a FWD car by many and for a time contested for the overall lap record at many venues.  

The record has been broken, not by a technological terror super machine but by a team that simply does all the basics well.  That team is Spoon Sport USA.  In a two year quest that started last year when the team unofficially broke the record in practice only to be thwarted by a broken splitter during the official attempt, the team came to the 2015 SLB with a more potent machine and breaking the record looked to be a sure thing.

After a tough two day struggle when all seemed lost, the team persevered and a new record was set with some brilliant last moment driving by Dai Yoshihara.  If you are interested in the background story and the changes made to the car for 2015 check it out!

If you want to see details of the car's construction look here.


Going back to when we last did a feature on the Spoon Sports USA car, you might recall that the car's powerplant was a very basic turbocharged K20A engine. Although built well, the engine was not radical and had a very modest power output of about 430 whp. One of the goals for 2015 was to modernize the engine's turbo system to produce a wider powerband, less turbo lag and to make a little more power with less boost pressure to help reliability and to reduce thermal load on the engine. The car also had overheating issues and another goal was to improve cooling so consecutive hot laps could be run which is useful when trying to set a fast time on a crowded track. 
The old HKS T04S turbo was replaced with a Garrett GTX3576R ball bearing turbo. The HKS Turbo had been in need of service and was losing power over the last few events. The GTX3576R features a double ball bearing center section with a floating bearing cartridge. The floating cartridge helps provide damping to control shaft motion which helps reliability. The ball bearings reduce friction which greatly reduces spool time and improves response. The turbo also features a ported shroud compressor housing which reduces surge under high load, lower rpm conditions. GTX series turbos also have modern CFD derived and hot test verified aero which delivers highly efficient compressor and turbine sections for minimal shaft power demands, cool intake charge temps and low backpressure. 
We wanted to have the weight of the turbo further back in the chassis and have the exhaust have a shorter straighter shot at the turbo itself.  Chris Eimer of Eimer Engineering who also happens to be Dai Yoshihara's Formula Drift crew chief did all of the fabrication for the new turbo setup.  With Chris's help the turbo was moved over a foot backwards towards the firewall and the header now has a direct shot straight into the turbine housing. 
Another goal was to simplify the intake charge piping to make it lower volume and shorter to improve response and to reduce turbine work and backpressure. To do this a K-Tuned intake manifold was utilized with a low mounted, centered throttle body.  This would allow the charge piping to be shortened and simplified.  The K-Tuned intake is also a large plenum short runner manifold that turbo engines love.  The manifold has internal velocity stacks and an 80mm billet throttle body.
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Monday, November 16, 2015 4:44 AM
Nice! Any links to in-car or outside of car video of the run?
Monday, November 16, 2015 5:57 AM
Congrats! Wonder if Rado will dust off the old F-Wing to try and retake his crown. Would be nice to see a new Time Attack rivalry flare up in the states. Now if only the ARK GT-R can get out, things could really get interesting...
Monday, November 16, 2015 10:49 AM
Great lap guys, super impressed at how fast cars are going now. There were a couple years there when not much was going on in time attack and I thought a lot of times were going to stand for way longer.

It does seem like the re-pave last year has made a pretty significant difference on lap times, plus there are better tires available now.

Oh, and I can think of a longer standing record- FXMD has had the top time at WSIR since 2009.
Monday, November 16, 2015 10:56 AM
Mike, did Dai say how much time he felt was lost by omitting 4th gear? Can't wait to see what a fully functioning machine can do!
Mike Kojima
Mike Kojimalink
Monday, November 16, 2015 11:34 AM
The track is more bumpy than right after the repave. I had to change the set up on both the Spoon car and the Evasive car to compensate. The gains in tire technology are really shocking in the street class more that limited and unlimited. Our Advans are really endurance tires from a spec series in Japan. Nothing radical.
Monday, November 16, 2015 2:47 PM
Is there a dyno plot missing on page 4? I see text for it, but no pictures with squiggly lines.
Mike Kojima
Mike Kojimalink
Monday, November 16, 2015 3:04 PM
We have in car video in the article on page 5 now.
Mike Kojima
Mike Kojimalink
Monday, November 16, 2015 3:47 PM
We had the wrong image up, the dyno chart is now in place!
Monday, November 16, 2015 6:38 PM
Wow that's incredible considering the condition the car was in. It also wasn't running well tune wise part throttle and between shifts from what I heard(can really see it in the dyno graph as well) so can't imagine what this thing can do once all the kinks are worked out. Also amazing that the FWing didn't go faster despite having more than 2x the power (and, a giant "FWing"...).
Tuesday, November 17, 2015 12:03 PM
Having driven a way overpowered street SE-R at Buttonwillow, I can very easily imagine why Rado "only" ran what he did. You pretty much FUBAR every single corner in a vain attempt to get it pointed straight ASAMFP. Still, it's a shitload of fun spinning the tires at well over 100mph in 5th leaving Talledega, and even the esses can be a challenge running clockwise with too much power.

Sometimes, "moar powah!" is not what's needed, and this Civic has proven it at B-willow. CA Speedway, on the other hand.... :)
Tuesday, November 17, 2015 5:24 PM
FWD just can't put the power down that well. This is clearly a more logical approach. Even 450whp is impressive if they're able to use it all.
Tuesday, November 17, 2015 6:35 PM
What ever happened with Chris Rado? He did drag racing and time attack and built some cool cars for SEMA. I hear nothing of him or World One Performance.
Thursday, November 19, 2015 6:16 PM
I don't know about Rado but World One in their previous guise closed at the end of 2009. The current form of the company is called World CNG and they do natural gas conversions from what I've heard
Thursday, November 19, 2015 6:20 PM
Or do you mean just World Performance? World One Performance was a performance garage out of Kent WA.
Mike Kojima
Mike Kojimalink
Thursday, November 19, 2015 7:23 PM
World now is a tuner of Mercedes and Porsche
Friday, November 20, 2015 9:37 PM
So are you trying to imply that the track is not faster since the repave?

Ventus TDs came out in 2012 and then the 2nd limited class car ever got into the 48s. The next year the track work happened and now we have a bunch of cars in the 44-47 range.

And world racing is still around, they are doing mercedes stuff now and no time attack though. Not the same as world one.
Friday, November 20, 2015 9:51 PM
Uh, can't edit here can you?

I'm really not trying to cut down what you guys did and re-reading my posts it kind of seems like I am. Sorry.

Car looks like a regular civic and not some monstrosity with wings sticking out everywhere and nos and a paddle shifted dog box and 1000hp. It's crazy how fast it goes.
Mike Kojima
Mike Kojimalink
Sunday, November 22, 2015 1:07 AM
The track is getting more bumpy since the repave. It is more bumpy than last year.
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