Project FR-S: Getting More Grip with Whiteline, Cusco, Rays Wheels and Achilles 123S Tires!

by Mike Kojima

In our last suspension installment of Project FR-S we were rushing to get the car in rolling condition for the SEMA show.  We had installed the stuff you could see, like lowering the car with KW Variant IIIs and installing the excellent StopTech big brake system.

Now we are back to working on the car, focusing on the things you can't see.  We knew we were going to be upgrading the wheels and tires for much bigger ones and we knew bigger tires were going to load the suspension a lot more due to greater grip.  More grip equals more body roll.

More grip also means more deflection in the bushings holding the subframe to the chassis.  We also wanted to add a bit more adjustability into the car's suspension.  Finally, more grip means more stress and flex being induced in the chassis.

To keep things tame, we went to Whiteline for a set of anti sway bars and subframe and transmission bushings and to Cusco for some of their extensive chassis bracing.  For wheels and tires we contacted Rays Engineering and Achilles Tires. Will this stuff help?  Check it out!

Want more Project FR-S?  MotoIQ Project Scion FR-S

For this go around we opted for Whiteline's 20mm non adjustable front bar (part number BSF45) as this was the only bar available for the FR-S/BR-Z at the time. The Whiteline bar is is 2mm larger than the stock 18mm bar.  Since stiffness rises to the 4th power of the diameter more or less, the Whiteline bar is around 50% stiffer than stock.  Currently Whiteline has 3 different front bars for the FR-S/BR-Z: 20mm non adjustable, 20mm adjustable and 22mm adjustable.  We will be evaluating them later.  The Whiteline bar comes with firmer bushings for better response and uses the stock end links.  The bar also has lock rings to prevent it from moving from side to side.

The rear bar is 16mm in diameter up (part number BSR53Z) from the tiny stock 14mm part and is about 70 percent stiffer than stock.  It is three way adjustable.  We really believe in adjustable bars for tuning a car that will see track use.  You usually can't manage a spring change with a grassroots budget when testing but it is easy to adjust a bar.  Like the front bar, Whiteline has three rear bars for the FR-S/BR-Z family. A 16mm non adjustable, a 16mm adjustable and a 18mm adjustable.  We will be evaluating some different bar options from Whiteline in the near future.

More loading from fat tires and supercharged power means lots of deflection in the stock rubber crossmember bushings.  This deflection can lead to wheel hop and a loose feeling in the rear.  The stock rubber bushings have big voids in them designed to give a smooth tide under the loads generated by the tiny stock tires.  These bushings will allow for over 1/2" of movement under load.  The Whiteline bushings (part number KDT922) part fill the voids in the stock rubber to give more firmness without sacrificing much ride comfort or quietness.  Whiteline has recently come out with replacement bushings for even greater stiffness and we will be evaluating those as well very soon.

The stock rubber transmission mount has a huge void in it.  We are amazed just how much flex and movement it will allow.  This will probably result in shifting difficulties and stress on the drivetrain.  There is so much movement it will probably contribute to wheel hop as well.  The Whiteline transmission mount bushing (part number KDT926) fills the void while retaining the factory rubber piece for smoothness.
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Tuesday, October 22, 2013 6:55 AM
I can't wait to see this thing hit the track. I was very skeptical of the FR-S upon its release, but after a few hot laps in the passenger seat at Spring Mountain, I'm very impressed. Although lacking in power in stock form, this thing handles well enough to keep a smile on your face all day long. I'm curious to see what MotoIQ does when this thing hits the track. Perhaps some laps after SEMA at Spring Mountain?
Tuesday, October 22, 2013 8:03 AM
Loving this series. As a former owner of an S13 (turbo KA), I have been very excited about the FR-S/BRZ since the first concepts were unveiled, and I'm really looking forward to seeing where this car can be taken with modification. Without a doubt this will be my next project car.
Tuesday, October 22, 2013 11:06 AM
Hey Mike where will those Achilles tires be for sale when they are released? Have you heard if Discount Tire/ Tire Rack will carry them?
Tuesday, October 22, 2013 2:52 PM
This car after these mods handles amazingly. Pretty much whatever you want to do with the car, directionally, it'll do, and the brake feel is not exaggerated in this article: pure magic.
Mike Kojima
Mike Kojimalink
Tuesday, October 22, 2013 3:26 PM
Matt the tires are already for sale. I know Rockwood likes it a lot and it's going to get even better. In the works are a whole slew of new parts from Whiteline. The most exciting are bigger fully adjustable front and rear bars and a rollcenter/bump steer kit. I think I am going to be able to get S2K like turn in on this bad boy. We are also about get get a bunch more power with an intercooler and more tuning. The cars is going to get better!
Der Bruce
Der Brucelink
Tuesday, October 22, 2013 7:28 PM
Um, any chance you guys are going after Evasive's TA times!?

I have no doubt you guys are going to have one of the baddest FR-Ss around, I'm just hoping you show it off on a course somewhere :-)
Mike Kojima
Mike Kojimalink
Tuesday, October 22, 2013 7:43 PM
Our car is a street car. It will probably evolve into a race car over time.
Tuesday, October 22, 2013 11:50 PM
Are you guys planning on doing anything different with upcoming projects? I'm sure whiteline swaybars, poly bushings and KW coilovers are great, but aren't there other things? How about experimenting with air springs? How about a comparo of regular springs and variable rate springs? How about playing with roll centers with a comparo test? How about comparing big spring small bar and small spring big bar cars. You could even do this with Whiteline and KW parts to keep your sponsors happy.

You guys really know your stuff, it would be cool to see you experiment.

Mike Kojima
Mike Kojimalink
Wednesday, October 23, 2013 9:41 AM
Funny you should ask. We are working on doing a story to see if we can get and air spring car to handle and have looks with real performance.

If you read this article, you would see that we are going to play with the roll center on this car soon. On several of our project cars we have moved the roll center around, our EVO IV, EVO X, and STI all have roll center correction.
Wednesday, October 23, 2013 2:05 PM
Hey Mike, did you pre-load the suspension and chassis braces with the car on the lift? Or did you do it with the car on the ground? Think it makes a difference?
Do you think the transverse strut bar would benefit from an adjustable pre-load?

Also, why no pics with the wheels/tires mounted and installed?

Suprising you didn't go with a Falken tire.....Hmmmm...Is this a sign of a big change for FD next year? ha haa haa. Great write up.
Mike Kojima
Mike Kojimalink
Wednesday, October 23, 2013 2:55 PM
We did the brace preloading with the car's weight on the wheels. I think it makes a slight difference.

I am against pre loading suspension other than the tension of the tender springs. I don't feel that this works well.

The reason for no mounted pics of the wheels and tires, uh this sounds lame but we realized that we didn't have any after we switched to different wheels and I started to work on this article. We are now running a wider front wheel and tire.
Thursday, October 24, 2013 10:54 PM
That's cool. Any chance we can get objective before and after data on the air springs and RCAs?
Monday, November 18, 2013 3:01 AM
Is this a positive or negative offset?
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