2013 FRS Mild STX Build.

[feldy]

After seeing some build threads I thought I would join in.

2013 - Scion FR-S Slushbox

With the help of a local friend I actually started to prep the car back in Winter of 2012 with the bulk of the work done in the spring.

I started off with a new set of wheels. I ended up with a set of 17x9+ 35 offset RPF1s. I had them mounted up on some oldish take off R1Rs in a 245/35/17 size. The gearing was really nice with my auto transmission. However the tires were old and grip was not what it could be. So I ended up with the Hankook Rs3 245/40/17 for the rest of the season. I did end up running Rivals in the same size for the last event. And that's what I will be starting this season on.

Next I started to address the understeer into snap oversteer issues. The stock shocks/springs are ok but needed better damping.

I know most people go the coilover route in STX. And I would have to but I really didn't feel like swapping stuff out during our winters to avoid rust. Thus on top of that corner balancing, Ride height and rake adjustments, Countless adjustment knobs were just not something I wanted to deal with.

I ended up with a simple solution that paid off well last year. I ended up with a Koni yellow/ Racecomp spring swap. The springs were matched ok to the Koni shocks. The springs were 250lbs front and rear. On top of that I ran some non-adjustable Whiteline tophats for extra camber.
That was a big mistake. I went through 4 sets in 4 months and one busted/exploded Koni shock. These top hats just could not take the extra caster and the bearings would go bad.

In the fall Nick Kelly actually sent me a free set of protoype springs to use this year. They say these are better matched to the Konis then the yellow springs were. These will bump up spring rates to 300lbs front and back.


Also I decided to take care of my top hate issue. It took 6 months but I ended up getting my money back and used the money to get a set of HVT camber plates. These come with new spring perches that can be used with coilover size springs. Or Oem size springs like the ones I run.


I plan to run a alignment similar to what I was running last season as it seemed really stable and confident. I may play with front camber and see how that goes. Still on stock sway bars as I'm not sure the car needs a aftermarket one right now.

Engine Tune.

With the FRS/BRZ it didn't take long at all tuning software to hit the market. I first went with a fa20club tune for both e85 and pump gas 93. The e85 made one hell of a difference however it was only legal for last season and no longer can be used. Once Fall started the car started to throw a weird code when I was on e85 so I stopped using it. By that time my tuner had become pretty popular and getting any type of tune update became painful.

I ended up switching tuners right before the last event last year and my god I wish I had gone with these guys the entire time. The pump gas tune I have now feels so much stronger then my e85 tune did.
After the entire exhaust is changed out and finished I will get some dyno numbers for comparison. I ended up using Circuit Motorsports for tuning.

Exhaust

At the end of the season last year I started to order my exhaust components for this season.

I currently have the Perrin Resonated Catback. I cant remember how much weight this shaved but it did help give the car a better sound and better looking rear end. God knows those dinky stock exhaust tips were just to girly.

I also replaced the Front pipe and cat with a Berk Front pipe with High flow cat. For even more weight reductions and some simple power mods.



Some misc things that were also done.

Corbeau Race harness for driver and passenger.
Avo Silicone intake tube.
Have bushings for rear camber and bushings for the front control arms. Need to install at some point.

Things to address in 2014

1. The driver. I need to get more consistent. Some events I will do really well and others I just let me emotions get the better of me.

2. Depending on Taxes. Get the header replaced. This by far reduces the amount of TQ dip these cars have in the 3000 to 4500 rpm range. This is a big thing since I have a auto keeping power in that area is big since I spend most of the time there. If there is extra moneys the overpipe that connects from the header to the front pipe should also get replaced.

3. Brakes... The stock factory brakes are still on this car after 20k miles and 400+ autocross runs. I want to get these pads changed out at the very least and new rotors up front. I can run the 02 to 07 wrx rotors and from the scales they drop about 4lbs a corner.

4. Lightweight battery. The factory one is heavy heavy heavy. I can get a 3 pound battery setup for around 200 bucks. Help get some weight off the front end.

I have no plans on switching the seats. I know I can save weight there but I still daily the car so I want to be comfy for long drives still.

I am nervous about doing the full exhaust replacement. Last year we took a trip up to Chicago and the other FRS with us was just obnoxious... way to loud for my tastes. I would be embarrassed with a car that loud.

The car drove really well last season. It took a few class wins. Took even more class wins with other people driving the car than I was able to but o-well. It did manage one FTDI. I do account that to most of our fast guys being away for nationals so I will take what I can get.


If any of you seen other observations last season that I should address first please let me know.

[jprice130]

Thanks for sharing your build @fedly! I'm definitely interested in seeing how you progress with your automatic FRS. I started with an automatic BRZ in June 2012 and competed with it for over a year in stock/RTR, but after co-driving a friend's manual FR-S for a few events, I decided to give up on my automatic and get a manual FR-S instead.

The gearing of the manual was noticeably more peppy accelerating out of low speed turns when driving the automatic and manual back-to-back during a local test-and-tune. That said, it sounds like your Circuit Motorsports tune will help offset the issue with the taller automatic gearing and you'll obviously have an advantage on faster courses where you can wind out 2nd gear longer than the manual FR-Ss/BRZs.

I'm now in the process of putting together a mild STX build as well and wrestled a long time between using the RCE Springs/Koni option or running a budget coilover. I ultimately decided to go with ST coilovers with HVT camber plates and Robispec rear tophats. I was close to considering the Com-C tophats a couple months ago, so I really appreciate your ongoing feedback about the Com-Cs in other areas of the forum.

Anyway, good luck this season and keep us updated!

[feldy]

I stopped updating this a while back but here are a ton of videos and what not of the first season of racing with the FRS back in 2012 http://www.ft86club.com/forums/showthread.php?t=11848