Jensen NASA ST4 race build
 

First time for me to make a build log...here's my story. I'll go into the build process on the next post.

Bought a new 2016 Scion FRS 5 years ago for my son's first car. At the time I had a 370z as my fun car but didn't know anything about HPDE/AutoX/Time Trials/Club Racing. In 2017, I actually thought about selling it but did some research and went to a track day event. After watching a few minutes, I knew what I wanted to do.

That night I told my son, I'm gonna build a track car and you pick which car you want as your daily. He picked my Z and I started building the FRS.

June 2017, first track event was TNIA at MSR Cresson. I did a few AutoX and HPDE events that summer with SCCA TX region and HPDE events with The Drivers Edge.
March 2018, first NASA event in HPDE3.
Oct 2018, first NASA TT4 event.
May 2019, first NASA ST4 race.
Sept 2019, first NASA ST/TT4 Championships at Mid Ohio. Got 4th in ST4.
Got lucky to finish so high, but realized some issues that put other cars (BMWs) at a big advantage.

Currently building for NASA ST4 Championships at Daytona for this year.

Originally I just wanted to build a fast car and have fun on the track. I got with a local shop and did a built engine with Jackson Racing SC on e85. Made around 340whp.
The car was fast, I wasn't.

Summer of 2018, I blew the engine on track. I didn't understand how to address ducting/cooling. Lesson learned. I decided to just use a stock engine and detune to 240whp for TT4 classing. I ran that setup for 2 years, Oct 2018-Oct 2020.

List of major mods
SPL Parts (full 86 catalog)
OSG LSD
AP Racing Sprint kit
DJ Racecars wing
DIY plywood splitter
JRZ Pro3 coilovers
GSpeed custom surge tank
Dashbuilt cage
MoTec ECU
C127 dash with data log

The 86 w/ JRSC was great for local events but not nationally....Time for a LS swap

That's amazing progress for such a short time. Congratulations. Looking forward to following along.

LS2 w/ stock cam (for now, we'll see how the dyno looks)
Dailey Engineering Dry Sump
Gforce GSR 4spd trans

Current status: custom driveshaft came in yesterday. Hope to fire it up Friday.
Next race is in 3 weeks. Locally, I'll be racing in ST2/TT3. May detune for GLTC too.

This is my goal for my FRS in the future. LS swapped NA goodness in a dedicated track car.

Fuel/oil lines are done. Wiring to MoTec and should fire up this week.

Excuse my ignorance.


I plan on building an FRS to track race. My curiosity peaked when you put in the LS3 as doesn't that restrict what series can be ran or bump you up to be in super competitive race bracket.


Do you need to log X amount of hours of training to get certified for the bracket you will run with the LS3??


Awesome to see this build and hope you keep us all update on your learning curve with the platform and what improvements you have made. Gotta have fun!

It's actually an LS2.
I race in NASA. Once you have a competition license, there's no restriction to what race class you're allowed to compete. Only restriction is making the car legal for class. Mine can be ran in STU-ST4.

Had my first race weekend with the new build.

WOW...that's alot of torque.
I'm coming from a JRSC stock engine making around 200ftlbs to this monster at 400.

Photos show initial full power tune and detune to meet ST3 class at 2800lb min weight.

Tested Friday and had issues with complete electrical power loss causing the ABS to shut off and all wheels to lockup. Re-wired some things and went out, 7 great laps and failed again...

Realized that if I broke earlier and didn't trail brake as I want, the power would stay on and I could race. It's not easy to hold back.

Saturday I won TT3 with 10 entries but .7 off the record.
I got 2nd in the ST3 race but DQd by punting a ST2 car off, I'll post the youtube link.

Saturday night I was stupid and decided to load my car on the trailer (after a pit party and too much whiskey) forgot to use the race ramps and broke my front splitter mount. quick fix that night and we'll see how Sunday goes.

TT session 1...splitter is dragging the ground...2 seconds off Sat pace
TT session 2....Two tenths off the record, let's go get it...power failure, lockup, DQd
TT session 3...tires are gone...spun off...DQd
finished 3rd, would have won Sun from session 2 if I had just pitted
Raced in ST2 and got 2nd.

Overall, it was a shakedown weekend and the car is solid.
I believe the electrical issue has been discovered, loose connection to a kill switch.

I've always used 245/40-17 R7 in ST/TT4 but this power needs more tire. I'll be running 275/35-18 at the next race. Eagles Canyon in April.

This is so awesome. Great job!

Very cool!

Last weekend was NASA TX at ECR.

On Saturday I competed in ST3 and TT4. Went out for the ST qual session and this happened.

https://youtu.be/VRFp_0JdIR8