Nicks Comprehensive 86 Build - Weight Savings
 

Driver Name: Nick Dugdale
Member as of: 12/30/21
Car Info: 2015 Subaru BRZ Limited - 6MT
Intent: Class appropriately in 'NASA TT5/ST5'

Thread Goals: Building a credible weight loss database demonstrating the weight shedding potential of the 86 chassis.

(Please reference this 'Google Sheets Link' to access my live weight sheet.)

Honorable mentions: (FT86Club Members)
• 'Official Component Weight Reduction Thread' The detailed contributions are valued greatly.
• 'Anthony's FRS 4 Step Diet Program' Just an epic thread for its time.

All weights are tested on one of two reliable scales in the shop. These weights are honest and can be used to figure your own losses/gains.

(ACCESS MY GOOGLE SHEETS LINK)


IG: nikko.zc6
Youtube: My Channel

Great write up. One question: Is there any downside to leaving off the fuel injector covers? I left mine off when I reinstalled my engine and made an aluminum bracket for the injector ecu. Seems to work fine. I'm guessing they are there in case of a catastrophic collision.

I personally do not foresee any negative side effects to removing those heavy PI covers. I've been tracking with them off for over 6 months now with no issues. IMHO it's just more weight off the nose.

I will be going down this path very soon!

My race car is 1030KG with minimal fuel

A bit more extreme I removed the loom from the car and thinned out all the redundant wiring that was over 5kG, about the same again in unused brackets.

things like the air bag impact sensors weigh a bit , only running 1 horn, lots of small things help

FUTURE WEIGHT REDUCTION

Speculative Weight Losses
- Fiberglass hollow doors -83 (Via HGK @ 8lb each)
- Carbon trunk lid ~ -17 (Via Marsh OEM = 21 Lb)
- Gut Headlights -5.2 (Via FT86)
- Cut up dash bar ~ -5
- Remove Fog lights -2.2 (Via FT86)
- Remove Dash board - 13 (Via FT86)
- Remove excess wiring looms ~ -4
- Lexan Windows Via P4P (F:-14lb / R: -7lb / Sides: -2lb) Total: -23.0
- Gen 2 BRZ aluminum knuckles -8
- Lightweight flywheel - 9
- Aluminum driveshaft -12 (Via FT86)
- Remove 9Lives wing - 19
- Remove center console -4
- APR carbon mini mirrors -2.5 (Via FT86)

WEIGHTS I CAN'T FIND ONLINE
- Wipers + Motor ?
- OEM trunk and lid arms ?
- OEM Steering column / Electric PS (From wheel hub to rack splines) ?
- OEM Roof ?
- OEM Dash Bar ?
- OEM Radiator ?

This certainly makes me wonder how heavy my car will be when its done. I'm aiming for 950kg or 2095lbs.

i could Probably take the wipers/motor out and tell you that.

do you have some info/pics on your car?

Many of the builds photo's you will find on my Instagram. Locking down the E85 tuning next week, pumped to start the 2022 NASA season.

The Lexan windows from Plastics 4 Performance should be hitting mainland US from the UK mid February.

Since I have a full race cage planned for the car 'October 2022' the mission is to take out as much weight as I possibly can in preparation for the additional weight the cage will be adding later on. 2,650lb is my MCW for class. Let the fun begin!

(Few photos attached from my IG)
IG: @Nikko.zc6

WHOA! Good work mate. I have been running ST/TT5 in my 2015 FRS. Guttted to the core (have heater/dashboard and wiring intact) but includes f/r BBK, fire system, full cage etc. With the side windows removed and doors gutted an touch over 2770lbs with driver (225lbs suited).

Do you plan to be at VIR in March? Which region do you plan to run in?

Cheers,

Lutfy

Thank you Lutfy,

Your personal build sounds great!

I recently moved up to East TN from FL and will be running predominately within the NASA SE and GL regions. I will be driving with NASA SE at 'AMP' March 12-13th this year.

The car is prepared for NASA's TT5 class and eventually prepared for 'Super Touring 5'.

Feel free to follow the youtube channel: Nikkos Garage

See you out there!

Just an off the wall idea: Would removing the power steering assist mtr for weight reduction cause any problems. These cars seem pretty easy to steer with the engine off.

This is exactly why I am looking for the official weight of the BRZ steering column with the EPS motor on it. Could be the best kept secret to eliminating that extra bit of weight on a track build. --- Yes, I am already all for it.

86 / BRZ Steering column from 'HGK' (Carbon = 4.1 lb / Steel = 7.7 lb): Carbon / Steel 86 steering column

I found a website that says the shipping weight is 13.5lbs. Official enough?

Carbon doors?

I predominately see weight savings here. With this being ST5/TT5 which is a Power:weight + modifiers class, what are you plans for the modifiers?

Tires, Brakes, suspension etc. Link to the class builder here for the folks following along: https://form.jotform.com/drivenasa/s...ification-form

I imagine that big brakes are not worth the point hit while really grippy tires are.

Once the cage goes in, potentially.

Would love to link up with a composites manufacture for this however.
Pricey indeed!

Gutting doors for now to see where that gets me.

You can find my TT5 paperwork submissions HERE

2023 NASA TT5 rules are about to be finalized. The car is going to see some changes for next season.

Gutting the doors next week. Let's see how much weight we can take out.

Weight info on these parts confirmed:
Front wheel liners -1.5 lb (each)
Wiper Motor assembly -4.6 lb
Wipers -1.2 lb (each)
Mini windows (in front of door) -2.3 lb (each)
Replace RUCA's (Racer-X) -4.0 lb (each)

What made you choose RUCA over the Verus poly LCA?

With the Verus you wouldn't take the spherical points like you will with the RacerX since you're retaining a balljoint rather than moving to a heim joint. Nice that they're letting us have one adjustable rear arm though.

There are many advantages to choosing the RUCA over the RLCA. It seems unjust to penalize the 'Racer-X RUCA' for using a spherical joint when in fact the 'OEM RUCA' uses a spherical joint in the same location. From my perspective there are no engineering enhancements / changes or performance advantages / disadvantages in light of 'deflection' as they are both spherical type ball joints.

Definition of a ball joint as it relates to vehicles (per Wiki): "Ball joints are spherical bearings that connect the control arms to the steering knuckles, and are used on virtually every automobile made."

I don't happen to know of any other way one would properly affix a control arm to a steering knuckle besides the traditional spherical joint. I could justify the penalty if a urethane bushing is replaced by a spherical design joint, but not if an OEM spherical is replaced with.... another spherical.

Standing by for apr.

I don't disagree, I was thinking from a rules interpretation point of view.

I am gutting the OEM doors this week (with removal of passenger OEM door beam.) Standby for aprox weight savings.

Lexan windows from P4P going in once my new nut-sert tool arrives in the mail. (Should shed -23.0 lb's in total off the top.) Stoked!

December 2022 has been a super busy month fixing and prepping the car for the NASA 2023 TT season. Parts are on order awaiting arrival and fenders and bumpers are coming out of paint ready to be bolted back onto the car.

Below are parts I have swapped out to save weight:

A1. OEM RUCA -8.7 lb (each)
A2. Racer-X RUCA +4.3 lb (each) [50% unsprung weight savings vs OEM]
A3. Wheel speed sensor brackets -0.2 lb (both)
Total unsprung weight savings = -9.0 lb

B1. Rear rotor shields -7.1 lb (both)
B2. Custom CNC cut 6061 aluminum hub shims +0.4 lb (Shouts to SendCutSend.com)
B3. Front rotor shield delete -2.0 (both)
Total unsprung weight savings = -8.7 lb

C1. Removed Eibach 7'' (2.25'' Ø) 700# springs (x2) -5.4 lb
C2. Changed to Eibach 6'' (2.25 Ø) 600# springs (x2) +4.2 lb
Total unsprung weight savings = -1.2 lb

I will be posting my 'Google Sheets Doc' link soon so you guys can have a real time update on the official weight savings sheet.

Standby.

Rear brake rotor shield delete must be swapped for a similar thickness 'shim plate' in order to maintain adequate distance for the wheel speed sensor to recognize / read the magnetic servo axial ring on the wheel hub.

I made sure to dial in all necessary caliper measurements before creating a oil negative photo of the flange surface. Once I peeled off a negative photo using paper and used oil, I scanned the image into Adobe Ai and went to work rendering out a vector file of the shim exactly to spec. I connected with Send Cut Send to have the shims laser cut from '6061 aluminum' to maintain strength and corrosion resistance while keeping things light.

• The OEM rear rotor shields weigh (~3.60 lb each)
• The CNC cut shims weigh (~0.19 lb each)
• Total savings of (~6.80 lb unsprung weight)

Huge unsprung weight savings off the rear suspension. My vector designed shims came out looking fire.

Those shims look awesome. In the picture, they look much thicker than what I would imagine the thickness of the original shield would be.

Appreciate it. These shims are in spec with OEM shields down to the thousandths.

Here is my official live updated 86 weight sheet - (Google Sheets Document)

I'll be updating this sheet as I find more weight to remove. We are on track to compete within 'NASA TT5' for the 2023 season at 2,550 lb. MCW.

Standby.

Another non-Hoosier convert? :)

Dave looks like he is saying the RC-1 is the obvious choice.

2023 NASA TT season update

This season I was able to achieve my (2,550lb) mcw in the Subaru BRZ for NASA TT5. From my understanding this is a milestone that hasn't been reached before within the US for TT/ST competition purposes. That is a pretty cool objective to claim if you ask me.

Secondly, since I dropped my min weight down to 2,550 pounds (1,156kg) I was able to run the 'MAXXIS RC-1' compounds this season along with a front splitter. I decided on running the legal 255/40/17 size compounds on my 17x9's and this is what I think about the setup for this season.


My personal feedback on the MAXXIS RC-1 compound
So far I have put 18 heat cycles on my first ever set of MAXXIS RC-1's. I found out that the MAXXIS RC-1 compounds have a quick regressive performance fall-off trend as opposed to a progressive-proportional trend of other race compounds on the market making these compounds ideal for W2W racers and short burst sprint shootout competition such as hillclimb. I found myself avoiding tire scrub on the out laps due to maintaining cooler patch temps in order to optimize performance longevity throughout my sessions. I am going to be honest, the MAXXIS RC-1 does not care for the heat. The compounds seems to prefer a temperature threshold of between (48-76F) from my experience. (Roughly a 30 degree temperature variation window where these compounds will perform at their optimal.)


In Conclusion
The MAXXIS RC-1 is a solid contender to the 100tw market with loads of user feedback providing the driver with consistent control and predictability while thrashing on the absolute edge every time. The MAXXIS RC-1 is a fun predictable mule of a tire but doesn't seem to maintain its performance on a sun soaked track where drivers compete the majority of the time throughout a season.

The peak grip performance is found on the out lap and tends to falls off abruptly after a few hot laps depending on the track and conditions (so try not to scrub much). The performance falloff is simply "abrupt" after a few hot laps which means TT drivers must get their flyer laps in within the first ~4 laps or its fighting an uphill battle to capitalize on the loss of grip performance to turn a fast lap after that.

Who these compounds are best suited for
• Super Touring (w2w) racers
• Hill Climb sprinters


Pros and Cons as it pertains to Time Trial competition

PROS
• Predictable
• Slip control
• Braking
• Pressure variation
• Longevity / wear
• Life consistency (environment dependent)
• High speed grip in most temperatures
• Medium speed grip on cool track
• Initial grip performance

CONS
• Acceptable steering feedback
• Medium to low speed grip on hot track
• Hot track performance
• Rapid regressive fall-off (warm environments)

I've run them for a few years and I completely agree with your assessment, I am super gentle on them on the out lap and I've got a couple of laps at most. Time needs to happen in the first or second session of the day too (assuming you're already consistent on the given track).

The MAXXIS RC-1's are great compounds for the money. I just wished they worked for my driving style and overall class setup especially running in warmer climates.

From a comparison stand point the FA20 in the 86 falls on the lower end of the power spectrum (both HP/TQ), as it relates to the overall TT5 field. I am glad I tested the MAXXIS RC-1's this season but I am forced to revert back to a Hoosier R7 since the car demands the extra grip and consistency to contend with the high power competition. End of day I will be sacrificing wear / longevity and budget for a better overall option for the car as it stacks up in class.

Revised 2023 NASA TT5 classification will reflect:
• 2,750 (lb) MCW
• 4'' Front splitter penalty
• 225/40 Hoosier R7
• Spherical joint penalty
• A-arm penalty
• 257mm with weight greater than 2,749 (lb) bonus

Ballast Project
I teamed up with a local metal market in South Carolina to cut n punch (10qt) 1/4'' 19.1 lb plates to flatten out the R/L weight ratio. I stacked 152 (lb) of plate in the passenger compartment on the OEM reinforced seat mount location utilizing a static 8.4 (lb) 'PLANTED' seat bracket and high grade hardware. The rest of the ballast with be in the form of fuel (~60 pounds in tank) as well as bell plate in the trunk to make an effort to balance out that F/R weight distribution. A huge benefit to this setup is that the weight is placed in ideal areas of the chassis and I will no longer suffer from fuel starvation. (I am working on revising the ballast design as we speak.)

(Corner balance / alignment Wednesday before I leave for NASA Mid Ohio this weekend.)

*UPDATE* I have plans for a motor swap this season. Still have my sights locked on NASA TT5/ST5 competition end of year.

True FA20 weight below:
Here is the FA20 out of the 2015 BRZ sporting an 10lb aftermarket flywheel and OEM clutch still on the engine.

Weight excludes fluids, AC compressor (+10lb) , injector covers (+5lb) and exhaust manifold (+15lb), OEM flywheel (+10lb)

My FA20 weight: 315 pounds as shown
OEM FA20 weight ~355-360 pounds

I know this is a few years old but do you still have the file to get these made from Send Cut Send? I would love to save 6lbs off the rear!