VajazzleM

Hello CL,
I am an intermediate level track head who has decided to start tracking his '19 GSF. I've owned it for a couple of years and before this I tracked other cars. It's entirely stock.
I am based in AZ and so I have some level of experience in the tracks out near Phoenix and Tucson area. I also run down at Podium Club in Casa Grande. I'm with NASA AZ running their HPDE 4.

I have noticed that in the last 2 sessions a couple of things about the stock setup:
1. I killed the OE front super sport tires really quickly, thanks to having little camber in the front
2. The TVD makes the car rotateable, but not smoothly rotateable without a lot more skill, sport S+ mode throttle sensitivity is WAY too high.
3. The front end tends to push quite a bit at the limit, due to the weight

I have been looking for information on what track people are running in their setups. I got some good info from people already, but I'm looking for grizzled veteran input who have been around the track block a few times, especially in my area.
I've searched CL for quite a bit, but the info mostly contains stuff on aesthetics and my primary focus is to get this car to go as fast as possible while keeping it street legal and not brutal to street drive.
This goes out to people all over the US, Cali especially as I know some of the tracks out there too.

1. How much camber is a good starting point? Do I need new control arms/bushings? I was thinking -2 degrees up front for Arizona Motorsports Park. Can the OE setup even do -2 degrees?
2. Figs vs RR: control arms, anyone have any input? They differ in price but seem to have similar feature sets.
3. I'm replacing the Super Sport tires on the OE wheels with Pilot Sport 4S. If I wanted to drive to and from the track, what street legal tires are others running?
4. Has anyone fiddled with front and rear sway bars?
5. I'm looking to put more tire up front. I heard 18x10"s up front are good with a square setup. If I were to keep a 19" wheel, what front wheels would be good if I wanted to run 275/285?
6. What track brake pads and fluid are people running? My normal goto is Motul fluid, but the OE fluid, rotors and pads has been good enough for moderately savage track work. I expect this to change I ramp up speed/effort.
7. any other thoughts or feedback is welcome. I used to track other cars but I am shaving down the fleet thanks to the wonky economy. I'm also running out of space in my small garage.

Thanks and have a good holiday folks, yes I have searched the CL forums quite a bit in the GSF section.

lobuxracer

iTrader: (2)

I haven't tracked the GS F, but I have tracked my IS F. Where are you wearing out the tires? Outside edge or inside edge?

VajazzleM

Whoops. Double post on reply. Sorry

VajazzleM

Definitely the outside edges. Basically the tread next to the outer sidewall was completely gone. The Super Sports were 4 years old, came with the car, so it's to be expected but I've been told that there is virtually no OE camber adjustment on these cars.

What is your track setup on your ISF like?
I am used to running about 2.5 degrees of negative camber in my previous track cars so I'm kind of surprised that the GSF wouldn't support more than half a degree or so.

lobuxracer

iTrader: (2)

There's no camber adjustment on any of the F cars from the factory. Sad but true. You'll have to go aftermarket to adjust camber. How much toe are you running?

VajazzleM

​​​​​​
standard oe alignment. But I can't tell how much to that is. Half a degree?

1A1

Be sure to get either the RRRacing USRS or the Figs equivalent.

Steve

VajazzleM

Thanks for your input Steve, would there be any significant difference getting one or the other aside from price?

Pittsy

Ive seen you around town a time or two.

on my RC350 im running a 295/30/18 Toyo R888R squared. Suspension wise, ive got the RRRacing USRS, FUCA, BBK, then im running CKS coilovers, and Megan rear camber arms. Ive been running -2.5* of camber in the front and -1.7* in the rear. Have toms strut braces and my studio rsr cage made the car a whole lot stiffer.

Ive been to a few of the tracks here, mainly wild horse and apex, but I just signed up for nasa this year. I wish I had a little bit more track experience to share with you, but the car feels incredibly dialed on the street. Like its on rails.

The USRS made such a big difference in braking stability, the car doesn't wander around while mashing the brakes like it used to. the RR FUCA have built in caster, which is nice. More camber at a higher steering angle.

lobuxracer

iTrader: (2)

So it sounds like you're running toe in pretty significantly. Sorting toe will fix a lot of problems right away. Steve is right about the front LCA rear bushing. It flexes a lot under braking and causes a lot of toe out. Since you're wearing the outer blocks, you're probably toed in (which is what most alignment shops will do to prevent inside edge wear), and fixing that will make a big difference. The setup on these cars is very high caster so you get a lot of camber gain from turn-in, and running a lot of camber isn't necessarily the best idea depending on the tires you are running and the temps across the tread when you pull in from a session. -2.5 is a lot of camber for a street tire, especially on this car.

On my IS F I run solid bushings on the rear of the front LCA and polyurethane on the front of the same arm. I have Figs upper control arms and the solid bushing for the front of the LCA, but have not installed them yet. Same with Ohlins DFVs - have them but haven't installed them yet. More work to finish on the Supra before I do that.

The biggest difference with the LCA bushings is braking stability. Hard on the binders from triple digits will make the rear end feel like it's wandering a little. When I raced motorcycles, we had the same experience with too much rear brake, and I initially thought the problem was brake bias, but despite the exaggerated front bias, when the bushing gets fixed, the car gets really stable. The only downside to this is if you like to trail brake, you won't get as much inside wheel turn-in with solid bushings.

Video evidence of the big squishy bushing being a big problem for toe control:

https://www.clublexus.com/forums/cl-...eo-inside.html

Lots and lots of discussion about alignment - what works and what doesn't both street and track - for the IS F. The GS F is expected to have similar problems because the design features are very similar with the biggest difference going from a coil over shock rear suspension to a divorced coil and shock suspension on the GS F. Aftermarket shocks eliminate the divorced spring in the rear and use a coil over shock solution (Ohlins, etc.).

https://www.clublexus.com/forums/is-...gnment-12.html

Think very hard about your shock choice. If you want adjustable units capable of delivering on the promise, there are few selections that actually work. Most of them are junk from the factory and are far from consistent from one unit to the next. If you really want to go budget but have a solid setup, you'd be wise to chat with Mike at Figs and tell him what you want to do and how much you want to spend. He will dyno the shocks you receive so you know they are properly matched. Most companies do NOT do this and you end up with mystery problems because none of the four corners match up.

If you really want to dig into this, there's a really solid website maintained by a national championship winning autocrosser with more information than you could ever hope to get at no cost. Tons of very solid information there for track setups from casual to very hard core competition.

Autocross to Win (DGs Autocross Secrets) - Dynamics Calculator

I got into cars long after I road raced motorcycles. I had a lot of relearning to do in my first few track weekends. I also figured out I do better with the stability controls off because I tend to push too hard with them on, and I find better balance when I have full control. Not everyone is like that, but that's what works for me. There are some threads here on CL related to track days, but that subforum has been pretty quiet for a while.

https://www.clublexus.com/forums/roa...nd-auto-x-239/

My "First Track Day" thread from my IS F:

https://www.clublexus.com/forums/roa...d-to-know.html

VajazzleM

Hey man! I've seen a couple of RC350's out there in Phoenix land, I didn't know anyone was looking
How's the rub on the 295s? That's quite a wide tire, and I presume the coilovers have lowered the car a touch. Did you have a specific reason to get the RR USRS vs anything else you looked at?

I hope I get to see you out there at some point!

-Bo

VajazzleM

I need to get another alignment for the car, I had one done like 5000 miles ago but it's time for another one. My normal alignment places are a bit booked up post holiday so we'll see what happens. Funny thing is the RR Racing upper control arms I looked at for camber adjustments dial up the caster even further than stock.

This is an interesting piece of food for thought - I've done hard-HARD braking on the OE pads and rotors on the GSF, both on my own and with an instructor, and the GS on Pilot Sport 4S doesn't really shimmy at all, even if the suspension geometry is similar to the IS. Maybe the ABS is modulating that, I don't know. It does wear the pads quickly, but I would expect that out of an OE setup.
However, I do agree that the suspension bushings need firming up, the video is clearly proof of that. But I can't decide between Figs and RR Racing. RR seems a bit cheaper for a similar feature set but I wonder if it just comes down to personal preference? I've heard praises sung about the Figs bushings before, and that was always on my list.

Unfortunately, I will be riding on the stock shocks for now. The 2017-2020 GSF models come with adaptive suspension that talks to one or more of the hojillion ECUs in the car. Unless you know of a suspension kit that is compatible with how it talks to Lexus' bus, I don't think I'll be getting any new ones any time soon. RR Racing does do like a 2016 ECU replacement that bypasses the adaptive suspension thing for tuning purposes since the 2016 didn't have adaptive suspension, but I drive my GS everywhere, and I don't want to start disabling features on it. New springs are probably on the table, though. I don't know much about springs. I tend to do suspension pieces pretty late in the game, since setup and tuning can get quite complex to dial in per each environment and it takes me a long time to get that kind of thing sorted out. Brakes, tires, and education is typically what I focus on before anything else.

Also, I suspect that a lot of more modern cars have traction control systems that are granular enough that leaving them on makes one faster. Since I'm still new to tracking this GS, I have yet to turn off all the nannies as I am still finding my groove in the car, but I might try to do that next DE session.

I really appreciate the info and links however, I've been sifting through those and it's a bevy of things I didn't have to consider that much before. When I do DE I am an arrive and drive kind of guy and have been used to basically rolling around on OE gear and then making incremental changes as I see fit. But all this is great stuff to see and learn about.

I have got to get the control arms/bushings and alignment situation worked out. For the front arms at least it doesn't look particularly painful to swap out. Thanks again for all the info.

-Bo

Pittsy

The R888R's have a feature called "self-clearancing". They're great haha.

No but seriously, I have an 18x10+40 in the front with a 10mm spacer. The wheel and tire clear everything mechanical in the wheel well. The liner is the only part that rubbed, but it doesn't rub anymore after some of that self clearancing lol.

I have the lexon Japan +7mm wider fenders that mimic RCF fenders without needing an RCF bumper or hood, but uses OEM RCF rocker panels. If you've seen the car around, its easily mistakable for an RCF without a second look.

I went with the RR USRS because ive purchased a lot of parts from them, their customer service is pretty great. Just kept sticking with them. The coilovers definitely did, I came from some RSR coilovers and they were great but the ride height adjustment was very limited without changing preload, as well as they were divorced in the rear. The new CKS coilovers converted the rear to true coil over shock, as well as gave me a lot more height adjustability without messing with my desired preload. The car sits about an inch and a half off the ground in the front, and about 3 inches in the rear at its lowest point. The car is really low.

Also saw your car here at work when you had it serviced last. your instagram handle got a lot of attention LMFAO

Pittsy

RSR makes a set of AVS compatible coilovers, but again it's a divorced setup, less than ideal, as well as the heigh adjustment ability sucks on them. Cant exactly recommend them for your purposes. Most people on here just unbolt the AVS modules and secure them in the trunk and under the hood out of the way, but leave them plugged in. No codes! No ECU needed.

VajazzleM

Hahaha 🤣 Oh god, yeah, that handle 🤣 no regrets on that username at least it's memorable.

I'll take a look at the R888Rs again. I had looked at them before but I was primarily a Michelin guy before, I'm branching out now. Thanks for the 411 on the RR Racing stuff. A lot of their gear is very tempting.

-Bo