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5425 Views 48 Replies 7 Participants Last post by  Chris1
Had a blast at CMP this weekend @ the HPDE1 level. Highly recommended to get in the HPDE1, if you have never been to a specific track from the NASA org. They would pair you up with an experienced instructor for all the sessions, you can ask to drive solo once you're comfortable with the track.

Best personal time:1:58
Best instructor time (driving at his 8/10, in my car): 1:54

Mods + fluid:
Fortune auto 510 7k front 8k rear.
Continental ecs 225mm.
Torque solution Rear lower control arms(i know they are knock offs of spl, but they were 200 bucks cheaper and served the same function).
Oil cooler.
Motul 600 brake fluid.
Castrol edge performance 5w30.
Perrin master brake cylinder brace.
Carbotech xp12 front.
Carbotech xp10 rear.
Advanced auto special rotors, in another words cheap rotors. (More about this later)

Ride height (measure from pavement to the top of the fender arch)
650mm front, 657mm rear. (Noted it was measure in my drive way, so it wasn't 100% horizontal)
Camber: -2.5 degree front -2.0 degree rear.
Toes: slightly toe out front, and slightly toe in rear.

The car felt extremely balanced with this Setup on ultra summer tires.
Turn in is excellent, the car points when you want it.
Corner exit is extremely well too. Once the car is balanced in mid corner, I could have throttle input to steer the car out of the corner as I unwine the steering wheel.
The brakes held up extremely well, however I think a few components is hampering the brakes performance.

The Continental tires was okay on track. But after a few fast laps, the tires's grip started to degrade. T3 and T8 got sketchy when I asked for 100 acceleration from the tires at corner exit, the car was happily to step out. However, it wasn't anything jarring.

The advanced auto special rotors could not help to dissipate heat quickly. After a cool down lap, the front brake pads temp reading was at 470+F, and the rotors' temp reading was at 700+F. I could only imagine how hot they got at big braking zone(T1, T8, T11,T14). Such that, it ultimately translated to my pedal sinking ever so slightly deeper at each deep braking zone. (Brake pads were still able to stop the car). So my speculation was that my fluid was boiling.

Solutions + future updates:
Currently I'm really happy with the handling of the car. I dont think I need anymore upgrades on the suspension componets, until I get some stickier tires in, then we will see if I need thicker sway bars to help with the extra grip.
Thinking to go with some 200tw tires at 235mm/240mm.
For braking, I should try out the dba blanks rotors to see if these rotors can push out the heat faster. Along with some stainless steel brake lines to give a firmer feels of the brake pedal.
However all the mentioned upgrades was just to inspire safety and personal confidence on the car.
The main factor can improve lap time on the current setup is to have more seat time. AKA driver mods. (If im 4 seconds off my instructor 80% lap time, I definitely have a lot to improve on)

Wish this can help y'all to further understand the new twins chassis. Feel free to leave a comment, to start a discussion.

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Great breakdown. Would larger (monoblock) calipers help with the heat dissipation (at least in the context of boiling the fluid)? I know that @DylanJZA has some of the 06-07 WRX 4 piston brembos in the front ($170 on Amazon). He said they were a huge help with brake feel as well.
Thanks for the pointers. However, my aim is to go into NASA's TT5, which I vaguely remember that there will be points reduction if I go BBK.

So it really boils down to either having brake ducts, or have a different design of rotors to push out that heat.

And it's cheaper to rebuild the calipers too.
Yo, was good meeting you. It was a hell of a lot of fun. Awesome that you were able to get under 2mins. Did you get that on the last Saturday session, or did you manage to get a lot of clean laps on Sunday?

Check this out. Me getting a point by from a Supra.
Yooooo bro!!!! It was lit!

Lots of clean laps. My instructor got hpde3 folks giving him point by 😂
Sick. Wish I could have been there Sunday. Also wish yellow Supra behind me had video of how much fun I was having on my Primacy's.
I hope you will come back soon. And do more des
I plan on doing a handful of events in 2023. Let me know which events you're going to, and I'll try to get out there. Not sure when NASA will post they're 2023 schedule.
Already posted lol. Thinking to head back to cmp again feb
I did 2 days at CMP in my 22' with crash bolts, Azenis RT660's (225's on stock 18's) and my main focus on going to CMP was on getting the brakes to hold up (CMP is the hardest track in SE on brakes).
Knowing the stock brakes are on the smaller side for instructor pace track use, I went with pads that have proven track record in the racing circles (club racing mostly). I went with Ferodo DS 1.11's and Wilwood EXP 600 fluid (I'd probably go with higher spec fluid if I was doing this all over now even though the Wilwood did fine).

Properly bedded the Ferodo pads did quite well with thermal management with the rotors and the pads looking great after 2 full days of 30 min sessions in 80F heat at about the same pace as your instructor. This event was solo and instructors only with my group being mostly low to mid 1:50's pace with open passing anywhere with a point and mostly running with lower hp track cars like 944's, E30's, Spec Miata, etc. so the brakes were definitely getting a work out.

Just showing you don't have to jump to BBK if using the top tier racing pads. CSG, Ferodo, PFC (if they had a fitment) are all good choices.
My experience with Carbotech is they are great for huge oversized brake setups, but throw a lot of heat in the caliper vs. the rotor and can boil fluid in situations where other pads wouldn't. I was there with Autometrics race team and lots of other club racers and you just don't see them running Carbotech or G-loc or Hawk at the highest levels where thermal capacity is at the edge.

BTW the stock rotors looked great after 4 track days and 500 miles of abuse. I have DBA's as well and they look like a slight improvement but I wouldn't expect miracles with stock sized replacement rotors. Pads are a lion's share of the equation in your case in my opinion.
Yeah, I'd say carbotech was great for initial few laps. The bite was there even at the end of the session. But I think it's boiling my fluid, I mean I triggered abs like 3 times in total of 2 days worth of sessions.

But thanks for your inputs never the less!
@vincentyang246 I can second @racer01 on the DS1.11 pads though I have far less experience, pace, and insight to others’ choices. I went with these pads based on previous posts by @racer01 combined with Castrol SRF fluid. Brakes have performed without a hiccup. I do need to find some higher temp grease though cause the Autozone packets you get at the checkout counter cooked off after about three laps and smoked for a hot second 😅. No issues or smoke in any subsequent sessions.

Question: what are your reasons for targeting TT5 over other classes? Just curious.
Power to adjusted weight ratio. I think it falls right at the TT5 mark.

And the auto zone special rotors aren't really helping either. However, already invested into the carbotech package, so I will see if I can combat the boiling fluid with better rotors + fluid.

But lots of the TT guys are running motul 600, I don't see a reason to change, if they aren't running top of the line shit.
I just saw you mention Motul 600....didn't see that initially. I know you are on here asking for advice and I get it that you don't know any of us or our experience, but I'd strongly recommend moving to Motul 660 or another top tier fluid (Brembo HTC, Motul 660, Endless RF650, PFC 665, SRF)
I have boiled fluid at CMP and had pedal go straight to the floor right after the kink in a FD Rx-7 so its no joke to be playing around. I have also lost brakes in a C5 Z06 at CMP. I raced a few years, hand around lots of full bore race teams, and tracked probably around 20 cars, many of them with mediocre stock brakes and I am quite tough on brakes. E36 M3, e90 M3, c5 and c6 corvette, a90 supra, are all examples of cars I had to get stock brakes to work with major handicaps like horribly small pads or really poor stock rotor metallurgy and cooling. On a spec miata I could be lazy with fluid and pad choice.
If you are sticking with Carbotech I'd really suggest at least get some of the top tier fluid in there. Don't just go by spec sheet (and if you do compare wet boiling point not dry) as Motul 600 "looks on paper" about as good as the others but trust me in the last 5 years of being at the track I have seen quite a few people boil Motul 600 running G-loc or Carbotech or other pad materials that tend to throw more heat into the caliper than PFC, Ferodo, etc.
Will do. Thinking better fluid + rotors.

Thanks for the advice
@vincentyang246 that makes sense on the adjusted wt / hp ratio. Do you know what people are using for average HP on these cars?
Seen mostly s2k + last gen twins (possibily k swapped, cus the engine sounds different). Not sure about all just yet, I think my instructor is competing in his 350z there as well.
Agree with CMP is very hard on the brakes. I used SRF brake fluid and PMU club racer advanced pads there (counter space garage has them) and they worked great and had much less wear than Carbotech 10. rotor temps of 700 are what I had there as well. I cut away the top part of the front dust shield (kept bottom to protect ball joints and abs line). I got 10 track days from oem rotors. Bigger/stickier tires will heat your brakes even more. Small amounts of pedal fade are normal. Remember that as the pads get slimmer the pedal get a little lower. My car is set up like yours with similar mods (no exhaust mod) and I recently added the AP racing endurance bbk with ferrodo ds1.11 and this set up did great at VIR but CMP is the big test. I hope to be there in early Dec with THSCC.
AP Racing BBK is def going to hold up for sure.

Loved it at CMP. Really technical track.

Once I'm done with carbotech, I will try out different options.
@vincentyang246 I meant more what 2022 GR86 / BRZ are putting up for average HP following the NASA calc procedure. There are lots of dyno graphs out there but it would be interesting to see what people are actually presenting to NASA.

A quick looks shows NASA average HP at something like 205 if we are being conservative (estimating high). Taking that and running a 10 HP sensitivity either direction, we don’t have a lot of points to spend before we get below the 14.00 lb/hp threshold!

Makes me wonder if TT4 is attainable but then you are competing with some real shit. TT5 probably is a good target. Would be interesting to see if anyone else on here has TT goals or experience with the current gen.
I dont think hp is really that much of a difference in tt5. I recog if we shredd some weight and get as close to the 14lb/hp as possible. Then the car can be really competitive, since it has so much torque compared to the s2k.
I’m more talking about what has been presented to NASA by current TT5 GR86 drivers using the NASA calculation methodology. Not really talking about how the GR stacks up to other vehicles. The reason I am interested is that a few HP does make a difference in what other points we might take (mods we might do). I have some questions about what actually “counts” in the 14.00 lb/hp mod factor calculation, but the below still illustrates the point: if people are presenting a 215 average HP from dyno results to NASA, we might have to stop at sticky tires to stay “above 14.00 lb/hp.” If the number is closer to 195 hp for the GR86 average power, we might be able to take those same tires, coil overs, and quality LCAs.

That's a really interesting point. And I have no answers for that. I can ask around to find out.

And it's interesting that it's only to our advantage if our average hp is at 195. It gives a lot more room for modification. We could always add a roll cage in, to make the wt/hp a bit higher. Almost all the competition cars are running areo kit. So if we run BTM areo, we can gain .4 point back, but def in a disadvantage at high speed corners.

And for coilovers, I think they are targeting coilovers with external reservoir. So we can see if we can find some two ways adjustments coilovers without a external reservoir to gain an advantage there without loosing points.

Lastly, if we do run areo, we are in a -1.4 points deficit here. We can also gain an advantage with toyo's slick tires + running below 257mm NASA calculated section width, that's totally of +1.9 points gain, but the drawback is that the slick tires have about 1 or 2 attack laps in them before they over heat.

And personal thinking, if we need the perfect cambers front and rear, we need a pair of rear lower control arms. So that's -.5 gone.

So here's the point gains.

With areo kit + tires combo + rlca + coilover without external reservoir: we broke even without gaining or loosing any points.

Without areo kit + tires combo + rlca + coilovers without external reservoir: we gained 1.4 points. This could be huge, if we do end up tunning our cars to 210 average hp. Even with the double a arms rear design (-.7), we are at 14.14. (Not enough points to play with)

We can add a half cage to increase our points for more head room to modification. So it seems like the theme here is to not run areo kits. The s2k guys have it lucky, their suspension componets out off the box is fully adjustable, whereas we have to loose .5 point to get the rear to be adjustable, or slam the car enough to have rear cambers (but induce bumpsteers and increase the body rolls due to the instant center and roll center gap increase). And they also have a mechanical throttle body, unlike our electronic throttle body. Another 0.2 point gain.

But we could always slap a blower on the car and bump the car up to tt4. We are just running the risk of blowing up the engine, and it's hard to find a replacement fa24.
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@vincentyang246 yea it definitely is going to be a bit of a game to find the most efficient way to keep the points up. I also suspect that most people going to TT will remove a lot of the interior, add bucket seats, and harnesses. This drives our wt/hp down even further. I wonder if it’s going to be more competitive as a TT4 car since we will be able to really “set it up” with proper alignment, suspension, brakes, etc.

Or maybe a full interior TT5 car is better!? I don’t know, and I have a long way to go to a TT license. That said, I think knowing where I’m trying to land is a good way to keep mods focused and be mindful before just throwing on parts. That’s my logic for thinking about it anyway. Cheers!
Yeah, lots of old gen owners complained that -0.5 on control arms replacement is pretty garbage. In order to get a good alignment we need rlca, which is total garbage that nasa forces us to use eccentric bolt that can change under heavy load. Especially when everyone is running Hoosier slick tires pulling more than 1 g.

Second, they also complaint that having multi link rear penalized us .7 point, where we a know that double a arms are better setup at front end over rear end. So people want nasa to change their rule to having penalty on multi-links/double arms to per axle.

Some folks even out the Plainfield by having counter weight at the passenger side to pump up the wt/hp ratio. So they can run areo or bigger tires.
@vincentyang246 yea it definitely is going to be a bit of a game to find the most efficient way to keep the points up. I also suspect that most people going to TT will remove a lot of the interior, add bucket seats, and harnesses. This drives our wt/hp down even further. I wonder if it’s going to be more competitive as a TT4 car since we will be able to really “set it up” with proper alignment, suspension, brakes, etc.

Or maybe a full interior TT5 car is better!? I don’t know, and I have a long way to go to a TT license. That said, I think knowing where I’m trying to land is a good way to keep mods focused and be mindful before just throwing on parts. That’s my logic for thinking about it anyway. Cheers!
So came across this thread. The camber rules have proposals. Which means us twins boys don't need to take .5 penalties anymore. Depends on the rlca design, we probably still need to take .2 spherical bushing penalty tho. However this opens up at lot more modifications, cus now I wonder if spl front lower control arms are permitted with only .2 spherical bushing penalty. But the upside is that we can slam the car as low as the kit permitted, while having 7 degrees of casters, that's like lowkey race car spec at that point.

That would be cool if it goes through. I’m pumped for next season. Trying to decide on coilovers as my next big mod. I like the car but I don’t want a $50k gr86 lol.

I wanted Ohlins road and track, but the local speed shop that did a lot of development and raced the previous 86 also recommended ST Suspension XTA plus 3 if I get tired of waiting for Ohlins:

Was couched to me as a galvanized KW club sport. Still pretty entry level as far as race suspensions go, but not bank breaking at 3.5k with camber plates.

Also considering just the Raceseng camber plates and LCA all around instead for slightly but not much less total cost. I contacted Raceseng and you can convert the plates from stock suspension to a number of coilover kits so it could be an option?

I don’t want to lower my car but I will if I must.

View attachment 17525

What are you thinking? I appreciate the thoughts and notes comparison, cheers!
Honestly if I can do it all over again, I wouldn't go with fortune auto 510s. But id look into racecomp's tarmac 2, they basically re-valved kw coilovers with stiffer spring rate.

However, just by thinking about rebound adjustment is a hand full for me on track. Adding compression adjustment seems a bit overwhelming for me. So if I'm just learning coilover set up, I think fortune auto 510 is a good starting point, or any digressive single rebound adjustments coilovers will be good starting point.

And I think the rule change will go into the record book, with further investigation. I think we can only have rlcas and rear toe arms for "proper alignment". So im not sure if front lca can be really modified.
What don’t you like about the fortune 510s? And Ive always thought highly of the tarmac 2s as well but my shop advised against them as very old tech.
Didn't know that tarmac 2 is actually an old tech.

But the 510s are just garbage on street, feel everything on the road 😂. So just personal complaint. They are weapons on track tho, at cmp I was taking curbs left and right, they never unsettled the car.
That’s a very fair complaint! I don’t have to daily this car but I do like to, and that’s a big part of not wanting to lower it. So I appreciate that feedback!

This is where I keep coming back to the Ohlins…. I asked them when parts? But no answer.
Small lower like 15mm to 20 mm can actually unlock some of the hidden handling, but too much would ruin the suspension geometry.

I dropped it for small amount about 15mm ish, the car won't scrape on anything on street at all.
Going back to the brakes. Do not cheap out on the rotors or they will crack. If you are really going to be pushing your car, go straight to RBF660 or other similar brake fluid as the RBF600 may be marginal with the heat we will produce in our OE brakes. "MY" experience with Carbotech has not been the best, but everyone has different experiences. I've used Hawk race pads and Cobalt race pads without issue. Aside from that, if you continue using Carbotech, there are more aggressive compounds that you can use which will stand up better to the heat and abuse. Aside from brake temperature, are you experiencing any deficiencies with the braking system?
Not really anything bad. Beside pedal sinking, the carbotechs didn't have any brake fades, but they were just throwing a lot of heat into the system. Personally thinking, since my next cmp track days will be in 2 months, I can try to look into some ferodos ds1.11 next. Maybe even some csg c2 compound.
Was the pedal drop sudden and you had to pump it to stop, or did you have a longer pedal but still slowed? Fluid boiling tends to be more sudden and pucker inducing. Pad fade will typically be more gradual. Just trying to help you figure out what the weak point was.
Pedal got longer. Never really just suddenly dropped to the floor. But once we bleed the brakes the following day, the brake system got better. Only a slight sink at the end of the day.
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