RCF vs A90 Supra (MK5)
06-20-20, 02:51 PM
#16
Lexus Test Driver
Thread Starter
I wonder about the brakes, they have a lot of "bite" when I do normal stops at traffic lights. However, when I do a panic stop and push hard on the brake, it is a very gradual and linear/smooth stop. Not the sudden, intense deceleration feel I would expect from these high friction pad. Ami I not understanding something correctly or they are simply old pads now as they are OEM pads that are more than 4 years old?
06-20-20, 05:24 PM
#17
Tech Info Resource
iTrader: (2)
OE pads are not exactly high friction. The Project Mu HC+800s (street/track) I run are a lot like Carbotech XP12s (full track pad) in terms of friction. Extremely light touch on the pedal generates a LOT of deceleration, and a heavy push slams the nose down enough to overwhelm the ABS and lock the wheels momentarily before the ABS can even respond. The same act on the GS F with the OEM pads took about 50% more foot pressure, but it is impossible to overwhelm the ABS with the OEM pads. No surprise there. It's always a significant mental adjustment when I get out of the IS and into the GS. I lightly touch the GS F brakes and not a whole lot is happening where I'd be bouncing off the shoulder harness in the IS F.
I'm really wondering about those Brembo pads. GG rating is reasonably high mu and two Gs means the compound maintains high mu at elevated temperature much better than the typical FF pad from the factory.
I'm really wondering about those Brembo pads. GG rating is reasonably high mu and two Gs means the compound maintains high mu at elevated temperature much better than the typical FF pad from the factory.
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05RollaXRS (06-20-20)
06-20-20, 05:46 PM
#18
Lexus Test Driver
Thread Starter
Thanks. Yeah, the foot is really welded to the floor for full panic braking and even at that, it is gradually slowing down with a very linear feel. I was expecting it to react a lot harder, but it feels like they are trying to overcome inertia from the weight and have to work hard to do that. The feeling is quite good as there is no dive on the front. It is very evenly distributed force front to back and car remains very flat under hard braking. Just not as reactive and powerful as I would expect from such huge brakes. Also, I have brand new Pilot Sport 4S tires so I was expecting the latest and greatest tires would significantly improve braking. Maybe, they did, but it is just a "feel" thing. Hard for me to say without using some VBOX etc.
Last edited by 05RollaXRS; 06-20-20 at 09:02 PM.
06-20-20, 08:41 PM
#19
06-20-20, 09:16 PM
#20
OE pads are not exactly high friction. The Project Mu HC+800s (street/track) I run are a lot like Carbotech XP12s (full track pad) in terms of friction. Extremely light touch on the pedal generates a LOT of deceleration, and a heavy push slams the nose down enough to overwhelm the ABS and lock the wheels momentarily before the ABS can even respond. The same act on the GS F with the OEM pads took about 50% more foot pressure, but it is impossible to overwhelm the ABS with the OEM pads. No surprise there. It's always a significant mental adjustment when I get out of the IS and into the GS. I lightly touch the GS F brakes and not a whole lot is happening where I'd be bouncing off the shoulder harness in the IS F.
I'm really wondering about those Brembo pads. GG rating is reasonably high mu and two Gs means the compound maintains high mu at elevated temperature much better than the typical FF pad from the factory.
I'm really wondering about those Brembo pads. GG rating is reasonably high mu and two Gs means the compound maintains high mu at elevated temperature much better than the typical FF pad from the factory.
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lobuxracer (06-23-20)
06-20-20, 09:39 PM
#21
06-20-20, 10:16 PM
#22
Initial bite felt good to me, but when step on them a little more, they felt more like street pads vs more performance oriented pads. Maybe the car is too heavy, or maybe Lexus specced that way for the car to behave more GT like. For the amount of dust they produced, I would expect them to perform more like a street/track pad, but they did not. They also eat the rotors too fast, maybe the OEM rotors were too soft.
06-22-20, 06:10 AM
#23
Now, as I have understood it more, I have grown used to the long gearing. Also, the exhaust has helped immensely. The 2020 RCF shorter gearing is nice (from 2.97 to 3.16), but I think most people would not notice a difference. Another easy way of playing with the gears is by trading some circumference for some more width. For example, going on the rear from 275/35/19 to 295/30/19. That will give you more width and shorter overall circumference, which leads to overall shorter gearing. That is a much safer and cheaper way to get shorter gearing without taking the whole differential out etc.
06-22-20, 06:16 AM
#24
Good run, the MKV is a very tuneable car from what I've seen but that was expected. I've seen some making over 700hp/tq that's impressive on the stock block and trans considering the GTR limits are around 650 on the stock block and trans. That's not bad for a car starting at $50K.
06-22-20, 04:55 PM
#25
Lexus Test Driver
Thread Starter
Here is another one.
RCF has Intake/PPE headers/exhaust (No tune)
Supra has dwownpipe/exhaust/ECU tuned
And a Civic Type R trying to troll in the background
RCF has Intake/PPE headers/exhaust (No tune)
Supra has dwownpipe/exhaust/ECU tuned
And a Civic Type R trying to troll in the background
Last edited by 05RollaXRS; 06-22-20 at 10:45 PM.
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rp2000r (06-22-20)
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