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R&T: IS300 outbrakes everything!!!

956 Views 9 Replies 7 Participants Last post by  TEG
Yes, it's almost true. 60-0, the IS300 outbrakes (113ft) every single automobile that R&T has in their road test summary (August 2000 issue), except the Ferrari 360 Modena (110ft) and the Porsche 911 GT1 (98ft). That's mind-blowing.

For 80-0 (203ft), the IS300 is only outbraked by:
Ferrari 360 Modena (188ft)
Ferrari 550 Maranello (199ft)
Lamborghini Diablo 6.0 (tie)
prev-gen Porsche 911 Turbo (199ft)
prev-gen Porsche 911 Carrera Cabriolet (201ft)

The IS300's rivals (loosely defined) are soundly trounced:
BMW 328i, 60-0(133ft), 80-0(239ft)
Audi A4 2.8 Quattro, 60-0(137ft), 80-0(229ft)
Mercedes-Benz C280, 60-0(133ft), 80-0(232ft)
Acura 3.2TL, 60-0(147ft!), 80-0(263ft!)
Cadillac Catera Sport, 60-0(139ft), 80-0(236ft)
Honda S2000, 60-0(119ft), 80-0(214ft)

Simple math. Compared to the BMW, the IS stops 20 feet shorter from 60mph and 36 feet shorter from 80mph. That's about 2.5 car lengths shorter. Can anybody say, "tight-course weight-transfer demon?"
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This could be from pad material alone. Who knows. Stopping distance is just a result of the brake torque and bias. That is definitely impressive but lets see how long a set of pads hold up. If you want short stopping on any car just throw some Perf. Friction Carbon Metallics on.
Well call it what you want to S38, but these are clearly stock numbers and they seem impressive.
The IS300 has EBD (Electronic Brake-force Distribution) which may (in some part) account for the superior braking. Most cars have an "old fashioned" brake portioning valve that gives a fixed % of the bias between front/rear. I wonder if EBD is smart enough to vary the braking based on decceleration, weight transfer or something like that...
Would EBD have the capability to reduce brake dive?
If it is due to EBD than it is impressive. If it is due to pad or rotor material choices than it is just a result of trading one benefit for another. eg. they may not last as long.

Put some carb. metallics pads on your car--than you will feel stopping power. Really amazing.
I agree with S38 in that the braking numbers are SO good I'm concerned about how they got such good performance. A good way to tell brake lifetime is how much brake dust people are seeing on their cars. Anyone seeing a lot of brake dust? If the brakes last 30k miles with reasonably sporty driving, then that's very impressive engineering.
Originally posted by S38:
This could be from pad material alone.... If you want short stopping on any car just throw some Perf. Friction Carbon Metallics on.
Maybe Lamborghini needs you to slap 'um upside the head and get them to spec some "Perf. Friction Carbon Metallics" on their cost/maintenance-unlimited cars.

Originally posted by S38:
Stopping distance is just a result of the brake torque and bias.
Thoroughly oversimplified. I can tell you that braking performance is determined by no less than these factors:

1. Tire and brake pad compound. The 225/45ZR-17 Dunlop SP Sport 2000E of the 328i are somewhat comparable to the 215/45ZR-17 Bridgestone Potenza RE040 of the IS300 in compound and size. The Michelin Pilot Sport that is supposedly going to come with the "graphite" wheel option should be in a higher performance/wear category. I have no real idea what the IS300 uses for its pads, but I seriously doubt that Lexus would compromise reasonable wear and completely overshoot the braking performance of it's intended rival, the 328i.

2. A much better indicator of braking performance than rotor size is swept area/ton: the more the better. The IS300 beats the 328i's 257 with 270

3. Load distribution between the front and rear axles during the weight transfer of deceleration: the more equal the better. This means that for a vehicle with a CG higher than the ground, maximal braking potential can only be approached with a rear weight bias (as in mid- and rear- engined cars.) This is actually a strike against the IS300 in its comparision versus the 328i.

4. Size of contact patch during the weight transfer of deceleration: the bigger and more even in pressure distribution, the better. Do remember that in order to maintain the outside front contact patch in a turn, the negative camber of the wheel is increased during compression of most suspension systems. But the increase in negative camber is compression dependent, not steering dependent (that would be caster, which is a whole other ball of yarn), which reduces both front contact patchs during braking compression with the absence of body roll. Together with the fact that the IS300 exhibits good turn-in but understeers at the limit, I suspect that the front suspension was not designed to significantly increase negative camber deep in its suspension travel, which also means that it does not lose much contact patch during braking compression.

Factors #3 and #4, in light of the degree of stability necessary for the target user, determines the front/rear brake bias. So it's not something out of the blue.
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Or could it be just a simple error? I'm not trying to provoke anyone here. I'd be happy to know the car has such phenomenon braking capability. But R/T did make rare mistakes sometimes. I know they made some mistakes with the Maxima statistics from a comparo test a few issues back.
Wow, DtEW you sure have alot of info.

More random stuff:

Factory rep told me 33% Bridgestone Potenza RE040 tires and 66% Goodyear Eagle GS-D.

Whoever originally said that the graphite wheels have Michellin Pilot Sports may have been mistaken.

The new BMW 330i has 17" wheels standard since they enlarged the brake rotors (by a whole inch!) such that you couldn't even fit a 16" wheel around those brake rotors anymore. The IS300 can have 16" wheels so the rotors aren't as big as on the 330i...

Super long life brake pads can be prone to squealing... Toyota has a rep for using long life pads that may squeal a bit. Perhaps the IS300 is different. In my mind, Audi is a company that uses "dusty" brake pads...

Yeah - the tires are a huge factor in the braking. I am guessing that the tires and the EBD are the main things that contribute to the excellent braking.

And it is not just R&T - many articles have praised the braking on the IS300...
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