G37 Coupe

Weight Distribution

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Old Nov 5, 2012 | 02:56 PM
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Weight Distribution

The perfect sports car has 50/50 weight distribution and I always wondered why our coupes have the calipers on the front side of the front wheel? Seems like the distribution would be better with them on the rear side of the front wheel.

Just wondering?
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Old Nov 5, 2012 | 05:24 PM
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You're asking why we have larger pot calipers on the front of the car, as opposed to the rears? It really doesn't have much to do with weight distribution. The calipers on the other hand are on the front for a reason. Think about when you're braking aggressively. The front of the car dives forward, not because of weight, but I suppose...physics? lol no expert here...but having larger calipers in the rears just wouldn't be as efficient in braking. The majority of the weight lies in the front...and without the notion of weight in mind, I'd imagine that there would be more drag in the rears if we have larger rear calipers.

By the way...our coupes may not have a perfect 50/50 weight distribution...but we're pretty darn close. BMW isn't even really 50/50, despite their advertisement.
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Old Nov 5, 2012 | 05:44 PM
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Because physics - like eksigned said when you brake, your nose dips down. Meaning there is increased downforce as well as friction on the front wheels. Therefore it makes most sense to brake the tires that have the highest coefficient of friction aka your front tires.
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Old Nov 5, 2012 | 05:52 PM
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Originally Posted by hinomura
Because physics - like eksigned said when you brake, your nose dips down. Meaning there is increased downforce as well as friction on the front wheels. Therefore it makes most sense to brake the tires that have the highest coefficient of friction aka your front tires.
Well said. The point that I was trying to make...lol
Forgive me, I'm a biological scientists...I HATED physics with a passion.
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Old Nov 5, 2012 | 05:56 PM
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hes talking about why our calipers are on the front side of the rotors vs rear side of the rotors. not about why we dont have huge rear calipers, which would leat to a proportioning issue that you guys are talking about.

to the OP, not sure why they calipers are on the front vs rear of the rotor. It was probably make next to no difference weight distribution wise to put them in the rear of the rotor like lets say a porsche. They don't weigh much at all, and they are unsprung weight anyways. Read about the weight ratio with the GTR. Nissan usually focuses on a dynamic 50/50 weight distribution, not static like bmw and whatnot. By that, I mean that when the car is static (sitting there not doing anything) it has a 53/47 weight ratio. However, when the car is dynamic (fully accelerating) it has a 50/50 weight ratio. This is what the nissan engineers figured out. It may not apply fully to our car as the GTR, but they probably use the same philosophy. As far as the calipers, I can't help you why they are front vs. rear. I would think if they mounted them on the rear of the rotor, the rotor would be able to cool faster as it gets more air through the vents for a rotor, but IDK for sure why they put them on the front
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Old Nov 5, 2012 | 06:08 PM
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Rear of the rotor on a ferrari


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Front of rotor on a g37

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Old Nov 5, 2012 | 06:32 PM
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there you have it. my mistake! I'd imagine that it's just by chance...depends on where the brackets are for placement? no idea...that's actually a great question...lol
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Old Nov 6, 2012 | 07:18 AM
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Weight Distribution

Thank You Ecain18, that's exactly what my question is about. I never knew about the static vs. dynamic weight distribution.
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Old Nov 6, 2012 | 07:44 AM
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Id like to know the Reason for putting the calipers on the front of the rotor vs the rear. Like you said, many proper sports cars have that
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Old Nov 6, 2012 | 09:36 AM
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From: Burleson, Tx
Originally Posted by ECain18
hes talking about why our calipers are on the front side of the rotors vs rear side of the rotors. not about why we dont have huge rear calipers, which would leat to a proportioning issue that you guys are talking about.

to the OP, not sure why they calipers are on the front vs rear of the rotor. It was probably make next to no difference weight distribution wise to put them in the rear of the rotor like lets say a porsche. They don't weigh much at all, and they are unsprung weight anyways. Read about the weight ratio with the GTR. Nissan usually focuses on a dynamic 50/50 weight distribution, not static like bmw and whatnot. By that, I mean that when the car is static (sitting there not doing anything) it has a 53/47 weight ratio. However, when the car is dynamic (fully accelerating) it has a 50/50 weight ratio. This is what the nissan engineers figured out. It may not apply fully to our car as the GTR, but they probably use the same philosophy. As far as the calipers, I can't help you why they are front vs. rear. I would think if they mounted them on the rear of the rotor, the rotor would be able to cool faster as it gets more air through the vents for a rotor, but IDK for sure why they put them on the front

I was about to say the same thing....the 350/370Z was designed this way too.

Whether the brake caliper is at the "front" or "rear" in relation to the front of the car makes no difference in braking. The rotating mass of the rotor is still going in the same direction so it does not matter where the caliper is placed. It basically is placed where it will fit and does not interfere with suspension components.
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Old Nov 7, 2012 | 01:13 PM
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From Road and Track:

/--
Because caliper placement relative to the rotor is immaterial to clamping force; the considerations in caliper placement are for airflow and packaging. The front-axle packaging is typically more constrained by the steering gear, and thus calipers tend to be at the 6 and 9 o'clock positions there. Rear calipers typically face fewer placement obstacles, and then it is the parking brake cable and other packaging issues that prevail.
--/

Start Opinion\
Since Super Cars are built on dedicated platforms this can be engineered into initial design where calipers are on the "inside" (closer to passenger compartment) of the rotor to help with weight distribution, squatting during braking, etc. As you move down the list of makes and edge into cars whos platforms are designed for multiple vehicles and types (like ours), then the placement of the calipers start moving around as this is most likely an afterthought.
\End Opinion

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