Who else is Amazed at the OEM Clutch & Brakes?

[WatchmaN]

Originally Posted by CSG Mike

Torque is either held or not held. It doesn't matter how it's driven. Instantaneous engine output (work/torque) is not affected by whether you're putzing around down doing a 2nd gear pull, or if you're racing on track.

Bad technique, however, can dramatically shorten a clutch's life.

Can you expend on this, seems interesting but I cant get grasp of what exactly you are saying. thanks

[sw20kosh]

It isn't under engineered either. This $25-27k car (achievable through partsbin'ing) was built primarily for the 95% of buyers that will just puts around on the street having fun and looking cool. They threw one bone to the 5% though and that is the chasis.

The 5% will be hardcore enough to change the things that need to be changed which is what you see happening.

If they built this car to live up to the expectations of the 5% then it would be ~$40-50k or more.

[CSG Mike]

Originally Posted by WatchmaN

Can you expend on this, seems interesting but I cant get grasp of what exactly you are saying. thanks

There's a few principals at work.

A clutch setup has a rated torque capacity that it can hold. If you exceed this capacity, then it spins, and you'll burn it up really quick.

A clutch has 3 states. Engaged, disengaged, and slipping (when you're partly on the clutch pedal).

When it's engaged, you're comparing the engine's torque output vs the clutch's torque capacity. If the engine makes less then the clutch's capacity, then there's zero wear, and the clutch transmits the power. If it's more than the clutch's capacity, then it will spin, and the engine's energy is (partially) lost to heat/friction of the clutch spinning. This heat/friction will destroy the clutch if not immediately addressed.

Disengaged = no wear.

Slipping is the only state that the clutch will normally see wear. Powershifting may result in the clutch not grabbing fast enough, and spinning momentarily with HEAVY load (from the pressure plate applying full force). Otherwise, the only slip it'll see is when you're slipping the clutch during a shift or starting from a stop.

[jamesm]

my car makes a decent load of power on e85 and i'm not left wanting for brakes on the street. of course i'm not doing back to back hard deceleration like in a track situation, but they are more than adequate for 'spirited' driving around town, even with a bunch of additional power.

[sw20kosh]

Originally Posted by jamesm

my car makes a decent load of power on e85 and i'm not left wanting for brakes on the street. of course i'm not doing back to back hard deceleration like in a track situation, but they are more than adequate for 'spirited' driving around town, even with a bunch of additional power.

Yeah they are fine for isolated braking events. Once you step on the track and have to brake at full capacity corner after corner, the system gets overwhelmed/over-heated and is compounded by additional power as you have to use the breaks even more.

[rusty959]

Originally Posted by CSG Mike

Torque is either held or not held. It doesn't matter how it's driven. Instantaneous engine output (work/torque) is not affected by whether you're putzing around down doing a 2nd gear pull, or if you're racing on track.

Bad technique, however, can dramatically shorten a clutch's life.

I can't decide if by quoting me here you were agreeing with me, disagreeing with me, or just adding onto. Because you say "It doesn't matter how it's driven" but then "Bad technique, however, can dramatically shorten a clutch's life". Technique, of course, is your way of driving.

I think this may be a comment on my track comment, but I will hold onto my concept that you can get away with more power for longer on a cluch on DD duty where most shifts will be slow and rev-matched where on a track they tend to be higher load more powershift like, as you say below.

Originally Posted by CSG Mike

There's a few principals at work.

A clutch setup has a rated torque capacity that it can hold. If you exceed this capacity, then it spins, and you'll burn it up really quick.

A clutch has 3 states. Engaged, disengaged, and slipping (when you're partly on the clutch pedal).

When it's engaged, you're comparing the engine's torque output vs the clutch's torque capacity. If the engine makes less then the clutch's capacity, then there's zero wear, and the clutch transmits the power. If it's more than the clutch's capacity, then it will spin, and the engine's energy is (partially) lost to heat/friction of the clutch spinning. This heat/friction will destroy the clutch if not immediately addressed.

Disengaged = no wear.

Slipping is the only state that the clutch will normally see wear. Powershifting may result in the clutch not grabbing fast enough, and spinning momentarily with HEAVY load (from the pressure plate applying full force). Otherwise, the only slip it'll see is when you're slipping the clutch during a shift or starting from a stop.

Or maybe I just have bad technique.

Regardless, I think we are saying similar things, just a bit different wording.

[CSG Mike]

just saying that excessive clutch slip when shifting or starting from a stop will result in a shorter life.

[Malt]

Originally Posted by LBC Por Siempre

I've been reading too many of these build threads and the brakes and the clutch seem to be one of the absolute last things the owners touch.

But what is the first question most folks ask on here when it comes to tuning up your car and how much power or whatever you want...? What are your objectives? You going to race your car, Time Trials, Track Days etc?!

Brakes and clutches (and decent coilovers) are the last thing people touch on this car because their priorities and expectations are different than what truely affects a cars performance. You'll see people with turbos and superchargers with stock brakes because they want the car to go fast in a straight line but give no thought about how long it takes to stop the car or how well the car handles.

I will bet a pretty penny that if you took a BRZ with a $4400 turbo/supercharger kit on it and everything else stock and compared it to a BRZ with a $2200 AP sprint BBK and a set of $2200 RCE T2's on a track, the one with the brakes and coilovers would destroy the FI'd car in lap times.

Simply put, most owners want the feeling of power on the street and don't think about the overall performance of the car. BBK's are not nearly as "cool" when you are trying to be speed racer at stop light to stop light.

If I could start all over again I would not have bought my 3" Perrin catback, 3" front pipe, and overpipe. They are amazing quality parts and I like the sound but instead I would of put that money into an AP racing BBK. The exhaust sounds nice but in the end thats pretty much all it did for the car. You can get to 200whp and 150ftlb of torque easily with an OFT and OFH and E85 tune for $1000 and the car is decently quick. The rest of the exhaust may get a couple of HP but all of that money spent would of been much better spent on something that would of actually improved the performance of my car. But hey, the car sounds nice Then again, my priorities may be different than other people. I have no interest in drag racing.

No need for a clutch or flywheel at that point because you are well within the acceptable torque levels of the stock clutch. Throw FI on it and you'll have issues with the clutch holding.

IMO if you are looking for actual improvements in the cars performance get the following:
Header (UEL or EL.. whatever floats your boat)
Tune (OFT or ECUTek.. again, whatever floats your boat)
Tires! (Don't skimp on the only part of the car that actually touches the road and allows your car to accelerate, stop, and turn)
Decent set of coilovers (KW V3, RCE T2's, etc...)
BBK

Flog it on the track and have fun while knowing you spent money on stuff that actually did something that was a good bang for the buck spent.

[moK]

Originally Posted by CSG Mike

just saying that excessive clutch slip when shifting or starting from a stop will result in a shorter life.

Do bad, jerky shifts and mistimed revmatches play a big part in shortening a clutch's life?

[CSG Mike]

Originally Posted by moK

Do bad, jerky shifts and mistimed revmatches play a big part in shortening a clutch's life?

Yes, mostly the mismatched revmatches. The clutch (and slack in the drivetrain) absorb the shock of bringing the revs to the appropriate level.

[CSG Mike]

Originally Posted by Malt

Brakes and clutches (and decent coilovers) are the last thing people touch on this car because their priorities and expectations are different than what truely affects a cars performance. You'll see people with turbos and superchargers with stock brakes because they want the car to go fast in a straight line but give no thought about how long it takes to stop the car or how well the car handles.

I will bet a pretty penny that if you took a BRZ with a $4400 turbo/supercharger kit on it and everything else stock and compared it to a BRZ with a $2200 AP sprint BBK and a set of $2200 RCE T2's on a track, the one with the brakes and coilovers would destroy the FI'd car in lap times.

Simply put, most owners want the feeling of power on the street and don't think about the overall performance of the car. BBK's are not nearly as "cool" when you are trying to be speed racer at stop light to stop light.

If I could start all over again I would not have bought my 3" Perrin catback, 3" front pipe, and overpipe. They are amazing quality parts and I like the sound but instead I would of put that money into an AP racing BBK. The exhaust sounds nice but in the end thats pretty much all it did for the car. You can get to 200whp and 150ftlb of torque easily with an OFT and OFH and E85 tune for $1000 and the car is decently quick. The rest of the exhaust may get a couple of HP but all of that money spent would of been much better spent on something that would of actually improved the performance of my car. But hey, the car sounds nice Then again, my priorities may be different than other people. I have no interest in drag racing.

No need for a clutch or flywheel at that point because you are well within the acceptable torque levels of the stock clutch. Throw FI on it and you'll have issues with the clutch holding.

IMO if you are looking for actual improvements in the cars performance get the following:
Header (UEL or EL.. whatever floats your boat)
Tune (OFT or ECUTek.. again, whatever floats your boat)
Tires! (Don't skimp on the only part of the car that actually touches the road and allows your car to accelerate, stop, and turn)
Decent set of coilovers (KW V3, RCE T2's, etc...)
BBK

Flog it on the track and have fun while knowing you spent money on stuff that actually did something that was a good bang for the buck spent.

I'll take that bet

[Malt]

Originally Posted by CSG Mike

I'll take that bet

Sell me an AP sprint set and meet me at VIR in 3 months and we will see who gets this beautiful penny!

[Pete156]

Originally Posted by LBC Por Siempre

You can put 500whp through the drive train and keep the brakes stock so as long as your not a nut, like I said before - sometimes you feel like a nut, sometimes you don't.

Well put!

If you're a nut, please upgrade!

[rusty959]

Originally Posted by Malt

Sell me an AP sprint set and meet me at VIR in 3 months and we will see who gets this beautiful penny!

Hmm. Maybe the resolution is just too high, but I feel like a prettier penny could easily have been found.