At least we agree on some of it.

It’s the front brakes that will be overloaded first. Not the rears. So engine braking is useless on a RWD car, as the rear will have a tendency to lock up first (it won’t because of ABS and EBD, but that’s an other story) in any kind of braking (going forward).

Well, you can lock the front wheels, but that is usually due to improper braking technique.

It’s not very good for the engine/drive train either and it burn oil.

Expect ~0.1g of deceleration with engine braking and peaks at 0.88g on the brakes with good street tires (from my data of MidOhio). It would be nice if we could just add these numbers, but it doesn’t work that way. Some engine braking is part of the .88g anyways since I don’t touch the clutch until I need to shift.

All in all, using engine braking for improved deceleration is a bad strategy. Try to stay nearer to 0.88g instead of dropping to 0.4g while fussing with the pedals.

 

Plus you have a good chance of locking up your tires when you down shift and don't rev match properly and drop the clutch. This is a kinda bad thing to happen at 90mph. I was lucky when the bolt slipped in my shifter connection and I ended up in the wrong gear that this did not happen. Since it was supposed to be 4-5 shift and I ended up in 3rd at ~110 . I did however push the clutch back in on this one, and coasted down until i wasn't so puckered up anymore

 

Yeah, that would be a nasty way to redecorate your pants...

 

dude.. grandma's are worth more points than kids. At least learn your point system b4 making those kinds of suggestions

 

I would have to agree with you, although not in those terms.

Aren't the stock brakes good enough to potentially lock the tires anyways (imagining that ABS is non-existent for argument sake). If the stock brakes could theoretically lock up the tires, then engine braking doesn't do much for you since you've already exceeded the threshold of traction.

 

The ability to lock up the brakes is a moot point. I honestly can't ever remember driving a car that couldn't lock the brakes up. Some of you people gotta be kidding me.

In a _panic_ stop, you never know when you might need to _panic_ accelerate just the same. **** happens in traffic accidents that you just can't control. Every situation is different and requires different inputs. Staying in too tall of a gear while braking is not far off from doing the most noobish thing you can do, which is taking it out of gear completely and using all brakes. You have virtually no control over the attitude of the car by doing that. Obvsiouly if stopping is your #1 priority it's going to involve using the brakes first and foremost, but that doesn't mean downshifting (heeltoeing) is out of the question.

Of course going into second at 80mph is not advised.

So now that we have basic driving 101 out of the way (hopefully), can we please address the issue of floating valves in the vq35de?? Has anyone here done it? Has anyone missed a shift and noticed anything afterwards? Has anyone had a valve job? I'm curious what it takes to float our valves, obviously since it's not something most people want to find out the hard way.

 

I love the random "The rev-limiter should have kicked in" comment that always makes its' way into these threads......So funny.

 

hopefully the tires would have skidded somewhat to relieve stress on the drivetrain and engine. A mate of mine likes downshifting to 2nd and overrevving his engine to drift through corners, and he ended up punching an exhaust valve through a piston head in a Z4 2.5L. Thats a risk we run with high compression engines.

 

1. Rev limiters do not WORK on downshifts, IN ANY CAR.

2. BBK will not stop you faster than STOCK brakes.
What a BBK will do is give you more cycles before fading. More cycles = Great for track. They also give you great Street BLING!

BBK manufacturers stretch the truth a little by saying, That stopping distance has to take into account reaction time.

Buy having a BBK that is setup closer to the discs, and with a full pedal, they say you are actually applying the brakes a little earlier and therefore stopping distance is reduced. (Reduced by the time it took for stock brakes to apply, assuming the stock pedal had to move further than a BBK pedal before the pads made contact)

But the fact remains, ABS does JACK for stopping distance. It releases the brakes. So it increases stopping distance, but it allows you to STEER.

Locked brakes do not steer.

To answer the age old question, Will you stop faster if you lock the brakes up, or if you go to nearly lock up. ANswer, LOCKED BRAKES DON'T STEER.

If you lock up, you can turn the wheel all you want and you will slide straight ahead into the object.

The ABS surges and momentarily releases the brakes and allows the wheels to turn so you can STEER.

I laugh my *** of at DUMBA$$ES that think there cars stop faster because of ABS.

The Only exception, is SOMETIMES on gravell where the surface causes the tyre to lock with light pressure, then ABS May stop a little quicker.

But On a normal road, BubKES BABY.

A Stock brake can lock a wheel just as good as a BBK can. (Locked is maximum that any kit can do. Once the wheel is locked more clamping force does nothing.)

Its Just a BBK can do it Over and OVER again before fade.

BBK = Better Cooling therefore more cycles. (Larger discs=more metal=disapate more heat faster)

Rarely will it mean faster stopping distances. (Unless you have over heated your stock ones)

You want to stop faster, Change your TYRES.

MJ

 

Yeah, I kept quiet on this one this time...

 

You all need to quit feeding into Bee Ess Pee/Jvan's delusions of being a racer.

 

thx for your optimism
i never said im a great driver, just i try...

 

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downshift can help you stop faster...but you're defeating the purpose when healtoe downshifting in an emergency stop situation. healtoe is to keep the car from losing too much speed, being in the right gear and keeping the car balanced among other things.

next time, just clutch and brake man...

 

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