Best way to slow down.

So if I were on a very slick surface, e.g. sheet of ice, then I could slow down by using the internal engine braking forces. Wow, good to know!

 

He is a nice guy... My wife is actually 4th cousins ... long story, but my wife's mom is English with her fathers Mother being Scottish... I like his chopper the best.. blue with St. Andrews cross on it!

 

He's certainly very proud of his heritage.....

I'm always reminded of why "we" built that wall up there - Keep 'em out!

Cheers,
Ian

 

or keep the English out... or Angles... to be exact
Ive always wanted to do one of those drives from Lands ends to John o Groats... in a Morgan or older Ferrari!

on the b roads as much as possible.

 

Can't this thread be made into a poll pro and against engine braking when racing sports cars?

With maybe also a "it's only a few times useful" choice?

 

It would have been better if a Mod who did performance driving said you were full of **** too. So no track days; no performance driving schools; but an expert at typing a lot and doing some graphs. yes, dangerous to newbies who would give credence to voluminous posts without questioning the source.

Anyone taking advice form this thread would do well to read post histories and actual experiences of those involved. Learn from the real-world experts (of which there are many on f-chat). I thank those who post from experience.

 

we should link this with the 'shifting into neutral' thread so people can get a full picture...

 

Well, this is supposed to be a technical forum. So I present my arguments with references, formulae and graphs, as well as with logical reason; in a polite manner.

You and others on the other hand, would seem to have nothing technical, no references, formulae or graphs to present or discuss; but would rather attack me personally which is silly since none of you even know me. So what are you doing here really?

It is not a sign of strength or intellectual integrity when a person resorts to personal attacks on a technical forum.

 

...and that would prove engine braking doesn't play a useful role in slowing cars while cornering on a track?

 

Actually it's interesting that someone, especially with your background in aerospace engineering, would make such a flying leap of assumption from that statement you quoted me on.

Surely as an aerospace engineer you've had to file reports, reference research and review articles, make presentations to peers and discuss ideas; rather than waste your time on silly personal attacks. Otherwise, you'd never make a living in aerospace engineering.

C'mon, use some of the technical skills and knowledge you've spent your career honing. Take a risk.

 

I think that would be a heck of a lot more educational than to pretend that nobody uses engine braking to slow a car on the track.

 

It would warn new readers about taking your advice about the dynamics of driving quickly. That'll be enough.

It's just like the guys on motorcycle forums that say bikes steer by leaning… even posting charts… versus listening to the guys who have great bike control who discuss and teach counter steering. One of those categories of people run off the track pretty quickly….

 

You seem to think readers are too stupid to think for themselves.

So rather than to try and prove your ideas in a polite, reasoned and civilized debate; you would prefer to jump in every now and then, and just vilify whomever you don't happen to agree with.

 

I don't see what is impolite about his reply. Perhaps he feels that everyone else has already proven enough?

To my knowledge, based on a quick review, no one in this thread agrees with you. Some of us have some pretty good credentials. Doesn't that, coupled with your inexperience on the track, tell you that you should learn from us rather than continue arguing?

I'll highlight a basic mistake you made, and no this is not me being hysterical or insulting you, it's simply a fact:

" engine braking will set up the car's suspension to reduce weight transfer to the front, reducing understeer while OTOH sole reliance on regular braking into a corner will promote understeer and scrubbing."

Ignoring the engine braking argument for a moment, the comment is still incorrect. You *want* to load the front tires of a car through weight transfer so that they can grip and aid turn-in. This is also a fundamental part of trailbraking and why it is such a good skill. The proper pressure to slow the car to enter the turn, then just the right amount to point the car and turn it in until you can get back on the throttle. Failure to transfer weight forward will actually promote understeer, not reduce it.

Another example of the loading you will see is drivers either tap the brakes, or lift off the throttle, to transfer weight forward, load the front tires, and then turn in before getting back on maintenance throttle. It really depends on the type of corner in question.

Again, these concepts are taught by the most prominent instructors in the world on day one of a school. There is literally a slide deck from the BMW performance driving school that explains this exact concept using the size of the tire patches front and rear, as weight is transferred, to drive the point home.

I'll give you another exact quote from Skip Barber's curriculum. I can scan the page if you like.

Skip Barber 3 day racing school handbook (page 11)
Section: Downshifting - Why, Where, How

Key Points:

1. The primary reason to downshift is to select the proper gear for the exit of the corner, not to slow the car down.
.
.
.

 

Poll added.

 

Thanks. The poll is a good idea and lets people express their opinions more easily.

BTW, I picked "Yes, it is a useful technique" but as I have stated a few times already, it doesn't mean I use it in all situations.

 

I think you miss the point of remaining objective in a debate. It's important to not get too personal because obviously it changes the subject. Perhaps you're not used to debating.

Apparently that's not the case if you look at the poll. Yes, I only voted once.

BTW, spirot's esteemed Scottish friend was also very specific in qualifying his telling remark... that "engine braking in modern F1 does not happen at all... because of KERS and ERS". He didn't make the much simpler, broader statement "engine braking does not happen at all in F1".

I wasn't aware that we are discussing credentials. If credentials were paramount in FChat discussions then everyone would have to shut up and listen whenever someone claiming the highest credentials pronounce his opinion, with or without explanations.

I hope you will agree that sort of thinking would nullify the whole point of forums like FChat.

There is a big problem with your criticism. Your argument assumes I don't brake at all whereas I actually wrote "SOLE RELIANCE ON REGULAR BRAKING...". I have said many times that you want to balance your brakes when cornering. I didn't say use engine braking instead of regular brakes.

Trailbraking is also nothing more than threshold braking done with continuous balancing adjustments for changing centrifugal forces as you round the corner. If you also entered the corner after downshifting to a lower gear, you can use the throttle and engine as well to control the balance of understeer/oversteer while transitioning the corner at the highest speed. Each corner you take is different and some corners present possibilities for better drivers to explore, that's why drivers who have a fine touch for the brakes and throttle are able to go faster around some corners.

Well, I don't think you meant the driver actually "tap" his brakes (in a fast corner). That would be too heavy an action. They may touch or feather their brakes to momentarily reduce speed and also increase understeer just as they might lift throttle to to achieve the same by virtue of reducing power and adding some engine braking. Compression braking is engine braking.

No need to scan as I agree completely...

"The primary reason to downshift is to select the proper gear for the exit of the corner, not to slow the car down."​

Engine braking is not performed to slow the car down. Engine braking is performed to allow the driver to modulate the brake bias and the attitude of the chassis... so as to go FASTER, not slower around the corner. The idea is to go FAST around the corner, not STOP in a corner.

Left alone, regular braking will slow the car very well in corners... but you will also transition a corner more slowly than you could otherwise, if you were more creative by combining brakes with throttle, all the way around the corner. This is even more important if you are contesting the corner with several other drivers. When you contest a corner, you cannot go slower than the other driver, you have to go as fast or faster and your angle of attack (for mid-corner corrections, not your rear wing) constantly changes as other cars maneuver. Your driving needs to be more dynamic and you need to use your throttle... this ability to be dynamic in a corner also translates into better maneuverability and agility that gets the more aggressive driver ahead of other cars in the corners. Corners are usually the best places for drivers to overtake along a course, especially if their cars are not as fast as the others in the straights.

Therefore, I would submit the "secondary reason" Skip Barber's school handbook might have implied (for drivers who have a finer touch) is to use the throttle to introduce engine braking as a means of altering the brake bias, as needed, when they make their way around the corner.

This is more advanced technique and not all drivers, even if they track, will be able to drive like Schumacher or other F1 drivers (if you watched the 2012 F1 video I posted), who obviously applied throttle to varying degrees in the middle of fast corners.

 

This is exactly right. I'm no track expert but I have attended many racing schools. This is day 1, before you even get in the car, weight transfer, tire patch management education. You load the front tires to turn.. there is absolutely no debate on this.. the only thing the poll will tell you is how many people have formal race training and how many don't

 

Exactly!

My credentials pale to others on the board, but having run Formula Renault ( 1990) and a number of schools - Winfield, Skip Barber, Bondurant Panoz, 40 + track sessions with instruction - FCA, BMW Porsche, etc... NASA & some SCCA ... i can categorically state that no professional driver coach that I've been instructed by has ever stated that engine braking is used to slow the car... or to transfer grip to rear tires to "unload the front suspension etc... as has been touted here."

I further would reccomend NOT following the engine braking advice here for your own and others as well as your car's safety on track.

 

You seem to equate applying throttle to the use of engine braking, when it is exactly the opposite. As soon as you go on throttle, you have eliminated any engine braking that had been occurring due to coming off throttle during the braking phase.

 

In the middle of the corner, unless you keep downshifting engine braking only occurs when you apply and then reduce throttle. Applying and lifting throttle is part of mid-corner correcting when you try to maintain speed through the corner.

When you lift throttle you get compression braking, which is engine braking. So it is a dynamic balancing process, it's not just "braking" at the moment of downshift. I've been trying to get this across right from the start. Engine braking is a means to help balance the brakes and chassis. When you apply throttle, you reduce rear braking. Engine braking occurs whenever the car is going faster than the throttle position is allowing the driveline to rev-match.

You can also apply throttle and brake at the same time, and this should lighten the rear, move the brake balance dramatically to the front, but at the cost of extra wear on tires, brakes and a bit on the driveline. If you watched the video you would have seen this happen. It's an interesting and agile way to balance the brakes and correct steering.

Engine braking occurs whenever you lift throttle, assuming your throttle position and gearing were providing motive power or at least keeping up with the speed of the car (i.e. you're not coasting or flying downhill in high gear). The fact that ERS and KERS negates engine braking by means of computer-controlled brake balancing and throttle control in current F1 cars doesn't mean engine braking does not exist when you drive less sophisticated vehicles.

 

We get this. We know what engine braking is and when it occurs. What I'm pointing out is just because you see someone on throttle during cornering doesn't mean they're doing it because they're "applying engine braking" to balance the chassis.

In fact, your initial story was that engine braking "hunkers down" (I think that was the term) the rear because it's applied to the rear axle instead of the front. This is the part where we are in very strong disagreement. Now that we're focused on the mid-corner throttle dance, this should be clear. During this maintenance period, adding power is what hunkers down the back. Lifting (i.e., when engine braking is happening) does the opposite; it absolutely unloads the rear.

 

Look.. I really meant it several pages above. I like ice cream

 

Now more than ever would be my guess. Perhaps a poll?

 

I’m out of popcorn since page 4 of this thread