Column: The Momentum Over Horsepower Debate

Define late braking; for a momentum car it means using less brake force throughout the entire braking process from threshold braking through to trail braking. I believe one of the top driving schools around the country says "brake lighter longer"

Trail braking is probably the most obvious way to make up time on the brakes, which is why I'm such an advocate of learning the technique. Raising the corner entry speed via trail braking also means you don't have to slow down as much

The stereotype for horsepower guys is to roar up to the corner, stand it on the nose (grossly overslowing the car) and then romp the gas pedal. I've had plenty of students in Miatas do the same, so for me it's more of a newbie thing than a horsepower thing.

From an instructor standpoint teaching people to rotate the car via the brake pedal makes a huge difference in lap times. So for me that counts as using the brakes to make up time. 

On the more literal definition of using the brakes to make up time; our D-sports racer pulled 3Gs on the brakes, in that car you literally roared up to a corner impossibly late and stood the car on the nose. The ability to stay on the gas for an extra 150 feet was huge. Because that car had a moderate amount of downforce you didn't need to trail the brakes as long nor rotate it near as aggressively as most other cars.

rustomatic said:

One metric that has been left out (somewhat) is the one that includes style of track.  Some tracks do not really reward horsepower as much as others.  From what I've been told, as an example, Road America has a straight that literally does not end.  From what I've seen, NOLA has something similar, depending on how they've configured it for the day.  From experience, both Laguna Seca and Sonoma can make you feel pretty happy with 350 HP (which is basically low power these days), depending on your skill (and grip) level.  As for my future track, I somewhat fear Road Atlanta, as I'm not sure if my car's brakes are up to task; grip and power will be sufficient, however.

It really is interesting how different cars play so differently with different layouts. Barber and CMP are very similar length tracks, roughly 2.25 miles. Our car on the same setup runs almost identical times at both tracks, both average and hot lap. A friend of ours runs 5-10 seconds slower on average at CMP. CMP is a more flatout track than Barber IME.

Road Atlanta only scares me on the final turn. Coming down under the bridge with that concrete wall in front of you is intimidating. It was relatively easy on brakes for us but we're a VERY momentum based car compared to most.

Keith Tanner said:

I've had a Porsche put on its brakes on the back straight at HPR to let me past in a high grip 150 rwhp ND Miata. Lifting off just wasn't getting the job done. It was pretty funny to see the thought process - point by, lift...brake lights. I did thank him later :)

Yes, if everyone is polite and paying attention it shouldn't be a problem.  Unfortunately such is often not the case.

What rustomatic says is true, 350 hp is now considered a low power car.  These days I'm driving an E46 M3 on track (one that's minus about 700 pounds from stock weight) and there are days when I feel like it's 20 years ago and I'm back in that stock Miata...

rustomatic said:

One metric that has been left out (somewhat) is the one that includes style of track.  Some tracks do not really reward horsepower as much as others.  From what I've been told, as an example, Road America has a straight that literally does not end.  From what I've seen, NOLA has something similar, depending on how they've configured it for the day.  From experience, both Laguna Seca and Sonoma can make you feel pretty happy with 350 HP (which is basically low power these days), depending on your skill (and grip) level.  As for my future track, I somewhat fear Road Atlanta, as I'm not sure if my car's brakes are up to task; grip and power will be sufficient, however.

On that note, who here has figured out how to make up time with brakes?  I did a fairly recent ride-along with a friend in a basically stock (Koni struts and track day pads) first-gen RX7 (not remotely poweful), and he did very well in not being passed by far, far faster cars on a track that favored higher horsepower (Thunderhill).  Granted, he would have killed for an LS swap, given less  

Brakes can be used in many ways. Not just to aide a fast lap. But also to gain position. The easiest to understand is if you have similar braking power you can position yourself to the inside as he swings wide to get his best corner speed. You can drive inside him and as you get your nose in front of his then you brake.  Naturally that will carry you deeper into the corner , off line. Now you are in front of him and he cannot accelerate. Yes your lap time will suffer but you have position.  
Another move is the outside pass position yourself to the outside. You are taking away his usual line slowing his corner speed making him brake harder and sooner. 
 

There are variations of both and counter moves 

Just remember position is king. 

In reply to frenchyd :

Isnt that known as "dive-bombing" ?

Keith Tanner said:

If you have the ability to put down serious acceleration coming out of a corner, you'll run a different line because it allows you to start to accelerate sooner. Giving up 5 mph mid-corner is worth it if you can add 10 mph to your exit speed, because you get that extra speed allll the way to the next braking zone.

This right here.  It's all about acceleration, one lap will include a sum of lateral and longitudinal accelerations, but it's much easier to find time with longitudinal acceleration.  The problem with sustained lateral acceleration is that it is the result of constant velocity which means it is a waiting period.  This waiting period is only a benefit if the combination of constant speed and distance of the momentum line between points A and B on the track is quicker than the combination of average speed, including decel and accel, and distance of the shorter point/shoot line between those same points on the track.  Both styles should have the same peak lateral acceleration, but one will sit at that high lat acc for a while (waiting), the other will only briefly touch it before getting back on the gas.

Of course the 'right' way to do it is only right until someone does it a differently and is faster.  Then there is a new 'right' way until the next, etc.

Volvoclearinghouse, a dive bomb is somebody who magically shows up right at the apex.

What frenchyd is describing is a classic slide job. Done properly the driver doing the pass will have left 1 -2 car lengths of room between the his rear bumper and the other cars front bumper.  (It's the margin I use)  

Done improperly the driver attempting the pass will run slightly wide allowing the other driver to execute the classic over under repass.

The key to executing a proper slide job is your entry speed needs to be 3-4 mph faster than the car being passed, you also need the ability to be able to chuck the car semi-sideways in order to scrub off that extra 3-4 mph to keep yourself from running wide and being repassed. 

80% of amateur drivers do not posses the skill or experience to pull this off. If you try to pull off this maneuver going 1/2 mile per hour faster than the other car, be forewarned it's going to end in tears.

codrus (Forum Supporter) said:

Keith Tanner said:

I've had a Porsche put on its brakes on the back straight at HPR to let me past in a high grip 150 rwhp ND Miata. Lifting off just wasn't getting the job done. It was pretty funny to see the thought process - point by, lift...brake lights. I did thank him later :)

Yes, if everyone is polite and paying attention it shouldn't be a problem.  Unfortunately such is often not the case.

What rustomatic says is true, 350 hp is now considered a low power car.  These days I'm driving an E46 M3 on track (one that's minus about 700 pounds from stock weight) and there are days when I feel like it's 20 years ago and I'm back in that stock Miata...

 

We did have a good laugh about it later.

There is a dramatic difference between driver behavior at Californian and Colorado track days. It's easier to drive an outlier car in Colorado in my experience.  There's also quite a difference in the cars - at the HPR days I frequent, I'm more likely to see a race-prepped 510 (talk about a momentum car!) than a 911. 

I've noticed that this discussion seems to be equating "momentum car" with "slow" and then it turns into self-proclaimed hero stories. I'm guilty of the former at the very least.

But that's not necessarily the case. Momentum cars just have their speed in different places. They can't accelerate as well as they can corner.  You see this decision in F1 occasionally where a mid-pack team decides to go with a wild downforce setup to give them a distinct difference in the grip/power ratio than the rest of the pack. Usually it involves low downforce so the car is less of a momentum car and can thus use greater straight line speed to pass/defend. There aren't many series where you can  adjust grip vs speed like this, but F1's aero does make it possible. 

A "momentum cars aren't slow" example. Minis were a dominating force back in the 60s and they're certainly not a point-and-shoot kind of car. Let's take the 500 mile Bathurst race at Mount Panorama in 1966. The Mountain is very much a power track, with a big climb up one side and a long, long, long straight on the flat - this was back before the chicane was added. It's pretty difficult to pass on the downhill section, most of the passing seems to happen on the long straight or the braking zones before the climb up the hill. Minis took the top 9 spots in the race, with V8-powered Valiants coming in 10-11. This was not an example of the Mini drivers putting their weak little cars where they don't belong, it was a triumph of handling over horsepower.

We saw momentum over horsepower play out over and over in endurance racing in the 60s. If I remember correctly, the 250 GTO would win on the handling tracks (a V12 Ferrari playing the role of the momentum car!) and the Cobra would win on the high power tracks. This doesn't mean the Ferrari drivers were better, simply that it was a better tool for some tracks and worse for others.

Keith Tanner said:

There is a dramatic difference between driver behavior at Californian and Colorado track days. It's easier to drive an outlier car in Colorado in my experience.  There's also quite a difference in the cars - at the HPR days I frequent, I'm more likely to see a race-prepped 510 (talk about a momentum car!) than a 911. 

I've been to Laguna Seca 6-7 times in the last year and a half. Every time there are guys with $50k-$100k cars that have no business driving them. With the Silicon Valley nearby there are a lot of people that are suddenly well off but have very little driving experience. In my 220hp GTI I've passed 911s, Caymans, Elises, Corvettes, Teslas, Alfa Romeo Giulias, BWMs, etc. As I've moved up the ladder the drivers seem to be more aware and courteous. I'm hoping that by the time I get into the groups requiring 10+ track days that the driving will be better. I wish they would break up the groups by lap times. 

Keith on the subject of Minis,

 They are around 1400lb with driver and putting 115-120hp to the wheels, which equates to around a 13 second 1/4 mile. So while they are not fast they are also not slow, they are in the same run group as me at vintage races so I am familiar with them.

Your point about momentum cars not necessarily being slow is well taken, Formula Atlantic  & F3 cars are fast but they are still momentum cars. 

The groups are split up by driver skill so that the rules for each group can be adjusted accordingly. You don't want a novice in a hypercar being allowed to pass in corners, no matter what the lap time. And you don't need to limit a top level Spec Miata driver to point-by hell just because their car does not actually possess the power of acceleration.

Your 200 hp GTi passing Caymans is not a momentum car issue, it's a skill level issue. That's completely different.

Tom1200 said:

Keith on the subject of Minis,

 They are around 1400lb with driver and putting 115-120hp to the wheels, which equates to around a 13 second 1/4 mile. So while they are not fast they are also not slow, they are in the same run group as me at vintage races so I am familiar with them.

Your point about momentum cars not necessarily being slow is well taken, Formula Atlantic  & F3 cars are fast but they are still momentum cars. 

I have a classic Mini that I've taken on track. It has very good cornering ability relative to its acceleration ability which makes it a textbook example of a momentum car. There are places where other cars hit the brakes and I shift into the next gear, but it takes me a lap to get up to speed :) 

CAinCA said:

Keith Tanner said:

There is a dramatic difference between driver behavior at Californian and Colorado track days. It's easier to drive an outlier car in Colorado in my experience.  There's also quite a difference in the cars - at the HPR days I frequent, I'm more likely to see a race-prepped 510 (talk about a momentum car!) than a 911. 

I've been to Laguna Seca 6-7 times in the last year and a half. Every time there are guys with $50k-$100k cars that have no business driving them. With the Silicon Valley nearby there are a lot of people that are suddenly well off but have very little driving experience. In my 220hp GTI I've passed 911s, Caymans, Elises, Corvettes, Teslas, Alfa Romeo Giulias, BWMs, etc. As I've moved up the ladder the drivers seem to be more aware and courteous. I'm hoping that by the time I get into the groups requiring 10+ track days that the driving will be better. I wish they would break up the groups by lap times. 

Broadly speaking, yes, the more advanced groups tend to be better in terms of awareness.  Intermediate groups are the worst in that regard, in my experience.

What track day organizations are you going with?  Laguna is a bit of an odd case, it's definitely a horsepower track and the sound rules mean that lots of people are driving strangely.  This is particularly noticable at high-db days where you'll get a bunch of people showing up with fast cars but very little experience there.

As for lap time divisions, as Keith says that's mostly a safety thing.  That said, organizations with multiple advanced/open groups will sometimes split them by lap time.

Kieth you probably know this already but your classic Mini and a vintage race prepped Mini are worlds apart.

So when I raced motorcycles practice was separated out by lap times; this worked well because there was open passing and you don't end up with the issues one has at track days.

As for track days; I run the F500 in the advanced group and the Datsun (due to how slow it is) in the intermediate group. The issue with the intermediate group is that a portion of the drivers are experienced enough to get their car up to speed but they don't yet have the capacity to drive at speed and be aware of their surroundings. Additionally some of the same drivers may be at a level where they now posses just enough skill to get themselves into trouble but lack the skill to get themselves out of trouble.

Note I am an advocate of people starting out in momentum cars.

Keith Tanner said:

The groups are split up by driver skill so that the rules for each group can be adjusted accordingly. You don't want a novice in a hypercar being allowed to pass in corners, no matter what the lap time. And you don't need to limit a top level Spec Miata driver to point-by hell just because their car does not actually possess the power of acceleration.

Your 200 hp GTi passing Caymans is not a momentum car issue, it's a skill level issue. That's completely different.

I guess I misunderstood your post above. I thought I was agreeing with it. What dramatic difference do you see between CA drivers and CO drivers?

codrus (Forum Supporter) said:

CAinCA said:

Keith Tanner said:

There is a dramatic difference between driver behavior at Californian and Colorado track days. It's easier to drive an outlier car in Colorado in my experience.  There's also quite a difference in the cars - at the HPR days I frequent, I'm more likely to see a race-prepped 510 (talk about a momentum car!) than a 911. 

I've been to Laguna Seca 6-7 times in the last year and a half. Every time there are guys with $50k-$100k cars that have no business driving them. With the Silicon Valley nearby there are a lot of people that are suddenly well off but have very little driving experience. In my 220hp GTI I've passed 911s, Caymans, Elises, Corvettes, Teslas, Alfa Romeo Giulias, BWMs, etc. As I've moved up the ladder the drivers seem to be more aware and courteous. I'm hoping that by the time I get into the groups requiring 10+ track days that the driving will be better. I wish they would break up the groups by lap times. 

Broadly speaking, yes, the more advanced groups tend to be better in terms of awareness.  Intermediate groups are the worst in that regard, in my experience.

What track day organizations are you going with?  Laguna is a bit of an odd case, it's definitely a horsepower track and the sound rules mean that lots of people are driving strangely.  This is particularly noticable at high-db days where you'll get a bunch of people showing up with fast cars but very little experience there.

As for lap time divisions, as Keith says that's mostly a safety thing.  That said, organizations with multiple advanced/open groups will sometimes split them by lap time.

So far I've run with SpeedSF and NCRC. The problems I've seen are probably at least partially due to COVID since the instructors can't go out with anyone. I've had people stab their brakes mid corner, point me by where they shouldn't have, or just plain refuse to let me by even though I was clearly faster. On the GTI forum it's been mentioned a few times that guys can not stand to let a $30k E36 M3 box pass their $60k dream car.

I understand WHY they break up the groups the way they do. I just wish I could run in a group of cars and drivers that all had similar lap times to me. I've had a blast chasing a C6 Corvette and Mustang GT that were running similar lap times. I've also had a blast running with a Focus ST and Works Mini. 

Anyway, this should be a separate thread.

In reply to Tom1200 :

Your last example here is what I meant to point out regarding the friend in the RX7.  He would literally wait until he was in the corner, aiming for a late apex, then slam brakes (hard) only enough to set and get.  He'd refined this process doing Lemons races for hours at a time.  It was hysterical, and I think I had some seatbelt marks after, but it was an effective approach that I never considered.  I've always just preferred doing everything but braking (momentum on the brain), but needs change when you can get those higher speeds in the straighter sections.  Karting can teach endless great lessons here.

CAinCA said:

Keith Tanner said:

The groups are split up by driver skill so that the rules for each group can be adjusted accordingly. You don't want a novice in a hypercar being allowed to pass in corners, no matter what the lap time. And you don't need to limit a top level Spec Miata driver to point-by hell just because their car does not actually possess the power of acceleration.

Your 200 hp GTi passing Caymans is not a momentum car issue, it's a skill level issue. That's completely different.

I guess I misunderstood your post above. I thought I was agreeing with it. What dramatic difference do you see between CA drivers and CO drivers?

Aggressiveness and ego. People don't win track days in CO and will give up a corner instead of putting themselves in a sketchy situation. Basically, drivers work together more. CA track day drivers seem to think they're racing and will be much more aggressive in order to come out ahead so they can claim the big prize. I've never won it myself so I don't know what it looks like, but it must be nice.

Obviously, this is a gross generalization. But it's prevalent enough that I do have to adjust my driving and the way I expect other drivers to move when I travel from CO to CA and back again.

As for the Porsche-killing 200 hp GTi - put the same driver in both cars, the Cayman/911/Tesla/whatever will likely be faster. You expect that to be the case which is why you called them out. So you're not passing them because you're a momentum car and they're not or vice versa, you're passing them because you have a higher skill level. Turn the tables and you wouldn't. That's got nothing to do with momentum cars.

Again, people are equating "momentum" with "slow". And "horsepower" with "fast". That's not true. It takes a certain type of skill to take full advantage of a car with a high power/grip ratio, and a different type of skill to take full avantage of a car with a low power/grip ratio. Those skills do transfer, so you can learn things in one type of car that you won't learn with another. A high power/grip car (aka point and shoot) will teach you a lot about throttle modulation and how to dance on the edge of the traction circle on corner exit. The throttle pedal isn't just a binary switch, it's a sensitive rheostat. It'll also teach you more about significant braking events. The low power/grip car (momentum) will teach you about how to maintain cornering speed and maximizing corner entry speed and drafting and velocity is precious so don't let it leak away - but it won't teach you much about throttle control because, well, the answer is probably "all of it" most of the time.

I know my fast road Mini is not a race Mini. But I don't expect they're radically different. And in my Mini example, they were racing against full-size family saloons with big horkin' V8s. You're not going to tell me that the Mini isn't the momentum car in that situation.

CAinCA said:

So far I've run with SpeedSF and NCRC. The problems I've seen are probably at least partially due to COVID since the instructors can't go out with anyone. I've had people stab their brakes mid corner, point me by where they shouldn't have, or just plain refuse to let me by even though I was clearly faster. On the GTI forum it's been mentioned a few times that guys can not stand to let a $30k E36 M3 box pass their $60k dream car.

I am not a fan of SpeedSF.  NCRC's open/advanced group is usually pretty polite, can't speak to the intermediates.

You might consider Hooked On Driving -- their events are more expensive, but folks there are usually quite well-behaved in this sort of situation.

Keith agreed both fast road Mini and race Mini are momentum cars but the race Mini is closer to the big V8 Holden in the slower corners than people think...........once the speed increases the standard Mini body is pretty much a parachute.  I've watched Minis out drag Spec Boxsters on race starts.

As for not learning throttle control in a low power car I disagree; in a low power car if you get on the throttle to hard to early you will end up with loads of speed scrubbing understeer.  So just like something with the ability to spin the tires one has to wind on the throttle progressively.

Great column and I am in agreement. I prefer balanced cars that handle well, especially on the street. Before I raced, I did track days and autocross. During those early track days in my normally aspirated 4's, it was interesting to get passed or gapped by high horsepower cars after corners, but catch up to them upon entry and be held up in the corner. For me driving a momentum car is more fun. My SCCA ITA car was an 87 Civic Si, momentum. For street driving 200-250 hp is plenty for me and does not leave me wanting more. 

All that said, we are all different and it's great that there enough choices out there so that we can drive what we like. 

codrus (Forum Supporter) said:

CAinCA said:

So far I've run with SpeedSF and NCRC. The problems I've seen are probably at least partially due to COVID since the instructors can't go out with anyone. I've had people stab their brakes mid corner, point me by where they shouldn't have, or just plain refuse to let me by even though I was clearly faster. On the GTI forum it's been mentioned a few times that guys can not stand to let a $30k E36 M3 box pass their $60k dream car.

I am not a fan of SpeedSF.  NCRC's open/advanced group is usually pretty polite, can't speak to the intermediates.

You might consider Hooked On Driving -- their events are more expensive, but folks there are usually quite well-behaved in this sort of situation.

 

I have run with HOD (5 x) , speedsf, NCRC, trackmasters and GGLC. Agree HOD are best organized and drivers are generally polite. I really like GGLC as well, very friendly drivers and "momentum" oriented.

Thread back from the grave!

One thing I've noticed is that the bread and butter cars are a lot faster these days than they were when I started HPDEs. Golf Rs and regular Camaro SSs have an awful lot of power and tire on non M3 E36s/46s and first gen Caymans. I miss the days when 200hp was plenty, and 300 was a lot. Not that you can't still have fun with that, but the goalposts have moved a long way.

Occasionally you'd see some eccentric in a Ferrari Challenge car or something, so I'm not sure the pointy end is much sharper, but the average machine is way up from my youth.

volvoclearinghouse said:

In reply to frenchyd :

Isnt that known as "dive-bombing" ?

Since there are counters to dive bombing  and a skilled driving can see the set up. It's just a technique. Sometimes people fail to use their mirrors  and are surprised by the move.  That's why when it's used in Vintage racing you need to know who you're racing with. Because of the 13/13 rile. No Contact
   In the end the first car to cross the finish line wins.   
     With less horsepower you can tuck in behind the more powerful car and have him pull you down the straight. Yes that's tailgating but permitted. As is "divebombing"