Horrible understeer

[TeeLew]

Was rereading this post again, after 4 HPDE Novice track days now 3 with instructors, I've been schooled that with your feet you are either braking, doing throttle maintenance or rolling on the gas when tracking out. The goal is never to be coasting, so if there's no throttle maintenance what are your feet doing? The OP has stated he knows how to drive track and is seems to be driving HPDE type events. Curious on the statement.

No no no no no no no no no no no no no no no! I feel very strongly about this.

You have been told incorrectly for the slower 2nd & 3rd gear corners. I can accept it for a high-speed corner, but it's wrong for most track corners. If the chassis is tuned so that you have to immediately get back to throttle to 'catch' the rear, then it's far too tail-happy and you're sacrificing all sorts of entry speed. The grip on the car goes where the driver puts it. If you load the nose with the brakes, you can turn. If you unload the nose with the throttle, you can't. I'm not interested in the guys who are crossed-up and hazing the tires. Color them slow.

There will be a point in every corner where you are able to roll to throttle in about a 1 second time period. As a driver, that's an important point to identify, because it's a good rule-of-thumb goal concerning throttle application rate. If you can apply the throttle faster than that, you're too late and probably too slow. If you have to apply throttle slower than that, you started too early (likely inducing understeer). Once this point is identified, our goal is to get there as fast as possible.

We all generally know about the traction circle. We brake as hard as we can in a straight line. As we turn in, we release the brake as fast as we can while leaving as much load on the nose as we need to actually turn the car. This keeps us on the grip threshold of the car. At the moment brake pressure goes to zero, the car is still slowing due to cornering drag/tire scrub. This is a part of the traction circle most people ignore, because when you've got both feet up, the car isn't talking to you very much. This is the portion of the corner which just takes patience. Allow the car to turn with no pedal input. In terms of time, we're talking 1/2 to 1 second in a slow corner (T11 at Laguna, for example). Just have the disciple to let the car turn enough so that you can apply throttle in one continuous motion without having to check up at the exit while keeping the throttle at an application rate of about 100 deg/sec.

So, if you're immediately back on the throttle, it's almost certain that you have underachieved corner entry speed, delayed the point at which you reach full throttle and will likely be tuning your car to reduce understeer when the opposite is more appropriate.

TeeLew-ism #1: The point where one initiates throttle is trivial, but the point at which one reaches full throttle is vital. It's almost always faster to delay the former if it hastens the latter. (Caveat: Up to that 1 second application rate.)

Sponsored

 

[gone_n_60]

No no no no no no no no no no no no no no no! I feel very strongly about this.

You have been told incorrectly for the slower 2nd & 3rd gear corners. I can accept it for a high-speed corner, but it's wrong for most track corners. If the chassis is tuned so that you have to immediately get back to throttle to 'catch' the rear, then it's far too tail-happy and you're sacrificing all sorts of entry speed. The grip on the car goes where the driver puts it. If you load the nose with the brakes, you can turn. If you unload the nose with the throttle, you can't. I'm not interested in the guys who are crossed-up and hazing the tires. Color them slow.

There will be a point in every corner where you are able to roll to throttle in about a 1 second time period. As a driver, that's an important point to identify, because it's a good rule-of-thumb goal concerning throttle application rate. If you can apply the throttle faster than that, you're too late and probably too slow. If you have to apply throttle slower than that, you started too early (likely inducing understeer). Once this point is identified, our goal is to get there as fast as possible.

We all generally know about the traction circle. We brake as hard as we can in a straight line. As we turn in, we release the brake as fast as we can while leaving as much load on the nose as we need to actually turn the car. This keeps us on the grip threshold of the car. At the moment brake pressure goes to zero, the car is still slowing due to cornering drag/tire scrub. This is a part of the traction circle most people ignore, because when you've got both feet up, the car isn't talking to you very much. This is the portion of the corner which just takes patience. Allow the car to turn with no pedal input. In terms of time, we're talking 1/2 to 1 second in a slow corner (T11 at Laguna, for example). Just have the disciple to let the car turn enough so that you can apply throttle in one continuous motion without having to check up at the exit while keeping the throttle at an application rate of about 100 deg/sec.

So, if you're immediately back on the throttle, it's almost certain that you have underachieved corner entry speed, delayed the point at which you reach full throttle and will likely be tuning your car to reduce understeer when the opposite is more appropriate.

TeeLew-ism #1: The point where one initiates throttle is trivial, but the point at which one reaches full throttle is vital. It's almost always faster to delay the former if it hastens the latter. (Caveat: Up to that 1 second application rate.)

Okay... always coachable and started this to a) enjoy the car and b) get good at a new skill, high speed driving. So is some of that advice because you start driving between 3/10th to 6/10ths and an instructor is just getting you to learn the line and turn ins without being too slow or driving off the track? I had two guys who progressively added more speed, faster turn ins and improving my ability to look ahead better. I ended up doing Solo Novice for an afternoon session. I just heard about the friction circle 2 track days back, so that's new. Just wondering if what you're describing is someone who can now drive from 7/10ths to almost 10/10ths.

 

[Jaymar]

No no no no no no no no no no no no no no no! I feel very strongly about this.

You have been told incorrectly for the slower 2nd & 3rd gear corners. I can accept it for a high-speed corner, but it's wrong for most track corners. If the chassis is tuned so that you have to immediately get back to throttle to 'catch' the rear, then it's far too tail-happy and you're sacrificing all sorts of entry speed. The grip on the car goes where the driver puts it. If you load the nose with the brakes, you can turn. If you unload the nose with the throttle, you can't. I'm not interested in the guys who are crossed-up and hazing the tires. Color them slow.

There will be a point in every corner where you are able to roll to throttle in about a 1 second time period. As a driver, that's an important point to identify, because it's a good rule-of-thumb goal concerning throttle application rate. If you can apply the throttle faster than that, you're too late and probably too slow. If you have to apply throttle slower than that, you started too early (likely inducing understeer). Once this point is identified, our goal is to get there as fast as possible.

We all generally know about the traction circle. We brake as hard as we can in a straight line. As we turn in, we release the brake as fast as we can while leaving as much load on the nose as we need to actually turn the car. This keeps us on the grip threshold of the car. At the moment brake pressure goes to zero, the car is still slowing due to cornering drag/tire scrub. This is a part of the traction circle most people ignore, because when you've got both feet up, the car isn't talking to you very much. This is the portion of the corner which just takes patience. Allow the car to turn with no pedal input. In terms of time, we're talking 1/2 to 1 second in a slow corner (T11 at Laguna, for example). Just have the disciple to let the car turn enough so that you can apply throttle in one continuous motion without having to check up at the exit while keeping the throttle at an application rate of about 100 deg/sec.

So, if you're immediately back on the throttle, it's almost certain that you have underachieved corner entry speed, delayed the point at which you reach full throttle and will likely be tuning your car to reduce understeer when the opposite is more appropriate.

TeeLew-ism #1: The point where one initiates throttle is trivial, but the point at which one reaches full throttle is vital. It's almost always faster to delay the former if it hastens the latter. (Caveat: Up to that 1 second application rate.)

I generally agree with this school of though. The always braking/accelerating notion is partially true but it has simplified an important part of the theory or of it. That line of thought should be to always maintain the tire at a level of X amount of work. That work can be braking, accelerating, turning or any combination of them that adds up to X. Turning is work just as much as accelerating so if maintenance throttle is used in the tighter, low speed corners you are pushing along below your maximum corner speed. This is just one aspect of tire use and not a complete picture of corner mastery but it has helped me identify what and when my feet should be working.

 

[TeeLew]

Okay... always coachable and started this to a) enjoy the car and b) get good at a new skill, high speed driving. So is some of that advice because you start driving between 3/10th to 6/10ths and an instructor is just getting you to learn the line and turn ins without being too slow or driving off the track? I had two guys who progressively added more speed, faster turn ins and improving my ability to look ahead better. I ended up doing Solo Novice for an afternoon session. I just heard about the friction circle 2 track days back, so that's new. Just wondering if what you're describing is someone who can now drive from 7/10ths to almost 10/10ths.

You're probably right. The coaches are probably trying to make you more comfortable and quicker without talking you into the fence. Many people hold the opinion that a driver must constantly have to be doing *something* with the pedals, but fail to appreciate that doing nothing _is_ doing something.

When working with a new driver, I prefer to work technique and just allow the speed to happen organically. If they never go any faster, that's just fine. I never encourage a learning driver to go beyond the point he feels comfortable. There's just no advantage to taking risks on a track day and it's really easy to talk guys straight into the wall.

 

[K4fxd]

Any opinions on this sta bar kit?
https://www.levittownfordparts.com/sku/m-5490-g.html

 

[bnightstar]

Any opinions on this sta bar kit?
https://www.levittownfordparts.com/sku/m-5490-g.html

This are the track pack sways for that price you can't go wrong though.

 

[tosha]

Any opinions on this sta bar kit?
https://www.levittownfordparts.com/sku/m-5490-g.html

Have them as part of magneride track suspension kit. Very very happy with it.

 

[GTP]

Totally, again I was rereading the thread and that statement about avoiding maintenance throttle just jumped out to me... now that I'm learning these skills.

Whit, remember turn 8 at Gingerman? It's a long right-hand sweeper. You have to drive around the outside of that turn so that you can put the apex right at the turn's end, which is immediately the beginning of left-hand sweeper turn 9.

I tried a few different techniques there, and what worked best for me was to sacrifice that turn in order to best setup turn 9. That required driving around the outside of turn 8 with a long period of maintenance throttle. I even shifted up to 4th (A10) in order to "mellow out" the car's balance.

 

[NightmareMoon]

Any opinions on this sta bar kit?
https://www.levittownfordparts.com/sku/m-5490-g.html

They've got collars on them (good), but only two adjustment holes on the front (might be fine). I'm not sure how stiff they are compared to stock

 

[K4fxd]

They are 37mm front, 25.2mm rear but I cannot find any rate info

 

[K4fxd]

Managed to find a track to test tire pressures, unfortunately it was follow the leader. Paced laps only. My JA slowed down when I did and he refused to speed up when I was pushing him, so I could not get true max limit corners.

The lower air pressures helped. Pisses me off I switched to Hoosier and believed their recommendations.

 

[Darkshadows550!!]

I did the Steeda springs on the stock OEM PP1 shocks/struts and it was an improvement over stock, but I wasn't happy, something felt off in tight high speed situations. Overall was better than the stock, but.... I had already added the front Steeda Brace, and IRS bracing which made a real difference, and immediately noticeable.

Fast Forward a few months and after saving my pennies, I pony'd up for the prebuilt Steeda Sport springs and dampers, with their camber plates for the front and shock mounts for the rear.

I discovered that the idiots in the shop did NOT cut the bump stops when they installed the springs front or rear, so at anything other than normal sedate driving, I was on the bump stops. The new setup has proper sized stops and the handling is much better. The difference on the Tail of the Dragon was night and day.

I'm not going to track my car, am too old and not interested unless it was just me on the track alone.

I'm super impressed with the handling of the car now. It was good out of the box, and its comfort as a grand tourer, not a track car

I recently took my 76 Porsche with spherical (rather than pressed suspension bushings), Bilstein shocks and stock torsion and sway bars. It was perfectly balanced and very fast and stable, and thoroughly satisfying.

Recently, on a similar 100 mile fast twisty road jaunt, though I have never found the handling of my 46 year old beauty wanting over the last 12 years, and driving it back to back with my E36 M3 then with the Bullitt and OEM and phase 1, but now with the full matched Steeda springs and shocks, with the other bits, the car is so dialed in, and aggressive and competent, I am looking at suspension upgrades for my Porsche.

To the OP, I'm NOT a racer, or a suspension guru, but I used to autocross Saab's and GTI's, and have driven my Porsche and M3 on track days, and I have a bunch of blanks in your situation particularly:

- Tire size, pressure, brand and condition.
- Speeds? What speeds are you talking about? What speeds and conditions produce understeer?
- Body transitions? You say the front end plows like a Mack truck, but what is the rest of the car doing?
- Lower front X or Straight brace?
- Rear Suspension bracing?
- Are you sure that your suspension setup is right?
- How did the car perform before the mods?

I've been driving 'fastish' sports oriented cars for 40 years, from original muscle cars, to euro (GTI, Saabs, M3) and a couple Porsche's (924, 914 & 911). The Bullitt was good out of the box, but with the mods is stellar. The rear is rock solid and planted, response is stellar as is front end bite. Step out with throttle is linear and controllable

I think you have something mismatched, and I would start by putting your front bar on the lowest setting, rechecking your alignment especially the rear if you messed with the links, lowering tire pressure to 30-32. See how that works, then look at adding more parts by starting with a stiffer rear sway bar. I'd also look at your driving and braking habits and position in the turns. Are you setting up right?

I'd also slow down to where the car performs as you want, and slowly increase speeds, pick different apex, brake and accel points and see how the car responds. I have to drive the Porsche exactly as you would a motorcycle, and very different than a front engine RWD car.

I'd also reach out to Steeda to get their feedback.

Because posts are worthless without pics, here are a couple.

GOOG LUCK!

Read you amazing post. Thanks for all the info. I’ve been in the air of getting the Steeda difm strut and spring set or the ford performance pre assembled kits. In regards to the Steeda and the bump stop not being cut, were they supposed to cut the bump stop and forgot? Would have to spec almost $2k and have that happen

 

[shogun32]

were they supposed to cut the bump stop and forgot?

apparently. And save yourself the trouble do NOT choose the Steeda 'adjustable' bump stops either. They are effectively solid. You want Eibach bump stops and cut them back by AT LEAST the amount of suspension drop your choice of spring results in.

 

[Darkshadows550!!]

apparently. And save yourself the trouble do NOT choose the Steeda 'adjustable' bump stops either. They are effectively solid. You want Eibach bump stops and cut them back by AT LEAST the amount of suspension drop your choice of spring results in.

What are your thoughts on the ford performance track pack? I already have the Steeda front and rear sway bars so I don’t need the fp bars. I would assume ford would make the kit ready to install

 

[shogun32]

What are your thoughts on the ford performance track pack?

it gets the nod from most people from a spring rate, drop, and damper performance perspective. I don't know what they do about the bump stops. Regardless, cut them back.

Sponsored