Kurt's Midlana videos

Post up your well-deserved pictures and self-congratulatory videos.
Midlana1
Site Admin
Posts: 3382
Joined: 19 Dec 2008, 16:44
Anti-spam question: 4
Are you a spammer: No
Location: Southern California

Re: Kurt's Midlana videos

Post by Midlana1 » 13 Jan 2014, 21:37

They do that because some modern cars detect speed on all four wheels, and if it doesn't meet what it considers "normal", will put the ECU into limp-home mode.

Midlana1
Site Admin
Posts: 3382
Joined: 19 Dec 2008, 16:44
Anti-spam question: 4
Are you a spammer: No
Location: Southern California

Re: Kurt's Midlana videos

Post by Midlana1 » 03 Nov 2014, 06:08

11/2/2014 drive into the local San Diego back country with friends.

https://www.youtube.com/watch?v=nylxGbH6rKA.

User avatar
freakynami
Posts: 809
Joined: 23 Dec 2008, 17:53
Anti-spam question: 0
Are you a spammer: Yes
Location: Adelaide, Australia

Re: Kurt's Midlana videos

Post by freakynami » 03 Nov 2014, 14:06

Awesome! Nice to see, paints so much more of a picture.

Interesting "noise" on the right handers, no idea what that is either :| All of the other noises are most pleasant though, ever since watching BTCC as a kid I love the sound of a straight cut gearbox :D

Midlana1
Site Admin
Posts: 3382
Joined: 19 Dec 2008, 16:44
Anti-spam question: 4
Are you a spammer: No
Location: Southern California

Re: Kurt's Midlana videos

Post by Midlana1 » 03 Nov 2014, 20:10

The camera was mounted on the main roll hoop diagonal, and nothing was brushing against the camera case, so I don't get it either. Because of where it was mounted, engine noise is accentuated. I'll try mounting it off one of the top tubes and we'll see how that sounds, though I expect wind noise to be a bit much if too high.

Midlana1
Site Admin
Posts: 3382
Joined: 19 Dec 2008, 16:44
Anti-spam question: 4
Are you a spammer: No
Location: Southern California

Re: Kurt's Midlana videos

Post by Midlana1 » 22 Jan 2016, 14:00


bozla
Posts: 1
Joined: 24 Jul 2011, 01:59
Anti-spam question: 4
Are you a spammer: No

Re: Kurt's Midlana videos

Post by bozla » 05 Feb 2016, 11:07

Midlana1 wrote:Willow Springs, 1/16/2016 https://www.youtube.com/watch?v=s8CnfEjfo5E
Kurt - Re your incident. (OK let me caveat this - it's very easy to make judgments from video but it simply isn't the same as have your butt in the seat feeling the grip so take my comments with the VERY large pinch of salt that it requires).

It was started by you going slightly wide and coming off the throttle to bring the car in tighter (which was correct), but you stayed off the throttle even when the car was pointing in the right direction. That's an instant spin due to the effect of engine braking. You should always have a bit of trailing throttle through corners otherwise you will have engine braking, and this is even more essential through the faster corners. Remember - throttle always - except when braking or getting the car to turn, even if it's only just enough to keep the engine running freely (i.e. get rid of engine braking).

Also, your reaction on the steering wheel was just a little too late. You need to learn to look at the horizon rather than the road - again especially through the faster corners. Look how far the mountains move in the slow motion replay before you react. Looking at the road gives you no clue whatsoever that the car in in-fact rotating very quickly. However, I think you would have saved it though if you'd have applied 1/3~1/2 throttle after the first correction.

The good news is that the car is working great.

Midlana1
Site Admin
Posts: 3382
Joined: 19 Dec 2008, 16:44
Anti-spam question: 4
Are you a spammer: No
Location: Southern California

Re: Kurt's Midlana videos

Post by Midlana1 » 05 Feb 2016, 11:35

Looking at the data logs, they show I came fully off the gas, so that's certainly a contributor, how much I don't know. You correctly picked up on coming in wide, or at least drifting wide. As it started to go, it wasn't real obvious when compared to the track surface since the car appeared to be following the right-hand curve - but it was actual rotating at a rate higher than steering had commanded.

What's much less clear is whether the rear suspension had bottomed. From the seat, it felt as though the rear just started to go on its own and there was no catching it. It's been a while since the bump stops were pushed down ("reset" if you will) and they were jammed all the way up. The catch is, it's not known when that happened. Next track event, they'll be checked after every session.

The 800-lb gorrilla in the corner that's hard (for any driver) to confront is: how much of the incident was directly caused by me. I admit that I'm afraid of going off backwards at high speed, pretty much just the way it happened, so I tend to drive way below its limits in high speed turns. On this same track in a car with 1/3 the power, I was only 4 seconds slower. In that car I was far more comfortable having the back end step out. With this car, it's still an unknown. It really needs to be run on a skid pad in order to safely find what it does on turns when I lift, stay neutral, or give it more gas. That's the plan for the next event.

WickedOne
Posts: 129
Joined: 01 Jan 2009, 08:51

Re: Kurt's Midlana videos

Post by WickedOne » 05 Feb 2016, 17:32

And then there's the issue of transverse vs. longitudinal. The weight loading/centralization/whatever you want to call it of the transverse vs. the longitudinal is more likely to cause snap oversteer ala Porsche, although no where nearly as bad since the engine is over the axle, not behind it.

Yes, I know you are going to say it's in front of the axle, but only a portion and even then it's barely in front. All I'm saying is that it's tougher to get it right the first time around that way and you can just consider this part of the tuning process. How many decades did it take for Porsche to tame it?

It's a given that a new design will have some teething pains and unfortunately those that you find at the edge tend to make the biggest impression. I'm sure you'll work it out.

Midlana1
Site Admin
Posts: 3382
Joined: 19 Dec 2008, 16:44
Anti-spam question: 4
Are you a spammer: No
Location: Southern California

Re: Kurt's Midlana videos

Post by Midlana1 » 05 Feb 2016, 18:11

WickedOne wrote:...Yes, I know you are going to say it's in front of the axle, but only a portion and even then it's barely in front. All I'm saying is that it's tougher to get it right the first time around that way and you can just consider this part of the tuning process..
Wheel centerline is 9" aft of crank centerline, which is effectively engine CG. I don't count that as "barely" but agree the CG isn't 18" ahead of the rear axle like it would be in a longitudinal drivetrain.

Regarding figuring it out, the bottoming issue should be resolved, leaving tires - and especially driver ability - as the next things to deal with.

WickedOne
Posts: 129
Joined: 01 Jan 2009, 08:51

Re: Kurt's Midlana videos

Post by WickedOne » 05 Feb 2016, 20:54

As I was saying, I'm sure you'll get it worked out. All new cars not following a formula will have sorting issues, but keep in mind that while in the transverse set up your crank is 9" ahead of the axle there's still considerably more engine weight over or extremely near the rear axle when compared to the longitudinal. The longitudinal set up spreads the weight out along the axis instead of concentrating it all around the axle.

I always think of a car like a pendulum and in a turn, if all other things were equal, the heavy end would want to go first. That's why Dennis tried to put everything in the center, which while it's neat on paper, really does limit the usefulness of the build. Especially if street car is anywhere in the design parameters. But that's also why a longitudinal engine would be easier to sort, the weight is spread out in a fore to aft manner. Of course those have different issues altogether such as transmission packaging which moves a small portion of the weight behind the axle.

Bottom line is there's no perfect, real world solution. You pick what things have the most value to you and then work around the resulting limitations. And let's face it,transverse engines are everywhere which gives you a lot more choices of engines & manufacturers.

Simply putting the engine behind the driver solves a lot of packaging and heat issues vs. a front engine.

In any case, hopefully different springs solves the problem. Driver skill always increases the more the drive and you always get better the more you learn a particular car. I've never been one of those that could hop into just any car and drive the snot out of it. It takes me a while to get the feel of that car.

Post Reply