April 5-6, 2014 THSCC HPDE at VIR-N - Registration now open!

Vincent Keene · **Posted:** Tue Apr 08, 2014 4:18 pm

Cash Davidson wrote:

I don't think it is that simple. The 6 uses CAN-Bus Protocol.

Yep, because prior to that running wires was hard and they never worked right. :roll:

They found a solution looking for a problem. It had to be a German who had the original idea.

Scott Johnson · **Posted:** Tue Apr 08, 2014 4:23 pm

Cash Davidson wrote:

I don't think it is that simple. The 6 uses CAN-Bus Protocol.

Damn technology! :soap:

HKS SLD? or a Hypertech programmer (kind of expensive...)

Cash Davidson · **Posted:** Tue Apr 08, 2014 4:37 pm

RickyBeam wrote:

Knock every other tooth off the wheel speed sensors? The ABS will still work, but it'll always see the car moving half as fast as it really is.

That's actually not a bad idea. :idea:

Cash Davidson · **Posted:** Tue Apr 08, 2014 5:02 pm

Vincent Keene wrote:

It had to be a German who had the original idea.

Winner-Winner! Originally developed by Bosch - a German company. :thumbsdown:

RickyBeam · **Posted:** Tue Apr 08, 2014 6:19 pm

Cash Davidson wrote:

That's actually not a bad idea. :idea: 8)

Except that the nubs are part of the hub (rear) and axle (front). (e.g. gear teeth... machining may be recommended.)

Cash Davidson · **Posted:** Tue Apr 08, 2014 6:48 pm

RickyBeam wrote:

Cash Davidson wrote:

That's actually not a bad idea. :idea:

Except that the nubs are part of the hub (rear) and axle (front). (e.g. gear teeth... machining may be recommended.)

Don't under-estimate the backyard engineer.

My keen intuition nearly makes up for my complete lack of judgement. :wink:

Andrew Jonell · **Joined:** Mon Mar 23, 2009 6:43 pm **Posts:** 1350

Updated video! Now with RaceRender overlays!

https://www.youtube.com/watch?v=eXG87aj ... e=youtu.be

JamesMilko · **Posted:** Wed Apr 09, 2014 12:05 am

I also made this. Compares Andrew's and my best laps.

http://youtu.be/b0jgboOEoi4

Roger McDaniels · **Posted:** Wed Apr 09, 2014 12:27 am

Andrew Jonell wrote:

Roger McDaniels wrote:

Yeah, Andrew, I did turn up the rear brake bias a bit too much there, my apologies. Did you notice if it was still doing it after I backed it off? I wasn't flat-spotting the rears, so I guess it wasn't too bad, but the tires were so noisy that I couldn't hear when the rears were locking up.

Nah, not that I could see. It was only that one time into T3 which is probably the one spot where it would happen (maybe T16 if you take the "I hope this works" line). Miatas lock up rears at autocross while dodging cones, but as long as the rears weren't locking before the fronts into T1/T7, you should be fine.

I was left foot braking T3, which may be why that was happening, although I'm new to mashing both right pedals, so I'm not 100% sure about that.

Roger McDaniels · **Posted:** Wed Apr 09, 2014 12:36 am

A lap each of me and Ricky with data overlay, my first attempt at doing that. They are not our best laps, but we didn't get video of all of our laps due to issues with the GoPro remote.

Me: http://youtu.be/0rgaC7FKARo
Ricky: http://youtu.be/4c9CbIJwWqg

Cash Davidson · **Posted:** Fri Apr 18, 2014 2:28 pm

Further analysis: Our torque curve is relatively flat from 4500 to 5200 - meaning this is the range where the car pulls hardest.

Let's look at the speed in each gear during this 700rpm sweet spot range:

With 25.5"dia tires:
Sweet spot torque:
1st: 26-30mph
2nd: 45-52
3rd: 66-76
4th: 87-101
5th: 113-130

From the video, you can see the car accelerates well up to about 100 or so. I sense the car is not pulling as the torque is dropping off so I shift from 4th to 5th. But when I get to 5th, I am well below the sweet spot of the torque curve and the car falls flat - damn 0.733 5th gear!! :twisted:

Who's idea was it to track a family four-door? :roll:

Scott Johnson · **Posted:** Fri Apr 18, 2014 3:58 pm

Cash Davidson wrote:

Let's look at the speed in each gear during this 700rpm sweet spot range:

With 25.5"dia tires:
Sweet spot torque:
1st: 26-30mph
2nd: 45-52
3rd: 66-76
4th: 87-101
5th: 113-130

From the video, you can see the car accelerates well up to about 100 or so. I sense the car is not pulling as the torque is dropping off so I shift from 4th to 5th. But when I get to 5th, I am well below the sweet spot of the torque curve and the car falls flat - damn 0.733 5th gear!! :twisted:

Who's idea was it to track a family four-door? :roll:

No matter what, in a non-race transmission the torque multiplication through the transmission guarantees that you will have more torque to the wheels in a lower gear at all times. I'd never think about short shifting (on a straight) unless I wanted to rest the engine.

Roger McDaniels · **Posted:** Fri Apr 18, 2014 5:08 pm

Can you change the final drive? I have the same problem with my Hondas, but it's relatively simple/cheap to put an aftermarket final drive in a Honda, and it really makes the car much nicer for the track.

Andrew Jonell · **Joined:** Mon Mar 23, 2009 6:43 pm **Posts:** 1350

Scott Johnson wrote:

No matter what, in a non-race transmission the torque multiplication through the transmission guarantees that you will have more torque to the wheels in a lower gear at all times. I'd never think about short shifting (on a straight) unless I wanted to rest the engine.

I shortish shift out of T6 and out of hogpen and it's faster (top of 3rd is close to 90mph, I shift going about 80mph). But I'm using an undersquare, FWD econobox motor that has nasty vibrations/harmonics on the higher end.

Cash needs to find a way to get a 5th gear that isn't super econo-mode, something in the .8 range should keep him riding the torque curve.

Cash Davidson · **Posted:** Sat Apr 19, 2014 11:49 am

Andrew Jonell wrote:

Cash needs to find a way to get a 5th gear that isn't super econo-mode, something in the .8 range should keep him riding the torque curve.

The Australian Ford Mondeo uses the same 3.0L Duratec but with a much more track friendly gear set in a completely different tranny

Mondeo ST220 MTX75 Gear Ratios
1st 3.417
2nd 2.136
3rd 1.483
4th 1.114
5th 0.902

Final Drive 3.560

Now that's what I need! Anybody have any Aussie friends?

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