GSlender's Track Beeotch!

gslender · Postby **gslender** » Wed Oct 29, 2014 7:17 pm

I don't have wide or sticky enough tyres. I also didn't want to start with an inherently oversteering car (with too much front grip vs rear).

G

The American · Postby **The American** » Thu Oct 30, 2014 8:04 am

Hi Gslender,
You've had both an AGI bar and an Automotive + bar in your car. I've fitted an AGI bar before and have read the install instructions for the A+ bar and the A+ looks much simpler. However, I'm 6'5" and need to find as much height as I can.

Do you have a sense of which bar was ultimately taller, and by what margin?

gslender · Postby **gslender** » Thu Oct 30, 2014 8:07 am

Can't confirm height but seat won't go back as far with AGI - I sold it because my head was touching the top bar as it was that much more far fwd.

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gslender · Postby **gslender** » Thu Oct 30, 2014 9:54 pm

Here's the inaugural E85 test (well E36 in my case because I filled up when the tank was half full of PULP98)

https://www.youtube.com/watch?v=fd0TC1knldw

Cool part is that it starts and idles just like normal, but is now running on a 36% Ethanol blend. As I run down the tank and fill up with more E85 it will re-adjust the fuel and spark compensation and continue to just work. So far very cool!

timk · Postby **timk** » Thu Oct 30, 2014 10:37 pm

That looks pretty neat, which flex fuel sensor are you using?

Can you try a tank of straight E85 and let me know how your cold starts are?

gslender · Postby **gslender** » Thu Oct 30, 2014 10:39 pm

Sensor is the GM sensor, a continental brand or something

gslender · Postby **gslender** » Fri Oct 31, 2014 9:40 am

Cold started this morning normal and it was saying 39% Ethanol - will use up the tank and refill with E85 and see how it goes. So far I'd say the idle and performance is better. Definitely more punchy but that's the butt dyno

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gslender · Postby **gslender** » Wed Nov 05, 2014 10:54 am

Left front and rear locks up first under hard braking. Rechecked ride height and left side is 5mm higher than right. Probably more with me in it.

Is that the braking problem? If I equaled height would that improve or worsen?

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plohl · Postby **plohl** » Wed Nov 05, 2014 11:42 am

Are you still using the standard proportioning valve

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gslender · Postby **gslender** » Wed Nov 05, 2014 12:10 pm

No, I've got an adjustable installed.

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gslender · Postby **gslender** » Wed Nov 05, 2014 12:12 pm

If left side is higher then shouldn't it be pushing down harder and that would mean grip would be better, not less right, so if anything, it should be locking up on the right? Yeah?

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Magpie · Postby **Magpie** » Wed Nov 05, 2014 12:49 pm

If rears are locking up first then your bias needs to be adjusted. The left front lockup is normal.

What hoses are you running? Tyre pressures? Weight distribution? Is the lock up happening when braking in a straight line? What pads?

Is it similar to this thread http://mx5cartalk.com/forum/viewtopic.php?f=19&t=64835&hilit=left+front+lockup ?

gslender · Postby **gslender** » Wed Nov 05, 2014 3:24 pm

Thanks Magpie - but none of that post covers why front left vs front right. Nobody actually explains it and explains how to balance it.

I called Fulcrum and they are 100% convinced the ride height is the reason. They have the view that having left side higher has shifted the CG to the right and with me in the car, made that even stronger and so the weight is now on the right side (more than the left). :frown:

The advice they'd give is to have only the front driver right 5mm higher to compensate for the driver weight and that should make the car balanced on the road/track. I guess that's why people corner weight the car to ensure the ride heights are even and then wheel align and then corner weight and so on... otherwsie you get what I've got which is a car that is a wee bit unsettled under brakes

So there ya go!

G

Magpie · Postby **Magpie** » Wed Nov 05, 2014 4:19 pm

Yep corner weight

It is a fun exercise to get the ride height and the corner weight spot on, normally you sacrafice a height adjustment to ensure that the corner weights are spot on. It is normally only a few mm.