Ross's extended city, easy entry Goblin- 06 SS/SC, NW Arkansas

Ross

Goblin Guru
Yesterday's autocross play day:
Still getting wheel hop during braking. It seems to be worse than last year. I think my front shocks may have no oil... so I am going to check/rebuild them. Brake lines arrived for the 260-12627 - Wilwood Brake Proportioning Valve, so that is going on too, which will allow for more rear brake bias.
 

ctuinstra

Goblin Guru
Kaleb is wanting to do autocross this summer. I should really look into it.

You probably already know this, but it seems like your dash is cutting out during the race.
 

Ross

Goblin Guru
Kaleb is wanting to do autocross this summer. I should really look into it.

You probably already know this, but it seems like your dash is cutting out during the race.
One of the benefits of a hood, is it protects the BCM, instrument cluster and power steering circuits from rain. I towed my Goblin thru the rain, and soaked those circuits, which they intermittently let me know for the last 3 days.
 

JBINTX

Goblin Guru
Yesterday's autocross play day:
Still getting wheel hop during braking. It seems to be worse than last year. I think my front shocks may have no oil... so I am going to check/rebuild them. Brake lines arrived for the 260-12627 - Wilwood Brake Proportioning Valve, so that is going on too, which will allow for more rear brake bias.
Good run!
Looks like you had a "little" passenger with you. Always good to spread the horsepower virus.... ;)
You will like the results with the brake proportioning valve.
And like Dale is always telling me - "Get on the gas!!!!!!" :0
 

Ross

Goblin Guru
Those are awesome bends. Thank you for those! I want to test drive it! I am rebuilding the front shocks, so the test drive will have to wait.
 

Rttoys

Goblin Guru
Sweet. Glad they worked properly. Now, can’t wait for the test drive. I’d like a second, third or forth confirmation of what I feel with mine.
 

Ross

Goblin Guru
Test drove it today. Turned the vacuum regulator off, to get full power to the brakes, then went to full restrictive on the front brake proportioning valve (57% maximum restriction) which skids the rear first. Then backed off the proportioning valve one turn... it is close, but still too much rear brakes. Will try 1.5 turns next trip. Probably should reduce the vacuum in the power brakes too, as the brakes are too powerful.

The QA1 shocks were full of oil, and working correctly. Took the springs off, and could feel the resistance change as I adjusted them. Put them back on Mad Max, (my Goblin), and tried using the shock adjustment to stop wheel hopping under hard braking. Started at 0 clicks, got wheel hop. Went to 2 clicks, got wheel hop, slowly worked my way to 18 clicks (full out) and still got wheel hop. Ug. Still searching for the wheel hop issue. There are lots of Goblins running the 275mm Toyo Proxes R1R front tires, I don't think they are getting wheel hop under hard braking.
 

Rttoys

Goblin Guru
Kind of disappointed that didn’t fix it, but it did get me to thinking. Maybe with that happening so many times, I wonder if your heim joints and arms have been fatigued enough that they are now weak and damaged?

did it at least help?
 

Ross

Goblin Guru
Are my wheel alignment numbers causing wheel hop?
22409


The wheel hop issue only occurs if I press the brakes hard, which, I basically avoid. So daily driving doesn't involve hopping tires. It basically prevents me from hard braking at autocross. When pushing & flexing the wheels, Garrett tire noticed a bit of flex from the top heim joint mount, so I have ordered heavier ones from Adam, but retorquing the bolts seems to have fixed most of this.
22412
 

Rttoys

Goblin Guru
I’m running about -.8 on camber and about 8 To 9 on caster, but I’m about to change mine a little to see if it helps or hurts.

ya. Those brackets need to go. They have been pretty hammered on. I like the beefy ones.
 

Ross

Goblin Guru
I talked to George Bradley, he suggests the front tires have too soft of sidewalls, and the high traction tires are grabbing the road, causing bouncing. So I will raise my tire pressure from 18psi to 25 psi, and see if that helps. The brake proportioning valve is great, as it allows the brakes to be balanced correctly for a Goblin, and not a Cobalt. When adjusted properly, it makes for a more predictable stopping.
 

Brian74

Goblin Guru
Are you seeing much benefit from the vacuum regulator? I’m guessing it affects pedal effort more than anything?
 

Ross

Goblin Guru
Yes, it affects pedal effort.
Without the vacuum regulator the front wheels would lock up when using half of the brake pedal stroke.
So I have reduced the power in the power brakes, and set the regulator to lock up the wheels near the bottom of the brake pedal stroke.
Now I have better brake control, and pedal feel.

Adjustable power brakes with the vacuum regulator,
and adjustable brake front/rear bias with the brake proportioning valve.
 

Brian74

Goblin Guru
Yes, it affects pedal effort.
Without the vacuum regulator the front wheels would lock up when using half of the brake pedal stroke.
So I have reduced the power in the power brakes, and set the regulator to lock up the wheels near the bottom of the brake pedal stroke.
Now I have better brake control, and pedal feel.

Adjustable power brakes with the vacuum regulator,
and adjustable brake front/rear bias with the brake proportioning valve.
More stuff to do on my build, lol. Thanks for the info.
 
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