Factory adjustable proportioning valve

I read somewhere about a car that came with a factory adjustable proportioning valve. They took a plastic cover off and there was a threaded adjuster underneath. Anyone know what car that might be?

A2 and A3 (1985-1998) Volkswagen Golfs and Jettas have a proportioning valve that changes rear brake valving depending on how much the rear twist beam is loaded. It's adjustable.

Classic Mini, I believe. Which also means there are probably dozens of other LBCs with the same setup.

Toyota pickups have a similar ride height adjustment valve. And I discovered this week that the E39 M5 has a ride height sensor on the front suspension, which I suspect is used for informing the ABS system.

Geo Metro, apparently.

http://www.motoiq.com/magazine_articles/id/1367/pageid/1617/the-best-engineered-lemons--2-the-metrognome.aspx

Keith wrote: And I discovered this week that the E39 M5 has a ride height sensor on the front suspension, which I suspect is used for informing the ABS system.

OR(could be AND too)..... keeping those headlights correctly adjusted for load

Alan Cesar wrote: Geo Metro, apparently. http://www.motoiq.com/magazine_articles/id/1367/pageid/1617/the-best-engineered-lemons--2-the-metrognome.aspx

I think that is the one I was looking at. Except I'm not sure its off a Metro. I will have to track one down and look at it.

Thanks for the help!

oldeskewltoy wrote:

Keith wrote: And I discovered this week that the E39 M5 has a ride height sensor on the front suspension, which I suspect is used for informing the ABS system.

OR(could be AND too)..... keeping those headlights correctly adjusted for load

Possibly AND, although my car does not have adjusting headlights.

You know you can buy a new adjustable prop valve for under $50, right?

Dodge Rampage... sorta.. Controlled the rears.. "load sensing"

Audi's along the same years as said VW's above had them

You know you can buy a new adjustable prop valve for under $50, right?

Yes I do, in fact I have two. But they are considered a performance part.

ronholm wrote: Dodge Rampage... sorta.. Controlled the rears.. "load sensing"

Several of the Dodge pickups starting in the '80's had the load sensing valves.

bearmtnmartin wrote: You know you can buy a new adjustable prop valve for under $50, right? Yes I do, in fact I have two. But they are considered a performance part.

is this a Chumpcar/Lemons build? if so, argue that brakes that are properly set up are a safety thing and thus don't fall under the "performance" umbrella. they let you spend all kinds of cash on upgrades at the wheels without penalties, so a prop valve to keep you from plowing into everyone else and/or the wall when your rear brakes lock up is a safety item.

novaderrik wrote:

bearmtnmartin wrote: You know you can buy a new adjustable prop valve for under $50, right? Yes I do, in fact I have two. But they are considered a performance part.

is this a Chumpcar/Lemons build? if so, argue that brakes that are properly set up are a safety thing and thus don't fall under the "performance" umbrella. they let you spend all kinds of cash on upgrades at the wheels without penalties, so a prop valve to keep you from plowing into everyone else and/or the wall when your rear brakes lock up is a safety item.

This kind of thinking is what will kill crapcan racing.

DILYSI Dave wrote: This kind of thinking is what will kill crapcan racing.

Actually, what would kill crapcan racing quicker than anything would be sky high insurance costs.

Also, an adjustable brake pressure regulator from GRM advertiser! Speedway Motors is $35 , versus the $100 for a replacement VW unit.

Dunno about ChumpCar but LeMons already says 'brakes are free', spend as much as you want. I see big rotors, Wilwood etc calipers, all kinds of stuff.

4.2: Safety Equipment DOES NOT Count Toward $500 Total: Safety equipment described in Section 3 DOES NOT count toward the $500 total. "Safety" refers to things that can save the driver--not things that can save the car. 4.2.1: Beside the items and processes listed in Section 3, the following are considered safety-related and therefore exempt: Wheels, tires, wheel bearings, balljoints, and brake components Exhaust systems downstream of the header/exhaust manifold (NOTE: Turbos and related components are NOT exempt from the $500 limit. Nice try.) Windshields and wipers. (Stock windshields, true Lexan, or circle-track mesh are acceptable; non-Lexan plastic is not acceptable.) Driver comfort & information (steering wheel, shifter, gauges, pedals, cool suits, vents, heaters, radio) All fuel hoses, fuel fittings, fuel filters, and related mounts All fuel-system components upstream of the fuel pump, including tanks/cells, mounts, fillers, vents, etc. (NOTE: Fuel pumps, carburetors, injection pumps, computers, and individual injectors are NOT exempt from the $500 limit.)

Maybe I'm wrong, but when we built our car a few years back for ChumpLeMans, IIRC the rules stated that any upgrades to the brakes were limited to 2x the cost of the OEM parts. Maybe I pulled that out of my freckle, but that's how I remember it.

You guys may be right about a covert spending war in the dirtbag leagues, but I haven't seen any of the high zoot calipers / pedal sets / NASCAR brake fluid recicurculating doo-hickeys. I guess I need to look at your cars

You guys are making the mistake of assuming Chumpcar and Lemons run the same rules. Chump has the 2X rule, Lemons has the blanket exemption.

2wd Nissan hard bodies had a load sensing valve like Keith mentioned on toyotas of similar vintage

Don't forget. Late model vehicles require two valves. You know, with the split braking system.

It's actually for my little hornet car. I use it for a few different classes, and none of them allow performance parts, which an after market brake valve certainly is.

oldeskewltoy wrote:

Keith wrote: And I discovered this week that the E39 M5 has a ride height sensor on the front suspension, which I suspect is used for informing the ABS system.

OR(could be AND too)..... keeping those headlights correctly adjusted for load

Probably the headlights. Auto-adjusting HIDs seems to be a German-car thing, while Japanese cars seem to prefer having a manual adjustment on the dash.

I know for a fact that Audis without air suspension use the height sensors strictly for headlight aiming.

Back to on-topic. Many cars had variable rear proportioning based on rear ride height. Common to almost all Tauruses, many VWs (my A2 Golf did not have it, surprisingly, but my Quantum does), and I even spied an adjuster mounted to an innovative linkage on an 8v Delta Integrale.

I have seen people mount a jackscrew/lever arrangement on the A2 Golf/Jetta prop valves (like the ones my Golf didn't have) to make a cheap cockpit-adjustable valve.

Me, I bought a lever style Wilwood for $25 at Summit. It's still sitting in its baggie