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While I think your method is spot on, a word of warning....
You want the fronts to lock up just a bit before the rear.
If you set it for 50/50, there are situations where the rear could easily lock up before the front. This is a bad thing as it can cause oversteer (back end breaking loose).
If you set the bias too heavily to the front, then you can cause understeer.
With drums in the rear, oversteer isn't much of a concern (drum brakes will have a hard time overpowering disk brakes). But with disks front and rear, it can be an issue.
That's one reason why I don't think it's a good idea to replace the LSPV in an 80 with disc's with a T, since the proportioning is 50/50 then you can easily cause oversteer.
Remember when you're testing this that you will likely be travelling in a fairly straight line, under/oversteer won't have much effect here. When you need to worry about it is when you need to steer around the object in the road on a corner in slick conditions at speed. In those situations oversteer can be downright dangerous.
In the image below:
The front calipers have more stopping power than the rear calipers. Which means that in order for you to lock up your rears at the same time as the fronts, you need more pressure going to the rear than the front.
Of course that's offset by weight transfer from the rear to the front when stopping, but 80's are actually very balanced weight wise (OEM) front and rear.
So PSI wise, when you have your rears locking up as quickly as your fronts I would suspect you are very near 50/50 PSI wise, either your LSPV is pretty much wide open or you've T'd off the brake lines.
EricE posted up earlier that the OEM spec is supposed to be 1138 front and 889 rear, which is then further reduced by the LSPV.
Considering the more powerful calipers in the front and the significantly reduced pressure to the rear, and you are no where near 50/50, either from a pressure perspective, braking power, or which calipers lock up first.
OEM these are designed with a buffer in them so the fronts lock up quite a bit before the rears, and thetruck is setup exactly that way while my truck has less bias toward the front (though still biased toward the front). Driving both regularly (and having performed hard stops and panic maneuvers in both) gives me a very good perspective on it.
Understeer isn't much fun, and I've experienced it in the
The fact is that recommending that someone setup their truck in a configuration that can introduce oversteer in an already dangerous situation is just foolish. If someone knows how to handle their vehicle and wants to set it up that way, more power to them. But most people don't, and making a general statement that it's good to setup their vehicle that way could lead to some bad situations.
Yes, it's not likely that several factors come together where oversteer could happen and injury or death could result. But I experience situations like that at least once a year or so, so they're not all THAT uncommon thanks to the idjits we have on our roads.
Slight oversteer may be "better" than slight understeer, but understeer is safer, especially for those who do not know how to handle it. Handling understeer is fairly intuitive, the hardest part is to stop the brakes from locking up and ABS will assist a novice driver there. Handling oversteer is not intuitive, in fact every single thing you WANT to do in an oversteer situation is the exact thing you shouldn't do.
) and so they taught me how to deal with under/oversteer from the start.
