JPhil
Huh?
OK so I finally installed the VBP bumpsteer block kit last night. It was pretty straightforward, went pretty smooth.
Installation:
I drilled out the OEM steering arms on my drill press. Bought a brand new 5/8" bit, set the speed to its lowest, 450 RPM, and used a lot of oil. Since it was enlarging a pre-existing hole, I did not worry about it staying true. I supported the arms on a couple 2x4s and just held them with my hand. They each snagged a couple times, but I still got a smooth bore. I radiused the top lip with a stone in my die grinder.
The holes in the arms and the holes in the blocks were off by about .015"+/-. This I attribute more to Chevy than to VBP. I thought about filing the arms to oval the holes, but decided I would have a better, truer fit if I filed the bolt threads instead. So I wrapped a piece of heavy cardboard (heavier than a beer carton) around each bolt, chucked it up in the drillpress and held a file against it to file down the threads on the top (bolt head end) 5/8" to make a narrower 'shank' for an offset fit through the arms. I did not take the threads all the way off, by file-and-fit, I removed a few thousandths from each bolt until they would fit through the arms and thread into the blocks.
All well so far. But after I had it all reassembled to the point of attaching the tie-rod ends, I found the tie-rod stud nut did not have enough clearance from the steering arm to go on. Five minutes with a rotary bit in the die grinder on the side of the steering arm and it went on. This was on the driver side only, passenger side was OK. A box end or socket will not fit on the nut now, open end wrench only. That's OK, those don't need a real heavy torqueing. But the VBP block must be a tiny bit thicker than the OEM steering arm, because my cotter pins would not fit. One more thread down and they would have, but I ended up having to use a skinnier cotter pin.
It took me about 6 hours, but I work slowly with lots of time outs.
Driving:
Well, since my last alignment I have replaced the rear t-arms, rebuilt the differential, replaced the front 460# springs with shorter 550#s, and put these blocks in using only a tape measure to the frame to set the toe-in. So each wheel is running in a different plane, the only thing they have in common is they all rotate in generally the same direction. But each one is going toward a different destination. However in my couple-mile drive around the neighborhood this morning, there is definately a different feel to the steering wheel, one that feels like the geometry of the steering assembly has changed. The car is dangerously out of alignment now, I will have to be very careful driving it to the hotrod shop to do it.
So far, there is no appreciable loss in the turning radius (I have to make a sharp turn to get in the garage and I was a bit worried about that).
All I can say is, I will update this after I get it aligned. (But dang, bad weather is supposed to arrive tonight--When will I be able to get it on the rack?)
Stay tuned,
John
---------------------
UPDATE: March 8, 09
Finally I was able to get into the shop yesterday for alignment.....
I've never done this before, but they just showed me how to run the equipment & said "Have at it!" Took me about 6 hours. Whoof. But next time it won't take me half as long!
The car was pretty out in all possible ways (see above). I'm surprised it handled as well as it did before, so a true 'before & after' comparison for these bumpsteer blocks is probably not realistic.
I strongly suggest that if you are considering this modification, do a good 4-wheel alignment first, before you proceed with it. (I've had a chronic problem with it pulling to the left upon hard braking--I had been blaming it on a brake system problem but decided to wait and sure enough, this alignment cured it. Woo hoo!)
OK, "Driving Impressions":
Wow it's like it's on rails!
The feeling of a steering geometry change is not there now, that must have been because my front toe was so far out (or rather, 'in') that Greg started laughing when he guided me onto the rack (I could hear & feel my front tires scrubbing & screeching on the drive to the shop!). The steering feels perfectly normal now. If anything it's a bit lighter but I attribute that to setting a little bit wider (open) toe on both front & rear than factory specs. It tracks beautifully, but it's 'lighter' and more sensitive.
And I have no bumpsteer at all, at least in straight-line driving. I drove down the county road where one or the other set of wheels is always in the chuck holes with my hands off the steering wheel. I took the railroad tracks at 35 MPH with my hands off the wheel. I have not yet taken it out for exercise, but the few corners I took were smooth & true, although they were not very bumpy.
As I pulled into the garage, I could feel I was against the steering stops (or at least maxed out on the linkage) where I did not used to be, so yes there is a slight decrease in turning radius. But I don't think it will make any difference except if you parallel park a lot or deal with tight parking spaces.
All in all I'm happy as can be. As I get used to it & exercise the car more, I will probably make some adjustments to the alignment. But I have so much more confidence in it's handling now, and not the least of it is it's ability to stay true over shitty road surfaces.
(If anybody is interested, I downloaded my alignment specs into 'my photos'. I did it with about 150 lbs of concrete blocks in the driver seat, so it's interesting to see the difference that made in the specs with & without. I know it's not exactly spot on, but damn, I think I got things pretty good for my first time! It's a hayl of a lot better than it has ever been before)
I'll update this again when I get more time in the saddle with it.
John
Installation:
I drilled out the OEM steering arms on my drill press. Bought a brand new 5/8" bit, set the speed to its lowest, 450 RPM, and used a lot of oil. Since it was enlarging a pre-existing hole, I did not worry about it staying true. I supported the arms on a couple 2x4s and just held them with my hand. They each snagged a couple times, but I still got a smooth bore. I radiused the top lip with a stone in my die grinder.
The holes in the arms and the holes in the blocks were off by about .015"+/-. This I attribute more to Chevy than to VBP. I thought about filing the arms to oval the holes, but decided I would have a better, truer fit if I filed the bolt threads instead. So I wrapped a piece of heavy cardboard (heavier than a beer carton) around each bolt, chucked it up in the drillpress and held a file against it to file down the threads on the top (bolt head end) 5/8" to make a narrower 'shank' for an offset fit through the arms. I did not take the threads all the way off, by file-and-fit, I removed a few thousandths from each bolt until they would fit through the arms and thread into the blocks.
All well so far. But after I had it all reassembled to the point of attaching the tie-rod ends, I found the tie-rod stud nut did not have enough clearance from the steering arm to go on. Five minutes with a rotary bit in the die grinder on the side of the steering arm and it went on. This was on the driver side only, passenger side was OK. A box end or socket will not fit on the nut now, open end wrench only. That's OK, those don't need a real heavy torqueing. But the VBP block must be a tiny bit thicker than the OEM steering arm, because my cotter pins would not fit. One more thread down and they would have, but I ended up having to use a skinnier cotter pin.
It took me about 6 hours, but I work slowly with lots of time outs.
Driving:
Well, since my last alignment I have replaced the rear t-arms, rebuilt the differential, replaced the front 460# springs with shorter 550#s, and put these blocks in using only a tape measure to the frame to set the toe-in. So each wheel is running in a different plane, the only thing they have in common is they all rotate in generally the same direction. But each one is going toward a different destination. However in my couple-mile drive around the neighborhood this morning, there is definately a different feel to the steering wheel, one that feels like the geometry of the steering assembly has changed. The car is dangerously out of alignment now, I will have to be very careful driving it to the hotrod shop to do it.
So far, there is no appreciable loss in the turning radius (I have to make a sharp turn to get in the garage and I was a bit worried about that).
All I can say is, I will update this after I get it aligned. (But dang, bad weather is supposed to arrive tonight--When will I be able to get it on the rack?)
Stay tuned,
John
---------------------
UPDATE: March 8, 09
Finally I was able to get into the shop yesterday for alignment.....
I've never done this before, but they just showed me how to run the equipment & said "Have at it!" Took me about 6 hours. Whoof. But next time it won't take me half as long!
The car was pretty out in all possible ways (see above). I'm surprised it handled as well as it did before, so a true 'before & after' comparison for these bumpsteer blocks is probably not realistic.
I strongly suggest that if you are considering this modification, do a good 4-wheel alignment first, before you proceed with it. (I've had a chronic problem with it pulling to the left upon hard braking--I had been blaming it on a brake system problem but decided to wait and sure enough, this alignment cured it. Woo hoo!)
OK, "Driving Impressions":
Wow it's like it's on rails!
The feeling of a steering geometry change is not there now, that must have been because my front toe was so far out (or rather, 'in') that Greg started laughing when he guided me onto the rack (I could hear & feel my front tires scrubbing & screeching on the drive to the shop!). The steering feels perfectly normal now. If anything it's a bit lighter but I attribute that to setting a little bit wider (open) toe on both front & rear than factory specs. It tracks beautifully, but it's 'lighter' and more sensitive.
And I have no bumpsteer at all, at least in straight-line driving. I drove down the county road where one or the other set of wheels is always in the chuck holes with my hands off the steering wheel. I took the railroad tracks at 35 MPH with my hands off the wheel. I have not yet taken it out for exercise, but the few corners I took were smooth & true, although they were not very bumpy.
As I pulled into the garage, I could feel I was against the steering stops (or at least maxed out on the linkage) where I did not used to be, so yes there is a slight decrease in turning radius. But I don't think it will make any difference except if you parallel park a lot or deal with tight parking spaces.
All in all I'm happy as can be. As I get used to it & exercise the car more, I will probably make some adjustments to the alignment. But I have so much more confidence in it's handling now, and not the least of it is it's ability to stay true over shitty road surfaces.
(If anybody is interested, I downloaded my alignment specs into 'my photos'. I did it with about 150 lbs of concrete blocks in the driver seat, so it's interesting to see the difference that made in the specs with & without. I know it's not exactly spot on, but damn, I think I got things pretty good for my first time! It's a hayl of a lot better than it has ever been before)
I'll update this again when I get more time in the saddle with it.
John
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Just wanted to know if you gained any tie rod knuckle clearance to the inside of the rim? The blocks move the knuckle inward and forward for more clearance, but the downward location could negate that? I want to use less back spacing on an 18" wheel.
