LCA bump stop clearance
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
LCA bump stop clearance
I did some searching on this subject and came up with a partial answer. I have VBP front monospring kit and I just finished the install. I lowered the car to the ground only to discover that she is really in the weeds. ground to fender is 26 3/4." I like the look and would love to keep it but my bump stop clearance on my lower control arm seems way too tight. About a 1/2." The picture bellow looks worse than it is, but gives you an idea of what I'm getting at.
My searching said that 1/2" is way too tight (is it with this kit?), but what it didn't say was how much clearance should I have? I only have the spring in setting 2 (setting 4 being the stiffest), so should I bump that up? Maybe raise the car about a 1/4"? Maybe I should trim the bump stop a bit? All three?
Here is my passenger LCA for reference:
They are both pretty even with the ground, possibly starting to point upward. Any and all help would be great guys.
Happy Labor Day!
My searching said that 1/2" is way too tight (is it with this kit?), but what it didn't say was how much clearance should I have? I only have the spring in setting 2 (setting 4 being the stiffest), so should I bump that up? Maybe raise the car about a 1/4"? Maybe I should trim the bump stop a bit? All three?
Here is my passenger LCA for reference:
They are both pretty even with the ground, possibly starting to point upward. Any and all help would be great guys.
Happy Labor Day!
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Make adjustment so as to put more preload on the spring [at each end]. From the look of the threaded rod going through the spring ends, there is too much adjustment left in there. Adjust it so the spring is almost to the end of that rod; that will increase the spring rate and move the front end of the car up. It should also increase the road clearance below that rod.
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Do you mean the ride height adjustment bolts? Won't lowering the nut lower the car, just like the rear? I guess I'm a little confused. Shouldn't I raise the nut instead to raise the car? Also, how does it change the spring rate? Since the car is currently in steady state, if I run the bolt up or down, and let it sit at steady state, the spring tension will be the same. Yes it will be activated sooner if the nut is lowered, like you said or raised, like I think. Am I missing something?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
I don't have one on the front end....but it seems to me that there should be a nut/washer on the top side and that "dropping" that nut down farther would increase the load on the spring [causing the car to raise]. OK, you boyz/girlz that have one, what should he do????
Racer
Joined: Oct 2000
Posts: 491
Likes: 12
From: Los Altos Hills, CA
I am not familiar with the VBP monospring kit so take this advice accordingly.
Cutting bumps stops is a standard practice on lowered cars. GM published a book called the "GM Power Book". It shows all the modifications they recommend for racing a Corvette. The racing ride height is quite a bit lower than the stock ride height. The Power Book shows how to cut the bump stops to accomodate the lower ride height.
Cutting bumps stops is a standard practice on lowered cars. GM published a book called the "GM Power Book". It shows all the modifications they recommend for racing a Corvette. The racing ride height is quite a bit lower than the stock ride height. The Power Book shows how to cut the bump stops to accomodate the lower ride height.
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Well that is pretty cool to know! Do you know what the corresponding spring rate was? I figure I could go with the hardest spring rate to make sure I don't bottom out, but I don't want to rattle my girlfriend's teeth out.
I don't mind if I need new teeth in a few years haha.
I don't mind if I need new teeth in a few years haha.
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Well I went straight to the source: VBP. The man was nice and said that If I raise it just a little I should be ok. Fender to ground is currently 26 3/4" and he said 27 1/4" to 27 1/2" is a little safer. He said the best thing I can do is just drive it and see what happens. I'll raise her to 27" and see if I hit the bump stops. If I do, I'll increase the spring rate a bit and maybe shave the bump stop a bit, like a 1/4" or so.
One more question: What does a bottomed out suspension feel like? I plan on testing it at some local cloverleaf highway ramps.
Thanks for your posts guys. Now for the tuning phase I suppose.
One more question: What does a bottomed out suspension feel like? I plan on testing it at some local cloverleaf highway ramps.
Thanks for your posts guys. Now for the tuning phase I suppose.
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Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Haha well I guess I'll find out taking it to work. I go over two sets and under one! Plus some speed bumps in the work parking lot. This should be interesting... Maybe I'll do a post on how I tune it. That is, if it's interesting enough for a read.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I would also suggest putting the long bolt the other way. That will it will not catch on anything. Mine is with the threads up to provide as much clearance as possible. I also run mine on the 3rd stiffest setting until I go to the autoX then it goes to the stiffest setting.
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
The bolt won't hit anything if it's the other way around? Not a bad idea. Too bad that can't be done with the rear bolts. I think I might just switch to stiff setting 3 and call it a day. If I can handle it, that is haha. Thanks for the idea
The ORIGINAL and bestest
Joined: Oct 2000
Posts: 10,009
Likes: 240
From: Toronto Ontario
Toronto Events Coordinator
I just installed that kit on my 72. With 255/50/17 tires I have the front ride height set at 27". I took the car to the local race shop to align it after the install, and I specifically asked about the bump stop clearance; he told me it was fine as it was. I am currently trying it out in the #2 spring rate for a while, then I plan on switching to #3 to see the difference.
One other thing to watch for is the reduced turning radius; I found it to be too bothersome, so I cut the huge VBP steering stops to gain it back.
One other thing to watch for is the reduced turning radius; I found it to be too bothersome, so I cut the huge VBP steering stops to gain it back.
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Ok then. Maybe I don't have much to worry about. I'll raise it to 27" and still put it on #3. I need to redo the rear spring anyway. I don't think it's center. Flipping the bolts in the front won't be an issue either.
I have read about the diminished turning radius. I'll see how that is then if need be I'll cut back the bump stop. From what I remember, the turning radius is nothing to be celebrate in stock form to begin with.
Thanks again guys!
I have read about the diminished turning radius. I'll see how that is then if need be I'll cut back the bump stop. From what I remember, the turning radius is nothing to be celebrate in stock form to begin with.
Thanks again guys!
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
well guys, I'm under the vette again and making things happen. I have the front set with a new ride height (still off I think but I need it to settle to make sure). Now I'm in the back wanting to lower my spring bolts, but I came across a snag.I think I have to disconnect my sway bar, remove the sway bar plate, jack up the spring and trailing arm just to get to the nut on the spring bolt. Is there an easier way? I feel like their should be. I was going to clamp down on the spring bolt itself, but I think i read somewhere that this is a no-no because it could start a stress crack. Please guys, any guidance would be great.
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Well, my friends, I think I found a solution! I used a jar opener pad (rubber) folded over a few times to protect the bolt from my vise grip jaws. Worked like a charm! Hope this helps someone else
Thread Starter
Racer
Joined: Jul 2007
Posts: 459
Likes: 1
From: Lindenhurst, Long Island, New York
Alright, so the whole job is done. I had a hiccup with a brake hardline replacement, but that's done and I got her back from the alignment shop last night. Freakin' awesome! Oh man, I love this set up!
On setting #3 she rattles my teeth on broken pavement, but that's ok for now.
I didn't cut any bump stops, but I will be cutting the steering ones because my turning radius is huge now.
I flipped the spring bolt around on the front and it works well that way.
My ride height is 27" front, 28" rear on 225/70 (or 60) r15's with no issues.
Thank you again my friends for all of the help. This project was worth every penny and hour I spent on it. Now I need to replace my radiator core support before I rattle that out haha.
On setting #3 she rattles my teeth on broken pavement, but that's ok for now.
I didn't cut any bump stops, but I will be cutting the steering ones because my turning radius is huge now.
I flipped the spring bolt around on the front and it works well that way.
My ride height is 27" front, 28" rear on 225/70 (or 60) r15's with no issues.
Thank you again my friends for all of the help. This project was worth every penny and hour I spent on it. Now I need to replace my radiator core support before I rattle that out haha.