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Poly bumps

Posted: Sat Dec 12, 2009 10:40 am
by Nick
Ok, i'm researching poly bumps for my build. I know that some will say that the stockers will work, but i'd like to go a step above those. Air bumps aren't really in the budget for now, so what else can i do without breaking the bank?

BajaChris, i know that your Dad said you run the nissan bumps, can you share any info on them? Part#'s, how they perform, how long they last?

Re: Poly bumps

Posted: Sat Dec 12, 2009 8:37 pm
by SteveG
You already know that I like rubber bumps, but if I felt the need to upgrade (and not use a hydraulic bump), I'd probably head to a wrecking yard and pull some of the foam type that mount in a cup.

Like these:
GM Bump Stop.jpg
GM Bump Stop.jpg (69.96 KiB) Viewed 3250 times

Re: Poly bumps

Posted: Sat Dec 12, 2009 10:44 pm
by baja-chris
Nick wrote:Ok, i'm researching poly bumps for my build. I know that some will say that the stockers will work, but i'd like to go a step above those. Air bumps aren't really in the budget for now, so what else can i do without breaking the bank?

BajaChris, i know that your Dad said you run the nissan bumps, can you share any info on them? Part#'s, how they perform, how long they last?
They are older Pathfinder rear bump stops and are a rubber that looks like a number 8 (small O stacked on a big O). I don't remember what years they used these on. They seem to hold up very well and I've been unable to hurt them.

Re: Poly bumps

Posted: Sat Dec 12, 2009 10:45 pm
by magic carpet XLT
i run these, they are about 4" tall press into a cup that mounts with 1 bolt and they compress almost completely flat. i've had those in for 2 years now, but they are so common at yards that i just grab them whenever i see them so i have enough to last like 10 years. if you want a couple to try i can send you a pair. they come from the rear of late 90s early 2000s S10 blazers/jimmys/bravadas.
Image

i swiped a pair of the nissan pathfinder ones too, but i don't really like how big they are or the way they mount (they would be best in a rear application where you have more room on the frame). i can send you those too if you are interested. they came on mid-late 80s pathfinders (the boxy ones)

on a side note, i was poking around the ford dealer looking at the raptor in the show room, all they run for bumps are on shaft rubbers in front and big rubbers in back.

Re: Poly bumps

Posted: Sat Dec 12, 2009 11:09 pm
by Nick
Thanks for the replies!

Andy, that would be great if i could get a set of each. Let me know how much.

Re: Poly bumps

Posted: Sun Dec 13, 2009 8:12 pm
by baja-chris
The Raptor uses bypass shocks (internal bypasses) and the position sensitve nature of the shocks somewhat mitigates the need for good bump stops. I suspect the last few inches of shock travel is valved about like an air bump.

Re: Poly bumps

Posted: Mon Dec 14, 2009 12:34 pm
by PBR
interesting story on poly vs. air bumps:

my good friend jon drives a very successful jeep in class 3. there we some complaints about the placement of his rear air bumps, they went through the frame and according to the people complaining that was not legal in class 3. so jon removed the air bumps, plated the frame back in just as it was before the air bumps were installed, and installed some poly/rubber bumps. he said that the truck is now faster than before without the air bumps and they are still winning races! he is sure his competition will find something else to complain about but for now he is very happy without the rear air bumps!

Re: Poly bumps

Posted: Mon Dec 14, 2009 7:51 pm
by tcm glx
PBR wrote:interesting story on poly vs. air bumps:

my good friend jon drives a very successful jeep in class 3. there we some complaints about the placement of his rear air bumps, they went through the frame and according to the people complaining that was not legal in class 3. so jon removed the air bumps, plated the frame back in just as it was before the air bumps were installed, and installed some poly/rubber bumps. he said that the truck is now faster than before without the air bumps and they are still winning races! he is sure his competition will find something else to complain about but for now he is very happy without the rear air bumps!

Hey Ollie,
Yikes and I talked to this said friend at a recent race, and he also removed the front air bumps... and your comments are spot on, he is very happy and continues to dominate without them. He did mention he did additional shock tuning and that he was all set now without the air bumps...

Re: Poly bumps

Posted: Mon Dec 14, 2009 9:07 pm
by ntsqd
I run the Nissan bumps on the rear of Patch. Thanks Chris for the suggestion years ago. I'm about to install a set on the front as Patch does have the room though the height is a bit of a concern. No, Patch is not a Bronco.

I've only ever seen what this page shows, but these might be interesting - originally built for CTD's:
http://www.thurenfabrication.com/dyskobumps.html
Image

Re: Poly bumps

Posted: Mon Dec 14, 2009 9:11 pm
by Rednek Renegade
For a $170 you might aswell go find a set of used air bumbs.

Re: Poly bumps

Posted: Mon Dec 14, 2009 9:31 pm
by Nick
Rednek Renegade wrote:For a $170 you might aswell go find a set of used air bumbs.
It will cost you a little more than $170 for air bumps...

Re: Poly bumps

Posted: Mon Dec 14, 2009 9:33 pm
by magic carpet XLT
PBR wrote:interesting story on poly vs. air bumps:
interesting indeed. does he run bypass shocks? does he run small hard ones <2" or big squishy rubber/poly ones >4"? just curious because it seems like a big soft rubber one will break apart quicker in a full race setup than a smaller denser one.

there is a guy on DR selling fox 4" bumps for $50 each right now...

Re: Poly bumps

Posted: Mon Dec 14, 2009 9:54 pm
by Polarcub
I think people miss the point of air bumps sometimes. They are not needed in every application as has been pointed out. I will use my bronco as an example. Before I moved the shocks over the springs there was no need for air bumps. The suspension cycled to the stock bumps and the amount of dampening they provided was adequate. Now though I am running a 12" bypass that by virute of positioning allows the axle housing to hit the bumps much easier than before. The bypasses while need to be revlaved I do not feel will be capable of really controlling the final 2 inches of up travel as well as a air bump will. I have extended the bumps and they work much better.
I like air bumps but for the cost most of us can use well placed rubber/poly with results that are as good or better than those achieved with a bump.
Nick many different poly bumps are available and as long as the material is of quality and placement is correct you cant go wrong. I know Energy puts out several versions as well. Good post!!!

Re: Poly bumps

Posted: Mon Dec 14, 2009 10:26 pm
by toddz69
Nick wrote:Ok, i'm researching poly bumps for my build. I know that some will say that the stockers will work, but i'd like to go a step above those. Air bumps aren't really in the budget for now, so what else can i do without breaking the bank?

BajaChris, i know that your Dad said you run the nissan bumps, can you share any info on them? Part#'s, how they perform, how long they last?
Attached are a shot of the Nissan bumps on the rear of my EB. Pathfinders started in '86? and they started using them from the intro up into the '90s sometime. Scads of them in the junkyards - cheap and easy to find in good condition.

Todd Z.

Re: Poly bumps

Posted: Mon Dec 14, 2009 10:30 pm
by baja-chris
Those are the ones I use on the rear of my bronco. They work great and are holding up under heavy use.

Re: Poly bumps

Posted: Mon Dec 14, 2009 10:56 pm
by Nick
I was going to make some comments on air bumps, but i'll save it for another thread.

Those nissan bumps look like they'll do the job nicely! Thanks all.

Re: Poly bumps

Posted: Mon Dec 14, 2009 11:32 pm
by Rednek Renegade
Good info, I think i have one of those nissans outback. Gonna need those bumps for my axle swap!

Re: Poly bumps

Posted: Tue Dec 15, 2009 9:43 am
by Polarcub
I think those would be a good choice.

Re: Poly bumps

Posted: Tue Dec 15, 2009 9:56 am
by tcm glx
Here is an exaple of one from Energy that bolts right up, and they run about 38 bucks on ebay

Image

Re: Poly bumps

Posted: Tue Dec 15, 2009 10:33 am
by ntsqd
What is your experience with those?
What I've frequently seen is that the plate stays with the vehicle, but the urethane goes MIA when they start getting worked hard. I've not used them though, just my observation. I have used the Nissan parts fairly hard and am impressed with them.