Poly bumps

[SteveG]

I've never used poly bump stops but have seen the same thing you described. A friend of mine used to call them his full-bump indicators. He said from behind the wheel he could never tell that the front end had bottomed but could tell when it had because the poly part of the bump stop would be gone.

The rubber and foam bumps are a lot more progressive, too.

[philofab]

Anyone have experience with the Light racing jounce bumpers? The look to be a hydraulic stop but I've heard they work better. The story I heard is the new Chevy Border Patrol trucks have them installed but they work so well the guys are twisting the frame in a way that causes the engine to fall out in the front!

[PBR]

if anyone is heading to a junk yard i would be interested in a few pairs of those nissan bumps.

[baja-chris]

Anyone have experience with the Light racing jounce bumpers? The look to be a hydraulic stop but I've heard they work better. The story I heard is the new Chevy Border Patrol trucks have them installed but they work so well the guys are twisting the frame in a way that causes the engine to fall out in the front!

I have Light Racing jounce bumpers on my wifes stock 04 Tahoe. They work very well but too expensive. I suggest a set of the old nissan pathfinder bumps from the junk yard. Almost as good and way cheaper.

[magic carpet XLT]

as far as destroying bumpstops goes, here are my thoughts:

the nissans are rubber bonded to metal, similar to the energy suspension et al haven't heard of someone destroying a nissan one yet, but i'm sure it happens.
the S10 blazer bumps are rubber that presses into a cup, as the bump compresses it fits tighter into the cup and is much harder to knock out. in the event that it does get trashed, the cup should be ok and replacing is as simple as popping the new bump in. i keep a couple in my truck box as spares (along with all the other spare shit that now lives in the bronco) but the only damage they have shown in 2 years of abuse is some scuffing from rubbing on u bolts.

i will keep an eye out for some nissan bumps ollie, nick already called dibs on the set i have now. i should be heading to the yard in the next week or so and i always find at least one pair for ~$20 (the blazer ones fit in my ammo can tool box and i can usually smuggle those out for free...)

[unreng]

Just wanted to add a couple different stops that are smaller versions of the pathfinder/blazer stop.

From left to right: mid 90's 4-runner, early 2000's blazer, early 2000's?!? Isuzu Trooper/Rodeo:

[Dust]

Great thread!
Bumps I have been wondering about...
Decades ago when I build a 79 Bronco to run fast I rather quickly hammered out the OE front bump replaced with the taller Energy one, then blew that off the plate. Because at the time I was working Tool & Die & we used Polyurethane as stripper springs and forming blocks I made the set of bumps that did the trick. They ended up being so progressive and on the front the lack of rebound damping was unnoticeable due to weight, and not being a racer. In the rear I tuned a bunch more to get the kick out due to the lack of damping.
Ok, there is my experience but that was Solid axles & WhiteCan shocks, will/is the TTB chassis going to react the same way?
"If so" I am thinking about a set of the Daystars in front (Clean, small package, semi tunable) and finding a used set of (or FOA) 'real' bumps in the rear.
My reasoning is as a play truck with all the compromises that brings; this compromise is...

[shockseals.com]

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!

What was failed to be mentioned was the significant shock tuning changes I made to the jeep to make it faster than before and fatigue the driver less....it wasnt as simple as replacing hyd bumps with ranger factory bumpstops! I spent sometime with that thing and its fast and comfortable. The first time they had to take them off was at the start line at primm last year and they just cranked the tubes and had to drive slow so as not to run the diff into the oil pan and they still won the race...since then all the complaining from other team only made the jeep even faster.

[shockseals.com]

I wouldnt use poly bumps for anything other than temporary (im using htem now for temp). Closed cell foam or rubber. Closed cell foam is best since it doesnt rebound like rubber does but rubber is most durable.

[Dust]

I wouldnt use poly bumps for anything other than temporary (im using htem now for temp). Closed cell foam or rubber. Closed cell foam is best since it doesnt rebound like rubber does but rubber is most durable.

Ok, is this a blanket statement, or one that has a budget attached to it.
I'm a recreational speed freak. I'll admit that I ain't going racing (if you want to pay me that is another story and I'm likely to say no) and if I was I would add maybe 30" to the WB so definitely not C3.
I will also probably never go back to Mexico, in-deed I will likely not venture south of my border for a race.
So my question is where does the budget come in to play? "In Your Opinion?"
I am being serious, and not looking for confrontation, only illumination.

[ntsqd]

Keep in mind that the polyurethane die springs that you used are a whole different class of product from the polyurethane bump-stops sold to the masses. The latter are no where near is good of product as the former and seem to be targeted at the guy who wants his bump-stops to match the color of his shock boots, but won't actually use them.

I'll go out on limb, but it is to these latter products that I believe Kris is referring to.

What you used are actually much closer to the closed cell foam bump-stops found on some late models. GM's in particular, that I know about.

BTW, Hi Kris!

[Broncodawg]

Don't want to beat a dead horse, but since the Primm race, who's been complaining about the ATK jeep's class 3 legality? Those complaining prior to that did so because the Score class 3 rules clearly state that no frame mods are allowed and in frame bumps violates that. Savage confirmed that and made a call at Primm, but haven't heard any bagging on him for it?
John and Clive answered the remaining concerns about the jeeps wheel base and track width after Primm, so it's all good now as I see it. Sorry about any animosity in my posts since then.
You guys built one hell of a racer and have raised the bar in class 3, so like to ask if we can't put this to bed and enjoy some good racing. Congrats on your Jeepspeed Cup victory at the Mint.

Thanks for letting me steal this thread for a bit, now back to our programming that is already in progress.

Greg

[Dust]

Keep in mind that the polyurethane die springs that you used are a whole different class of product from the polyurethane bump-stops sold to the masses. The latter are no where near is good of product as the former and seem to be targeted at the guy who wants his bump-stops to match the color of his shock boots, but won't actually use them.

I'll go out on limb, but it is to these latter products that I believe Kris is referring to.

What you used are actually much closer to the closed cell foam bump-stops found on some late models. GM's in particular, that I know about.

BTW, Hi Kris!

It is true that there is poly and there is poly.

[shockseals.com]

I wouldnt use poly bumps for anything other than temporary (im using htem now for temp). Closed cell foam or rubber. Closed cell foam is best since it doesnt rebound like rubber does but rubber is most durable.

Ok, is this a blanket statement, or one that has a budget attached to it.
I'm a recreational speed freak. I'll admit that I ain't going racing (if you want to pay me that is another story and I'm likely to say no) and if I was I would add maybe 30" to the WB so definitely not C3.
I will also probably never go back to Mexico, in-deed I will likely not venture south of my border for a race.
So my question is where does the budget come in to play? "In Your Opinion?"
I am being serious, and not looking for confrontation, only illumination.

Blanket statement for vehicles that are going to be "used" offroad.

[shockseals.com]

Keep in mind that the polyurethane die springs that you used are a whole different class of product from the polyurethane bump-stops sold to the masses. The latter are no where near is good of product as the former and seem to be targeted at the guy who wants his bump-stops to match the color of his shock boots, but won't actually use them.

I'll go out on limb, but it is to these latter products that I believe Kris is referring to.

What you used are actually much closer to the closed cell foam bump-stops found on some late models. GM's in particular, that I know about.

BTW, Hi Kris!

There are tons of different blends/brands/qualities of poly. Open cell poly from BASF is nice and a few places use it but its expensive becuase cure time is 24 hours.

Polyurethane in general doesnt like unsupported compression as it squirts for lack of better term and when it squirts it goes into tension and break/rips/fails.

[shockseals.com]

It is true that there is poly and there is poly.

Yes...but we are talking the 70 or 90 durometer standard urethane most aftermarket bumps are made of. Not the open cell foam bumps that are a an inexpensive knock off of closed cell bumps as they are a completley different make up.

Factory OEM bumpstops(closed cell foam or rubber) if you arent going hydraulic are the best shit out there...find one that fit your application and run it. The aftermarket stuff is not near as good.

An OEM Chevy HD front lower arm bump might make for a really nice TTB bump, but the TTB stock bump is pretty good and only $5 so its hard to beat.

[shockseals.com]

Don't want to beat a dead horse, but since the Primm race, who's been complaining about the ATK jeep's class 3 legality? Those complaining prior to that did so because the Score class 3 rules clearly state that no frame mods are allowed and in frame bumps violates that. Savage confirmed that and made a call at Primm, but haven't heard any bagging on him for it?
John and Clive answered the remaining concerns about the jeeps wheel base and track width after Primm, so it's all good now as I see it. Sorry about any animosity in my posts since then.
You guys built one hell of a racer and have raised the bar in class 3, so like to ask if we can't put this to bed and enjoy some good racing. Congrats on your Jeepspeed Cup victory at the Mint.

Thanks for letting me steal this thread for a bit, now back to our programming that is already in progress.

Greg

Thanks for the congrats!

Nobody protests something unless they feel its an advantage...Savage was just doing his job based on the protest, had nobody protested he wouldnt have said a thing just like he didnt when he tagged it. There is no animosity considering the jeep is faster now than it was then.

There is no animosity here. I dont know you guys I just know the story and find humor in the outcome of the truck being faster now.

[Dust]

I wouldnt use poly bumps for anything other than temporary (im using htem now for temp). Closed cell foam or rubber. Closed cell foam is best since it doesnt rebound like rubber does but rubber is most durable.

Ok, is this a blanket statement, or one that has a budget attached to it.
I'm a recreational speed freak. I'll admit that I ain't going racing (if you want to pay me that is another story and I'm likely to say no) and if I was I would add maybe 30" to the WB so definitely not C3.
I will also probably never go back to Mexico, in-deed I will likely not venture south of my border for a race.
So my question is where does the budget come in to play? "In Your Opinion?"
I am being serious, and not looking for confrontation, only illumination.

Blanket statement for vehicles that are going to be "used" offroad.

Cool, so all I am left with is figuring out if I will use this Bronco.
"Off Road" is easy as I can almost do that out the front door; though today it would be in the fresh snow that is coming down.

[Dust]

http://www.timbren.com/aeon-rubber-springs.htm

[philofab]

http://www.timbren.com/aeon-rubber-springs.htm

Those work really well on trucks with heavy loads but I have no idea how well they would work in our application. They are not cheap either.