I’m almost wondering if this should be on the dragrace/autox forum, since it seems like everyone over there has done it.

Anyway, what I’m wondering what you guys are doing, how much of the metal you’re cutting out and mostly, are you replacing the bumpstops with something else or mounting bump stops somewhere else?

 

You prob seen my pic's already.

I cut the complete hump area out. And planed to plate it in. and just do a bump stop setup on a adj. bolt.

Do you need to do something for the 18x?? Rims?

 

 

Factory bump stops removed for ride height clearance, not tire width clearance. I use Koni shaft style progressive bumpstops.

 

Dean, Do you have any pic's of yours? Can't say Ive heard of progressive style bumpstops.

N/M Im gonna guess they are like the bumpstops I have on the front shafts of my coilovers. just for the rear also.

 

They are hidden up under the dust sleeve. I would have to pull them off to get a pic. Koni sells two diffent shaft bumpstops, these are the taller ones. The first set I got I slit and then zip tied under there but to my assumption they did snap the zips and moved. The next set I had to disassemble the ceimped fit upper mount bushing cup so I could slip them onto the shaft like they were intended- I'll admit, my first attempt of slitting them was stupid and I knew this going into it but was lazy and in a hurry to get the car ready for a challange race the next day. They work great in conjunction with my softer starting progresssve rate springs I run. If I recall I have about 1 1/8" free travel then they begin contact-progrssively. Remeber, that is 1 1/8" at the shock, not the tire so the axle can stll articulate laetrally more than that but will not compress mor than that both side together on a large bump. Here are the squish rates on the 2 5/8" tall Koni stops-
1/8 30
1/4 45
3/8 60
1/2 70
5/8 85
3/4 100
7/8 110
1" 145
1 1/8 195
Next is the factory rear which is 2 5/8" tall
1/8 45
1/4 65
3/8 95
1/2 125
5/8 150
3/4 200
7/8 280

 

Well, it wouldn’t hurt to post or link them again… if you don’t mind… but yea, I think I have.

Sounds like Stephen’s setup, which is probably the best known pic on this board.

Where are you running the bump stop on an adjustable bolt? Contacting what? Maybe I haven’t seen all your pics…

As they sit right now I don’t think I need to do anything, the closest spot is the front inner wheel well and I suspect that’s mostly because of the taller tire height (26.x” tall), just like most drag tires need to be clearanced. But the 295’s on 10.5” rims are _very_ close to the bump stops, I don’t think that I could fit an 11” rim or a 305wide tire on there with the same offset without hitting them.

Rigth now this is just a simple “while I have the back half of the car apart doing body work it’s a good time to do this without making a mess of things in the future” and that I’m thinking that eventually I’ll run narrower spacers in the back to tuck the wheels in further and then it will probably make a difference. I know that my formula with the 275/50/15 DR’s on the back (I’ve posted pics of that all over the board), would need it if I was going to drive it around like that since the bulge in the tires would hang up on the bump stops if I jacked the car.

 

I thought someone here tried those…

Koni lists 10 pn’s , ranging from 10mm to 55mm tall, any idea which ones or what the pn was, hell, I’ll attach a pic of their chart.


Was this over koni yellows or something else?

As a side note I find it very curious that you seem to like progressive rate springs on a serious handling setup, what rates are you running? I’m assuming this is with the lowered PHR?

 

I have the 70.34.53.000.0 55mm tall soft progressive (its about 2 3/8" tall and whitish in color) The dampers are in fact Koni Yellows- standard over the counter valving and on the 3rd firmist (of 4) rebound setting on the rear and maxed out rebound setting on front

I am a big fan of heavy front springs/ light front bar and light rear springs /heavy rear bar for the most part- I taylor from there.

Why i am fond of prgressive rear springs? They do not unload as much under braking yet increase enough when set to level a balanced steady state in the corner.
You get a good articulation but then becomes more ridgid when finally set which helps promote my roll underster geometry.

I do not even have the rates of these springs. I believe they are vry old SSS springs I had lying around off of god know what othercar in our family it came off of- We have so many performance cars its too much to list-(I have 5 brothers and a father all into racing over the years). Anyways, I do remember these were the 3rd set of spring combos I tried on this car years back and I was very pleased with the results. I would guess they stated life as a 135-240 range 5" pigtail and then I trimed a few coils off the lighter progressive side to the desired ride hieght- They are "quasi-progressive rate springs" I would guess them to be around 160-240 range and my frionts are in excess of 800lbs I have posted many times as I am sure you have read. I do have a solid 34mm front bar and a massive 25mm solid rear bar ans yess the rear roll center is lowered about 2". Getting into the bumpstop further increases the rate rapidly when set very hard into a compession bank turn. It also allows me to take passenger weight in the back of the car without grounding out or being too soft for the added weight. It serves such great purposes and gives a great ride quality whether empty or loaded.

 

Stephen, I just noticed something that I never noticed before… that pic is of a 4th gen… anyone have similar pics of a third gen?

 

Thanks, were they much hassle to get the ends apart to get the bump stops over them?

Anyone else have any ideas/answers? TPI383, do you have any pictures or better descriptions of your “bump stops on a stick?” (I don’t know if anyone will get the reference about a jalapeño on a stick…)

 

Jeff Dunham (sp?) and Peanut. I have seen him 3 different times years ago at the old Laughstop that was in Newport Beach, Ca. He was Johnny Carsons favorite comedian.

I had to put a slight grind on the pinch tabs of the shaft to get the bushing washer off, was not that bad from what I recall. I was stupid not to jsut dothat the first time but was more in a hurry getting the whole car ready. Cost me twice for new bushings the second time since I slit the first ones to get them on.

The car was dialed a few years back, but I have made a few changes here and there in weight reductions and such and the back is sitting a little higher than before so I am not feeling the suspension at optimum feel when in it by myself. It fels great when I have my wife as pansenger and my 15yr old daughter in the backseat @ about 100 lbs and the rear sits back down where these stops are more utilized and firms the back like it used to sit how it did with just me in it. I need to do some work on this car since I just drove it for the first time 'by myself' in probably 6 months and did not like the slight push
it has. I mainly drive this car about 2-4 times a month and always with the family in it and it drives great with the extra weight load and the cursing speeds we do- no push fell at all. Cars of this magnitude also change and require maintianace to keeps things at optimum settings.

Plus, I have made the comment on many posts recently about how I just hate thes tires that I put on it just shy of 2 years ago. I hate even touching this car till the wife burns these tires up and I go back to something good- then I will reset this car back to optimum.

 

jalapeno on a stick.. AWESOME comedian.

No I don't have any pic's It was on the vert that got cut to pieces and went off to the scrap yard. I'll see if I can dig anything out. ISoon as weather turns to the good side Im cutting these wheel wells out and puting the tubs in. So I'll deff. take good pic's again

 

Has anyone tried running koni bump stops on the front? I switched to some spherical bearing camber plates on the front, and every now then I manage to find a pot hole bad enough to cause metal on metal. 55mm stops seem way too thick for the front though. I just want to prevent metal on metal. Thanks