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View Full Version : Quick ?/thought on Bump stops.



HuckleberryB4
08-25-2014, 02:17 PM
Say you're using a 3" Christmas tree style with and you're using the first inch to gain rate. Let's say that inch equals 200 lbs of rate gained. Now we cut off the top 1/2" BUT use shims to make up the 1/2" we just lost, so the bump is being engaged at the exact same travel. Will that inch now equal the same 200 lbs or will it be more? My guess is that it will equal more, since you are using more of the bulk of the bump?????

MasterSbilt_Racer
08-25-2014, 06:53 PM
Say you're using a 3" Christmas tree style with and you're using the first inch to gain rate. Let's say that inch equals 200 lbs of rate gained. Now we cut off the top 1/2" BUT use shims to make up the 1/2" we just lost, so the bump is being engaged at the exact same travel. Will that inch now equal the same 200 lbs or will it be more? My guess is that it will equal more, since you are using more of the bulk of the bump?????

You stiffened the bump just like you stiffen a spring when you cut coils off it.

HuckleberryB4
08-26-2014, 09:17 AM
Just as I thought. Thanks Mastersbilt!

hucktyson
08-26-2014, 09:27 AM
It also makes the point where the rate shoots off the chart a 1/2"sooner , and if that half inch puts it in the operating range on the race track it will push the right front when you hit that point.

HuckleberryB4
08-26-2014, 10:01 AM
Had that happen and definitely need to keep it in mind. But I think I might be able to make it a bump more tunable with the use of a travel indicator.

MasterSbilt_Racer
08-26-2014, 11:59 AM
Had that happen and definitely need to keep it in mind. But I think I might be able to make it a bump more tunable with the use of a travel indicator.

An indicator, the amount of load typical on your RF spring at mid-corner, and a force vs travel graph of your setup are all very useful.

hucktyson
08-26-2014, 12:46 PM
The issue with an indicator is the it only records max travel which could have happened only once when it hit a bump. To be accurate with that you would almost have to have a go pro camera on it to see where it runs on average. Or you can do like Kevin Rumley and BGR and have linear potentiometers on the corners and 5th coil and feed the real time data to your lap top via satellite .

FlatTire
08-26-2014, 12:58 PM
huck- I heard BGR was wanting to hire a data acquisition specialist....I gave them your name! :-)

hucktyson
08-26-2014, 01:49 PM
I highly doubt a senior level product design engineer with Lockheed Martin like Brian need any help .... Brian actually invented data acquisition