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Title: How to measure exhaust springs? Post by: Blue on June 11, 2013, 06:57:30 PM I picked up a set of high mount exhausts for my 2000 M900ie. The cans are held to the mid-pipes with two springs, one top and one bottom. The pipes came with 3 of 4 springs and I need to know how they are measured in order to order another spring. Are they measure from coil to coil (~51mm) or from hook to hook (~80mm). Thanks for the help. [thumbsup]
Title: Re: How to measure exhaust springs? Post by: ducpainter on June 12, 2013, 01:31:21 AM Inside of hook to inside of hook.
Title: Re: How to measure exhaust springs? Post by: Blue on June 12, 2013, 06:14:08 AM Inside of hook to inside of hook. Thanks!Now, I might be dwelling on this too much but measuring the used spring as stated above came back at 78mm. I found springs at 75mm and 80mm. Should I assume that the spring has stretched and was originally 75mm? Also, the spring gap from exhaust to midpipe is ~95mm top and bottom if this helps to determine the spring length. Is there a rule for this? Thanks again. [thumbsup] Title: Re: How to measure exhaust springs? Post by: ducpainter on June 12, 2013, 08:44:24 AM I wouldn't assume that the spring has stretched. Chances are that's the length they were made.
The only 'guideline' I know of is you want the installed length not more than 20% more than the free length. If you do the math 78 mm is 18%, 75 is 22%, and 80 is 16%. I think the numbers are close enough you could use either. I think I'd go with the 80mm springs. They'll give you less trouble installing. Title: Re: How to measure exhaust springs? Post by: Blue on June 12, 2013, 12:34:39 PM I wouldn't assume that the spring has stretched. Chances are that's the length they were made. The only 'guideline' I know of is you want the installed length not more than 20% more than the free length. If you do the math 78 mm is 18%, 75 is 22%, and 80 is 16%. I think the numbers are close enough you could use either. I think I'd go with the 80mm springs. They'll give you less trouble installing. Thanks for the help; I will get the springs ordered soon. I will be going for the 80mm springs. |