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NC Spring Perch Installation

Posted: Tue Mar 19, 2013 6:30 pm
by skeeler
Brian,

I'm interested in your delrin spring perches for the rear of the NC:

http://www.good-win-racing.com/Mazda-Pe ... -0197.html

Can you explain more what you mean by this?
INSTALL NOTES, you need about 3/8th spacer to get the shock more straight so it won't rub the Delrin adapter (and 5mm longer bolt). Depending on the coilover you may also need to look at the sleeve that slides into the bottom of the shock (on our Ohlins the provided sleeve is sufficient).
Where do the 3/8-inch space and longer bolt go? Also, a friend who did his own conversion a couple of years ago told me that the lower top hat lip surrounding the mount for the stock spring is tilted. He had the top hat machined flat in order to fit his adapter. Is that necessary with your adapter?

Thank you for your help.

Re: NC Spring Perch Installation

Posted: Tue Mar 19, 2013 9:34 pm
by Brian
We don't machine anything to use the adapter....we just put it in.

The spacer goes between bottom shock and it's connection to the car (and you need longer bolt as result). The stock shock is traveling in an arc, that's why the stock spring is high clearance 'bee hive' shape. Thus, to convert to standard spring you are moving out bottom connection so shock travels normal straight up and down.

Re: NC Spring Perch Installation

Posted: Wed Mar 20, 2013 6:56 am
by skeeler
Brian,

Thanks for the prompt reply. Looking under my car, I understand what you mean. I have a few of follow-up questions, if you don't mind:
  • You say the delrin adapter works with 65- and 70-mm springs. I assume it is machined to work with 65-mm springs, and there's 2.5 mm of slop on each side when used with 70-mm springs. Is that correct?
  • On a related note, is your helper-spring adapter for the bottom designed the same way, to work with both 65-and 70-mm springs?
  • Do you recall the diameter, pitch, and length of the required longer screw? Similarly, what ID and OD are required for the 3/8-inch spacer?
Thanks again.

Re: NC Spring Perch Installation

Posted: Wed Mar 20, 2013 7:03 am
by Brian
I don't recall the spec on the bolt, just pull and match it up with longer version. Yes, Delrin part milled for 65mm but we usually use 70mm because you need less spacer that way. As the picture suggests, the spacer was designed for use up front with 65mm springs.

Re: NC Spring Perch Installation

Posted: Wed Mar 20, 2013 7:22 am
by skeeler
OK, Brian. Thanks for your reply. You have the spring rate I'm interested in from Swift, so that would make for 1-stop shopping for me.

Re: NC Spring Perch Installation

Posted: Tue May 28, 2013 5:06 pm
by Auto-x-er
Brian,

Just to be clear is this what you are talking about?
Image

The washers I found were about .110" each so 3 is a bit under 3/8" and 4 would be a lot over. Which is better to get the shock behaving with the spacer?

Re: NC Spring Perch Installation

Posted: Wed May 29, 2013 9:02 pm
by Brian
Looks good. Just keep an eye on things, inspect after a few days of use just to made sure spring is not scrubbing the shock. Remember to use a bolt that is longer by amount the same amount as spacer you used.

Re: NC Spring Perch Installation

Posted: Thu May 30, 2013 7:20 pm
by Auto-x-er
Yes, I picked up a longer bolt to get good thread engagement. It looks pretty close when I was moving it up and down with the floor jack, but seemed to not rub. You can see that even with the spacer the shock moves to the outside as it goes up.

Re: NC Spring Perch Installation

Posted: Thu May 30, 2013 7:34 pm
by skeeler
Do you know the thread size and length of the stock bolt?

Re: NC Spring Perch Installation

Posted: Thu May 30, 2013 7:52 pm
by Brian
Sorry...I don't recall. Pull and measure the bolt you have and add the length of your spacers.