Nb top hat on na

mx589 · Postby **mx589** » Mon Jun 23, 2014 8:46 pm

Hey guys I know this has been covered a million times and I googled and looked and got a lot of people saying nb top hats bolt straight onto na shocks and some saying mods are required.

I have koni na front and rear shocks with king springs.
Will nb top hats just bolt straight on in place of the na top hat?

Some people say it will lower the car 10mm
Other people say 20mm?

Any help will be appreciated
Thanks

zossy1 · Postby **zossy1** » Tue Jun 24, 2014 12:55 am

Yes, it is a direct swap and they will fit.

10-20mm is about right. You will lose some droop travel also (staying with NA dampers), so be prepared for that - but you gain an equivalent amount of bump travel of course.

EDIT: minor mods may be required depending on the shaft size of the damper. Some dampers, and I think konis are an example, have a larger than OEM shaft diameter so you may need to drill the hat and the bush washer/retainers for them to fit.

mx589 · Postby **mx589** » Tue Jun 24, 2014 2:11 am

thanks for the info zossy1

noobee · Postby **noobee** » Tue Jun 24, 2014 10:21 am

you will need to buy or make an extended shoulder nut for the shock rod similar to the one here.
http://fatcatmotorsports.com/FCM_Koni_p ... .htm#mount
http://fatcatmotorsports.com/igallery/g ... ntents.jpg
easy enough to do if you have access to a lathe or a friend in engineering.
then you will have to find appropriate rubber or polyurethane shock mount bushings.
probably also good to read this too.
http://www.fatcatmotorsports.com/FCM_sh ... shings.pdf
Mick

zossy1 · Postby **zossy1** » Tue Jun 24, 2014 10:58 am

Is the shoulder nut necessary for OEM bushings when doing the swap? I don't remember having to do that with the Bilsteins I swapped over a cpl of years ago, maybe my memory is worse than I thought.

noobee · Postby **noobee** » Tue Jun 24, 2014 11:58 am

some pics of na vs nb skock threads and mounts,and some extended nuts I started making when I had my na6.na shock is the silver one,note the difference in thread and shoulder on the rod.rubbers are stock nb.nuts made from 20mm unbrako bolts.

IMG_20140624_103826.jpg

IMG_20140624_104127.jpg

IMG_20140624_103826.jpg

zossy1 · Postby **zossy1** » Tue Jun 24, 2014 1:01 pm

Well there you go - thanks for the pics, that makes sense for sure. Still wondering why mine fit - maybe they were NB Bilsteins with NA hats?

noobee · Postby **noobee** » Tue Jun 24, 2014 1:56 pm

with na hats on nb shocks you would have a mile of rod hanging out or rattling around.na shocks are a solid bolt to the tophat,that is why the thread is so short.there is a rubber sandwich within the na tophat itself.nb hats if done well appear to be a good improvement for a na.you get a little lower without scraping everywhere,standard length springs,more travel and better behaviour as you hit the bumpstops.
Mick

mx589 · Postby **mx589** » Tue Jun 24, 2014 2:37 pm

I see what youve done with the bolt machined down at the top

noobee · Postby **noobee** » Tue Jun 24, 2014 2:48 pm

yep 20mm x 50mm unbrako 12.9 bolt.not cheap to buy as far as bolts go but we have plenty at work.easy to grab something like this if you have to machine a little widget.

mx589 · Postby **mx589** » Tue Jun 24, 2014 11:01 pm

Got them were I work also so I'm laughing heheh

4sfed5 · Postby **4sfed5** » Mon Jul 14, 2014 8:16 am

what size does it need to machined down to (i'm running konis)

what length bumpstop do you run to stop the shock from bottoming?

i have read about guys using wheel nuts also..anyone used those?