Sean's Coilover Conversion

Sean, great to see progress! I bet the old girl has felt a little neglected lately due to the new addition to the family.........This should cheer her up!

I had to do a "double take" as it's been some time since you have posted a topic regarding the RS [:u]

Your quest is almost at an end - adjustable spring seats on the way so now you just need to find that illusive mint RS bonnet

Next step was to make up some gussets for the struts... these were made from 3mm mild steel plate. The following pic shows two of the gussets along with a threaded tube ready for welding to the strut.



Here is a pic of the complete coilover kit to be used (courtesy of SPEAD Design)




Before fitting threaded tubes I had to deterimne at what height they should be welded to the strut tubes. I wanted to maintain my current ride height but also have equal amounts of adjustment both up and down so it was fairly crucial the threaded tubes be in just the right place. Whilst the old struts were still in the car I measured their length from underside of guard down to the stub axle so I knew this was the dimension I had to maintain for the new struts. Using an estimated figure of 250kgs to each front corner of the car I calculated how much the new 250lb coils would compress. The coils would compress at a linear rate of 1 inch for every 250lb's applied. 250kgs = 551lb's, so therefore the springs would each compress a total of 2.2 inches (56mm) under the dead load of the car. I also cross checked the calculations against the old 200lb coils which were in the car to see if their compressed length correlated with the formula. It seemed the old springs were compressing a little more than what the formula suggested, but I just put that down to sag over time. So, taking all the new components into consideration and using the calculated compression of new springs I was able to determine exactly where on the strut tubes the spring seats should sit. This in turn allowed me to determine where the threaded tubes had to be positioned on the strut tubes. I drew the following diagram to help me get my head around the calculations, showing both old and new setups...




Once the threaded tube location was determined it was time for welding them to the struts. Phil kindly welded both the threaded tubes and the gusset plates to the struts for me. Once these bits were welded in place I tidied the struts up ready for painting by grinding down some of the welds slightly and using body filler to smooth out the transitions between the welds and strut tubes (I should point out that this is not an indication of poor welding but rather me being pedantic about that 'show car' finish). Below is a pic of the struts ready for primer.




That's all for tonight... more updates to follow...

Good thread Sean, I'll be watching keenly as my coil-overs are made up for the rally car but just have to weld them together now.

Lot's of calculations being done, good to be comprehensive.

Timmeh

Strut legs, hubs and steering arms are now in primer...





New wheel studs have also arrived and seem to be a good fit. Hopefully they don't turn once I start tightening wheel nuts.




Also, whilst at the garage tour of BrakeSmart in Wollongong I had some braided brake lines made up to replace the cruddy old rubber lines...

They look great Sean,did you end up having to sand blast the hubs or did you just rub them back by hand[?]

quote:

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Originally posted by Phil
[br]They look great Sean,did you end up having to sand blast the hubs or did you just rub them back by hand[?]

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I just cleaned the hubs using the old wire brush on electric drill routine

"They" tell you 3-4 weeks...but realty is 6-8 weeks.