280zx Front Struts

[bluesbrother30]

Apologize if I missed something already posted....

I have come to own a barn find 510 ITC race car that I am doing some upgrades on for possible vintage racing. I just bought a set of 280zx struts from a wrecker in the bay area. I also bought a set of Ermish coil over threaded sleeves, lock rings and 8 inch, .250 diameter, 275 pound springs, all new, off a guy on CL. Do I need to modify the overall length of the stock 280zx strut? I see my friends race 510 has what looks to be one inch alloy spacers that are bolted (sandwiched) into the struts on his car near the bottom of his 280 struts. Also heard that a reasonably priced insert is a single adjustable KONI. Comments??

Mike

Sacramento, Ca

[okayfine]

Strut length depends on insert used, unless the insert is just slightly shorter and you want to space it internally. The lower you want your ride height, the more you have to think about a shorter insert and, hence, shortening the strut tube.

[Dave Patten]

I've used Koni 8610 (single adjust) inserts in 200SX and 510 struts. I believe the tube ID is the same on the 280ZX, but you should check.

It requires sanding the paint off the cartridge to allow them to slide into the tube.

And is the tube has been cut/re-welded it has to be perfectly aligned and zero weld protruding into the ID.

[JordanTr]

I ran stock length ZX struts/inserts on my first round of coilovers and it was miserable since I'd hit the bumpstops a lot. Choose your ride height desire and let that decide whether or not you want short inserts (ala mr2, rabbit or others).

This is a pic of ride height for reference. Shortened S12V6 struts for mr2 inserts.

[Dave Patten]

JordanTR hits the nail right on the head.

Let the ride height and wheel/tire combo set the strut tube length. You will want a 50/50 split on bump/droop travel and remember to take into account the bump stop.

2.5" of bump stop doesn't leave much travel room, opt for shorter ones. I've use 2 - 1/4" thick rubber washers on my racecar, but make sure the stop, when fully compressed doesn't allow the strut to bottom internally, that will destroy it.

[bertvorgon]

I will reiterate what Dave said, and, you just never want the suspension to bottom out, as that can give sudden and instantaneous loss of traction and control.
In an ideal world, getting 2.750" to 3" of travel up front is what is required, and that is with a fairly firm spring, so you do not blow through that travel.

I run a small rubber washer as my final bump on the shock tube, about 3/8" thick approx.