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Bilsteins appropriate for ~200lb/in springs?


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I'm looking to do a ground control style coilover setup in the near future. I'm having a difficult time choosing dampers. I'd like to run springs in the 200-220 lb/in range. The car will be used for some autocross and track days, but mostly street driving.

 

I'm absolutely alright with sectioning the struts and other fabrication, I currently have access to a full machine shop after work and welding stuff at home.

 

I've been considering the bilstein's used in the sticky(mk1 rabbit, correct?), illuminas, or tokico blues.

 

I'm really not sure how these different dampers will behave with these springs and my intended uses, I'd appreciate any advice.

Edited by letitsnow
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The strut thread has about 14 conversations, no clear topic or direction, but reading through it several times, it seems like most guys are running revalved bilsteins with 300-350lb/in springs on dedicated racecars. I've not found a useful dyno chart of the factory valving, I found one, but the velocity increments are pretty huge. I can't find a single dyno for an illumina (full length or sectioned).

 

There was a comparison of various civic shocks posted in that thread, it appears that the bilsteins(for a civic) are very similar to single adjustable konis on 2. Are these valvings even remotely similar to a Z?

 

I might just go with the mr2 illuminas and sectioned struts if nobody has any input on using the factory valved bilsteins. They are known to work pretty well already.

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I wouldn't try to use Bilsteins off of a different car compare with the Z struts. I would think that the stock valving would do great with 200 in/lb springs. The revalve that everyone is getting isn't changing things a whole lot. Specs are in that thread, but I seem to remember the stock valving was something like 72/256, and the revalve is 100/300.

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Yeah, those numbers sound pretty close to what I've found elsewhere. This is some dyno data I found, the pic is huge. The revalve is 100/300.post-3420-037900300 1305413586_thumb.jpgpost-3420-046403800 1305414539_thumb.jpg

 

My main worry is that I'd be over damping the 200lb springs to the point of unnecessary harshness or packing down over bumpy sections of road.

 

I doubt I'd be able to do anything useful with the adjustability of the tokicos, my time would be better spent learning to drive instead of fiddling with everything. :lol:

Edited by letitsnow
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I don't mean to continually bump my thread, but I've been doing a LOT of reading and new questions are coming to mind.

 

I did a little research on the original application, the common not-retarded-low aftermarket mk1 springs are in the 150-250lb range, which gives me another data point on how these should work for me.

 

The linear valving does make me wonder how they will ride, has anyone other than JustinOlsen used the 3000gt 36mm piston inserts? Did he ever get them fully installed even?

 

I don't really want to revalve, but does anyone have any experience with the 'slightly digressive' 30mm piston?

Edited by letitsnow
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I believe its the first one you describe.

 

I put them together left-to-right as they are in this picture:

step30-installation-order.jpg

So its drill bushing, then the coil over top slides over that, then thrust washer (is sitting on top of the coil over top in that picture), another washer, bearing, washer. I may have added more washers until the coil over top clears the strut top.

 

Does that help or hinder?

 

Dave

Edited by thehelix112
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I'm sorry dude, I don't know off the top of my head. I didn't keep very good (any) records of what I did beyond what's in that article, but I think I was shooting for a 1.5-2" drop in static ride height. The static height controlled by the length of the shock insert (Bilstein) and the amount of pre-load applied to the spring. So even if you got it back up close to where it was you might need a fair bit of preload on the spring to do it. Least I think that's correct.

 

Dave

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I'll have to do some measuring when I get it apart then, I'd like to go 1-1.5" lower in the back and 2-2.5" in the front. I'm pretty sure my front is sitting much higher now that I got rid of the massive bumper.

 

 

I've started to get some parts in and I'm looking at the front steering bearing. Why did you go with the small torrington bearing instead of the factory bearing?

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I think the std bearing's ID was too big so the coil over top was actually sitting inside of it, putting all the weight on the corner of the bearing and a single point of soft alu in the coil over top. It's also very tall, and there is limited thread engagement of the shock insert into the strut top, and I wanted enough that the lock nut would at least hook a little bit.

 

Dave

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It looks like the drill bushing clamps the bearing together. IMO, the bearing should not be clamped by the shaft, that will bind the bearing and make it not much better than a spacer. The bearing should float with the spring hat and only see load from the spring, that is how the factory did it with the big ball bearing.

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