rebuilding struts.

[97jltanner]

has anyone put strut inserts in stock strut tubes? I really want to build some coilovers and I have done some research and I think that a MR2 insert will fit in the stock tube and will let me go lower with out bottoming out. kind of like what this guy did.

 

In comparison to the koni installation, it is quite a bit more involved. With Konis, you cut the top of the strut off, drill a hole in the bottom, slide the insert in, and secure it with a big bolt that threads into the bottom of the koni insert.
What I did was the same kind of idea, but instead of drilling a hole in the bottom, I converted the struts into fully servicable units. For those who are unfamiliar with servicable struts, when your struts blow, you don't throw your struts out and get new ones, you remove the guts from the strut, and replace it with either factory guts, or an insert made by many many aftermarket companies. So the strut bodies should last the life of the car, but the guts inside can be changed. 
The advantage of converting them to fully servicable units is that you can use a zillion different inserts, as listed above. When you modify your struts the way Koni wants you to, you can only use koni inserts and nothing else.

So what I did was buy a set of four front 1991 MR2 inserts, since the MR2 also came with servicable struts. This is how they looked like when they arrived:

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But to secure them in, instead of using a big bolt on the bottom of the strut, they are held in place using a big gland nut that closes the top of the strut off. But to use the gland nut, the top of the strut body must be threaded to accept gland nuts. Since the LC struts don't have these threads, I used the tops off of 4 AE86 struts, which are also servicable units. Here is the top of an AE86 strut with the threaded inside: 

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Then you put the MR2 insert inside the strut, put the AE86 strut top on the LC strut, and then close it off with the gland nut. This shows just that, LC strut, AE86 top, sealed with an AE86 gland nut, holding the MR2 insert in: 

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Then what you do is you weld them together. Of course, take the insert out before welding or you'll ruin it. I just put it in to line up the tubes straight, put on 4 tack welds to hold it in place, removed the strut, and then welded the tubes:

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At this point, once the tubes are welded together, you have a fully servicable strut! Now you can throw in whatever insert will fit, including the ones listed a couple posts above. I chose Tokico Illumina because it's adjustable and within my budget. If i get bored of the Illuminas, it's a quick fix and really simple to pull the illumina inserts out and throw in something more elaborate like HTS 45-way double adjustables.

So yeah, I would say it is a lot more work than the Koni install. First of all, because you need 4 donor servicable struts to hack up. I had 4 extra AE86 struts that I got from the junkyard for $10 canadian each. It doesn't cost too much if you can do the work yourself. But if might cost a bit if you need a shop to do it. And there are only a select FEW shops who are knowledgable in this type of strut conversion. If you or a friend is handy with a welder, you can do it yourself. 

Also, to take it a step further, you can actually cut off the stock spring perches off the struts, weld on a small perch, and put some coilover sleeves onto the struts. This is the TRUE way that coilover sleeves are supposed to be installed. I would have done that if this was my race car, but it is not. It's my daily driver! I want stock springs!

[Datsunrides]

_{Be sure to measure your strut tubes as the MR2 struts have 2 diameters. Gen 1 MR2 rear has 1 3/4" tubes and gen 2 front are 2".}

[97jltanner]

i just ordered some for a 92 mr2 because the guys in some of the Datsun forms said they were 1 3/4. Have you done this be for or how do you know?

[Datsunrides]

Yes, I have used both for coilover conversions before, just not on a Subaru yet, but a strut is a strut for the most part. The 92' will be a 2" strut. For the 1 3/4", you need to use the gen 1 (86'-87') rear strut if you are shortening. Not a big selection for performance inserts anymore. Last ones I did I used Koni yellows. VW rabbit is another short insert option.

 

Mark