JMortensen

ztrix.com IMSA fenders are wider than the YZ stuff if that sounds appealing to you. I have read that back in the day they ran 16x14 or 16x15s. I have rear flares that were taken off of the molds for Frisselle's car, and they fit my 15x14s like a glove. Always thought the BSRs looked a bit wider, might be where the 16x15s come in...

So you're not using the big ass bolts on the ends of the arms? I recall Jeromio and maybe one or two others had the experience of the bolts coming out and the arm slid back far enough to fall out of the bushing and disconnect itself from the car. I see you've made a cradle to capture both bushings. Lots of force there, just hope it's strong enough.

Looks pretty sweet! Are those Jongbloed wheels? Nice job on the exhaust too. Really tight up against the bottom.

3KGT strut arrived. Here's what I learned. 1. It's short. Really short. The housing and strut totals about 18" before the studs at either end. The internal portion that would fit into the strut tube is about 3.5" shorter than the Mustang strut tube, which is 13.5" deep. So I'd have to weld the plate that the strut bolts to in the Mustang tube 3.5" from the bottom of the tube. My friend said he could have them shipped to me with the end plates loose, but I think it would be a serious PITA to weld the plates in that far up the tiny tube. Don't think I could even do it with my mig. 2. It has less travel. I'm measuring 4.75 to the bumpstop. I'm told the bumpstop is 2" and that looks about right, as that would put the 40mm part of the inverted strut flush with the case. Travel is about the same as the P30 from the VW, but quite a bit shorter than the Mustang. 3. The OD of the Mitsu strut is about 1.807". The ID of the 240 strut is 1.690" according to an old post by John Coffey. Was hoping I might be able to hone out the strut housing. Ain't happening. So now the question is do I get the Mustang struts instead and have the top stud cut down, or do I work with the 3KGT strut? Thinking Mustang strut might be easier, but I have had pretty bad luck with machinists generally speaking. It's nearly always late and more expensive than I was quoted, and I generally hate dealing with them. The one pro here is that I could have the top stud turned down to 5/8 and not have to use bushings like I do with the P30. Suggestions appreciated, although I'm guessing the answer is going to be buying the Mustang parts and machining the studs.

3KGT strut ordered.

Yes, there are similar pistons, shims, etc for the 36mm stuff and he's telling me if I rebuild the Ohlins pistons are better, so apparently from more than one manufacturer. I don't think 36mm is as popular with racers as the 46 which is used on pretty much all circle track stuff, but it's still a lot more available than the 30 stuff, it seems. I did come across one pretty big issue, the Mustang strut has about 4 or 5" of shaft sticking out the top where it goes through the camber plate. Definitely wouldn't clear the hood. Thinking I'm going to buy a tube for the Mustang and buy a strut for the Mitsu and see if I can put them together. If that works, then I might just go for it, buy 4 mitsu struts and revalve, then mod the housings. Also I misunderstood and the tube can't be cut down, but as it works out it's almost exactly the right length. Looks like if I pull the stock tube out of a 240 strut and install his, the tube height from the base of the spindle to the top of the tube will be 14.5" or so. My sectioned P30 was cut to 14.75" so just about dead on. His tubes have 2 bushings inside, one at the top and another one right in line with the piston (which doesn't move up and down relative to the housing), plus a dust seal top and bottom. The one issue is that the rear strut tubes need to be longer so would need to cut the original strut tube and weld together with the new one maybe 2 or 2.5" up, not unlike sectioning the tube. Coffey suggested doing that at the bottom of the tube, but I always did it at the top and thought it was kinda weird to do at the bottom, seems like that's where all the bending load is. Not the biggest problem. If I felt like it wasn't strong enough would be super easy to get a 3 or 4" long section of 2" ID tube and slide it over the top and weld. I'm just about ready to pull out my wallet and make some of this happen. Likely won't be with adjustable struts though. Just revalved. A big problem is the adjusters are on the bottom of the inverted struts, so you'd have to pull the steer knuckles off just to see them, let alone adjusting correctly. Maybe could cut a window in the strut tube, dunno. Sounds sketchy...

I hope you do better than that...

That's essentially what my Mustang engineer friend has done. They made a 2" OD tube that fits a 36mm Bilstein and has bushings in the tube and a seal on top. So gets around all the issues with the 240 strut tube. I need to look at the shock tech post again and verify, but I think they had a gland nut that fit the 280Z, but I don't think it fit the 36mm strut, just the 30mm. If they had a 36mm gland nut could probably use the 3KGT insert and save some money vs the Mustang parts. The problems I see are that the Mustang strut has 7" travel where the Z has 6. He is telling me I can cut down the tubing a ways before I hit anything inside, but I need to make sure I can cut enough so that I get the right amount of bump travel. Also says you can limit droop from inside the tube. I need to have more droop than necessary because I use 2.5" tall spacers to lift the front so that I can get the car on my trailer. Bunch of little things to make sure of, but I think this is sounding like a really good solution.

NA stroker. I can't give any specifics, but Mark Belrose sold his race car with 3.1 stroker to a guy in Oz. Rebello motor with 50mm Mikunis, I think it was making 370 bhp or 390, can't remember. Anyway the new owner wanted more and built it again and was saying 400+ but wasn't an L24. Here's a vid of the car blowing a halfshaft at Bathurst:

LOL. Thanks for posting Bob. That one pops into my head every now and again: "WTF cam did that guy have in that thing anyway?!!?" Apparently it wasn't magic. We have had some people get their 240s down to 1800ish pounds, and engine builders in Australia are pushing 400hp NA, but haven't seen anyone put the two together yet.

I had a lot of runout when I first bolted them up, I shimmed it straight with .002" washers between the hat and rotor. Now there is more runout. One side is straight the other is about .020" out, thinking about cutting the rotor. We talked about that here 10 years ago or so and determined shimming was the right way to do it, but cutting sure seems easier. Shimming was a PITA. And yeah, my friend is able to make a Fox body Mustang legitimately fast, so he's doing something right. Between him and Cary (tube80z) you can get a ton of good info.

Akshully, since you brought it up... Same engineer suggested I ditch my aluminum hubs because he said the hub and bearing expand at different rates and it's pretty common to spin a bearing in the hub at high temps. Most people who buy this all this blingy stuff just drive on the street, but for those of us who really push it it's a different story. I have a completely separate front brake setup with steel hubs and I'm going to get it all prepped and take it with me when I finally do a track day, and I'll be prepared to swap hubs if I have problems at the track.

I think I already said it in this thread, but an old racing buddy and engineer made a point of saying that the straight hole with a thick spacer preferable to a tapered hole stud that uses spacers. It makes sense. The diameter at the large end of the tapered hole is quite a bit smaller than 5/8" so it's only going to get weaker from there. As to the aluminum vs steel, never underestimate the selling points of BILLET aluminum: 1) OMG it's BILLET!!1!!1!! and 2) its legitimately lighter weight.

Can't you put a one way check valve in the line between the scavenge pump and the tank?

I'm going to wait to hear from MCA. Looks like they do an upright monotube. Not my favorite. If that's the case, I'm thinking really hard about these 2" strut tubes for the Mustang. That really seems like it solves a lot of my problems. Should be easy to weld to the 240Z strut housing, fits the 36mm Bilstein, then I can get some revalved and it's been suggested to use Ohlins pistons in the Bilstein strut, as the piston machining is better and the struts are supposed be more consistent. Then it's really down to how much the DA strut tubes and the rest of the parts add. Looks like they're $3K, which I might stretch for, or I might just go with a revalve and then try to resist the temptation to change spring rates, but man, I'd really love to have adjustables and know what the adjustments do, and put the valving I want now in the lower 3rd of the adjustment range. Then I could go a little softer or a lot stiffer. Decisions decisions...

Looks like they also don't invert their struts... hmm.

Koni's road course tuning instructions: https://www.koni-na.com/en-US/NorthAmerica/Racing/Road-Course-Tuning-Guide/ Autox tuning: https://www.koni-na.com/en-US/NorthAmerica/Racing/Autocross-Tuning-Guide/

Koni has some rough guidelines on how to tune shocks but if you're doing it by feel that's subjective and what you like might not be what is best. I prefer to do it by the numbers, and what I'd really like to have is some dyno plots, so that if I changed the spring rate (which I've already done a couple times) I could move to the next closest adjustment. I have a feeling I'll end up with more Bilsteins and they won't be adjustable... Side note - I did talk to a friend of mine who does Mustang stuff and he can get me inverted 36mm struts with a 2" OD tube. It's what they use on old Fox body Mustangs. The stock 240 tube is 2" OD or 51mm which is very close, so might be able to grind off the weld at the base of the knuckle, remove the original tubes, and weld these in their place. They'd probably need to be trimmed to the right length, but it sounds very doable. Problem is struts through them are more expensive and likely not valved right. I have an email in with MCA. I think that's my preferred solution right now. If that doesn't work out I'll probably look at the 3kgt stuff since it's the cheapest. If I can figure out how to install them I'll go that route, and if that doesn't work I'll adapt the Mustang parts.

I've heard of a few people have had issues with the upper bushings in the Konis, and I suspect that there are a lot more who have the issues but don't know it. Cameron aka Heavy85 is the one I can point to off the top of my head. Opinions on shocks are kind of like brakes IMO. You get people who put gigantic brakes on the front of their Z and couple them with rear drum or crappy tiny rear disc and then they report that the car stops so much better, etc. Most people, IMO, don't know what proper brake bias feels like, I say this because I was actually one of these people. I went to a driver's school with my Toy 4x4 setup in front and 280ZX disc and drove through a puddle and slammed on the brakes and the rears didn't lock in water. One of the driving instructors told me that, then I figured out the fronts were way too big, and ended up going back to stock front calipers and I was able to dial in the bias correctly and only then did I know what correct brake bias felt like. I think the same thing is true with shocks, and that there are people racing with worn out strut bushings who just don't know, and the vast majority don't know and couldn't tell you if their shocks were valved anywhere close to correctly. Doesn't mean they're not fast, but being fast doesn't mean that they're right either. Add in the fact that a good shock setup costs so much money, and a cheap ass Chinese coilover is cheap, and I think if you polled Z owners you'd probably find that Chinese coilovers are the best option, Konis are too expensive and they suck because you still have to buy the coilover parts, and the kind of stuff I'm looking at is just stupid because it's either hyper expensive or not adjustable. Aydin, I think the rebound is more important generally, and single adjustables do actually adjust both a little bit. This page might help: https://wilhelmraceworks.com/koni-shock-dynos

After taking a step back, I started thinking about the revalved 3000GT struts. Called Bilstein, they are no longer doing revalves in house. They also don't make 46mm struts anymore, FYI. They said they farm out rebuilds and revalves to Performance Shock Inc, who apparently is at the Sonoma race track. Called them 800-965-5664, they said $320 each for a revalved 3kgt shock, and if I sent them my graph, they could try to hit those numbers. I asked about revalving the P30s too, and Bilstein did say that I'd be much better off with the 36mm, Performance Shock said the cost to revalve the P30 would be about the same as buying the 36s and revalving them. One issue is that I really need to get my hands on one to see how I will have to modify the strut housing. Would like to do that before I commit to 4 of them. I'll reach out to MCA and see how their stuff compares and make a decision.

What did that cost you, Richard? Their single adjustable setup is about $2300 US which is pretty reasonable. BTW I was talking about this some more elsewhere and someone suggested DG's Far North Racing website to give shock valving suggestions. I've quoted that site here many times, didn't realize it had the shock valving suggestion page though. Bought the guy's book yesterday too, just out of appreciation. My rear shocks are surprisingly close to their suggested valving. Graphs are in different scales, but man, it's right there despite the lack of digressive pistons. Fronts are pretty far off though.

I had that prop valve on my Miata. Worked fine.

On another forum someone pointed out that the LCA isn't built to handle the loads from a shock. I was going to argue, but then I realized that the stock shock loads go through the tire, spindle, into the strut housing and to the strut tower, and the LCA doesn't see that at all, so I'd be putting significantly more load into the LCA than it was designed for. Hmm...

One issue would be putting all that force on the rod end mount for the sway bar. I think that's likely too much to ask. But could still do a shock mount to the LCA inside of where the sway bar bracket is. Again, this would reduce the throw as compared to the stock strut...

Possibly dumb/brilliant idea. Why not attach a shock to the sway bar and to a fabbed mount on the chassis, like welded to the front or back of the strut tower? Could just weld a shock mount to the strut tower and hook it up. That would insulate it from twisting with the strut. Would just need a shock that had enough travel. Then I could strip out the bilstein guts and run the same strut housings with the same springs and all, and just have the shock next door hooked up to the sway bar arm. Only real concern would be wheel/brakes/ducts hitting the shock when turning. I'm already fabbing up the sway bar arm anyway. One problem would be that if I mounted in front of the LCA it wouldn't move as far. IIRC that makes the shock harder to tune correctly because it isn't using as much travel. Could make the sway bar arms long and give the shock more travel/better resolution. That would make the shock angle change as it went through the bump travel, but if I put it straight up and down at ride height, shouldn't be too bad I wouldn't think. Then the question is how stiff would I need the sway bar arms to be? I know shocks put more force into the chassis than springs. Maybe I'd be better off working with the solid ones. If I did this I really could use some of those cheapo used race shocks.