260DET

As a general observation I don't understand why inevitably aftermarket suspension suppliers don't publish any changes they make over stock specs and the reasons for such changes. It would save so much questioning plus add credibility to their products.

Your option 2 would be fine to 300 whp only, drags and drifting excluded, a Z32 box is fine for 400 whp, you will need a R200 diff with suitable CV axles. Plenty of LSD options, my choice would be the most expensive (as usual) a OS.Giken. 400 whp can get quite expensive for it to all hold together and take a bit of abuse.

Go with your first choice, the 4x114 to 5x114 adaptors. As you said they are available in the thicknesses you need and are a structurally sound option.

My dreams exceed my capacity so this idea has been put to bed. But there is a turbo version of the Mazda 2.5 which obviously has a lot of potential, if I was proceeding that would be a favourite.

OK, no Z this time, one of my favourite cars at the Nurburgring.

That's one of the good things about the US, if it works there is no need to change. Elsewhere there is too much trendy keeping up with the latest, good or bad, appropriate or not.

What you have done is better, it's added very little extra weight while adding considerable strength where needed.

Manuals are so yesterday, get a DCT conversion, it will shift faster than you can and they are not relatively heavy. Particularly compared with a CD009 lump. That's if you want the best performance option, what is the point in handicapping a good engine with a less than optimal transmission?

I'm liking what has been done here and the thought process involved. Keep going. What was done to my sills/rockers was to simply run some square tube underneath against the pinch weld flange and weld it in place. Makes jacking easy too anywhere along it.

Seems like you have not made a decision yet on door area impact strength. My decision was to go with composite doors incorporating a separate light weight tube steel frame to connect to the hinges from the latch. The doors were then filled as far as practical with foam which cushions and spreads impact. Importantly the car has a basic cage which adds to impact protection and stiffens the body too. So what I suggest is deciding if the car is going to have a cage and go from there. I'm quite confident that my setup will provide excellent protection.

Historic spec S30 showing how to drive this circuit.

Always post pics, gets more interest. I understand that you are looking to blend the kit panels into the body, as grannyknot said your 'panel bond' should come with instructions but blending is the problem. I'd like to know the answer to that too without adding excessive weight.

Epic thread in the just cause of losing weight, great to see, just don't forget that Group 3 cars weigh up to 1,300 kg and do lap times that us Z punters can only dream about with modest power.

Agree, may be OK for crash protection but no good for chassis reinforcement, particularly on one side.

Another vote for strong frame rails no matter what the application. What i do is weld some RHS along the pinch well and brace it back into the body in a few places. A bonus is it can be used as jacking/stand points, very handy.

As far as coilovers go MCA have a well deserved superb reputation in my country, see https://mcasuspension.com/shop/catalog/302/240Z They did me a three way custom setup years ago, low and high speed bump, rebound. On my favourite circuit there was a turn in problem with one corner so after doing some research I did two clicks on the low speed bump, problem solved, unreal. That corner was the straight entry corner, two clicks to go from 'turn in you bitch' to whoah, PB coming up. My point is that the best dampers and knowing what the adjustments do is everything. Before you get to that though the black art of damper valving is paramount, anything less can lead to endless frustration for the end user.

OS.Giken rules, no doubt there. If anyone has to go helical then perhaps a Wavetrac would be the best option, if available of course. No OSG available for my non Nissan project, the Wavetrac seemed to be the best choice out of the various helicals.

As an Aussie I don't mention Aussie gear unless it's world class, included in that list would be, MoTec, Kmac, Haltech and MCA.

Sometimes a reality check is needed and that can be provided here by looking at Z race cars and their results. The fastest Z's have always used the basic stock suspension, it's great that there are those who think outside the box and who are willing to put their $ where their mouth is, Once they do that however they need to turn a profit so they have to be commited to their product. What does not seem to be widely understood by potential users is the complexity involved in any suspension redesign. At the very least the actual dimensions and locations of all components needs to be established using proven methods. Until that is done we have what is basically promotional comment. Bye, getting real is often not popular.

Great post Jon but no no no, the supplied speedway arms are only used for the part that clamps onto the bar, the rest is cut off and chucked with suitable light weight arms welded on. The design of the replacement arms is dictated by the load involved not the bulk of the clamping part. The advantages of a splined set up are too good to be discarded.

You won't do better than these https://mcasuspension.com/shop/catalog/302/240Z priced in Aussie $.

What about an aftermarket ECU with it's own V6 harness that can be adapted??

We can't make those sorts of decisions for you but in my experience a project car should be built as a hobby, not as a job. It helps heaps if you have another car that can be used as a sort of substitute while building The Project.

Am about to get a Wavetrac helical LSD for the non Z car. Is it really the same as all the others or does it do what is claimed?

One thing that I note with older US used parts is the amount of rust, is that part of your ecological programme? Rust is recycled iron so that's good, it's seizure effect is there to persuade you to throw the part away and buy new which is good for your economy. Or China's?