Designing the "perfect" suspension setup

[johnc]

The stock rear LCAs on a S30 have been race proven for 40+ years. You do not need to replace them to win road races even with power levels approaching 400hp. The folks running the current Easy African Safari Rally run stock 280Z rear LCAs with Energy Suspension bushings. I know, earlier this year I sent ten sets of the bushings and twelve LCAs to a six car S30 race team that's headed down there now. These are 300+ horsepower 240Zs racing across dirt paths in Kenyan and Tanzania. http://www.eastafricansafarirally.com/

[johnc]

I'm always surprised at how quickly folks new to the S30 world discount or ignore what the old hands have learned racing these cars for decades. And how quickly they toss aside the OEM parts figuring the aftermarket makes better. Well, that's not always true:

 

http://forums.hybridz.org/index.php/topic/102968-aftermarket-control-arm-failure/

 

I don't want to sound like an old curmudgeon. Again, its cool if you want to replace the front and rear suspensions on the car. But that's primarily an emotional decision or something to do to see if it would work - and just plain fun to do. You don't need to rationalize it in any way by citing costs, better performance, etc. If its something you want to do, go for it. What I get grumpy with is when people try to assert that their mod is better then what originally came on the car, with their only proof being that their parts are a newer design.

[Snailed]

The weight of the narrowed Q45 setup with R200 will be about 25lbs heavier then the S30 stuff with comparable disc brakes. I have weighed both setups and will have final numbers once I buy rotors and get shorter shafts.

 

John, I understand what you mean about the diff and shafts not being part of the suspension but if you look at the whole package (which is really what it comes down to) the 240/skyline/q45 stuff is FAR cheaper as a whole setup. My goals are similar to the original poster, that's why I posted in this thread. I want to have a nearly bullet proof rearend and suspension. A stock 240 with LSD would do the job fine for 400-500whp a stock S30 would not. Getting an R200 into an S30 could easily eat up $300 (right?) and you still have weak stub shafts, weak axle shafts, little brakes, 4 lug hubs and poor geometry if you want the car to sit a lot lower than stock. I know it's a lot more than $300. I'm curious honestly, what does all the good stuff cost to handle big tq #s, stop fast and not have the camber heading positive once the control arm is past horizontal? I bet it's over 2 grand excluding rear coilovers since both setups get those usually. I don't have the $ to get all that stuff, but I do have the use of a fab/restoration shop and the skills to make it work properly. I know this is a touchy subject on here because so many have had success with upgrading the stock layout. I think that's great and I'm not trying to convince anyone otherwise, just sharing what I am doing on my car to get what I want out of it.

 

Ibang, I won't be spending a dime on bushings or colorful arms anytime soon. The factory eccentric bolts work great if you have stock geometry (LCAs not pointing at the ground like your average "slammed 240") So the only real cost is coilovers which I would buy for either setup so I don't see that as anything additional.

[iBang]

John, definitely not trying to argue that what I'm doing is the best possible way of doing things, just trying to see if it is the best for my personal application. You've actually given me enough info that I may not go down the S13 rear suspension route after all.

 

On the stock rear lower arms - they certainly may be strong enough, but what adjustability will I be giving up with them? I know that the TTT arms have adjustability to center up the wheel in the wheel well which the stock arms do not. I haven't actually done enough research on what the stock pieces are capable of since I was planning on ditching them so I don't know what I would be missing in stock vs. TTT arms.

 

I am still concerned about the lowered geometry as Snailed pointed out, but given that I'm not planning on running the car slammed, it may not be an issue. I do want the car to be low enough to give it a nice look, but I'm not planning on tucking tire in the wheel wells. Not sure if my ride height will end up being a problem or not.

 

If the weight difference is as low as 25lbs that is a small price to pay for the additional performance and the fact that I already have most of the parts.

 

Snailed - that's great that you are planning on doing the work without any of the trick adjustable parts, but since I already have a very nice set of SPL adjustable arms I'm definitely keeping them in play if possible. They are great for dialing the rear alignment in for different ride heights, and I have to admit they do look nice back behind a nice set of wheels.

Edited October 26, 2011 by iBang

[iBang]

I think the title of my thread may also have been incorrect. Realistically what I'm doing is determining what the best suspension setup is for my particular application and budget. There is no "best" setup, only good setups and bad setups. I don't think what I have/had planned was bad, however it may not be the best for what I'm trying to achieve.

[johnc]

Guys, do the swap. Its cool.

[iBang]

For me the determining point will be when I get the car moved into my new house so I can dissemble it. For now it has to remain rollable so I can trailer it over.

 

Once I have it apart I'm going to do a side by side comparison of the parts and decide which will be the better way to go. I'll document all of it in my thread so we have more than a lot of guesses.