Dark Regent

I am building a 2004 S2000 as a new project car. It will be a canyon carver/back roads car mostly. Maybe someday down the road, it'll see a track (don't really have one nearby), but probably no auto-x. I already have another 2004 S2000 running 225/255 tires, so I am looking to try something different with the new car. I am planning on going with a square setup, with 255 tires all around. I'll probably be running RE-71Rs. I was planning on trying some Ohlins DFV coilovers, so I'm interested in Sake Bomb's FPSport coilovers with their 11k/11k spring rates meant for square setups.

I'm not sure yet, which FSB to go with. Sake Bomb recommends the Hardrace bar (32mm) that they sell, and that they run on their car. They said it gives the car a neutral handling feel, which is what I'm looking for. I haven't been able to find actual specifications for the Hardrace bar, but I'm guessing it's comparable to the Eibach FSB (368/416 lbs/in). That's mildly stiffer than the OEM FSB in my 2004 (300 lbs/in), but not much stiffer than the original AP1/CR FSBs (393/392 lbs/in). I was hoping to get some additional opinions, on whether or not the Hardrace bar is actually enough to give the car neutral handling characteristics, or if I should be looking for something stiffer.

I've searched the forums, been through the STR thread, etc., but I haven't really found many people running a similar setup, with the FPSports. I had been looking at trying either the Whiteline FSB or the Saner/Moddiction bar. However, I haven't found any reliable specs for the Whiteline. I do like the adjustability of the Saner, but I want to make sure that it's not overkill.

alSpeed2k

There's a few threads in the R&C section of this forum. Guys going square on track seem to like to use a beefier FSB. Karcepts is nice, very adjustable, but also big $$$! That being said, SBG does seem very knowledgeable; don't they have the rates for the Hardrace bar?

B serious

You could start with the stock bar and go from there.

You may find that you're fine as-is.

There probably isn't a perfect setup.

But...00-01 bars are cheap AF. Try to find one from an eBay junkyard.

I'm sure there are adjustable bars out there too.

But you'll need to have some idea of what amount of understeer you'd want to induce...or how much front end stabilization you want.

So...again...Id probably just use the stock bar for now and then figure it out. Baselines are important.

For street use, you'll likely just want the bar that FEELS good.

For autocross or track use, you'll want one that actually makes a difference in traction at the limit.

andrewhake

Definitely don't change it until you have tried the car with the stock swaybars.

DanielB

I'm running the SakeBomb DFV setup with 11k/11k and stock bars from MY00 which are stiffer than your 2004 but have a similar front/rear balance. I just changed to a square setup for the track with 255/255 on 17x9. I was a bit concerned the car would be too loose as so many people talk about the need for a larger FSB in order to tame oversteer, but I just haven't had a problem with it. I intend to stay with the stock bars.

That said, handling balance is a personal thing so you might not like it. But before you change it, I'd recommend trying the stock bars.

Dark Regent

I asked Sake Bomb for the stiffness specs, and all they told me was that it is a 32mm bar, which I already knew. That's why I'm guessing it's similar to the Eibach, but I don't know what the actual wall thickness is. I checked the Hardrace website, too, and didn't find anything. I'm sure I could send them an email directly, and they should know.

That is good advice, thanks.

I'd been reading about your setup which seems sorta similar (albeit stiffer), with the ASM bars. That's one of the reasons I wondered if the Hardrace/AP1 bar would actually be enough to make it neutral, as the ASM FSB isn't very stiff either.

That's good to hear, because that's the sense I was getting, too. I know the even spring rates front and rear definitely change things, so thanks for your input.

Thanks for all of your advice guys. I'll focus on the coilovers first, and try it out. I can always pick up an AP1/Eibach front sway bar if I decide it's still a bit too loose. I wondered if it was worth jumping on the Saner while it's actually in stock, but it sounds like I can forego that.

Nitroturtle

In almost exactly the same boat myself. Have already ordered FPSports from SBG and also a sway bar from Moddiction. I'm also going to be switching to 255 square.

Might stay with stock bars initially just to try it out, but everything points to increased oversteer so I ordered the bar expecting to use it. I figured it would be easy enough to offload if I end up feeling it's unneeded. I'd like the car to end up feeling neutral with just a whole lot more grip.

I'm also going with Powerflex bushings throughout. Car has 136k on it, so I'm hoping to see a nice improvement with the refresh. Found it interesting to find someone else with pretty much the same purpose in mind, choosing all the same equipment. Hopefully we're both on the right track.

DanielB

I don't mean to be argumentative, but as I said above, I think everyone has their own preferences for how a car handles. The right balance for me might not work for you. If you enjoy the balance, and can drive it with confidence, then it's probably right for you. As someone who grew up driving rear wheel drive cars, I hate understeer - it just wrecks the fun factor for me. And in the end, the only reason I go to the track is for fun (the talent scouts don't frequent my tracks and I'm past that point in life anyway). But for others, a loose rear end is scary and takes away the fun. That's one of the great things about the S2000; it's a very tunable platform and there are plenty of aftermarket parts to let you find the balance you prefer.

Dark Regent

Unfortunately, I didn't get a chance to pick up the FPSports last week. SBG jacked up the price on them before their Black Friday sale. So, I focused on picking up all the engine mods I need for my 2.4L stroker build. The FPSports will have to wait.

Please post your impressions of the setup after you get it all installed. I'd love to hear your opinion of how the FPSports perform with the Moddiction/Saner bar.

davidc1

I've done this, and I researched it quite a bit, because my goal was the same as yours. I first went to the CR spring and shock because it was by far a more neutral handling car that the regular S2k. It changed the setup by making the front springs stiffer than the rear. But, while going to a square setup, you will massively improve you front grip and can go to far higher corning limits, you also transfer the balance far, far towards the front of the car.

This will make the car far looser, which is easily felt on track. In the canyons, if you go to the limit, it'll be felt as a roll down the cliff wall next to you.

Anyway yes, tire width absolutely dominates handling, and a little change in tire width can have the same effect as a major change to spring rates. Going from 225/255 to 255/255 changes your ratio of "available grip" (so to speak) from 44/56 F/R to 50/50 F/R. That's a huge change!

To give you an idea how big a change those 255 front tires are: if you wanted to just, say, stiffen up the front springs a little to get back to the load balance of your previous CR setup, you'd find that you can't do it without killing the CR damper: all else equal, you'd need to use front springs that are about 780 lb/in! Alternatively, you could delete the rear sway bar entirely. (That would actually go a little too far towards understeer.) Of course the best solution is a big front bar and/or rear wing as we talked about before. Looks like you'd need a 700 lb/in front bar (31mm solid or equivalent) to get there.

I will also make the disclaimer here that balance is a preference, and what one person may call loose, another may call perfectly balanced, but only in reference to what they like.

But, physics doesn't lie.

At the lower speeds of the canyons, if you want to bring balance back closer to neutral, you need to stiffen the front end. My first, and cheapest, suggestion is to swap to CR springs. Stiffer in the front and softer in the year. This would be the first step instead of a sway bar because the springs control the overall balance of all four corners. Another option is the Swift Spec-R springs. Very highly thought of. They are 9% and 14% stiffer front vs rear than the CR springs while lowering the car and inch or so. The sway bar should always be the fine tuner after other things are done.

I feel that the front should be stiffer than the rear, and not equal all around. So, personally I don't agree with the equal spring rate option. Also, many people would think an 11k/11k spring rate is pretty damn stiff and can decrease ride quality from OEM, especially with shocks matched to it. But, that is a preference also.

Getting a stiffer front bar to help restore balance is necessary in my opinion as well. But....it has to be a lot stiffer according the physics.

If I remember correctly, physics says you need a front bar on the order of about 700 lbs. The only people that make that bar for our car that I know of are Gendron, Saner/Moddidiction, Karcepts and Whiteline. I bought the Gendron, but it ain't cheap. A used version cost me $450 a few years back. Saner of course deosn't make their bar anymore, and although Moddidiction picked it up, I don't see it on his website anymore.

What will also help a bit is he CR front bumper. As far as I know, it is effective at producing downforce as low as 60mph, although not a whole lot of course. It's not always easy to find the OEM ones, but Ballade Sports sells a very well made one piece version that includes brake duct cut out and ducting mounting parts

If you are tracking the car, you will hit speeds that will considerably lighten the rear end and induce oversteer, pucker factor on a spinning car at 100mph is high. So, you really should get a rear wing if you've gone with a square set up. The mildest, and pretty much only normal street wing, would the CR wing. A replica that is good is also made my VIS. Thats what I got. The CR wing won't actually produce downforce, but it will reduce lift by 70%, which is a lot. It also shows you how much lift a non winged S2k has at high speeds.

If you'd like the read the definitive paper of S2k springs, shocks and sway bars, here it is. Written by out very own Twohoos.

https://www.s2ki.com/forums/s2000-br...prings-818884/

Now, while doing all this will make the tire/spring/sway bar/ balanced, that doesn't always mean you will like it. But, it does give you a mathematically correct starting point from which you can future balance if needed.