beefystud

Suzuka Sprinter | J’s Racing S2000 Aims for the C3S Time Attack Record

Top Fuel S2000 Monster WTAC Contender - DSPORT Magazine


the top fuel s2000 and j's racing s2000 are arguably the 2 fastest track s2000's around , both use 295 square set up with full body kits , my question is why stop at 295 ? why not 305 or 315 or even 345 , these cars have full body kit and im sure money is not the limitation , is it a matter of diminishing returns on a 2200lb or 2600lb car ? is it to hard to warm up for such a light car ?other members of this forum have sucsesfully "shoehorned" in 305/315 tires onto there own personal track cars , so why not the best in the world ? also why do these 2 cars run a square set up instead of staggered , is it to rotate the car through turns better ?

Motorsport_S

j's setup is not square. it says 18x9.5 - 265 front and 18x10.5 - 295 rear

warmmilk

J's (I'm assuming the TF car runs the same tire) car runs a Yoko A050 and the biggest size that comes in is 295. that being said, if they went to yokohama and asked for a bigger tire, they'd prolly make it

Chibo

Does anyone actually go in depth on the setups on these cars? All of these tuner showcases throw out uselessly broad information like 26k/28k springs on the Top Fuel car, but if you actually look at the pictures it shows them using a very short length (4", maybe?) Eibach ERS spring with a helper spring on top. I would also be interested in their general valving strategy (obviously everyone plays this very close to their chest). I'd also be curious if pickup points were modified and what kind of swaybar rates they have going so you can kinda get a picture of what the balance of the car looks like. The J's car is much closer to a traditional setup.

King Tut

I can tell you the fastest S2000 in the US runs a wider 305 front and 315 rear Hoosier A7 setup. My guess is they run the best tires their tire sponsor has available, and that isn't Hoosier.

thomsbrain

I suspect available tire and wheel sizes from the car's particular sponsors are the limiting factor. I think that was also the case on the current BW13 S2000 record holder. Based purely on the available room, you should be able to cram 295 under the "regular" J's front fenders on 11s, and more than that under the full body kit fenders, especially if you are notching and plating the upper frame rails. On the rear you can cram 295 or more under the stock fenders with correct offsets.

One other factor is that above 295 the tires start to get tall and increase the effective final drive. Not so much an issue if you're boosted, but for an NA car you definitely don't want taller gearing.

I've really wanted to run 295 square for a while but it's a huge investment when you figure the need for custom wheels, expensive tires, fenders, paint, and the potential need for new springs/valving to cope with the added grip. And it's an all-or-nothing investment. You can't piece it together over time.

beefystud

"the potential need for new springs/valving to cope with the added grip" can you explain more on this ?

Chibo

If you increase mechanical grip you need to increase spring rate since you're now generating more g-force (and therefore more weight transfer, more or less), otherwise you're going to blow through your travel and ride the bumpstops (effectively a very high spring rate) and work in an area of suspension geometry that may lead to alignment factor changes very quickly. There are cars that are set up to corner on the bump stops, but those are edge cases. There are also cars that are set up to have a lot of travel and suspension geometry change through the travel range (WRC cars).

If you increase your spring rates you also need to alter your valving to control the higher amounts of force on the movement of fluid in the shock body (among other things). Think about your average JDM-flavor-of-the-month coilover with high spring rates that bobbles over every bump, this is not how a properly set up damper rides, even with higher spring rates. It's also worth noting that not all companies valve in the same way and end up taking different routes to get to similar results, but with a different feeling. Koni vs Bilstein is pretty black and white if you drive them back to back and listen to the car.

There is no one way to do suspension setup, it comes down to what makes the driver comfortable, matches their driving style, and lets them go quick.

beefystud

im about to stuff a set of apexi N1 ExV coil overs into my 95 hatchback civic, are these "JDM-flavor-of-the-month coilover" and is my future to " bobble over every bump"

Bullwings

Yes