it's about switching to an ap2 cat from an ap1. the emissions laws are different between the us and japan and i don't even kno if we have the same cat over here. and it seems most people just switch to a test pipe or full catback exhaust anyway.

 

Yeah that's a typo, it says later that they are 255s, the 265s are on the 18s

 

I need to get this newest hyperrev

 

I have this HyperRev at home and can read Japanese.

Basically on that cat page, it talks about the highly restrictive AP2 catpipe (MY06+ in Japan), and suggest using a high flow cat or an AP1 cat. Honda had to switch over to this new catpipe to meet emissions requirements. For AP2 tuning, HFC/test pipe/AP1 cat is a must.

I read this and was curious, so I checked US part numbers, 06 DBW cats have a different part # than 00-05 cats which are the same, so it appears US has changed cats at the same frame as well.

As far as the article on the wheels, I don't recall all that was said but I can look into it after work.

 

^ A interesting bit of information.

 

wow thanks man!...learnt something new today...

Would you care to translate page 81 for me? That's one of the pages i really wanted to understand. I believe it talks someting about alignment/suspension, and how bumpsteer kit will help the car.

 

I just went over the OP's pictures on the wheel setup, so here's a rough quick translation:

17" OEM Size:

Wheels - F: 17x8 +44 | R: 17x9 +63
Tires - F: 215/45/17 | R: 245/40/17

No modifications to fenders needed , no rubbing. However, since these are factory sizes, there's limits to increasing tread with wider tires. Visually, these will not be that aggressive.

17" Size-Up:

Wheels - F: 17x9 +54 | R: 17x9 +40
Tires- F: 255/40/17 | R: 255/40/17

This is likely the most common setup for those who track S2000's regularly while still seeing street duty. With 255's up front, there's added grip, and also gain something visually with wider front wheels. Requires rolling front fenders and shaving bumper tabs to fit properly. With even more fender modifications (wider fenders), you can run +40 offset in the front.

18" Full Track Setup:

Wheels - F: 18x9.5 +40 | R: 18x9.5 +40
Tires - F: 265/35/18 | R: 265/35/18

This is for those that track their cars exclusively. Requires modified wider front fenders and shaved bumper tabs. Even with modified fenders, taking harsh bumps or turning the wheels over bumps will cause rubbing. While you lose alot on the street, you gain incredible amounts of grip at the track that you cannot get with 17's. If you want to run 18's on the street, you can go with 18x7.5 +48 with 225/40/18 up front.

 

I also forgot to mention on the cat page...there was a lot more being said about VTEC changeover points in relation to the cat being used...I'll get to them tonight, because it's a huge strain on my eyes trying to read the small text on a jpeg

BTW, the AP2 cat has double the cell count of the AP1 cat! No wonder it makes fewer hp...

 

Page 81 in a nutshell:

They consulted J's Racing on how to properly "tune" the S2K suspension, and to get most out of aftermarket coilovers. This is all based on having coilovers installed on the S2K. You need much more to properly balance the suspension.

When the S2000 is lowered, of course FR/RR camber are altered (negative camber). However, front camber will always be less than rear camber. Where the rear camber sits at 3.5 degrees, front will only be at 2 degrees. In addition, the roll center geometry of the car is compromised, as seen in the diagram on Point 2. The lower arm angle changes as the car is lowered, which compromises the car's roll capability and becomes unstable. A roll center adjuster fixes this, but not completely to factory specs - even with roll center adjusters, you'll get close but will not achieve the factory roll axis, in the diagram under Point 2. In addition, front camber joints are recommended to fix both front roll center and front camber deficiency. For the rear, a rear roll center adjuster is all that's recommended. The effect of all this is handling feel will be more direct and precise.

In addition to fixing roll center, you'll want to do something about bumpsteer. Bumpsteer is more likely to occur on a lowered vehicle due to most coilovers having a stiffer character over stock, and also the FR tie rods and RR control arm angles change (geometry changes) once the car is lowered. J's Racing recommends tie rod ends and control arms that are designed to fix these changes in geometry and lessen bumpsteer. Especially with the J"s rear control arm (bumpsteer kit, in other words), the peaky/twitchy character of the rear suspension is stabilized.



In summary, J's Racing recommends the following J's products to fix both roll center geometry and bumpsteer issues:

Front camber joints + front tie rod ends
Rear roll center adjuster + rear control arms.

 

im very curious as to why they would choose 18s over 17s. Also whats the advantage between 17s and 18s if you are using the same tire width.