JDM Q: Differences between JDM GT and Spec B?

[SC GT]

I know the struts and springs are different. And the rims and tires. And the front bumper. Are there any other differences? Front and/or rear sway bar? Engine tweaks?

[apexjapan]

What the Spec B has different from a GT: Dampers (firmer) Springs (I have heard that they may actually be the same) Wheels/rubber Bumper skin Pedals Shorter transmission ratios Everything else is identical, including the engine. Fuel economy differences are directly tied to the more aggressive rubber of the 050's vs. the 050A's, and the shorter gear ratios. Performance is a combination of the damper and spring settings and the more aggressive rubber. Theoretically, the handling difference between a Spec B and a GT would be decreased by simply using identical rubber. Advantages of the GT: Lighter at each corner due to the construction of the 050A's and smaller rims/rubber. Reduced unsprung weight, better turn-in in slower corners. Fuel Economy. Better ride/performance compromise. Cheers, Paul Hansen [url]www.apexjapan.com[/url] (waits for apexjapan2's counterpoints) :twisted:

[SC GT]

Thanks Paul. As always, great info. Do you know the size of the GT/Spec B anti-sway bars? Someone posted that the USDM sizes are front 20 mm and the rear 16 mm, and I was wondering if that is the same as JDM. Thanks again. SC GT

[apexjapan2]

LOL @ Paul - the inter office banter hots up a bit :wink: In general I have to agree with Paul, but I really liked my spec B while I had it. But I have always been griping about my "soft" B4 RSK, too... I'll go dig out the specs one of these days of both set ups (I think I have them somewhere). Honestly though, the devil is in those numbers as many of the "rates" are terribly misleading. That is partly due to the Bilstein dampers (on both the GTs, and 3.0R), which use trick valves that change their characteristics at different piston speeds, so looking at a "rate" can be pretty misleading, IMHO. Of course the combo with the tyres etc has a huge effect. And Paul is bang on with the tyres. Personally, the 18s were the pick. They are much more stable across the tread face (and this is not just good for the track!), and the sidewalls show admirable resistance to getting in a flap when shown consecutive sharp/hard inputs. Of course, they are also less pliable than the softer, less performance focused 17" version, but no more noisey except for when you cop a big joint on the expressway - then you can hear some tyre slap (yep, they're stiff!). And that is not to say the 17s are bad, but they are not quite an RE-01 either. There are gearing differences in the transmissions, but it is worth noting that the GT's tyres are 626mm dia, vs about 648/650 for the spec B IIRC. So just whacking a set of 18s from the spec B on GT is gonna make for some interesting moon shot gears :wink: That'll have to do for now... Cheers :)