So I spotted someone mentioning an "HKS final drive gear" so that you can go faster for the same RPM in another thread talking about Evo 8/9's in autocross. I can see already that the tight gears on the Evo X 5 speed are just a bit TOO close ratio for my taste. This is amplified with the lack of no 6th gear "highway cruising" gear. Driving at 80 MPH in 5th is ear wracking with the new stiffer front motor mount because the engine is at almost 4k RPM's.... just slowing down to 75 MPH seems to make it much more livable so the question is, will there be a similar Final Drive Gear available for the Evo X?

I would imagine that gas mileage would improve at the cost of some slightly slower acceleration times, although once these cars get to 400+ horsepower we start running out of gear and RPM to stay in 4th for the dragstrip unless we can rev higher with built up engines or larger diameter tires. I think there would be a good market for taller gear ratios in the Evo X, anyone know of any plans?

I spotted this in a SSC article, looks like they intentially put a shorter final drive in for the X , just not quite as short as the 8/9 RS models:

http://www.erzperformance.com/Produc...HKS-KSS-KXM003

Speeds are in KPH so you have to do some calculating...

Looks like it adds around 11 MPH breathing room to 4th gear @ 7k RPM on the evo8/9

5th gear at 3500 RPM's improves from 75 mph to 83 mph at the same RPM which would be a nice change for sure if we could get a good 8-10 MPH on the Evo X.

 

I'm sure Shep will come out with something. Going from the VIII (tallest gear set of the 8,9, and 10) to the X was painfull on the interstate. But on a positive note I don't worry so much about speeding tickets anymore since I cruize at 80 now instead of 95

 

I can see where 95 MPH would tend to attract attention in an Evo.

I'll have to keep an eye on Shep when it comes to Evo X stuff!

That SSC article mentions the X having "shorter final drive gears" (4.687 against 4.529). Is that the right way to say it since the number is higher but the max speeds in all the gears get lower? Hah that is confusing...

 

Especially a yellow one

Yeah, higher number = shorter gear.

 

Can't wait to put 3.73's in this bad boy... Wait, wrong car forum.

 

Lol, yeah a new final drive would significantly help for highway cruising, you could drop down a fair amount I'd think and not suffer that much of a loss in low end. Maybe something like 4.55's or 4.30's but I'd assume the cost to be the deal breaker, if it's anything like I imagine, it would be about $1500-2000 to regear the Evo.

 

noob ?....dropping gear ratio, hows that effecting the low end times? 1/4 and 0-60....

 

It's possible that some people would be interested in sacrificing 0-60 and 1/4 mile performance to get a better highway cruising gear as well as top speed. When your car starts making mad horsepower it really doesn't help to have super short gears since by the time boost hits you practically have to shift again and traction can be a handfull off the line. Using larger diameter tires can achieve the same thing but you can only go so big before having to modify the fenders.

There can also be times when a car will improve it's quarter mile times if it avoids having to shift into 5th and lets you ride out to the rev limiter in 4th gear. Now granted, usually people swap in a taller final drive so that each gear gets shorter and more powerfull but for those that use the car as a daily driver or drive dates to dinner we have to think about making the car somewhat liveable. If we had a 6th gear for cruising I think the ratios would be just fine but we don't.