mkl22

maybe the 4.777 final drive should have been standard from the begining. But i think the reason why 4.44 was used was for 0-100km/h timing. cause if 4.77 was used, the 2nd gear in the 6mt can't hit 100km/h and will require another gear change to 3rd gear and so the 0-100km/h will be slower and thus affect its "performance" timing. well this is the usual marketing strategy we usually see from car manufacturers.

kennyyeo

Gfoo, do u know which brand do final drive for RX8 beside Feed and Knightsport.

How much is the Knoghtsport one cost including install.

How long it take you to get it install?

Do you have to remove the diff at the back too ?

DO monster garage have stock now?


Thanks

Sorry for asking too much

gfoo

Kenny, best is to email monsterg@singnet.com.sg or pm coupe07 for orders/price.

No, other than FEED or KS, no other final drive i know that's japan-made. The US folks are talking about using a Kia FD at 4.778 but i wouldn't even touch that with a barge pole. Others are talking about using the supra or something etc - do a forum search lah

It's a full day job, not easy to install. i left my car the night before and it was ready for collection mid afternoon the next day.

I don't think you will remove the whole differential - just replace the final drive gear bit.

I believe stock is arriving soon, best is if you check with coupe07

coupe07

so long as they are rotary tuners, they shld have the final drive. Wat brand do u wan? U wan premium brand, then RE AMEMIYA. But u have to pay premium price.

final gear is not at the gearbox side. Its at the LSD side.

Stock wise, August.

sqflyer

kennyyeo, I'm not sure where the speedo reading is taken from. I think it should be read as accurate as possible to the actual movement of the vehicle which means it should be at the wheels, therefore only changing rims/tyres/type pressure will affect the speedo reading. If it is read upstream of the wheels to the point where changing the final drive will affect it's reading, then it's probably going to be the opposite of your example; meaning the speedo will overread instead of underread. Eg. Actual speed 75km/h and speedo speed 80km/h. As it is, the speedo is already overreading by about 3km/h for my stock setup. Which also explains why the Gtech does not capture a 0-100 time if stopped exactly at 100km/h.

Are you absolutely sure that 4.777 final drive cannot reach 100km/h on 2nd gear? Don't misunderstand it as doubting your statement. It's just that I'm interested to know the real answer. If nobody has the hard facts, it's ok. Somebody will provide the answer or test it out soon enough.

mkl22

I think i found your facts.

http://www.artex.co.jp/Pages/CarLife...C_03_06_11.jpg

found this in one of the old posts.

after calculations, with 4.777 Final drive will be 94.8km/h

gfoo

mkl22....dead link

EBS

Bro sqflyer is correct. Stock car speedo will show higher speed than actual after the final drive. At lower speed (less than 100km/h) the diff will be around 5km/h ie speedo reading 100km/h actual around 94 to 95km/h. Speedo showing 130km/h, actual speed ard 121km/h etc.

This was the fig diff on my colleagues Cl7R when he had his FD done (diff ard 0.4 oso).

Cheers

mkl22

fixed.

mdw1000

I realize i'm reviving an old thread here, but i'm thinking of doing this to my 4 speed AT with the GT package (LSD). Sounds like from the comments here, this wiill be a defininte improvement for 0 to 40 mph? I don't read the language that the road test is written end, so can someone summarize it for me?

I know you talk about gains, but how much of this is due to the final drive and how much is due to your ECU?

Thanks very much in advance!

derekwcw

Well, yes and no, maybe still boils down to the fact how the driver launches.

Seen auto 8s with Final Drive losing to stock auto 8s many a times, so how effective it is when installed, maybe good but maybe useless too I guess. But one things for sure, when on the move the pick up is slightly better.

As for ECU, not so much the power gains, think this been mentioned before, but more for turning the cooling fan earlier, smarter smoother gear shifting when on full auto, and maybe just slight improvment of fuel consumption.

S2SEXY

do you still have your stock 4.44's let me know what your asking,also i can get them brand new for $360.

GRapify

how do you launch an AT Rx8??

drift_drift

Isn't Speedo tie to wheels and not gear? How can changing final drive affects the speedo reading? Also 6MT with 4.777 should reach 100 by 2nd when hit 9500rpm... if tyre profile is not too much lowered.

sqflyer

Yes, speedo should be tied to the wheel, more specifically the rotation of the wheel and not the actual circumference of the wheel+tyre because there is no way the car can read a wheel circumference that is constantly changing. Therefore, changing a different final drive ratio does not affect the speedo other than having a different speed while in the same gear/rpm than before the change of the final drive (hope I didn't make it sound too confusing). If the 6MT with 4.777 final drive has a THEORETICALLY speed of 100km/h at 9500rpm on 2nd gear, that means it's impossible to reach 100km/h on 2nd because the redline is at 9000rpm unless you remove/over-ride the rev limiter/cut and risk blowing the engine.

Vanquish

Very tempted to try this final drive but seem to have conflicting reports... anyone can hazard an intelligent conclusion on this final drive, does it really does improve pick-up 0-100 or not??

No offence to anyone... Thanks!

sqflyer

I'm pretty sure it will improve your pickup, but because you will probably need another shift to 3rd gear to reach 100km/h, it will come down to your shift speed. Anyway, unless you race 0-100km/h for money, I think it should not be of concern.

Vanquish

Thanks bro!! much appreciated... forgot to mention my 4AT... any significant difference??

mdw1000

I should be picking up my car tomorrow with the new diff with the 4.77. Dropped it off at the mechanic's about an hour ago!

Vanquish

From Monster Garage?? Got stock already? Called last week no stock...

Is yours a 4AT or 6MT?

mdw1000

No, I am in the US. It is the FEED gear from JonDemand. Had the new diff built by mazmart in atlanta and then had a local mechanic install it.

Mine is a 4AT.

First impressions are pretty much the same as others have said. Revs faster, rpms are higher at a given speed and gear, acceleration is improved. Acceleration hasn't made a great leap or anything, but is definitely better. Time will tell if I decide it was worth the money

My total outlay for shipping, building, installing, etc is going to be right around 1600 USD.

My mechanic did say the diff swap was more time consuming than he thought it would be.

mdw1000

After driving it again, I'm starting to appreciate it more. It really makes it a fun car around town. Revs quite a bit quicker.

Vanquish

Thanks for sharing mdw1000!!

JMKuco

UP !
Need more info !
I hesitate to add this to my car but want to know excatly what I gain and what I loose !

mdw1000

Your stock gear is a 4.44, so this is about an 8% lowering of your rear gear. Basically has the effect of making every gear lower. You'll gain some acceleration at the expense of top speed in each gear and a slight loss in fuel economy.