CUSCO 4.55 FINAL DRIVE installed.

[Jive Turkey]

can't really run 16's or smaller since i'll be upgrading brake to sti brembo's...

so what'd this cost in the end? i know you said its a long install, but is it straight forward?

[OrbitalEllipses]

Originally Posted by Jive Turkey

can't really run 16's or smaller since i'll be upgrading brake to sti brembo's...

Waste! Factory Brembos are crud in this application IMO. I need to recondition my set so I can sell it to some 86er Need to reimburse myself for my AP purchase!

For most people, changing gearing through running shorter tires isn't possible. Most of us are changing tire/wheel sizes and often ending up with a slightly taller tire. In NA form this shorter FD seems sexy as hell...but I bet you the turbo guys will eventually be swapping out to the 3.7xx FDs from Japan.

[Jive Turkey]

Originally Posted by OrbitalEllipses

Waste! Factory Brembos are crud in this application IMO.

go on....mind you i didn't pay for mine

[Racecomp Engineering]

i think the Cusco retail is like 1200.00 plus most will pay 6hrs shop time.

Finding the proper lexus FD with diff would be i friggin deal ! Some have found them for less than 500 in junk yards I see on the Lexus forums.

Mw

[Racecomp Engineering]

Originally Posted by OrbitalEllipses

In NA form this shorter FD seems sexy as hell...but I bet you the turbo guys will eventually be swapping out to the 3.7xx FDs from Japan.

DUUUUDE...I cant even imagine a 3.77 with 300 whp and 2500lbs !

ok back to NA reality(for me)....

Myles

[OrbitalEllipses]

Originally Posted by Jive Turkey

go on....mind you i didn't pay for mine

I'll PM you.

Originally Posted by Racecomp Engineering

i think the Cusco retail is like 1200.00 plus most will pay 6hrs shop time.

Finding the proper lexus FD with diff would be i friggin deal ! Some have found them for less than 500 in junk yards I see on the Lexus forums.

Mw

...I could buy a crappy mechanical LSD for that kind of money. I'll definitely look for this in a yard or Lexus forum.

[carbonBLUE]

Originally Posted by Racecomp Engineering

Here's the table I was looking for.

- Andrew

my graph isnt 100% accurate but is close enough for comparative measurements
I went ahead and took 5 min to make a table showing the difference in gear ratios between a 4.1 and 5.125 for BOTH the automatic and manual


speed shown is in MPH

the difference in my chart and cusco is i used dynamic rolling radius where they used static rolling radius
my graph accounts for (at a very simple level) how the tires expand when they start moving down the road at a higher speed

[philstar]

Awesome! Exactly the same route I plan to take with my car!

I may have to PM you with some questions in the future when its time for me to do the same!

[03Z33]

Cusco Retail on the 4.556 is $937 but discount structure is different than other Cusco products since it's a rebranded OEM Toyota part.

The 4.556 was previously a TRD Japan part # 41201-SE100 (now discontinued) which used to retail for $700'ish in Japan

The Toyota part numbers originally posted by Jeff Lange are:
3.58:1 - 41201-80125
3.73:1 - 41201-80050 (OEM Base FR-S/86/BRZ)
3.91:1 - 41201-80052
4.10:1 - 41201-19605 (OEM Torsen equipped FR-S/86/BRZ)
4.30:1 - 41201-29606 (OEM MK3 Supra Manual non-turbo w/LSD) (Included pinion seal will not fit) Currently available in USA from Toyota dealer for roughly $700
4.56:1 - 41201-19557 Toyota Japan only, does not come up in USA parts catalog (Included pinion seal will not fit)

Auto Factory sell the OEM Toyota 4.556 in Japan for $500
http://autofactory.jp/product/topv.p...&cate=7&seq=13

Auto Factory also offer 4.8 & 5.1 gears which require a spacer (included) to work, those retail for $825

http://autofactory.jp/product/topv.p...s&cate=7&seq=6
http://autofactory.jp/product/topv.p...s&cate=7&seq=5

Revolution also offer the 4.8 & 5.1 gears for a slight mark-up around $920:
http://revo-tune.jp/catalogue/detail.php?id=287
http://revo-tune.jp/catalogue/detail.php?id=286

Revolution also offer the 1'st & 2'nd gear same as Cusco but for less at $1840
http://revo-tune.jp/catalogue/detail.php?id=288

MFactory also offer 4.44 & 4.67 final drive for $749 retail, these are not OEM Toyota parts but aftermarket made overseas (Australia or Hong Kong I believe)
http://www.teammfactory.com/final-drive-gear_Subaru

I purchased my 4.556 from Cusco because of the convenience and because I didn't want to wait since I have the diff cover and GT LSD all here ready to go in the car this week.

Just figured I'd share my research leading up to this $$ purchase in case it helps anyone else in future.

[Captain Insano]

Thanks for the info 03Z33 and carbonBLUE!! Looking at that AT with teh 5.1 is VERY interesting. It essentially becomes very similar to the OEM MT as far as MPH per gear. Pretty cool mod if the AT software can accomodate it.

[Jive Turkey]

so wait, if i'm reading this correctly then the is250 rear diff is a direct bolt on that is already a higher final drive?

or what can be done, besides this cusco route and pulling my own diff apart? this seems like a real drivers mod. good shit RCE!!!

[WolfsFang]

Im a little confused on this stuff. With our power its better for a 4.55 (higher) finial drive since the gears are shorter? If we strap a turbo on will a 4.55 be advised or a longer gear to account for the power? What are the disadvantages to having a shorter/higher FD? My two last platforms were not big on changing the FD so i have no idea whats going on.

[wootwoot]

Just FYI....I have been shopping around for a Lexus LSD and haven't found one with a 4.55 FD. Not sure what year it needs to be... USDM? JDM?

[Racecomp Engineering]

Originally Posted by Jive Turkey

so wait, if i'm reading this correctly then the is250 rear diff is a direct bolt on that is already a higher final drive?

or what can be done, besides this cusco route and pulling my own diff apart? this seems like a real drivers mod. good shit RCE!!!

correct some IS300's and IS250's came with LSD ANDthe 4.55 FD. Some guys on the Lexus forum found those in salvage yards. Not a easy find but normally cheap.

Yes this is VERY much a drivers mod making better use of our limited power and light weight.

One of my employees says all it needs now is a sequential box !



For sure 6th is an overdrive gear as RPMS do drop down there. But thats kinda good in this case. If 6th was a linear upshift from 5th then we would only need like a 4.33.

I'm 250lbs but this spring I will get a friend of mine who is a serious drag racer AND weighs 145 (constipated) to run my car in the quarter. Kind of curious what it does with 190whp and 2550 lbs and 4.55 Final.

Gotta find 6 whp some how !

Myles