GTS4 diff ratio - help a lady!

[SHRED1]

Hey guys,

 

I'm looking to find the diff ratio for a r33 NA GTS4 (unfortunately, the car is automatic).. I've been online and I've read so many different answers.. Can someone help a lady out?

Looking to drop a RB25det into it..

Appreciate it!

[SHRED1]

Addition: the car is AWD*

[Duncan]

I don't know....but I do know you don't need to know the diff ratio to change the engine. you just need to re-use your current sump to keep the current front diff ratio.

If no-one knows the answer for sure the quick way is to turn count how many times the tailshaft turns for 1 full turn of the rear wheels. More accurate is taking the rear cover off the diff and reading the number of the diff's pinion gear.

My guess is that it's 35/8 ie 4.375. It could also be 37/9 ie 4.1111

[KiwiRS4T]

Your car will most likely be 4.363 (don't know if the auto is different).

However if you want to drop an RB25DET in it and retain the AWD your best bet is an AWD Stagea engine - preferably a Neo - and as Duncan says bolt your existing sump on it to retain  the correct gearing. Or you could keep the Stagea sump (with most likely a 4.1 diff) and find a rear diff to suit.

[SHRED1]

Thanks guys!

[jhjones]

nvm

Edited February 14, 2017 by jhjones