One for the tech heads.
If I wanted a 6th gear for a higher top end.
What alternative gear box can I use for the ST205 GT4's which can be mated with the gen3 3SGTE?

option 1

swap 5th gear from a LExus ES300 / Camry V6, they have higher final drive 3.9X if I'm not mistaken as opose to 3.6X

Option 2 get custom gears / custom trans made for your car like Tufy did.

i dont think you have any option, replace 5th gear for another gear? you cant just add a 6th gear, where is it gonna go?

I didn't say add another gear, but replace it, it's a common mod between celica / camry 5th gear to get some top speed, also Mr2 turbos use Camry v6 trans to get some top speed as well, and since the e153 and e154f are internally the same, the 5th gear swap will work as well.

oh yes that you can definatly do, i have taken the E153 apart from an MR2 and an ST185, i dont see any reason you cant bolt the transfer case to a solara E153

that's also a way of doing it, to do so, the diff from teh e154f would have to be transfered to the solara e153 trans, but yes, it'll be bol on affiar, and the top speed gain is like 25 MPH higher or something like that, there was a post on mr2oc where they compared the top speed of a stock e153 and a Camry V6 trans and the difference was ~ 20 - 25 MPH on the top which is very significant.

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So just the 5th gear can be bolted on? What complications will I face? Are you sure you can do this for the gen 6 GT4 gear box?
at the moment top speed is around 145 so I could expect around 160?
Any pictures?

as long as the year of the transmission from the camry matches the year of the transmission on the GT4 it will be bolt on affair, actually you don't even need to remove the transmission from the car since the 5th gear can be access by removing the.. 5th gear cover .. the small cover at the end of the transmission on the left side.

complications ? if done correctly none, I would advise to replace the gear synchro at the same time.

if you do remove the transmission and want to have a newer transmission all around, you can open the ST205 transmission and use a Camry v6 ( the newer the better )

if you use the camry transmission ( V6 manual ) you need the differential from teh ST025 transmission in the camry transmission and bolt on the transfer case to make it AWD, this will give you slightly longer gears rather than just 5th gear, all gears are either euqal or longer, I knwo for a fact 3rd gear is longer and so is 5th gear, the top speed on standard tires of this transmission is ~ 167 MPH, some MR2's have achieved ~ 180 with larger tires.

Very interesting!
Can I swap a 4th and 5th gear? Just so that it's not such a majour step up from 4th to 5th if I only change the 5th.
Also do you have a part number for just the 5th gear or know where I can get hold of one?
I have a 94WRC GT4 so I take it the year must be of a 94? I dont know if all the ST205's have a differnt transmission or not.

does anyone have the part numbers for the bits required to do this,has anyone on here done it before