1jzchris

Hey guys,I have a 1995 SC400. I did a 1jz auto swap, the car runs good,but i noticed that when i am cruising at about 60-65mph the RPM is kinda high at about 3500-3800rpm. Also when ever i floor it the rpm will run all the way to 8000rpm before it shifts gear,sometimes beyond if i dnt let up.
I am thinking its because of the Gear ratio in the SC400 and my fix will be to get a SC300 Diff. Any ideas or is anyone else having the same problem.

Also have a turbo log before 3400rpm,but thats a nother post,LOL.

2jzLextasy

iTrader: (1)

i believe i read somewhere on the forums that if you do a swap in the 400 that you had tach issues. Not to sure probably need someone to clarify but i will look for the post.

1jzchris

the tach is working fine. The engine RPM is a bit high when cruising.

Slow_Sc3

iTrader: (1)

you have a 4.30 differential change it to the mkiv 3.73 or gs400 3.26 youll be much more happy.

as for the lag your twins are on the way out or you have a major boost leak.

1jzchris

how about a sc300 differential,will that work.

Slow_Sc3

iTrader: (1)

pretty much the same thing as the 400 unless you find a 5 speed

IOWNALEXUS

iTrader: (14)

Your tach is calibrated for a V8 and you have an inline 6 so even though it works it reads higher than it should. A stock 1jz does not shift at/over 8k and rear end gears have NOTHING to do with when the tranny shifts and wouldnt make that huge of a difference in RPM anyway. However it can make a difference on turbo spool, if the gears are too steep it wouldnt build boost as easily.but your tach is reading off so you are being tricked into thinking its spooling later than it is anyway, they are probably spooled up by 2500rpm you just dont know it LOL Go get a cluster from an SC300 and try that.

snowfox444

My regular 1uz engine does the same thing.. revs high, but no upgrades have been made? whats the difference between the motors anyway? Can you not turbo or supercharge the 1uz?

1jzchris

thanks for all the input guy,i am going to try to get a SC300 cluster and see if that makes a difference.

vrsc400

iTrader: (1)

You could also try a tach adapter in the event an sc3 cluster is unavailable. I dont know about where you live but where I am it damn near impossible to find anything sc related!
Props on the 1jz-sc400 swap!

1jzchris

Tanx it wasnt a hard swap....................................I am in Miami so its not that hard to find SC parts.

joeazy187

iTrader: (1)

im doing a 1jz swap in a sc400 as well and was wondering what you did to make the tach work

RawkusX187

iTrader: (4)

Some people just change to a SC3 cluster, it'll make it a bit more accurate

Bubbas SC

iTrader: (1)

Can anyone direct me to a legit shop that can source 1jz's? I know of Jhot, but does anyone know of shops closer to California that has good reviews.

RawkusX187

iTrader: (4)

You should have many places local to you since you're in Cali