st165 vs st185 3sgte - Toyota Nation Forum : Toyota Car and Truck Forums

Sharkbite86 · 07-10-2007, 02:30 AM

Ok so I have been doing a lot of research about the 3sgte but I can't seem to find much info on what the differences are between the st165 and st185 3sgte engines. I know the st165 has less horsepower, has an air-to-water intercooler, and the turbo is a little less refined, but what else is different? How much more difficult would it be to upgrade an st165 vs an st185? The reason Im asking is because I found a st165 at my local junkyard and I might be able to get it for $150 w/o the turbo.

Cel7Teen · 07-10-2007, 09:38 AM

150???

holy crap!!! well unfortunatley I can't tell you too much as far as the major differences with the internals or any thing like that. but, I do know that with the nissan sr20 motor, there are very small differences internally. the biggest thing with those is that the turbo is bigger. thats why people buy an s13 sr20 and put the turbo from an s15 sr20 on it. the horses obtained are very near that of the s15 sr20. of course each generation of each motor has new technology that can now go in. for example, it wasnt a new idea but like you said they did go from air-to-water to air-to-air on the intercooler. I say if you know that it runs... GO FOR IT. hopfully someone else can give you more info and tell you if you can take the turbo off a 3sgte from an st185 or even an st205. Im pretty sure you can but can't be 100%. the only other things that may be different is probably a couple of sesors. good luck and if i find out anything more I'll let you know.

Sharkbite86 · 07-10-2007, 11:10 AM

thanks! I have no idea if the motor actually runs (hence why it is so cheap) and the turbo as well as the exhaust manifold are missing (not to mention the thing is pretty dirty). I also learned that it has less compression compared to the st185. What I am most concerned about are any differences in the head. If the head is different/tuned different than that could cause possible issues for me. I plan on upgrading it to 300hp if i can so I am well prepared on taking it apart...

Cel7Teen · 07-11-2007, 08:55 AM

well good luck. I wish you the best in you tuning. about the heads... if they are different, you may be able to take the head off of an st185 or st205 along with the manifold and turbo. but by the time you do that... if might be more expensive then just buying an st185 or st205. but I dunno. good luck.

AWDios · 07-11-2007, 02:16 PM

Pretty sure the 205 head only bolts to the 205 block, or is it just the intake manifold? I forget.

stylin_leo · 07-17-2007, 02:08 PM

I am currently installing the ST165 into my 91 GTS. Let me tell you its been a nightmare. The Throttle body sensor had to be modified and all of the wiring is different. We opted to use the existing wiring harness. The exhaust does not match up and some other modifications were required. There are quite a few more sensors on the ST185 over the ST165. In regards to power you are losing 40 HPS (ST165 is 185 HPS@ 6000 rpm; ST185 is 225 hps@ 6000 rpm) this is mainly due to the difference in Turbos. The ST165 has Single Entry CT26; the ST185 has Dual EntryCeramic CT26. In regards to differences in the motor you can get more info here...
(url:http://gtfour.supras.org.nz/3sgte%20table.htm)

Sharkbite86 · 07-17-2007, 03:36 PM

wow thanks! Well I plan on putting the engine in another car entirely and I plan on using all the parts that come with it (wiring harness, ecu). Looks like the only difference in the long-block is the valve lift in the head. How easy is it to upgrade those if I had too (although I probably will not)?

alltracman78 · 07-18-2007, 10:02 PM

There are way to many misconceptions about these cars......

165 was 190 hp.
185 was 200 hp in the US and 225 in Japan.
The HP jump comes mainly from the ECU, not the turbo.

The 165 and 185 have basically the same sensors.
The 165 does have some older versions of the sensors though.

The heads are very similar. I believe you can even bolt on a 185 head to a 165 block.
The main difference is the camshaft journals are different sizes so you can't use cams for the 185/205 in the 165.

I believe you can also bolt a 185 manifold and turbo to the 165 head, but it will take some mods.

Use the 165 harness, it will make your life SO much easier.

Leo, who told you to use the 184 harness on the 3S?
They made your life MUCH harder. The 5S harness is missing ALOT of the wiring and connectors you need for the 3S.

Sharkbite86 · 07-18-2007, 10:36 PM

oh man, the ecu huh. would flashing the ecu for performance fix that, or maybe a piggyback?