KahnBB6

iTrader: (5)

Excellent upgrade!!

On an SC400 I didn't think the alternative factory higher output UZ alternators would need any modification to fit at all other than the plug type that they use. Don't 1UZ engines use alternators with that third mounting ear?

Usually this upgrade is done on 2JZ engines where you MUST shave off that extra mounting ear plus 5mm off the back of the upper mounting point (after measuring to be 100% sure).

When I did this upgrade (and those two physical modifications to the alt housing) on my 2JZ SC I used a 2003-2010 SC430 alternator that is 6-phase, 130 Amp and which includes the same oval style plug that most later SC's and MKIV's use.

In my case I left the stock 120A ALT fusible link alone and did a Big Three upgrade with an in-line 150A fuse on the extra alternator positive cable direct to the battery.

For me this was a no-brainer upgrade when it came time to handle another 18A of sudden current draw from my SC's three auxiliary electric cooling fans that kick on all at once.

......

There is also a 150A ALT fusible link that some SC400's got (if yours doesn't already have one from the factory) which can replace any 120A ALT factory fusible link.

The biggest advantage in using one of these newer OEM UZ alternators is the upgrade from 3-phase to 6-phase technology for better amperage output at idle.

Also if you ever need it there is also an OEM UZ 150A 6-phase alternator available from either the 2004-2007 Sequoia or some years of the Tundra with the towing package (P/N 27060-0F050). I know that some years of the Lexus GX470 also got one of these alternators.

CLass of 1

Awesome find dude!! The 100 amps is barely enough, so that it a great pickup; 30% more juice with zero drawbacks!

I eventually want electric fans so I can eliminate the hydraulics associated with the stock fans, so this type of mod is a must! Thanks!

Nick

DrAtomica

The 1UZs came with a 100 amp on the SC400s and LS400s, I may be wrong but also for the GS400. The stock alternator fuse is rated at 150amps so I should be good with the 130amps too.
Next step is to do the electric fan conversion, what setup did you go with?

I didn't know about the Sequoia and Tundra alternators but if the 2UZ one fits than that'll be a great upgrade for the future!

Electric fans will be very nice although I will miss the quietness of the hydraulic fans, especially on idle.

CLass of 1

Yeah I totally agree. I actually love the hydraulic fan for its smooth and quiet operation but it’s just too big and bulky.

Nick

KahnBB6

iTrader: (5)

I was not aware that even SC400's only got 100A factory alternators even with some models getting 150A ALT fusible links. I could have sworn that I saw a couple of model year SC400's that received 120A alternators from the factory but I must have been mistaken.

In my case with an SC300 and the 2JZ-GTE swap I only fitted auxiliary electric cooling fans and retained the main non-hydraulic mechanical cooling fan. The main mechanical fan driven off the engine is always spinning and the fan clutch controls how close the blades get to 1:1 but the auxiliary fans help keep the extra underhood heat under control as needed.

I recreated the 1997-2002 MKIV Turbo Automatic auxiliary cooling fan setup: x1 main mechanical fan with clutch, x2 pancake auxiliary electric fans on the side of the fan shroud and x1 big auxiliary fan mounted in front and on the side of the A/C condenser. The mounting points and refrigerant pressure switch for that big A/C condenser fan are already there on every SC/Soarer chassis so the factory assemblies just bolted in.

The relays and rest of the control system were not however, so I had to look up and get all those parts and recreate the whole factory 30A Fan circuit that MKIV TT's have. A very similar auxiliary cooling fan circuit came standard on all 1991-2000 Toyota Soarers with 1JZ engines. The automatic 1JZ cars all got that same condenser cooling fan... a nearly identical version to what Supra MKIV TT Auto cars also got which all bolt in exactly the same way onto the chassis.

In my case those extra fans operate exactly the same way they do on Soarer 1JZ and Supra MKIV TT vehicles: the relay control circuit keeps the fans off until the A/C pressure switch *breaks* the trigger circuit whenever refrigerant pressure gets to a certain level and it doesn't *complete* the trigger circuit again until the refrigerant pressure is down to a certain level again.

There is a coolant temperature switch in this factory circuit design which is located at the bottom of the radiator: Whenever the coolant temperature reaches 207F it also can *break* the auxiliary fan control circuit which then triggers on all the aux fans. That coolant temperature switch then keeps the fans on (ie: trigger circuit broken) until the coolant temperature goes back down to 196F.

There are two relays in the system that get mounted on a bracket under the headlight (accessed by removing the panel that covers the PS Cooler lines): one is to control power to the circuit and the other is what actually controls the fans whenever the trigger sensors turn it on). It's an oddball "double negative" kind of relay circuit. The fan control relay actually gets triggered in a manner inverse to how a normal/common automotive relay works-- it keeps the fans off as long as the 12V trigger circuit is constantly flowing but will turn them on any time that 12V trigger current flow is broken.

In both cases the trigger switch sensors are set up to not turn the fans on and off constantly. These days a vehicle computer would control helper fans according to its own whims.

In an SC400 it is possible to run just the additional MKIV TT Auto / Soarer 1JZ Auto A/C condenser fan with a much simpler circuit or a recreation of the control circuit that I used. See my further thoughts below on that in reply to Nick.

It's all covered here in this big Supraforums thread! Just ignore all the JZ-specific case modifications to the UZ alternators mentioned therein.

https://www.supraforums.com/threads/...ngines.683340/

The thing about it is... the OEM Denso 6-phase 130/150 Amp alternator options that come from UZ engines turned out to be a better solution (after modification) after the initial research done in that thread for a factory JZ direct fit 130A alternator. One such alternator actually exists for some JDM vehicles that came with JZ engines.... but Toyota wanted $1,500 USD before shipping from Japan for EACH example. That killed the community interest and prompted others to look into modifying factory alternators from the UZ engine family to fit JZ engines.

Nick and DrAtomica, so far the best fully electric fan setup that I've been aware of that will work for our cars with factory reliable results regardless of whether the engine is a JZ inline-six or UZ V-8 is a combination of:

--An MKIV TT aftermarket radiator
--An external transmission fluid cooler for automatic applications
--OEM 2001-2005 Lexus IS300 dual factory cooling fans and fan blades (heavy duty cycle motors)
--PHR's custom IS300 dual fan to MKIV fan shroud
--A custom control circuit to power and regulate the fans that operates them

I am not sure if they are variable speed mode fan motors or not. They may be an on/off design or they may have low and high speed modes. I haven't looked into them in depth so I can't say at the moment. Looking up exactly how they operate in a stock 2001-2005 Lexus IS300 will answer that... and also clarify if they can be run in an always-on low power mode and then in an additional high/full power mode for high cooling demand temperatures.

I'd think the thinking would be that there should always be at least one fan spinning to that the engine bay doesn't heat soak but maybe that won't be needed for a naturally aspirated 1UZ-FE...?


Anyway, of all the aftermarket electric main cooling fans that people have used on SC's and MKIV's the consensus seems to be that the factory IS300 dual cooling fan motors tend to be the most long lasting and reliable of all.

For JZ turbo engines that produce a LOT of engine bay heat the stock mechanical fan plus helper fans still collectively flow the most air... but a close second and very good alternative are those dual IS300 cooling fans. They have the benefit of being engine application independent of course

....


In addition, just to help with the A/C it is totally possible to use a Soarer or Supra MKIV factory condenser fan hooked up in a very similar manner to what I did with my aux fans so as to allow the A/C pressure switch to request on-demand extra refrigerant cooling any time the pressure gets high enough. Even on NA cars I think it actually can help on hot days. Any of the info needed to set that extra circuit up I'm happy to provide if needed.

In the 1997-2002 Supra MKIV TT Auto stock fan setup those three extra fans all turn on together and pull a solid 18 Amps of current collectively. However by itself that A/C condenser fan motor only ever pulls 7.4-8.5A of current so it is not a heavy extra electrical load to account for.

.....

Nick, with your renewed effort to continue with your 1GZ swap I think the IS300 dual fan setup with the PHR shroud would be a good option for you. If your build will include an aftermarket ECU and custom tune then I think it should be no problem for you to address the cooling fan control directly from the ECU.

CLass of 1

Craig, I 100% agree on the IS300 fan setup. It’s what I had planned to do. OE fans, in my experience, are always the best to choose. They’re typically robust, long lasting, and move a ton of air. For my use, I had planned on running them, just as you described, with a relay system to trigger a low & high speed with 12V triggers sent from the standalone.

Nick

KahnBB6

iTrader: (5)

Yep! I think they will be the best option just for their reliability alone but also because most MKIV Supra owners tend to like them for that and their ability to flow enough air for a turbo engine bay, second only to the 97-02 MKIV TT factory multiple cooling fan setup.

For both you and DrAtomica I think it will be the best choice overall. Plus you then can upgrade to a thicker Supra MKIV style radiator once combined with that PHR shroud for the IS300 fans.

psichotic

Nice write up. I just snagged a cd009 out of an '06 350Z. My intention is to go with Fisch but didn't realize until reading this that their bell is as big as the cd009 bell. My '95 is insanely clean and I hate to have to bash on the tunnel to fit their stuff.

CLass of 1

I have heard that it fits without modification. Fisch themselves don’t know but I’ve read other member’s that it didn’t require any tunnel mods…

Nick

psichotic

That's good to know, thanks.

DrAtomica

Been a while since I updated this thread.
Currently not too much going on with the car itself. I have been quite busy working on my Celica but for the time being this is what I started working.

This is supposed to go with your stock 98+ wood trim, instead of having the auto shifter there you'll have a gated shifter. I have yet to do many measurements and check clearances but that's what I'll be doing and 3D printing some test prints to check fitment.
Now this will be specifically for the SerialNine shifter and I have no idea if it will work on another SC with the same setup. Another piece will be added to the shift rod as well so it can pass through the gates giving it that notchy feeling of a gated shifter.

CLass of 1

That looks GORGEOUS!

Nick

KahnBB6

iTrader: (5)

I like this! Looking forward to seeing how it comes out in ABS!!

DrAtomica

I did some measurements on my shifter setup, checking the distances between each gear, ran into a interesting problem. The shift rod provided by SerialNine is a bit too thick, its at 11mm and the distances between each gear are about 7mm-10mm which means if I make a 11mm gate there just isn't enough space for the rod to go through since it occupies a lot of space.

I thought of a few options,
#1 Create an entire new shift rod which will be something like 5mm or less, the question then it will be enough to withstand force from shifting.
#2 Add an extension on the shift rod that is thin so it can click on the gates (it may not look that great)
#3 Scrap the gated shifter idea and place something new there, maybe something like how an automated shifter works (sliding mechanism underneath)

I'm going to try and figure option #1 and go from there. But any ideas will be highly appreciated! Definitely inspiration on this one since it will be a bespoke piece.


The outer square is the trim perimeter, the two square inside are the distances of how much space I have with shifting with reverse gear which is the second smaller square.


On this Ferrari gated shifter, you can see the shift rod is thinner than my bulky SerialNine one

RudysSC

Love the gated shifter design. I'll be curious what your research and experimentation leads to!