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1UZ for my Superlite Coupe SLC

Jacob666

New Member
Picked up this from a local yard last week:

From a '99 GS400
T-belt changed @90k although unsure on overall mileage. Overall its looking like a well maintained engine all things considered.

Goal for SLC build: I want to go for a street-oriented build that may go to the track occasionally, but primarily street-oriented. To reference what I am talking about, go here: http://superlitecars.com/superlite-coupe/

Goal for engine: I want to get it in top running condition but remain N/A. However, if cost effective I'd like to build in the ability to go mild FI down the road (6-7psi). I will also be most likely mating it to a Porsche G50 transaxle.

First order of business: The wiring harness is hacked up fairly badly, but I do have it and so I have 95% of all the connectors. Which route would everyone recommend?
A) Repair existing wiring harness and buy a stock ECU?
B) Buy new wiring harness and buy a stock ECU?
C) Go with aftermarket standalone and completely bypass stock wiring/ECU?

If I go aftermarket I would probably go MS3/ms3x... but any suggestions/comments are welcome!

Second order of business: Maintenance. I am all about doing maintenance now rather than waiting for something to break and having to fix it later. Thus far I have this on my list to do:
-T-belt plus accessories (tensioner etc)
-Water pump
-Oil pump
-Valve stem seals
-Gaskets from the heads up (minus head gaskets since I dont think I will pull the heads)
Is there anything extra you would recommend or anything you would recommend I take off the list?

As mentioned in the title, I'd love your input :)


I also need to get my hands on 3 COPs, since mine only had 5 when I bought it. In addition I also need a TB and an alternator. As far as the TB, if I go aftermarket ECU, how hard would it be to use/wire in a universal TB? (Since VVTi TBs are rather pricey from what i've seen) So if anyone knows where I could get my hands on any of these?

cheers!
-Jacob
 

hiluxfan

New Member
Hi Jacob
Great looking car! :cool:
As far as the ECU is concerned I think you will have issues with the security features of the standard unit. You may be able to find one somewhere without this but the majority will have it. There are clever guys here on the forum that can bypass it. Speak to Gloverman.
I would suggest going for an aftermarket standalone unit. Seeing as you want to have a bit of track fun it is always good to have some kind of data logging. Most of the modern aftermarket ECUs has this already built in. The Mega Squirt units certainly do.

Your list of Maintenance items looks good. I don’t think it is necessary to replace the oil pump. They are almost bullet proof in standard form. Just inspect it and ensure that it is still in good condition. You will definitely have to add some kind of baffles in the sump for track use. It looks like that car will pull some G’s! :D
 

Jacob666

New Member
Thanks! As far as the oil pump, anything specific I should look for to ensure its still in good running order?

And yeah that was my concern with going stock ECU, and I wont have a regular trans to plug into among other things.
 

hiluxfan

New Member
Hi Jacob
You can inspect the oil pump and measure if there is any wear to the gears or body. A good workshop manual should give you the specs. If you see any scouring or scratching then rather replace it.
The standard ECU can be run without the standard trans. There are a few threads on the forum on the subject. I will be running aftermarket though. :)
 

cribbj

"Supra" Moderator
Staff member
The rods in these engines are the weakest of the UZ family, so be sure you have a working rev limiter on whichever ECU you go with. With the stock rods, I wouldn't push these engines much past 7500.

Again, Gloverman has had more experience with the VVTi engines than any of us; he could advise you better. Most of the brain trust here know the earlier engines pretty well, but the VVTi's were $$$$ and hard to come by when the rest of us were acquiring our "core" engines years ago.
 

spf_lexus

New Member
Even though this engine has the weak rods, they can still handle a nice bump in torque before they throw a fit. I too have a vvti and did a lot of reading on FI builds with OEM rods. What I found is that 5-6psi with a centrifugal blower or turbo is perfectly safe. When boost is raised to 7-8psi+, your in the danger zone. This engine in stock form can handle a little more than 400bhp 400btq. I feel that this is partly due to the centri's lack of low end torque. If I ran a roots blower or small turbos, I would keep it at 5psi just to be safe.
 

cribbj

"Supra" Moderator
Staff member
Sean, I'd be more worried about overbuzzing it and ending up with a whole load of bent or broken rods, especially in a lightweight racer like the SLC.

Overboosting is certainly a danger too, but in this case, since he said in his first post that he's initially keeping it N/A, then perhaps FI'ing it down the road, overboost shouldn't be a problem in the beginning.
 
Very nice car. For the harness and ECU, I would go for the MS3-Pro with no MS3-Pro harness included, but including the MS3-Pro ECU connectors (2) and pins, and see if you can cut off the original Lexus ECU connector, then mate the MS3-Pro ECU connectors to that harness.

On my project, I plan on doing a variation of this with a 2UZ motor. I have one more step. I am having a set of mil-spec plugs being used at the firewall. The original 2UZ engine harness is still used, but the ECU side terminates to a pair of mil-spec plugs. On the firewall will be 2 matching mil-spec sockets, and that will be wired to the MS3-Pro ECU inside the car (Supra).
 

Jacob666

New Member
OK I need some more input. Turns out the scrapyard that sold me the engine made a mistake. They had two 1uzfe's in stock. One is a '94 for $250 and the other a '99 for $1200. They sold me the '99 VVTI engine for the '94s price. Now it was all legal so I legally have the '99, no hard feelings. HOWEVER I am half debating on whether or not to work out some deal with them and go with the '94.

Here is why:
Non-VVTI could make wiring/tuning simpler
Stronger rods
Lower compression ratio for possible turbos down the road
The turbo kit Fran (SLC Designer) has from his original 1UZ was designed for Non-vvti and so if I want to go TT down the road, it would be bolt-on basically.

*See attachment for his TT-1UZ*

*Edit* also, does anyone know if a VVTI style intake manifold will still bolt to non-vvti heads?
 

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cribbj

"Supra" Moderator
Staff member
On your 2nd question, AFAIK, a VVTi manifold will not bolt onto an early engine.

The early engines have an angled manifold interface (about 22 degrees from horizontal IIRC), while the later ones have a horizontal interface.

If you haven't bought the SLC yet, why not the Apex, and instead of an LS4, why not a 1UZ with an E153 FWD manual transaxle. You could turbo it or leave it NA, and either way it would go like stink.

IMO, you'd have a much better looking car than the SLC for about half the money.
 

Jacob666

New Member
If you haven't bought the SLC yet, why not the Apex, and instead of an LS4, why not a 1UZ with an E153 FWD manual transaxle. You could turbo it or leave it NA, and either way it would go like stink.

IMO, you'd have a much better looking car than the SLC for about half the money.
#1, not going with an LS4 either way.

#2, Can a 1UZ even fit? And not a big fan of FWD...

And "go" is only 1/3 of the reasons behind going with the SLC. The other two are: no donor vehicle & supercar looks (Apex looks sporty, but not supercar realm whatsoever)
 

cribbj

"Supra" Moderator
Staff member
From what I understood, Fran has designed the Apex to move the whole engine/transaxle setup from the FWD Eclipse to become a midengine setup, driving the rear wheels, and he just announced that the LS4/FWD package from the Impala would be supported also in the same way. Stands to reason if he can stuff a 5.4 liter Chevy V8 in there, the 1UZ ought to fit too.

Looks - well I suppose beauty is in the eyes of the beholder. I'm not a fan of the SLC styling at all, although many are.
 

Jacob666

New Member
keep the vvt-i motor!!!! add pistons and rods later (as you would do to a 94 1uz anyway)
UPDATE: I talked to the scrapyard and they said regardless of swapping, they will give me the non-vvti engine for $200... thinking about picking it up. Then if I frag the bottom end on the vvti, I could use the beefier bottom end. Thennn if I frag that, go forged. For $200 it almost seams like a no-brainer especially when I ran the VIN at the lexus dealer and turns out it was the parts/service manager's LS that was meticulously maintained...

Here is my thought: Could I feasibly take the rotating assembly from the non, and put it in the vvti? That way get the beefier bottom, while retaining the advantage of the vvti intake system? Or is that more hassle than benefit?
 
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Jacob666

New Member
Potential intake problem:
In the SLC, the engine goes up against the rear bulkhead and leaves basically no room out front for an intake. People using LSx engines just flip the intake around like this:



The VVTI 1UZ has the intake out the front similar to the LSx style intake. However it can't flip it like the LSx engines can.

The original 1UZ used in an SLC was non-VVTI and thus didn't have this issue:


Now I have ~4 inches of room to fit the TB and intake:


What do you think, is that enough room to make a 90* turn... or any other ideas?
 

Jacob666

New Member
Why can't the 1uz VVti intake be flipped around?
From what i've been told, its not mirror image. Though I only tested it quickly...

brb...

Oh snap! So I was told it couldn't be done so I only quickly tried by rotating the upper intake, not the whole thing :rolleyes: So you are correct... I feel both dumb and awesome at the same time right now haha :eek: :cool:
 

Jacob666

New Member
Well here is the progress so far with the engine:









I know its not the greatest, but from just hand/wire brush I think so far its turning out pretty well =]
 

cribbj

"Supra" Moderator
Staff member
Very nice! I hope you're flushing with carb cleaner and compressed air to blow out around the pistons after the carbon removal?

You sure don't want broken wire brush fines, or carbon particles fouling the rings and possible breaking one when you start it up.

Don't forget the eye protection!
 
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