M112 sc400

JBrady

Moderator
This was the first I noticed/realized you had a manual transmission! Very interesting project indeed. Too bad Lexus didn't offer the manual with the 1uz as that would have really created an enthusiast following.

Notice you have the IMF headers. Did you/could you measure the runner outside diameter?

When do you expect to dyno?

Strange that the boost climbs to redline. It should climb from idle to peak fairly quickly and hold steady with a slight dip to and from torque peak and a slight rise towards redline. Do you intend to measure heat?
 

LP1

New Member
I couldn't measure the runners accurately, looks to be 1 3/4". Chase is on line here somewhere he can provide the right number.

The M112 is oversize for the engine, I think it produces more boost than the engine can use. Although I haven't done a lot of high rpm testing as I didn't have the water-meth injection dialed in and have all stock internals.

Don't plan to measure heat or dyno as I don't push it hard. However, my son has a '93 we will be supercharging (it was his idea to supercharge, I did mine first to piss him off). We installed a R-154 in his and there is no way he will be keeping his foot out of it. I suspect we will dyno and tune his.
 

SuperRunner

New Member
Nice job!!!

As for the M112 being oversized? NO WAY. Stock psi on a cobra is about 8psi. At 5200 feet, it only 6psi. On my setup, the stock pulley for cobra would probably only give me 3psi, as the lightning pulley only gave me 5. I am now running a 2.75" pulley and I still only get 6.5psi. The 1UZ crank pulley is just too small.
 

JustenGT8

New Member
Nice job!!!

As for the M112 being oversized? NO WAY. Stock psi on a cobra is about 8psi. At 5200 feet, it only 6psi. On my setup, the stock pulley for cobra would probably only give me 3psi, as the lightning pulley only gave me 5. I am now running a 2.75" pulley and I still only get 6.5psi. The 1UZ crank pulley is just too small.
That doesn't sound quite right...i got 16psi with a similar sized pulley out of the slightly larger M122. I wonder if your internal bypass valve isn't closing fully?
 

SuperRunner

New Member
sea level vs 4200 feet.

Cobra at sea level 8-9psi
Cobra at 4200 feet 4-6 psi

Also I Have check the bypass valve. Functions just fine and seals
 

silver98bullitt

New Member
LP1, it looks like you did an excellent job building your supercharger setup. I've got a question though. What are you doing for engine management? Stock ecu, SAFC, or something more?
 

LP1

New Member
Stock ECU

I'm running the stock ecu. At low boost, less than full throttle you can tell it has more in it and could benefit from a tune. At WOT it goes like stink and the ECU has no issues. Again, I'm sure there is more there but it has plenty of oomph for a daily drive. I noted the cold start idle issue above, likely from the larger injectors.
 

gloverman

Well-Known Member
Very nice setup.

A couple of questions. What model vehicle did you get the 3.27 diff from and how much of a job is fitment? Also what is your 100km /60mile cruise RPM?

Cheers
 

LP1

New Member
Very nice setup.

A couple of questions. What model vehicle did you get the 3.27 diff from and how much of a job is fitment? Also what is your 100km /60mile cruise RPM?

Cheers
Got it off ebay cheap, LS 430 I think. Any of the following works:

LEXUS GS430 01-05 (3.266 ratio)
LEXUS SC SERIES 98-00 8 cyl (3.266 ratio)
LEXUS LS430 01-02 (3.266 ratio)
LEXUS SC430 02-05 (3.266 ratio)
LEXUS GS400 98-00 (3.266 ratio)
LEXUS LS430 03 (3.266 ratio), thru 4/03

Can't remember the rpm exactly (car is up for the winter) 2300 I think but that might be the 110km cruise . It's just about perfect.

It bolts right in, a one hour job assuming the exhaust bolts are willing.
 
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