Hello everyone. I hope noen of you have to deal with my recent issues, but if you do, here is a summary of my experience with rebuilding my ENTIRE drivetrain. Rebuilt trans and new driveshaft under warranty 1.5 years ago. Noise/vibration from rear end shortly thereafter. First, Passenger side rear wheel bearing replaced (oringal bearing [nylon] bearing locators failed, all ***** then go away from pressure points ( accel, road grade shifts, braking, etal). Next the differential was confirmed, after being suspected, to be bad ( ring/pinion and cage gears going doa, as well as outshaft bearings).

In any event, Lexus wants well over 3k for a new differnetial,so, the LONG hunt for good pull from a wreck was begun - after 4 months, we found a used one at a wrecking yard in CA for $650 w/ shipping and a very brief, but comforting, warranty. Also had half-shafts inspected, degreased, new boots, and driver side bearing/hub seals replaced.
New drilled rotors, calipers, nice pads, etal... All mounting (rubber)bushings still good (Nevada car). Anyway, costs totalled near 2,000 dollars.

Summary - Differentials and passenger wheel bearings are key issues with modified SC400's like mine. Half shafts and driver-side bearing were, in my case, not relevant, except, labor costs made it cheap to deal with them while the Differential was being replaced. FYI.


Mike Torst
92 sc400 modified.......

 

agiagi, what mods are done to your SC?
- Jon

 

Hi. Well, brakes are grooved and drilled Brembos, streetable Bendix pads, Dunlop 255's. The exhaust is custom from the manifolds back, including hi-flow shared chamber cat, Dynaflows and 2.25 pipes. TRD modified computer, special program developed on their baseline programming by me and a few techs. I still had to pay them, but by going down to Torrance w/ the car, and testing (over 10 different times), we came up with the current mapping now in the computer. The airbox / K and N filter project, front clip from a '2000 model (accident repair allowed me to update the forward exterior at no cost to myself). Oh, new tranny - torque converter, rebuilt rear end (all of it), new driveshaft, wheel bearing, the usual stuff.

The biggest improvements? exhaust, computer and intake...

Have a good one!

Mike
'92 modifed SC400

 

TRD modified computer, hmm... interesting. Can we get one as well?

 

TRD in torrance... a new office?

I know the engine building shop is in Costa Mesa (near Stillen) and the sales office/warehouse is in Tustin (this is also where they house the TRD show cars 7 trucks), but Torrance? Are you sure you weren't at G-Force?

 

Over 4 years ago. The shop area only did computer programming.

Perhaps they have closed that oepration and consolidated, moved... In any event, about 6,000 sq. ft., about 6 techs on site ( it was a friday, late afternoon). Was connected to them by my Lexus dealer.

Again , over 4 years ago... It was $700, using my computer, which we pulled from the car and de-chipped, put the chip in the burner, programmed it, and reinstalled, etc... Testing was done on a nearby industrial road - simple 0-to 70ish stuff. Also remember it was past several aerospace concerns ( seen as I was heading west) close to the coast.

Mike
'92 modified Sc400

 

They have an office next to South Bay Toyota. It is not new. Well, not since I've remembered. It is on Western Blvd.

 

Hey, you were right - I just went though my receipts - It was G-Force OOOOPPPSSS!!!

Sorry everyone, AM I Bad..//

Mike
'92 modified SC400 - w/G-force ECU - silly me

 

Further info on G-force ECU project. Chip was initially desoldered and a socket installed, if memory serves me right... I elected not to spead the extra hundreds to do the same w/ the tranny chip though ( it was another $600 or so, if I remember right... )


The guys had two or three baseline programs. I had had a lot of experience on prior custom ECU systems on my prior turbo cars, so I modified the timing map (no fuel mods) with a bit more aggressive advance table, and really extended by several more degrees the upper rpm advance, which on the baseline G-Force tables had been designed to taper of almost as fast as the stock timing tables, especially from 5,000 rpm to redline. After each couple of mods, we put the computer back in the car and ran it, until eventually I have what I have now.

Anyway, that about it.


Mike
'92 modified SC400

 

Ever dyno it? My Unichip has timing and fuel modification, and the setup was custom when I had it done (first time it was done that way far as I can tell). The tuner guy from WR got a ton of power from the car, around 30 ft-lbs over the whole rpm range and almost 40 horsepower. The computers in these cars are detuned to the point of being a little ridiculous.
Did you ever experience a slight cavatating and surging at about 40 mph?

 

As to dyno -no. as to 40mph issue, no.

A side note - the fuel curve was not modified because they wanted more money than it was worth. A/R ratios remained a bit rich even after computer/exhuast/intake mods.

As I hold the GS 400/430 in high regard, I have found that I can SLIGHTLY pull a sotck GS400 and stay within a car length (standing start) with a GS430. In both cases the 5-speed on the GS cars give them a 'burst' of sorts up to 50ish, then I run with them AOK. Boy, I would love to have a 5-speed and the variable valve system.... and then modify my car... Alas, My car is paid for, and, in all frankness, I have had incredibly fast cars before my little ole' SC400. I LOVE my SC, even if is much slower than my prior rides which had pressurized induction and nitrous. Hey, I am stuck in traffic most the time anyway...


Mike
'92 SC400 modified