- Differences between the SC300 & 400

- Aftermarket potential for the SC300/400

- Common problems on the SC300/400

- DIY fixes for common problems

- Power Steering Pump
- Trunk lift supports
- Door hinges
- Burnt bulbs

- Recommended vendors for the SC300/400

- Available bodykits for the SC300/400

- 1997-2000 full body conversion parts listing

- Model year differences/changes for the SC400

- Model year differences/changes for the SC300

- DIY mods for the SC300/400

- Converting cornering lights to foglights (92-94 models)

- Other available mods for the SC300/400

- Bulb, tire, wheel, and speaker sizes

- Compatible Supra parts for the SC300/400

- Part numbers for common parts

- Wiring diagram for Lexus stereo system - (provided by mycrobyte)

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Differences between the SC300 & SC400

The SC300 comes with a 3.0-liter Inline-6 (engine designation: 2JZ-GE) and a choice between a 4-speed automatic transmission with overdrive or a 5-speed manual transmission (from 1992-1997). The SC400 comes with a 4.0-liter V-8 (engine designation: 1UZ-FE) and a standard equipped 4-speed automatic transmission with overdrive (from 1992-1997). Manual transmissions were never offered for the SC400 and were discontinued after 1997 on the SC300. In 1998 the SC400 received a 5-speed automatic transmission with gated-shifter (from 1998-2000), while the 1998 SC300 received a 4-speed automatic transmission with gated-shifter (1998-2000).

The SC400 came stock with 16x7.5-inch wheels and the SC300 came stock with 15x6.5-inch wheels. The SC400 came with larger front brakes, power automated telescoping/tilting steering wheel, and the third brake light was mounting inside the spoiler as opposed to on the rear dash behind the windshield in the SC300. SC300s with 5-speed manuals do not come equipped with traction control either - (info provided by Nick T).

Aftermarket Potential for the SC300 & SC400

SC300: The SC300's major power upgrades lie in turbo kits. As of now, there are two production turbo kits that are direct bolt-ons for the SC300. One is offered by Toyomoto and the other is offered by F-Max. The Toyomoto is generally regarded as the better turbo kit because of its higher quality parts and reliability, however the F-Max kit is a few thousand dollars less in price. The SC300 shares the same engine as the naturally aspirated Supra MKIV and therefore engine build kits and aftermarket parts for the Supra are interchangeable with the SC300. The Supra Getrag 6-speed manual transmission is also capable of being transplanted into the SC300. Injen makes a cold-air intake system for the SC300. ImportToys.com and LexusSC400.com both sell MAF/VAF adaptor plates that allow you to remove the stock air box and use high flow conical air filters in place.

SC400: The major power gains on the SC400 are still in their infancy stages, but soon there will be two supercharger options and two twin turbocharger options. Currently, two different twin turbo kits are under development for the SC400, one bolt-on supercharger kit under development, and one other supercharger kit is already available for sale. One of the turbo kits will provide an intercooled twin T3 setup with underbody mounted turbines, Weapon-R fuel management, and is being developed by Leo at Weapon-R. The other turbo kit provides a similar twin T04 turbo setup built by Powerhouse Racing. Neither have been completed with performance results therefore prices are not yet set and gains haven't been recorded, but goals on both are +300rwhp at around 1-bar of pressure. The supercharger under development is being manufacturered by Area 51 Fabrications and will be sold in Stage 1, 2, 3 setups with Stage 1 set to achieve roughly +80-100rwhp. This set up uses a Vortech blower and will clear the stock hood without any major modifications. The other supercharger is being sold by Forced Air Technologies and would require a custom replacement cowl hood or hood scoop to accomodate added engine height.

Weapon-R makes a cold-air intake system for the SC400 with available piggyback ECU. Injen also makes a cold-air intake system for the SC400. ImportToys.com and LexusSC400.com both sell MAF/VAF adaptor plates that allow you to remove the stock air box and use high flow conical air filters in place.

EXHAUST: The exhaust system for the SC300 and SC400 are indentical, however the JDM Soarers do have variations with the mid-resonators and piping. Some of the mufflers and cat-back systems that have been used on the SC300 and SC400 include: Veilside Titanium mufflers, Greddy MX mufflers, Blitz Nur-Spec cat-back, JIC Twin Spartan cat-back, Phoenix Target mufflers, Magnaflow Race Series mufflers, Magnaflow Street Series mufflers, Do-Luck mufflers, Weapon-R mufflers, Rod Millen Motorsports cat-back, G-tech mufflers, Lukey mufflers, and Dynomax Ultraflow mufflers. The stock piping on the SC300 and SC400 is 2.25-inches from the catalyic convertors on back.

TORQUE CONVERTOR: Swift Racing/Precision Industries makes a torque convertor for the automatic transmission SC300s and SC400s. They are reported to knock off over half a second on the quarter mile times and yield similar 0-60mph track numbers out of the 92-97 SC400s as the GS400.

AIR/FUEL MANAGEMENT: Apex'i's SAF-C will work to optimize the air-fuel mixture on both SC300 and SC400. Weapon-R's piggyback ECU will do the same air/fuel optimization a bit more effectively.

SUSPENSION: Eibach makes Prokit springs for the SC300 and SC400 that will drop the ride height about 1-inch all the way around. Intrax makes springs that drop the ride height 1.5-inches in the front and 1.3-inches in the rear. Eibach Prokits designed for the MKIV Toyota Supra are compatible with the SC300 and SC400. OEM Supra NA and Supra TT springs work with the SC300 and SC400 as well. See more details on Supra suspension here. Tokico makes gas shocks for the SC300 and SC400 as does KYB AGX. OEM Supra struts work as well. Tein makes 4-way adjustable coilovers for the SC300 and SC400. Canover makes an air can suspenion for the SC300 and SC400.

Common problems on the SC300 & SC400

Here's a list compiled by Todd Matsubara of TM Engineering LLC showing of some common problems experienced in the SC300 and SC400. Once again, this is just a list of some of the more common issues to arise with owners. More than likely no single SC300 or SC400 will experience more than a few of these in it's entire lifespan....

• Burnt needles: Some of the older SCs report having burnt out LEDs in the gauge needles. Lexus Dash is a company based out of Plano, Texas that specializes in permanently fixing the burnt needles.
  
  
• Burnt bulbs: Some of the older SCs have burnt out bulbs in the instrument cluster and climate control unit. Replacement bulbs are slightly dimmer in brightness in order to increase longevity. Part#: LX 84999-60360 are about $7/ea - (info provided by Ryan)
  
  
• Leaking power steering pump: Some of the older SCs have a faulty seal in the power steering pump, which can leak power steering fluid onto the alternator and destroy both parts if the problem is neglected. Replace the seal for ~$1 or rebuild the PSP for ~$125.
  
  
• Cracked/dried/hardened leather on the seats: Older SCs tend to have cracks and callous leather seats, especially if kept ungaraged in dry/arid climates without window tints. If the sun damage is severe, Leatherseats.com offers a complete genuine leather replacement kit for the SC for ~$600. Custom leather applications also available there.
  
  
• Cracked dash vents: The most common issue with the SC is a crack in plastic trim around the center air vents. The cause is rapid hot-cold air changes expanding and contracting the plastic until it snaps. A replacement center vent is $100-700 depending on model year. $100 for 1992 & 1997-2000, and $700 for 1993-1996 due to the integrated passenger airbag. - (info provided by SMARK, Hermosa, & jwar)
  
  
• Cracked window sill: The second most common is a small crack in the leather wrapped around the window sill. This is caused by a weak spot in the plastic frame around the window. The plastic underneath, right by the screw hole, cracks from the pressure of an arm. Leather repair shop quote: $50 - (info provided by joelchicago)
  
  
• Worn front suspension bushings: Some of the older SCs may have squeaky control arm bushings caused by deterioration of the rubber. Daizen bushings from TM Engineering are a permanent fix at $100/set.
  
  
• Bad door hinges: A few SCs have experienced sagging/drooping alignment of the door originating from the double-jointed door hinges. Cause is the weight of the door on the bearings over time. Lexus dealership replacement: $400/hinge
  
  
• Fogged/faded headlights: Some SCs have cracked headlight housings allowing for moisture and condensation to get trapped inside creating a foggy mildew coat. Replacement headlight assemblies are $290/ea.
  
  

DIY fixes for common problems

Replacing the Power Steering Pump:
info provided by lexcoupe94:

The pump brackets are mounted at about a 45 degree angle looking at the pump from the front. The outside bolt is higher. After you remove the airbox, overflow tank, pump reservoir and bracket, belt and pump pulley, and some type of vacuum valve on the passenger side of the motor, the side bolts can be removed. They are tough to see; you have to feel for them. I think they were 14mm. Then disconnect the high pressure hose and remove the two front bolts. You gotta pull the pulley off for access to the front bolts. I carefully pried the pump off with a crowbar by prying one side, then rotating the pulley 180 degrees and prying again. I would recommend using a puller, though-would be easier and safer.

Rebuilt pumps are available from PartsAmerica.com and AutoZone.com for reasonable prices.

Bleeding Air From P/S/ Pump:
info provided by lexcoupe94:

- Check power steering fluid level. Fill if necessary.

- Warm up the car 5 minutes or so to heat up the p/s fluid.

- Jack the front end up and prop up on jackstands so that the wheels turn free.

- Take off the p/s fluid reservoir cap and stuff a rag aroung the reservoir to catch any fluid.

- With car running, turn the wheel full left and right 10 times or so, then straighten wheels and check fluid.

- If fluid level is down, fill to proper hot level and turn full left & right 10 more times. Repeat until no more air or fluid burps out.

- Lower wheels back down and recheck fluid.

Replacing trunk lift supports:
info provided by PERRYinLA:

Here are the instructions - some of it won't make sense until you actually start the process:

Try to enlist a friend to help - to hold up the trunk lid, but you can do it yourself using a sturdy pole to prop it up.

1. Inside the trunk, peel off, from the top, the interior cloth-like panel that separates the trunk cavity from the back seat/gas tank area. It's held down with little plastic clips. These clips will release if you give them a tug. You should then be able to see the gas tank and the lifts attached to the trunk hinges.

2. You can't just pop the old lifts off because they are not yet fully extended. There are a pair of little black plastic bumpers that clip onto the tubular metal connecting the trunk to the struts. Pull them out so you can lift the trunk to its full height.

3. Using a 12mm open end wrench unscrew the ball portion of the ball and socket joint that is on the top part of the lift supports. It may be hard to start because it has Locktite on it.

4. Using a screwdriver, unclip the metal retainer that secures the bottom part of the lifter cylinder to a stud on the car body. If you won't be re-using your old struts, you can just jam a screwdriver and bend the clips so that they release. (I had to be more careful, since I knew I would be re-using them.)

5. Now you reverse step 3 for the replacement struts.

6. Clip the bottom part of your new cylinders onto their round studs.

7. Put those rubber bumpers back into place, paying attention to the little key piece that fits into a hole on the tubular trunk arm.

8. Put the interior piece back into place with the clips.

These pneumatic cylinders are under a lot of pressure, even when they're too weak to hold up the lid. Don't cut them or get your finger in the way when they are compressed. Also, take care not to nick or scratch the polished metal rods on the struts.

If you REALLY want to extend the service life of your lift supports, keep in mind there is a slight chance that your trunk currently has only one strut shot, but the other is in good shape. So replace the struts one at a time. If replacing one strut results in a trunk lid that will stay up, you may wish to hold onto the extra strut until the time your other strut gives out.

Rebuilding Door Hinge:
info provided by Ian Miller:

click here

Replacing burnt bulbs:
info provided by Ryan:

click here

Recommended vendors for the SC300/400

click here for official ClubLexus vendors

click here for Parts.Com's top Lexus OEM resellers

Available bodykits for the SC300/400

AB Flug Type 1: [pic 1] [pic 2]

AB Flug Type 2: [pic 1] [pic 2] [pic 3]

AB Flug Type 3: [pic 1] [pic 2] [pic 3] [pic 4] [pic 5]

Barramundy: [pic 1] [pic 2]

BN Sports: [pic 1] [pic 2] [pic 3] [pic 4]

Bomex: [pic 1] [pic 2] [pic 3] [pic 4] [pic 5] [pic 6] [pic 7] [pic 8]

C-One: [pic 1] [pic 2]

Do-Luck: [pic 1] [pic 2] [pic 3] [pic 4]

Do-Luck DK400: [pic 1] [pic 2] [pic 3] [pic 4] [pic 5]

Evolution/Auto Couture: [pic 1] [pic 2] [pic 3] [pic 4] [pic 5] [pic 6]

Exclusive: [pic 1]

Extremor Arising 1: [pic 1] [pic 2]

Extremor Arising 2: [pic 1] [pic 2] [pic 3]

Explosion: [pic 1] [pic 2] [pic 3] [pic 4]

Garage SPL: [pic 1]

Hiro: [pic 1]

Inspection: [pic 1]

Include: [pic 1]

JIC Magic: [pic 1] [pic 2]

Kaminari: [pic 1] [pic 2]

Mythos: [pic 1] [pic 2] [pic 3] [pic 4] [pic 5] [pic 6]

Runner Widebody: [pic 1] [pic 2] [pic 3] [pic 4]

Sard: [pic 1]

Shot: [pic 1] [pic 2] [pic 3]

Target: [pic 1] [pic 2]

T&E: [pic 1] [pic 2] [pic 3] [pic 4] [pic 5]

Veilside: [pic 1] [pic 2] [pic 3] [pic 4]

VIS Vertex: [pic 1] [pic 2]

Wilder: [pic 1] [pic 2]

Wise: [pic 1] [pic 2]

Wise Sport Lip: [pic 1]

Wald Executive: [pic 1] [pic 2] [pic 3]

info and pictures gathered with help from do-luck sc, Lvangundy, tggoodrich, .star., Lex Luthor, howiedoit, TurboSC, & AzLex

1997-2000 Full body conversion parts listing - info provided by Din & SDSC300:

Below is the complete listing for all parts required to perform an exterior body conversion for 92-96 models to the 97-00 style SC300/400. Prices provided are Lexus list price and can be found elsewhere for cheaper.

Description	Part Number	List Price
front bumper cover	52119-24914	315.64
front grill insert	53114-24020	104.33
front absorber	52611-24030	48.57
front-left foglight	81220-24040	--.--
front-right foglight	81210-24040	--.--
left body rocker panel	75851-24900	236.37
right body rocker panel	75852-24900	236.37
rocker panel clips	75868-24020	1.82
rear bumper cover	52159-24905	324.82
rear-left quarter panel	76973-24902	88.72
rear-right quarter panel	76974-24902	88.72
rear-left retainer	52587-24010	13.45
rear-right retainer	52586-24010	13.45
left tail light	81560-24070	204.20
right tail light	81550-24070	204.20
rear spoiler	----- -----	---.--

Model year differences/changes for the SC400

Click here for model year differences and changes for the SC400

Model year differences/changes for the SC300

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DIY mods for the SC300/400

Converting cornering lights into fog lights
(Installing a basic automotive relay)

First you'll need to buy a few items: a 4 or 5-pin 30-amp automotive relay, an inline fuse holder, a 30-amp fuse, about 20-ft 12-awg wire, a box of t-taps (5 is all you'll need if you don't mess up), roll of electrical tape, and good solid connectors: either use solder or buy male-female disconnects. All of this stuff is available at Radio Shack and should cost you no more than $10-15.

Now you need to get to know the relay. A relay is essentially a mechanical switching device that is activated by a low voltage input to activate a high voltage switch. In this application, your low current trigger will be tapped off the parking lights. Your high current output will be the power supplied to the auxiliary lights by the battery via the relay. The relay itself should be a 1-inch black plastic cube with 5 spades on one face, and some sort of mounting tab on another. The 5 spades are labelled something like 30, 85, 86, 87, 87a (at least these are Bosch's labelling).

- 30 is your input voltage for the switched device.
- 87a is an open circuit (no power).
- 87 is a closed circuit that supplies the high current to your auxiliary lights.
- 85 and 86 can be interchangeable, but they are the low voltage leads from your parking lights.

You can choose either headlights, city/parking lights, or sidemarker lights as your signal trigger. I used the city lights because they were easiest to access, the relay can be switched with an input signal as low as 150mV, and in case anything went wrong, no big deal.

Hopefully everyone here already knows that every DC electrical device requires two connections: a postive (live) and negative (ground). The colored wire is always ground (yes black is a color) and white is always the live wire. (in AC it's slightly different)

STEP 1
Basically, your first connection is going to be two t-taps off the both cornering lights' positive wires. Now connect the two t-taps you just made with two runs of 12-awg wire, and lead both wires back to the battery pan. Twist the two wires together into one single wire and connect them to the 87 spade.

The 87a spade will have no connection because it is the open switch.

STEP 2
Lexus uses a switched ground system which presents a problem because your cornering lights aren't always grounded. So to resolve this issue, go back to the cornering lights and t-tap both of the negative (ground) wires. Run two lengths of 12-awg wire from these t-taps---the same way you just did with the positive wire---to the negative post on the car battery. Your circuit is now properly grounded.

STEP 3
Next send a wire from the battery's negative post to the 85 spade.

STEP 4
Now make another t-tap off of the positive wire from your chosen signal trigger (in my case the city light), usually the closest one is the best. Once you've established this t-tap, run another piece of 12-awg wire from the t-tap to 86 spade.

STEP 5
Last is to establish the big power! You will connect the battery's 12v positive post to the 30 spade. BUT before you do that, use that inline fuse holder you bought. It will be a black, plastic, well... "fuse holder", with a looped wire running from one end to the other. Cut the loop into two bare ends. Connect one end to the 12v positive battery post, and connect the other end to the 30 spade on the relay. You may need to splice or crimp extra wire to make the run to the 30 space. It is critical that the fuse holder is very close to the battery. Like less than 12-inches of wire between them both. Make sure you weren't eager and stuck a fuse in that fuse-holder yet, because that would create a live circuit.

STEP 6
Right now the relay system is completely wired up, but there is no fuse in the holder. Therefore no current is running through it so it is still safe. At this point, you'll want to check all connections from and to the relay and once you've determined all is secured and well, insulate it! You want to make the relay water and weatherproof. I did so by wrapping the entire thing in 6 layers of electrical tape. Feel free to use more if you want. Then tuck or mount the relay somewhere safe (IE somwhere away from water exposure and engine heat). I put mine next to the battery pan which remains relatively dry and cool.

STEP 7
Now you can insert the 30-amp fuse you bought and test out the relay circuit. Turn the light wand in your car to activate the parking lights. Your cornering lights should turn on as well.

Other available mods for the SC300/400

ClearCorners.com has designed a custom one-of-a-kind tail light for the SC300 and SC400 using orginal parts, they've created LED lights with clear-lens coverings. They also offer clear sidemarkers for the SC300 and SC400 as well.

Illusion-Lighting.com has custom fabricated the world's first HID retrofit for the SC300 and SC400. The retrofits use BMW E39 OEM parts from an actual BMW 540iL and are transplanted directly into the SC headlight housing with a very OEM look. Other custom options are available including other BMW and Audi applications.

Bulb, tire, wheel, and speaker sizes

The SC300 stock wheels are 15x6.5 inches (all four), and the stock tires are Bridgestone Potenza RE940 215/60ZR15

The SC400 stock wheels are 16x7.5 inches (all four), and the stock tires are Bridgestone Potenza RE940 225/55ZR16

The speakers on the stock Pioneer system and on the Nakamichi premium sound system are 4-inch midranges front and back, 1-inch tweeters in the front, and 10-inch free-air subwoofer in the rear deck.

The low beam bulb is 9006/HB4. The high beam bulb is 9005/HB3. The city/parking light, front/rear sidemarker, step/courtesy light, license plate light, and trunk light all use 168 and 194 wedge bulbs.

Compatible Supra parts for the SC300/400

Supra wheels will fit the SC300/400 perfectly. OEM Supra springs and Eibach Supra Prokits will work with the SC300 and SC400; However, you do need to buy either Tokico struts, KYB AGX struts, or Supra struts for the rear axles due to differing perch heights. It is recommended that you replace all four struts instead of just the rears if you go this route. Installing Supra Prokits without the Supra/Tokico struts will result in a lifted rear end, higher than stock height. Supra NA and TT struts will fit the SC300 and SC400 fine. Supra sway bars will fit the SC300 and SC400 - (info provided by PCMW). Supra braking systems will fit the SC300 and SC400 as long as you use 17x8-inch wheels or larger. Supra braking systems will not fit on the SC300 or SC400 with stock wheels mounted.

Part numbers for common parts

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Compiled by:
- Rich Wang, Webmaster Intellexual.net
  09/20/02

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