JIBBBY Posted July 14, 2006 Share Posted July 14, 2006 I have been upgrading my 1992 SC400 for over two years now and I am pretty much finished...I would like to share the results of all my mods...This will be a story, so grab some popcorn get comfortable, and read... :) Presicion Dragon Torque Converter - I immediately noticed a huge improvement with throttle response from a dead stop....0-30mph speeds were dramatically increased....Very impressive off the line...With the torque being transfered to lowend the topend power suffers a bit... There is a give and a take with this mod.. At high rpm's the car becomes slightly sluggish...To gain back that topend power that is lost I would say changing out the rear half of the exhaust system to highflow will bring it back to what it was.. Driveability remains the same...This is one of the best mods I did and really wakes the car up..$1200 :) Apexi piggy-back ECU - While 10hp or so is gained and felt by allowing the stock ECU (computer brain) to put out increased fuel and air mix to the engine, the downside is you will notice a tiny hit at the pumps..Helps with engine tuning too...but I did have my Apexi piggy back ECU malfunction so another brand may be worth considering... A good mod for power and tuning..$400 :) Exhaust mods - Replacing the stock mufflers with straight thru stainless steel mufflers. (Megan N1 circular mufflers)...I immediately noticed an improvement in power at high rpm's..I was pleasantly suprised with the difference made over stock.... To compensate for the increased exhaust noise levels I installed two high flowing stainless steel resonators on the rear exhaust section just after the mufflers...That cut the noise in half without sacrificing performance...$100 :) Exhaust mods - Replacing the main center catilytic converter and Y pipe to high flowing also made a noticeable difference at at higher rpm's to my suprise...I installed the magnaflow 2 into 1 catalytic converter with the built in high flowing Y design....Again, power at high rpm's were clearly noticed..$150 :) Exhaust mods - Installing a set of S&S Headers was amazing and the most dramatic exhaust mod change.20-35hp or so was gained, noticed and felt...Although the S&S Headers were originally designed for the GS400 they are being sold for the SC400's as well and there is a slight difference between the two cars.. What is suppose to be a bolt on mod is really not..When installed and connected to the stock exhaust system the exhaust hangs way to low to the ground.. Shortening the down pipes and deleting the two smaller cats is needed and installation was a nightmare, this mod cannot be done in your backyard... EKtuning.com headers would be a better choice for installation... Noise levels to my suprise are really not increased...rumble rumble just a little and a tuff sounding noise, maybe 10% louder..However, I like to keep things quiet so I added two more stainless steel high flowing resonators on the rear exhaust section and that has helped alot with keeping the car very quiet at idle, like stock...... Great mod for power...$1100 installed.. :) Intake - I combined the BFI intake design, Rod Millen pod filter, and Enjen snorkel tube...A custom heat sheild was also made..No noticeable gains were felt, but my feeling is the intake upgrade flows better then stock and allows the engine to breathe better... I still give this mod a thumbs up on looks alone, bling bling...$200 :) Installing the Flex-a-lite dual electic fans - In contrary to what most think there are small power gains to be made when deleting the oil drive hydraulic stock cooling fan and then changing to dual electric fans... These fans once installed combined with a new stock sized radiator cools the car better then I would have imagined...The car now operates slightly colder at all times and I experience no cooling problems on the hottest of days and sitting in traffic with the A/C on full blast...My SC4 always runs at a quarter temp reading and doesn't move.... Noise levels are increased but it is a good sounding noise...Note: the electrical crap that comes with the fans are all garbage, thermo stick, control box, etc..all junk...I elected to use a different control box (relay) and heat sensor...I could not be happier with this swap...One side effect to this swap is the oil sensor light comes on every now and then on the instrument cluster...No big deal, just annoying...Need to remove the bulb... Oh, and with this mod the front end weight reduction is around 25-30lbs...$250 :) Nitros Dry System 100-150hp shot - BIG BIG difference in power....Immediate torque is felt at the wheels when running the nitrous oxide.. The NOS does create traction problems for me in first and second gears so timing the activation is key for fast runs... Second gear is manageable but I still get both rear wheel spinning loose at times...Feels like the engine actually doubles in power on a good run...Down sides are: untimely tranny shifts at times but not often, non controlled acceleration kinda stinks...Bottle refills every month cost $80 or so on average (but I ride the nos regularly and often), also rear tire wear is increased dramatically. Changing, opening and closing the nos bottles is an inconvenience at times...Benefits that come to mind is the car remains in stock reliable N/A form..Gas mileage remains the same as apposed to a Turbo or Supercharger setup..Passing emmisions is not a problem...No delay what so ever with nitrous..After two years of almost daily use the engine still idles perfect, does not use oil, tranny may be suffering abit but still works fine with 100,000 miles on the car.. No reported breakdowns what so ever since I bought the car, which is big to me.... One other thing in contrary to what people think nos is safer even then gasoline and is not flamable...Nitrous Oxide when it is fused with gasoline then becomes flamable.....So you will not go up in flames.....$1200 :) Supra Torsen Limited slip differential - I picked up a 1995 Supra TT (automatic) torsen LSD complete and installed it with no problems, all the bolts patterns alligned perfect and is basically the same fitment as stock... The differential gearing seems to be very close but is not identical. I did notice the speedo was off just slightly after the swap.. This leads me to believe there is a lower gearing change between stock and the Supra Torsen LSD. It is a good change in my opinion...I believe it makes the car slightly quicker but reduces top speed by just a bit... No more one wheel burnouts, now I get two wheel burnouts...Better traction also in weather conditions, etc.. Most importantly for me is that off the line traction is gained.. There is no difference in driveability or noise either...Runs like the stock open end differential... This is a very good mod in my opinion for hotrodders and others that live in poor weather conditions. The Traction control feature is not the same either on these cars.....$500 :) Electrical upgrades - Removing the stock big block battery to a smaller, lighter in weight, and more effecient Optima battery is a good idea for front end weight reduction and performance.. I also changed out the original crispy old ground cables...Installed copper connections, high performance spark plug wires...Also installed a hyper voltage regulator that helps stabalize the batteries electrical current...The combination of all these mods made the car run crispier and feel more responsive...No more dimming of headlights at idle, just smoothe electrical even current flow throughout.. $350 :) Replacing the stock rims and tires made a big diffence in traction and looks...Reducing the rear tire "diameter height" size and reduced rim weight from stock helped a bit with 0-60mph performance and weight transfer..More rubber on the road obviously helped too....I went with the 10.5 inche light weight alluminum Allessio rims with 275/35/ZR18 tires and could not be happier...The car really grips the road now and most importantly off the line traction was gained...Looks awesome... The front end of my SC4 now actually lifts abit at launch as apposed to before.. $1200 :) Eibach springs and Tokimo shocks - It was hard to give this one a smiley face, but compared to stock I do believe there is a huge difference in the cars handling abilities and looks...Down sides are - reduced suspension action by almost 50%, slight steering wheel drift on freeway (minimal). I have been running on these for about two years now and when first installed I was extremely dissapointed...However, over the years the suspension softened up, became more confortable to drive, and no more rear wheel hop when launching...The almost two inch drop allows the car to grip better on launches and when cornering (night and day from stock) The car does not bottom out but you can feel dips and bumps pretty well...I give it a shaky thumbs up...Tein Coilovers would be a better and more costly choice for a daily driver...$400 :) Removal of the stock heavy spare tire, rim and tools in the trunk along with the heavy 12 CD changer (I use the IPOD and MP4 instead of the changer) this near 100lb weight reduction made a slight difference and gave the car a little more spunk, maybe.....Traction did not suffer from what I can tell...Fuel economy probably increased slightly too.. I am just hoping I don't get a flat... $ Free :) Supra Lower Control Arms and OEM bushings - After trying out the Daisen LCA front end bushings, I discovered I did not like the feel at all...I noticed premature bushing wear and noise...I then purchased a new set of Supra Lower Contol arms that come with the stock OEM bushings. Installed perfectly and immediately noticed an improved feel in steering and suspension...Could not be happier with the change...The daisens ended up in the garbage can...New Supra Lower Control Arms $500 :( Tower Bar - When installed I could not notice any difference in performance or stability at all...The tower bar I have is not a TRD but it is not an Ebay special either...It is solid.. This mod could have been a waste of money... $75 :) Upping the stock tranny line pressure - I can't say for sure if it actually made my car faster, but shifts seem to be more crisp and maybe even more timely.... Does not slam into gears but there is a noticeable difference over stock.. It is a cheap mod (turn of a screw) that actually preserves the life of the tranny from what the experts told me, reduced tranny wear with upped line pressure is what I here......Downsides - hard clunk or shift when going from Park to Drive or from Drive to Reverse...I would have to lean toward saying it does help a little with the transmissions performance... $100 I am going to stop here as these are the most dramatic mods that I have done to date..Also I may be wearing out my keyboard and fingers with this post...... In conclusiong: My 1992 SC400 is still running with the stock engine internals and stock tranny and this car is fast now and can beat and or keep up with most newer elite sports cars.. I have researched, inquired, tried and failed with mods over the years and would like to save people some time and trouble by posting this thread. This thread is a quick guide on how to make your SC400, GS400 and or LS400, 430's too super fast..... I will also include old and new car pic's with all this mod crap..No order of pic's just throwing them out there.... Hope I didn't put anyone to sleep with this thread ...I Had some free time to kill....See ya Quote Link to comment Share on other sites More sharing options...
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