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Result Of Mods To Sc400

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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


































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If anyone is interested in this thread, I can continue further with more mods.. I understand this is not a Lexus performance forum, but you guys don't know what your missing out on....There is alot of potential in these small V8 engines...Many restrictions at factory....

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Very nice list with pros and a con version.

Thanks Sk, it's been a hobby of mine for the past couple years or so...My goal was to make this car as fast or faster then the new Vette's and or AMG E55's, and I am getting very close...

Still considering two more mods....

Mild set of performance cams which would bring an estimated 30-40 gain in horse power...Lextreme.com is currently manufacturing a set or regrind cams for the 400's..and should be available soon for distribution. The cost should be no more then $500-$600 for the set of 4 cams.... The only concern I have about the cams is that the stock rev engine cut off limit could peek and then the fuel feed is cut off by the cars ECU or computer brain....I redline now hard at times while using the nos, and with the addition of performance cams that typically allow the engine to rev even higher then normal, that may cause me problems.....We will see...

A shift kit for the stock tranny, not sold on this mod yet, and I don't want to sacrifice the little luxury I have left in this car....Agin we will see...

Just for someone whom may consider modifing their SC, money spent to date totals for my car is at $18,000...I originally purchased this 1992 SC400 3 years ago for $8500 with 89,000 miles on it...After all the above mod's, new leather interior, factory quality re-paint job, additional little mods, etc... I am now at $18,000 and that includes the original purchase price......This is not a cheap hobby....but I am not complaining with the results......

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I would venture to guess most of the people on this site are interested in increased perf., I apreciate the opinons and research of the products youve tested. My 95 400 is the same color as yours with tinted windows as well. Would like to know what you did with the headlamp !Removed!. as I have one that gets cloudy from time to time.

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I would venture to guess most of the people on this site are interested in increased perf., I apreciate the opinons and research of the products youve tested. My 95 400 is the same color as yours with tinted windows as well. Would like to know what you did with the headlamp !Removed!. as I have one that gets cloudy from time to time.

Well I removed the headlights and stuck them in the oven for a few minutes to heat up the glue and then easily removed the clouded lenses... I then I purchased a three step plexi glass cleaner at the local auto shop...Rubbed on the three compounds on front and back of lense and they were restored to like new.... Grabbed a silicon sealer tube and re-sealed the lenses... Reinstalled the headlamps and they look like brand new... The hardest part is removing the headlamps from the car, the rest is easy and doable just as I described....

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Nice thread Jibby!

I have same year , same colour SC400 as you do. I bought the car while working in NY. I have left US 3 years ago but the car is still with me in Europe!

150k miles now. no big problems with it. However there are couple things replaced this year - radiator and water pump due to leaks.

I thought of installing some aftermarket parts and first things pop im my mind are Dragon Converter and NOS.

Would you suggest to start with NOS?

Anyone knows what is HP gain at flywheel or wheels?

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Hey I am glad you enjoyed my thread....Really all you need on these sc4's is a true progressive 150hp nos system and the car will fly....The Dragon torque converter is really great for non NOS runs... With NOS and the Dragon TC you will get major traction problems in first and second gear...unless you plan on getting a limited slip differential, fat rear tires, and or a progressive nos system.. I don't recommend the combination with the stock traction setup.....

It is nice to have the car motor well without the nos too....The exhaust, DTC, LSD, intake and ECU piggyback makes that possible...For rude power NOS, turbo, and or supercharging is where it is at for sure...If you got money a Eaton M90 supercharger would be nice and fit right in, or turbo's can and have been installed on these engines too...Your looking at $5000 for those in most cases, and nos is closer to $1000....

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  • 2 weeks later...

Thanks for the info. , wandering what you did with the headlight !Removed!., one of mine gets cloudy from time to time.

You need to remove the headlight as you have a leak in the seal of the lense if it clouds or gets moisture on the inside....What I did is remove both headlights, throw them both in the oven at 450 for 15-20 minutes...That heats up the silicon holding the lense on...Remove from the oven and remove the lense...I used a 3 step product called PLASTIC SHINE... used the three liquids and cleaned front and back of lenses...Bought some siclicon sealer and re-glued the lenses back in the casing and reinstalled the head lights...Came out like new with no leaks....Hardest part is removing the headlamps from the car...People are selling them on EBAY in new condition after using that method I just mentioned... Hope that helps..

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  • 2 weeks later...

I just wanted to ad this information for those SC400 owners that may decide they want to install headers...I installed the S&S Headers and experienced fitting problems...They have just came out with new true direct bolt on headers at EKTUNING.COM...They claim 20 hp gains but it is really closer to 25hp with the two small cat deletion....The price is $900... The S&S headers cost me $600 plus like $500 for custom fitment....

Headers are not much noiser then stock to my suprise...big noticeable power gains....

A upgraded torque converter and headers is a wicked and effective combination for more performance...Something to consider if you want to keep up with those Mustangs and Camaro's...

These are pretty much the only headers that are available

1) The short headers in picture 1 is the S&S Headers (S&Sheaders.com) which I have in my SC400. (Major fitment issues)

2) The mid size direct bolt on headers in pic 2 are the EKtuning (Ektuning.com) headers.. (which I recommend, direct bolt on headers are easy and practical)

3) The long tubed headers in pic 3 are the TEX Headers (planetsoarer.com) that can only be purchased from Australia...(these probably flow the best)

Hope this info helps someone....




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Great write-ups JIBBY! This is exactly what I've been looking for. Keep it up!

My Dad just bought a new IS300 and I asked to take his '94 400 off his hands to fix up. I'm traditionally a Bimmer guy, and always will be, but I like the SC and it has a lot of potential. The market is tough to find stuff, but guys like you have made it easier. My biggest complaint, other than cosmetics I'm working on (e.g., new leather from leatherseats, some LexTech work on the gauge cluster, etc..), is the off-the-line performance. It is not a low-end torquer as you well know, so I want to get the most out of it as I can. I'm not a street racer, nor do I care to beat mustangs or camaros around town, but I do want the pice of mind that I can get off the line in a hurry when need be.

I plan on going with the muffler and cat-back set up you've described, the airflow issue, possibly the battery/electrical upgrade and some Seafoam claening among others.

I do have a question about the brakes...they're HORRIBLE!!! They're REALLY indecisive and mushy. He put the car through the 100K reconditioning via a dealership ~38K miles ago, but this thing doesn't seem to want to stop with any authority. The rotors and pads look good, and I assume the lines are fine, but I think the rotors, pads, calipers and possibly the lines need a serious upgrade....any suggestions of what to go with and where to get them? I would like to upgare the wheels and tires eventually, but for now I plan on making the stock rims work.

This is a hobby car and I don't plan spending huge amounts (at once), so with that in mind, what order should I refurb/mofidy/upgrade my car? I have a good idea based on what I've read, but I wanted to see what you thought about my specific plans.

Thanks again.

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My pleasure to be of help....

There is only one way to get the sc's moving from a dead stop and that is with an upgraded torque converter...That pretty much goes for any automatic Lexus SC,LS,GS, etc..They are all slugs at launch.. A cheap or let's say cheaper alternative for this upgrade is at Lextreme.com, where you send in your stock converter and they send it back recalibrated a week later...What I would do is first pick up a used stock torque converter for like $50 at a local junk yard and send that one in so you don't disable your car at some tranny shop for a week.....$400 I think is the cost for the recalibration and it should be no more then $300 for the complete install by any tranny shop... That will definetely get the car bolting 0-30mph...I know for me the Precision dragon torque converter for $900 got both my rear tires spinning from a dead stop and that was when my car was completely stock....It was hard to beat at that time 0-30moh.. The stock factory torque converter was designed for older folk by lexus, a huge flaw in my opinion...... Oh and driveabiltiy does not change, so you need not worry about neck jerks......You will still get those smoothe luxury take offs with the upgraded torque converter unless you hammer the throttle...There really is no other alternative solution to correct this horrible Lexus problem other then a supercharger or NOS system setup which is not a consideration for most......No premature transmission wear, or anything of that nature will ocure..Reliability will remain the same..I have had my upgraded torque converter for two years now and love it..

That takes care of that problem..

Brakes...Get on EBay and buy a front and rear set of Drilled and Slotted rotors for your SC400...Maybe cost around $150 or so...Then also try and buy the best quality brake pads and not some Pep boys cheap specials that will probably squeek anyway...Those changes will dramatically improve your crappy current braking system...$200 is a cheap price to pay for safety....I did that and literally got a %30-%40 increase in braking power...I have had these new rotors and OEM pads going for almost two years...No noise, good looks, even wear, no warping or cracking, etc..and I promise you will be pleased....Brembo rotors are the best, but I went with a no name brand of D/S rotors..and they have been vantastic and have givien me no problems to mention over two years...As you know with my car braking is a must....

That takes care of that problem... (no need to upgrade brake calipers or master cylinder)

THis is what the new D/S rotors will look like minus the rims..they look nicer even on the stock lexus rims...Hope this helps...good luck...


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whats the 0-60 time and quarter mile?

thats a lotta mods. good job

thanks for sharing

0-60 is in the low 5's maybe, I can hang with the new 400hp Vette's so what do they do it in? Without the nos I beat out my best friends G35 infinity and can barely edge out the new stock 350Z... I have never ran the timed quarter mile, but plan to shortly....

I did dyno at 201rwhp which is like 260hp just yesterday without my computer management (Apexy piggy-back) hooked up and no NOS either....With the piggy back installed and tuned I should dyno closer 210RWHP or (275hp) which is the best I have ever seen on any stock internal 1992 SC400 in the United States...That was suprising to hear... I am posted on the lexus high performance forums, and that is what they are telling me.......In 1992 brand new these cars dyno's at around 175whp...Over the years the cars dip off considerable in power...Clogged exhaust, engine wear, electical all suffer and contribute to lost horse power...

This is the dyno sheet I got yesterday...The 193whp was the first dyno with the A/C on by mistake the second dyno was better at 201whp with it off....Also a pic of my dead and disconnected Apexi piggy back ECU. I don't have a scanner so it is a little blurry...



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Thanks for the help JIBBBY. If you don't mind I'd like to pick your brain some more.

I saw those rotors on another site, so I'll look inot those. I will also look into refurbing my torque converter. Do you have a contact for getting the work done?

What about the cat-back and mufflers? I read your comments earlier, but what would you do to improve performance for the best price. I am willing to pay for quality, but I don't want to spend anything more than I need to. It sounds like this is a mod that I can take care of myself. Where did you find those Megan mufflers? I think I found the Y Magnaflow 2-to-1 Cat on the web.

What about air filters? I think I know what type, but I'm not sure. See attachment. Nor do I know the best brand to go with other than each company's rep.

I bought some Seafoam and plan on cleaning things out, then replace my plugs with some good ones, as well as new oil, oil filter. What's your experience with Seafoam?

Should I replace my spark plug cables and distributor cap, or are they generally fine as they are? What about my battery? Other than weight, do you see any real improvement with a more expensive battery?

I bought a JuiceBox from eBay in an effort to bump things up a notch. Unfortunately, I read that the Toyota ECU learns, so the improvement will be short lived.

Sorry to bombard you again, but I don't have anyone locally that I can bounce this stuff off of.

I saw some sets for Quick Pro for $290 for just the rotors, but I'm unsure which ones I should go with.

I found this on eBay...whatcha think about this for $190?


2 Front + 2 Rear R1 Concepts' E-Line Performance Brake Rotors

4 Front + 4 Rear R1 Concepts' Premium Semi-Metallic Brake Pads

R1 Concepts' Premium Semi-Metallic Brake Pads

Our premium, semi metallic with Kevlar formulation brake pads combine durability with solid performance for worry free stopping. This semi-metallic material is formulated to provide economy, medium to high level friction. While it remains disc rotor friendly, it has low wear rate, minimal noise and low dust characteristics.

R1 Concepts' E-Line Performance Brake Rotors

Cross-drilled and slotted rotors give the maximum braking for performance cars under all necessary braking conditions. Precision machined holes or slots on the rotors will allow hot gases from brake pad to escape quickly to prevent skidding or locking up. It also provides quicker response to improve faster stopping power and enhancing the look of your car. Each rotor is also zinc plated to prevent rusting and made of the best quality metals. Cross drilled and slotted patterns are precisely CNC machined for perfect fit to OEM specs for use with stock calipers and stock wheels. No other modifications are needed.

Then there are these from CQuence for $170...

Includes 2 Front + 2 Rear Ultimate Cross (Cross Drilled & Slotted rotors w/ free silver zinc plating):

Our rotors are dynamically engineered for maximum stopping performance. Our rotors will improve pedal control, reduce braking distance, and give you that extra braking power that you are looking for. The Cross Design rotors are the exact same size as the factory default rotors and meet all required OEM specifications. There is no modifiation to your existing brake system needed! We gurantee them to fit!

Our rotors are precisely CNC machined for maximum durability and performance. The Cross Design rotors offers a cooling effect by allowing air to freely flow thru, which allows fast heat dissapation, avoiding rotor deterioration. Our rotors also help dissapate water, dust, and dirt that is built up from braking. All our rotors come with free silver zinc plating to keep them looking new and free from rust. The Cross Design rotors are precisely Chamfered to keep them lasting longer. Each rotor is drawn to scale and engineered with a specific scaled pattern.

You can get any of our rotors in silver, gold or black plating. The default Silver zinc plating is free. Gold or Black zinc plating is an additional $30.00.


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DAWG - you can pick my brain I don't mind...That is what the forums are for...INFO...

BRAKES - The brakes you are about to purchase should be fine and you will definetely notice an improvement...Go for that...... Front and rear D/S rotors and high quility pads should be the objective.... I think OEM pads and Brembro rotors are the very best, but your listings to buy items should be just fine....I used China made no name D/S rotors and OEM pads..Bought them both off Ebay... I noticed a .30% increase approx. in braking power after the install.....After your new brakes are installed I also suggest doing a brake fluid change out or flush, that can help too if that has never been done on your car or if you have air in the lines......

INTAKE - The intake you should look into is the BFI intake for cost savings and efficency...... The BFI intake costs nothing and is an easy way to open up the airflow to the engine to help it breathe better...Better efficiency usually means better gas mileage too....The BFI intake is a custom modification of your stock filter box which is really proven to work better then all the expensive aftermarket intakes like mine.....Go to planetsoarer.com and look into the BFI intake....If you want to keep it simple just get a K&N filter to replace your stock filter and be done with it.....You will never see big power gains with these SC's when upgrading the intake or air filters...The stock intake is really not all that restrictrive... The BFI intake or a true cold air box intake are the best two intake designs for the Lexus's...Mine is a mix of everything and is probably equal to either but not better...

Electrical - Replace the Negative big ground cable going from your battery to the engine block...It is about 3 feet long...The original ground cables can get crispy and deteriorate over the years and lose there potentcy.. Most people don't realise that you can lose power off those ground cables, and that is a proven fact.....That would be my first change out......Secondly for cost savings, I would get new Bosche spark plug wire sets and new Bosche spark plugs and install...I got mine off EBay for cheap...They are a good choice and not to costly...Thirdly, I would replace the two distributor caps and rotors as when recommended per the dealer scheduled maintenance.. I did all those things at once and noticed a difference... I also did a few other things too...That should cover your needs without breaking the bank...

Seafoaming I have never tried and can't really comment on it.. I have not heard bad things about it...

Exhaust- Ebay is where I got my Megan N1 straight thru mufflers. Really any straight thru mufflers will do, I picked Megan because they were on sale..They all pretty much perform the same... High flowing resonators are a must to reduce the exhaust noise....The final result of those changes will be slightly louder then stock...The Magnaflow 2 into 1 center cat is probably the best choice available when sticking with the stock exhaust piping..You cannot go wrong with Magnaflow cats.....The Blits Nur rear exhaust systems are a good expensive exhaust upgrade for around $700-$900...That is if you want to retain the stock exhaust look.... However, the Blitz will not out flow the straight thru mufflers and resonators that cost in total maybe $200..

The Cat and mufflers changes will bring a smile to your face...You will notice improved power and better better fuel efficency...The stock exhaust is so very restrictive... Exhaust mods are a must in my opinion on the older Lexus cars...

Feel free to ask questions I don't mind answering...That is how I started out years ago....

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Now I have a solid game plan, I'll be sure to keep you in the loop...if you care. I'm sure I'll come a callin' again sometime soon.

Thanks again for taking the time.

No problem bro!!! Hey I looked into Seafoaming and that is a fantastic thing to do on these older SC's...It has been reported to free up to 10hp on some of the older SC'S...I am doing my car tomarrow...Apparently there is massive carbon buildup on the internal combustion chambers that occures year to year.. so cleaning out the crud really helps especially if it has never been done before.... The process creates a lot of smoke when doing so, so I hope you have friendly neighbors....Once a year this should be done according to the experts..... Oil seafoaming is beneficial as well from what I have read, I need to look more into that aswell....

Also running one quart of transmission in with your oil for a few weeks is a good idea every two years or so....The one quart of transmission fluid acts as a detergent to clean internal parts...A complete oil change is needed after this process...I do that every other year or so..Helps clean, lifters, valves etc...

Dawg - Your seafoaming suggestion has helped me out... I never took that process seriously until now....Thanks..

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That's what I read as well. I had NO idea what the heck these folks were talking about when they mentioned Seafoam. Then someone as confused as I asked the question. I found it at AutoZone for both the fuel and the transmission. Do you think it would be OK to use Seafoam's transmission cleaner in the oil, or stick with actual transmission fluid?

I plan on buying all new spark plugs, caps, wires, oil, oil filter and air filters, then accomplish the cleaning...feel the HUGE improvement all at once!

I found some good stuff about the oil cleansing as well. You just have to plan on replacing spark plugs, oil filter and oil after your done. So, if you have some nice new stuff, they recommend using older or cheaper stuff (or stuff that's due replacement) in to gunk up, then once its finished burning off the crud, replace the aforementioned parts with the good stuff. I read that the best success was both. Let me know how it goes and any recommendations. Here are the threads I found for Seafoam...



I'm THRILLED that I was actually able to help you out for a change!

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Dawg - Make sure you change your spark plugs after seafoaming...As the combustion chambers are extracting all that carbon buildup by seafoaning there is a good chance it could foul the spark plugs that are exposed to the carbon and foam.....A few SC owners that have tried seafoaming and had to change their spark plugs after the process....My biggest concern is if this seafoaming cleaning clogs the cats and or mufflers as all the years of carbon buildup is sent thru and out the exhaust system...I only have one main center magnaflow catylitic converter, and straight thru mufflers so I will probably be ok...but a stock SC exhaust system has 3 cats and two oval mufflers and I would be a little concerned about clogging.....I am waiting for some replies to these questions...I will post on this thread when I hear back from my Lexus buds....

Apparently the seafoam is mixed with water and you have to suck up the seafoam thru the brake booster line..You will also need to plug the other end of the booster wiht your finger so the car does not stall...Once the foam is in the engine they said turn it off and let the foam sit in the engine for 10 minutes or so....that is what everyone has done with their SC's.......Turn the car back on and major white smoke will come out the exhaust for a few minutes...I am finding out more and more about this seafoaming process.....I will get back to this thread shortly...I know about as much as you Dawg about this seafoaming but some guys said running it thru the oil and fuel makes a difference too, they said it really cleans the injectors and other things...I am just working on the engine seafoaming for now, tranny, oil, fuel I cannot comment on yet...Need more info, those ClubLexus links I will read over now....Thanks...

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A few other suggestions that I would like to share to help make the car run more efficent -

- Spark plugs and wire change- The bosche platinums spark plugs are probably the best after market spark plugs available for our lexo's for the price....Most of the high performance guys praise them over the stock old OEM plugs...Bosche wire sets are ok too...There are far better sparkplug wire sets available but they are usually twice the cost of the bosche wire sets....Wires and plugs help if you are do for the change and or tuneup.....

- For a smoothe idle cleaning/spraying out the throttle body and opening and closing throttle body fly and spraying that too with STP carb cleaner has helped on several occasions when using aftermarket air filters or if it has never been done on your Lexo....Cleaning the fuel system via the seafoaming from what I just learned also helps if you are experiencing a bouncing or rough idle...Every time I sprayed out my throttle body the car idles much smoother...Something to consider...

- Steel braided hoses....In my pictures you will notice I have no rubber hoses in or around my engine as I have fitted my original hoses with steel braided lining, even the smaller vacume hoses too......The steel braided hoses are slip ons that you can buy at most auto parts stores, Ebay, high performance shops etc......They are basically steel braided sleeves that slide onto and fit over the your original hoses.. I bought two steel braided hose kts for $50 each and that did the entire engine job...It is said you will never get a leak again as the steel braided hose covers preserve and protect the rubber hoses for the entire life of your car...Should never have to change out another hose again...Looks great and sheilds the heat and elements...A win, win, win in my opinon....DO NOT BUY SPECTER brand steel braided hoses as they are cheap and crap. Any other brand should work just fine if you decide to do this...

- For interior decore lookd and upgrades look into Lextechlighting.com...This company can upgrade all your interior dash, climate control, and stereo lighting...I did my cluster to bright white as you can see in the pictures after my needles blackened out....$200 and way better looking then stock as shown in the picture above......



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Regards from Santa Monica, Ca...

Great area. For a few glorious years I lived in the Sea Castle, right on the beach, next to Shutters. I miss the sea air, along with the all the kooks from the boardwalk and pier!




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