Result Of Mods To Sc400

[JIBBBY]

Hey fellas glad I can offer you guys some direction...

Update - I was just about to purchase a used Supra Auto TT tranny the ohter day to swap into my SC400 but recently found out from LEXTREME.com that a torque converter alteration would be needed..That means I would have had to dump my Dragon Torque Converter...Well that's not going to happen so I have decided to go with a company called Boost Logic (boostlogic.com) which takes your strock tranny and rebuilds it for $1800 to support much more horsepower, etc.. It's been proven to be a good mod in regards to tranny upgrades....I will be sending mine in a few months...The great thing about this is that no alteraations will be needed just send it out and get it back stronger...The newly re-built tranny's supports around 500-600whp but unfornatunately still perform like stock. Still no more tranny hinderance with that...Just for the record my stock tranny is still holding up after two years of beating on it almost daily...These cars are really built very well indeed......

Also, I am glad that there is interest with this thread.. When I first wrote it I didn't think one person would read it on this forum...Just wanted to let you guys know what you are missing out on.....These SC400's really do have some potential and with just a few mods you can start to get these slugs moving and looking sharp too..As I said before these Lexus were designed to please the older folk so the perfornance is restricted at stock...The performance is their but just needs to be brought out.....I felt it was necessary to share...Good luck with all your mods everyone...

Will post my local shop hookups shortly....

[JIBBBY]

Wow Jibbby, I must say you have influenced and lead a lot of performance enthusiasts on here, who were very rare before you joined.

If moderator positions are still up, I nominate you to be the mod of SC forums. You are a perfect candidate for the SC forum and a great asset to LOC.

Thanks for the perks but as far as moderating goes...I must pass, as it is not my thing..., Besides, SK perfornance does a fine job on this site and also probably knows a little more then me about these SC cars....Sk was around when I first started modify'ing these cars which is now going on for about 3 years now... I remember asking him questions years back and getting quality answers...

[GaDawg]

for JIBBY and for DAWG about doin his exhaust ( I read the whole thing too) and all about the seafoaming which i plan to try

DAWG-Most mufflers, if you go cheaper (which really doesnt matter to much) will come with a 2.5" inlet, so thats probly the best size to go with in case you find some down deal on ebay or somthin, yuh know.

Also it would probably be worth your time (if possible) to find a good shop in your area where they might do custom work. Like i had this guy custom build my exhaust right in front of me in about 2 hours, $450 with labor and looks as professional as any. Its 3" piping that splits into dual 2.5" pipes. Also had radiator put in for $150. He also had used resinators for like $15 bucks a piece. And this weekend im puttin on some different 3.5" outlet stainless steel mufflers which i spent $30 a piece (its the same *BLEEP*). My point is that there are many shops that and could save you big bucks and time, rather than ordering all name brand stuff.

JIBBY- you basically have lead my path for me doing a lot of the same mods as I plan on doing on my SC (except im keepin my spare, are you crazy) And i plan on using maybe more like a 50 shot depending on how hard it seems to run it. But reading about your mods has been informing, i appreciate it. And I soon am going to be on the hunt for that supraTT tranny aswell.

And oh yah i kinda what to paint my front end, bumper mainly. You got a place thatll do a good job up there, how much you think? $$

Thanks for the good read you guys. Good luck dawg

I SeaFoamed last weekend and I can tell a definite difference. My car seems a bit more responsive and smoother. It should really be noticeable after I run through this tank of gas, replace the plugs with NGK's, replace the plug wiring with a higher-end version, as well as swap out the stock filter with a K&N.

I agree completely with you and Jibbby...I am going to have the exhaust work done by the pros. I'm going to go with the resonators, Borla tips, Magnaflow mufflers and cats, with customized 3" piping split into 2.25".

I'll let you know how it goes when the time comes...if I can sell my Mazda6 soon, it'll happen ASAP.

[JIBBBY]

Dawg - I have not done the sea foaming yet because I don't want to upset the neighbors from the mushroom cloud of smoke that will be created......Will do it soon though.......Did you get alot of smoke when you seafoamed? Oh, and change the plugs and you may then see a difference as you said....Let me know how it goes......

Dawg - Good luck with your exhaust...Post up a picture or two afterwards...Dawg you need to go with 2.50 inch non mandrel exhaust piping on the lexus 400's....That is the best flowing fit for your SC...3" piping won't flow as good... 2.25" mandrell exhaust piping is proven to be the absolute best fitting and flowing exhaust for the 400 engines...Expensive too... I argued with the guys over this for awhile until I was proven wrong...Something about the way the exhaust crosses and circulates threw that 400's smaller sized piping makes it flow faster.....Not the case on many other cars with straight pipes, bigger is usually better, not so here........The muffler shop may try to talk you into larger piping but don't do it...trust me...

I would either get -

2.50" inch non mandrel exhaust piping...That is the tubing that is bent customly to fit into your exhaust system.. Usually right their at the exhaust shop...The only problem with that is at the bends the piping size is reduced..At each bend exhaust flow will be restrictied just a bit...Not so with Mandrell piping...

or the best and more expensive is -

2.25" inch mandrell piping - That is exhaust tubing that is bent but at the bend the size is not reduced..It's a true 2.25" inch exhaust pipings through out....Muffler shops can't make you those in house......

Again don't get the 3" inch exhaust piping on your SC4 unless you have future plans to either turbo or supercharge...With a turbo or supercharger the exhaust piping can be bigger because more air and exhaust will be pushed thru so larger piping is ok...Hope this helps..

[GaDawg]

Dawg - I have not done the sea foaming yet because I don't want to upset the neighbors from the mushroom cloud of smoke that will be created......Will do it soon though.......Did you get alot of smoke when you seafoamed? Oh, and change the plugs and you may then see a difference as you said....Let me know how it goes......

Dawg - Good luck with your exhaust...Post up a picture or two afterwards...Dawg you need to go with 2.50 inch non mandrel exhaust piping on the lexus 400's....That is the best flowing fit for your SC...3" piping won't flow as good... 2.25" mandrell exhaust piping is proven to be the absolute best fitting and flowing exhaust for the 400 engines...Expensive too... I argued with the guys over this for awhile until I was proven wrong...Something about the way the exhaust crosses and circulates threw that 400's smaller sized piping makes it flow faster.....Not the case on many other cars with straight pipes, bigger is usually better, not so here........The muffler shop may try to talk you into larger piping but don't do it...trust me...

I would either get -

2.50" inch non mandrel exhaust piping...That is the tubing that is bent customly to fit into your exhaust system.. Usually right their at the exhaust shop...The only problem with that is at the bends the piping size is reduced..At each bend exhaust flow will be restrictied just a bit...Not so with Mandrell piping...

or the best and more expensive is -

2.25" inch mandrell piping - That is exhaust tubing that is bent but at the bend the size is not reduced..It's a true 2.25" inch exhaust pipings through out....Muffler shops can't make you those in house......

Again don't get the 3" inch exhaust piping on your SC4 unless you have future plans to either turbo or supercharge...With a turbo or supercharger the exhaust piping can be bigger because more air and exhaust will be pushed thru so larger piping is ok...Hope this helps..

Jibby,

I just plan on printing up your advice when I walk into the shop and use that as my guide...danke schon.

When I SeaFoamed, I didn't get any smoke. When I crank it up after its sat for several hours, it'll let out a small amount of white smoke for a second, then its done. When I talked to a very knowledgeable chap at the auto store he said that SeaFoaming via the gas tank cleans most of the componenets over a longer period, versus the crankcase route, which does it all at once...hence the HUGE amounts of smoke. He had a guy (after he told him not to) put it in via the PCV and it put out so much smoke that it shut down a four lane road behind it...unreal. I plan on burning off all of this tank, then swapping out the plugs (and cables, just to add a little oooomph). I would go ahead and put the SeaFoam in a full tank (1 1/4 cans), but as you know, put some crappy/old plugs in to collect the garbage until the tank's done.

I'll keep y'all in the loop for sure.

Cheers

[Homer 94sc300]

so .....

did you only put it in your tank? and if so is that proven to be just as effective as adding it to the block, or intake? Because im not the most educated when it comes to the mechanics of a job, i want to find the safest way to do this. I read almost that whole thread about the seafoam, but i went from being amped on finding such a good product, to just being sketched out and full of questions.

What do you think jibby, what would be the most effective, yet idiot proff way to do this. And remember im really not good with mechanics (yet), and what goes where kinda stuff.

Thanks Again

[marspe]

Hey fellas glad I can offer you guys some direction...

Will post my local shop hookups shortly....

Hi Jibby,

Just wanted to drop in and see if you had found all your shop contacts. I'm really excited to get started.

One thing, if you don't mind... I've been servicing the car at Lexus of Westminster and for the most part have been happy. However, my 'Check Engine' light has been going on and off for a year now, and they have finally traced the problem to the "Main Engine Wire Harness." According to them, this part cost over $1200 and it will take around 12 hours of Labor to install. The bill is estimated to be around $2700. Does this seem resonable? To me it seems a little steep for a 'wire harness', but then again, I don't know much about cars. Your opinion is much appreciated.

Thanks!

[JIBBBY]

Dawg - THe bottom line is the inside of these older lexus motors have alot of grim and spent NOX buiildup and the more smoke that comes out the more cleaning action is going on...The experts from Australia told me to use the brake vacume line to suck up the seafoam into the engine combustion chambers.....Then let it sit for 10 minutes and crank the engine...Tons of smoke should come out as the engine is being cleaned rapidly....I inquired about the fuel feed, they said the seafoam ratio to fuel feed going thru the injectors will not clean the engine chambers as there is not enough seafoam hitting the buildup...The little whitie smoke you see is probably just the fuel line, tank, and injectors being cleaned by the seafoaming action...That is what I was told and that makes perfect sense to me....They also told me to change the spark plugs after the process. That is it..

Marspe - Wow, I get so saddened when I hear about people taking in their older sc's to Lexus dealer for repairs....They do the job correctly but are sssoooooooo expensive....The only thing I would use the dealership for is hard to find parts or a diagnostic check to locate and determine where a hard to find problem like your wire harness is.....$1200 is crazy...What you need to do now is - now that you know what the problem is, you can open the yellow pages and call around to import mechanic shops in your area for the best pricing...Lincoln Blvd has a ton of them... Ask them how much they charge to change out the wire harness on an older SC400....You will save alot of money, and changing the wire harness any mechanic shop should be able to do correctly..It's all plug in wires on the harness...That is what I would do if I did not want to do it myself........I would venture to say it should cost you half that much...The wire harness itself should be the most expensive part..Good luck...

Hookups - I have not unboxed my crap yet but found two cards to my two most used shops...

A shop on Linclon Blvd named A+ Complete auto repair located in the city of Santa Monica, - (310) 314-3104 and talk with LEO the owner.....He's a Nice mellow guy and he has a "very good" in house mechanic working on the cars..They know the import cars very well....He is a small shop and is very busy because he is good and inexpensive..Appointment only usually..... He custom fit and installed my S&S Headers and deleted my two smallerl cats..He also made and installed new custom fitting down pipes for me with flanges.. Not an easy task for most muffler shops and did all that for $500 cash....., He installed a Kaaz LSD on my stock rear open end differential which I later dumped for a Supra LSD complete..He also installed my Dragon Torque Converter for $300 which requirs dropping the tranny out.. So I would recommend Leo's shop all day long......Mr Kools Muffler shop did all the other exhaust work located in South Central LA.... If you use A+ Auto pay Leo in cash and ask for a better deal and he will go for it... Good luck....and please don't use the dealerships they are too frigg'in expensive........Other mechanics can do all the same work for half the cost of a dealership...

A+ Complete Auto Repair

2700 Lincoln Blvd., #5

(310) 314-3104

Tell Leo the tall guy John with the suped up tan Lexus SC400 sent you, who knows he may give you an even better deall...He knows me well, and is impressed with my ride......

Mr. Kool Wholesale Distributors

(exaust work and raditators only)

5975 S.Hoover St.

Los Angeles, Ca. 90044

These guys changed my radiator on my SC400 and on my 1993 Toyota Land Cruiser, they installed my Magna flow center cat, and my 2.50" rear exhaust bent piping. THis was all done in shop for really the best price around..I shopped.....I would not have them do the Headers even though they probably could... All parts they stock in house which is makes things easy...

Hope this helps...

[JIBBBY]

For you guys that live near the LA area in California....The paint shop to visit is...

JC Auto Body Shop - (For painting and body work)

They re-painted my 1992 SC400 for $1000 cash almost two years ago.....It still looks amazing...Came out like new and like factory...No Orange peal at all and they removed every dent and ding...They remove all the lights, molding, etc..when prepping they also apply several Clear coats and color sanding...A 1 year warranty included....They may want $1500, but offer $1000 cash and they will take it....Probably the best deal around...I shopped it too...

JC Auto Body Shop

7314 S. Avalon Blvd.

Los Angeles, Ca. 9003

1 323 752-5059

It's in the hood but they keep the car gated, covered and secure during the painting process..

[JIBBBY]

MORE MODS -------

One of the nicest mods that you can do besides Turbo, supercharger, and nos is replacing the 4 stock cams...

Unfortunately there is only one company that I know of that supplies the four upgraded cams for the 400 engines (xuz-fe) and that is Kelford.com cams located in New Zealand...About $1000 bucks for the set of cams shipped but with that upgrade you can gain 45-50hp which is mostly at mid range to topend power....50hp is impressive...These big gains are probably the most noticeable besides the Dragon Torque converter to really get the SC moving....Something to consider if you have some extra cash to spend... These cams bring the same power that a VVT-I setup would bring...Again the torque converter upgrade should be considered first before cams and headers are installed. WHy? because the car will rocket at higher rpms with headers and cams but will remain a slug out of the blocks and or from idle with the stock torque converter.....

Kelfordcams.com or kelford.com is the company to order on line...You can PM the owner of the company for specific questions that is what I did......I am not aware of any domostic companies that supply upgraded cams for our 1uz-fe sc400 motors....Lextreme.com is currently working on developing a mild set of perfrormance cam that will bring about 30hp or so...THat project is a few months away...

These are a few pics of the engine...

[Homer 94sc300]

how much are the dragon torque converters, and how much do you think it will boost me up in hp. Or would you do headers first?

[JIBBBY]

The Precision Industries "Dragon Torque Converter" runs for like $900 and should cost no more then $300 to install....A cheaper solution is thru Lextreme.com....You need to send your stock one in for re-calibration so your car will be disabled...Unless you pick a used one up from the wrecking yards...Anyway that will cost you like $400 and $300 to install....

The very first mod I would do for a stock SC400 or LS400 would definetely be the torque converter upgrade...That really wakes the car up off the line from like 0-40mph.... Headers will give you nice mid to high range power gains but your takeoffs will still suffer and even more so then ever...Why you may ask? Because with headers you will lose just a little lowend low RPM power, not much but a little as I did with my S&S Headers.....

Mods I would do in this order -

1) Torque Converter

2) Highflowing cats, Exhaust pipes, and mufflers..

3) Headers

4) Piggy Back ECU

5) BFI intake..

6) Supra 93-98 limited slip differential...off an automatic tranny TT....

[GaDawg]

The Precision Industries "Dragon Torque Converter" runs for like $900 and should cost no more then $300 to install....A cheaper solution is thru Lextreme.com....You need to send your stock one in for re-calibration so your car will be disabled...Unless you pick a used one up from the wrecking yards...Anyway that will cost you like $400 and $300 to install....

The very first mod I would do for a stock SC400 or LS400 would definetely be the torque converter upgrade...That really wakes the car up off the line from like 0-40mph.... Headers will give you nice mid to high range power gains but your takeoffs will still suffer and even more so then ever...Why you may ask? Because with headers you will lose just a little lowend low RPM power, not much but a little as I did with my S&S Headers.....

Mods I would do in this order -

1) Torque Converter

2) Highflowing cats, Exhaust pipes, and mufflers..

3) Headers

4) Piggy Back ECU

5) BFI intake..

6) Supra 93-98 limited slip differential...off an automatic tranny TT....

Jibbby,

Long time, no speak...I finally have the exhaust in the works.

I made some slight alterations to the plan. I decided to keep the car stock to just aft of the center cat instead of adding a Magnaflow 2-in-1. For the $300 price, I decided to stay with stock because I'm not quiyte sold on the slight increase in airflow being worth the cost (obviously a personal opinion). However, after that I'm reducing the pipe down to 2 1/4", straightening then out and removing the resonators and the stock mufflers and tips. I'm adding polished stainless steel Magnaflow mufflers ($150 a pair at AutoAnything.com) and Magnaflow tips ($84 a pair at HottExhaust.com).

I'll be sure to take some pics for ya.

Thanks for your guidance up to this point.

[JIBBBY]

Dawg - How goes it....I understand your reasoning for not replacing the center cat for $300....I paid $150 for mine...Anyway, the stock center big cat is restrictive and the Y bends that enter into that stock center cat really disrupts the exhaust flow...If you look you will see the extreme bends that enter the cat....When I changed the to the magna flow cat with the built in high flowing Y, I immediately noticed power gains to my suprise..Almost as much as changing out the mufflers, but not quite that much....

Trust me that mod is worth considering, just look for a better deal then $300....Good luck..

The most restrictive parts in the SC400 exhaust system go in this order in my opinion -

- Stock headers

- Stock mufflers

- Center cat and Y's

- Two small down pipe cats

- rear exhaust stock piping

Solutions -

- EKtuning.com direct bolt on headers

- Magna flow ovals or straight thru circular mufflers

- Delete the cat and install a high flowing X member, and or go with the magna-flow 2 into 1 high flow center cat. converter

- Delete the two cats, or find high flowing ones that fit..(don't no about replacements)

- 2 1/4 inch mandrel piping, or 2 1/2 inch bent exhaust piping for replacement...(Blitz nur is fine system)

[GaDawg]

Dawg - How goes it....I understand your reasoning for not replacing the center cat for $300....I paid $150 for mine...Anyway, the stock center big cat is restrictive and the Y bends that enter into that stock center cat really disrupts the exhaust flow...If you look you will see the extreme bends that enter the cat....When I changed the to the magna flow cat with the built in high flowing Y, I immediately noticed power gains to my suprise..Almost as much as changing out the mufflers, but not quite that much....

Trust me that mod is worth considering, just look for a better deal then $300....Good luck..

The most restrictive parts in the SC400 exhaust system go in this order in my opinion -

- Stock headers

- Stock mufflers

- Center cat and Y's

- Two small down pipe cats

- rear exhaust stock piping

Solutions -

- EKtuning.com direct bolt on headers

- Magna flow ovals or straight thru circular mufflers

- Delete the cat and install a high flowing X member, and go magna-flow 2 into 1 high flow center cat

- Delete the two cats, or find high flowing ones that fit..(don't no about replacements)

- 2 1/4 inch mandrel piping, or 2 1/2 inch bent exhaust piping for replacement...(Blitz nur is fine system)

Thanks for a little more guidance/push.

I'll keep searching out there for a better price on the the 2-in-1 cat. I found the tips and mufflers at half the price the shop quoted me, so I don't know why I can't find the cat for half as well. If I can go that route, then I would have addressed all of your solutions except the headers. More to come.

BTW, did you try the Seafoam?

[Chase Croft]

this faq is extremely helpful, i will try to follow it when modding my car (as soon as i get the money)

i guarantee i'll be back with questions though lol

[GaDawg]

this faq is extremely helpful, i will try to follow it when modding my car (as soon as i get the money)

i guarantee i'll be back with questions though lol

Where in Hotlanta are you from?

[Chase Croft]

Marietta, Ho! lol

[GaDawg]

Marietta, Ho! lol

Cool. I graduated Norcross High in '86 and UGA in '90. Parents still live near there and I plan on heading back there as soon as I retire form the AF in 2011. Love my town and miss it BIG!!!!

Dawg - How goes it....I understand your reasoning for not replacing the center cat for $300....I paid $150 for mine...Anyway, the stock center big cat is restrictive and the Y bends that enter into that stock center cat really disrupts the exhaust flow...If you look you will see the extreme bends that enter the cat....When I changed the to the magna flow cat with the built in high flowing Y, I immediately noticed power gains to my suprise..Almost as much as changing out the mufflers, but not quite that much....

Trust me that mod is worth considering, just look for a better deal then $300....Good luck..

The most restrictive parts in the SC400 exhaust system go in this order in my opinion -

- Stock headers

- Stock mufflers

- Center cat and Y's

- Two small down pipe cats

- rear exhaust stock piping

Solutions -

- EKtuning.com direct bolt on headers

- Magna flow ovals or straight thru circular mufflers

- Delete the cat and install a high flowing X member, and or go with the magna-flow 2 into 1 high flow center cat. converter

- Delete the two cats, or find high flowing ones that fit..(don't no about replacements)

- 2 1/4 inch mandrel piping, or 2 1/2 inch bent exhaust piping for replacement...(Blitz nur is fine system)

Jibbby,

OK. I'm sold. I will replace both the forward cats and the center/rear cat. I've found MUCH better prices all over the place, but I need some clarification. Everywhere I've looked have given me some conflicting info.

First, I've found Magnaflow Universal Cats that supposed fit the '94 SC400, but I've found both 2" and 2.25" in/out pipes...which is it?

Second, I found a 2-in-1 cat on eBay (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26satitle%3D8072154583%26fvi%3D1&rd=1&item=8072154583), but once again I'm unsure on the sizing. I will go to 2.25" after the center cat for sure, but it looks like I'll go with a 2" in/out up front, then 2" in/2.25" out on the center cat.

Third, several sites show the rear/center cat as a single pipe, not the Y 2-in-1 like OEM. WHy would they show that unless they expect us to add a Y pipe before the center cat. If we have to do that, what do you think the effect on airflow will be?

Finally, where did you find your 2-in-1 center cat...that will solve half of my problems right there.

Thanks,

Dawg

[JIBBBY]

Magna flow 2 into 1 center cat should have 2.25" sizing....Don't get the 2" sizing..... Get that and then just drive to a near by muffler shop and have them install it...

[Chase Croft]

haha yea marietta is pretty hardcore, we gave birth to the rap group c-side

more of a novelty then an actual talent

nice to hear though, come back home soon

oh and i'm sorta confused on the exhaust systems

you should only get 2.25" sizing on all piping correct?

and what exactly all do i need for a full new exhaust system, excluding headers

i'm looking for something with a hp gain and a moderately (not too loud) aggressive, deep and throaty sound, none of that high pitched rice burner crap

any links to where i can buy something or something you have on your car would be greatly appreciated

thanks,

chase

[Homer 94sc300]

hey JIBBY- I picked up a can of seafoam and im getin ngk spark plugs. Ill have to read that thread on the seafoam again but thats all good, but i looked at where the spark plugs are and i noticed that piece of steel going across right behind the plugs, am i supposed to take that out? How do i go about doing this, first time ive done it (obviously) and i dont wanna F up. I appreciate any help

thanks

and sorry im a little off topic

[JIBBBY]

Hey Homer - That is not an actual steel peice that covers the plugs and wires it is a long plastic piece with small bolts securing it down...Simply remove the holding nuts and it comes right off...Then you can access the plugs and wires...Make sure you seafoam first then change the plugs....You should be good after that....It's all very simple...

[Chase Croft]

me next jibby haha :-P

[Homer 94sc300]

Hey Homer - That is not an actual steel peice that covers the plugs and wires it is a long plastic piece with small bolts securing it down...Simply remove the holding nuts and it comes right off...Then you can access the plugs and wires...Make sure you seafoam first then change the plugs....You should be good after that....It's all very simple...

Yah i didnt really take long enough to look at it when i posted that, about 25mins after that i figured it all out so tomorrow im goin at it.

anyways im just hopin this will fix my problem