Result Of Mods To Sc400

[Chase Croft]

would u guys say its a good idea to take out all of the cats so i can get maximum gains, because they are just used for emissions and actually restrict the exhaust right?

or should i just leave like the rear cat and take out the two fronts so i can atleast pass emissions

also:

i found this website which deals in magnaflow mufflers

http://www.hottexhaust.com/magnaflow_stainless_steel.htm

should i go for oval or round?

and it should give me a deep throaty sound right, not any of that high pitched crap

if somone could out of those mirror finish ones on the site, just pick out the right size and stuff and tell me which part on there i should buy and if im gonna need two for each side, i just want to be cautious and know that i got it right before i deal out the money

i think depending on your answer about the cats im going to keep only one of them and just do custom stainless steel piping up to the engine

piping size needed on an sc is 2.25" correct?

these questions might seem dumb but im a noob at these things lol

thanks,

chase

[GaDawg]

would u guys say its a good idea to take out all of the cats so i can get maximum gains, because they are just used for emissions and actually restrict the exhaust right?

or should i just leave like the rear cat and take out the two fronts so i can atleast pass emissions

also:

i found this website which deals in magnaflow mufflers

http://www.hottexhaust.com/magnaflow_stainless_steel.htm

should i go for oval or round?

and it should give me a deep throaty sound right, not any of that high pitched crap if somone could out of those mirror finish ones on the site, just pick out the right size and stuff and tell me which part on there i should buy and if im gonna need two for each side, i just want to be cautious and know that i got it right before i deal out the money

i think depending on your answer about the cats im going to keep only one of them and just do custom stainless steel piping up to the engine

piping size needed on an sc is 2.25" correct?

these questions might seem dumb but im a noob at these things lol

thanks,

chase

You have to ask yourself if you need the car to pass emissions. If I remember correctly, GA still has the testing. If that's the case, I would replace the OEM cats with high-flow Magnaflows as Jibbby suggests. It'll pass emissions, but you'll still get the boost from a higher-flow system. Jibby could probably address the wisdom of taking any or all out. It will definitely increase the flow, but I'm not sure if it has any effect on back pressure (unlikely), but should definitely effect you chances to pass emissions.

I bought my mufflers (part#14335... http://www.hottexhaust.com/detail.asp?PRODUCT_ID=14335) polished stainless steel oval mufflers from HottExhaust.com for ~$150 for the pair. I went with them because I like the look of the ovals without a rear air dam and they work with the existing bracket set up. But you can go with a straight through part#14315 ... http://www.hottexhaust.com/detail.asp?PRODUCT_ID=14315) if you like the round style (part#14615... http://www.hottexhaust.com/detail.asp?PRODUCT_ID=14615), you'll get a hair less exhaust restriction because they're straight through..not much, but a hair more. Pure taste.

I still owe you guys pics, so I'll try better at getting them on the site this week.

I have a real nice throaty sound, nothing remotely close to any high pitched crap...its a smooth V8 growl.

Yes 2.25".

You don't have to replace the piping between the two front cats and the center/rear cat, but you can if you want to have an all new set up. The OEM piping is high quality stainless steel, so if its not broken you don't have to fix it, but I do understand if you want the whole thing new...which is probably where I'm headed next.

There are NO dumb questions, just look at the a**pain Jibby went through trying to educate me...pay it forward dude. These sites are full of noob's we have to start somewhere.

Ciao!

I got the tranny cooler for the power output I am producing and not because of the torque converter...You do not need a tranny cooler with a torque converter change...You need a tranny cooler when you slap a 100whp Nitrous system on your SC.... Don't sweat the cooler...

Try Ebay, Supershops, and maybe try google search for "magnaflow cats" and see what comes up....

Throttle cable is not the problem...I have never heard of the throttle cables ever being an issue with the Lexus's..I have been around these cars for years and years...Don't know where you heard that one bro.. If your car is sluggesh at take offs, and you think it is a mechanical problem, change the fuel filters, spark plugs wires, caps and rotors, clean the throttle body, and lastly replace the main negative battery cable...You should see some benefits to those changes... Rarely would your problem be from clogged cats, Electrical and or ECU problems, and lastly a bad sensor read....(usually the check engine light will flash if it is ECU or a bad sensor) Those are some things to consider...

Roger that Jibbby. Then just the Dragon Precision Torque Converter it is.

I found the front cats, but not a magnaflow 2-in-1 cat...I found a universal one that should work fine.

I read on either this site or ClubLexus about some guy tightening the pedal acble because of excess slack that caused his pedal to travel too far before it engaged the throttle...my travels a hair, but nothing major.

Its not sluggish at take off, just not as responsive as I'm used to (BMW 3-Series, Mazda6s, etc...). If I punch it, it'll go, its just that small transition from stop to the V8 doing its thing. I think the torque converter, cleaning the throttle body and replacing the ground wire will do it. I already reaplced the plugs with platinum NGKs and the wire set with Bosche, so they're great.

Did you buy your Dragon converter from their site, or did you find a better deal somewhere else?

[Chase Croft]

thanks man :-)

oh and one last thing, what should the positioning be

it tells me that when purchasing a muffler you can get it aligned right, center, or left

would i just get center on each one or what?

or right on one and left on the other?

and will diamter matter on a round one? thats wut i think im gonna go for

or the length, 6" 7"?

[GaDawg]

thanks man :-)

oh and one last thing, what should the positioning be

it tells me that when purchasing a muffler you can get it aligned right, center, or left

would i just get center on each one or what?

or right on one and left on the other?

and will diamter matter on a round one? thats wut i think im gonna go for

or the length, 6" 7"?

If you're getting the round version, then, "yes," it is centered on both. Get under the car and you'll see exactly what we're talking about. I went with the oval/offset because it fit perfectly with the existing space, as well as the existing bracket. However, Jibby's seemed to match just as well, so either way, you're good.

The oval muffler can be positioned whichever direction you want, its the same on both sides. You're choice is round or oval (mine), straight thru or offset (mine) and polished (mine) not polished. The pipes come in on the stock, and the offset (14335) that I bought, inboard on the underside and exit the pipe outboard of the centerline. Offset or straight thru is all you need to focus on. The stock muffler's length, as well as mine is 14" for the body, 20" overall. If you notice, the straight-thru 6" wide version that I attached is the same length as the 14335 offset that I have. The 4" round one is a resonator, not a muffler, and as far as 6" vice 7", I would go with your choice, but the 7" will bigger, hence more visible.

[JIBBBY]

The bottom line when doing your exhaust is to think of the exhaust gases traveling threw your pipes, any bends in pipes, stock headers, Y bends, cats, resonators, mufflers all slow down the smoothe exhaust flow.....So deleting the cats and stream lining the exhaust is always your best bet for performance.... However, when necessary to keep that stuff the High flowing Cats, high flowing Mufflers, better flow Y's and high flowing resonators will offer very little flow resistance, but there is still some resistance.... Also the straighter your exhaust pipes the better the flow...You really want to limit or minimize the bends and curves so the flow jets out...It's really that simple...

Oval mufflers will sound the best, Straight thru mufflers will perform the best and make the most noise, too...The flow continues right thru the straight thru mufflers as if they were a straight pipe..There is some muffled sound too....It not rediculous in sound.....With oval mufflers the flow is muffled more but also disrupted more....There is a difference....Now the stock mufflers are like a big wet spunge that offer much resistance and extreme muffled sound...

Piping sizing...This is a bit confusing for most...For the best flow from chart comparisons the 2.25" mandrell exhaust piping is your best bet. For non turbo'd SC4 exhaust frow output...Any thing bigger then 2.25 will not flow as well for some reason...Something about the exhaust gases swirling threw the smaller 2.25 mandrell pipes offer the best flow rather then larger 3' pipes for example....That one took me along time to digest... I had always thought no exhaust is the best exhaust or larger is better, however that does not necessarly apply to the Sc's as it would with most any other cars....2.25" inch mandrell piping is the ticket for N/A SC400 engines....

Hope this helps...

[Chase Croft]

thankyou guys,

reading through what you have said i have decided to go with this one...

http://www.hottexhaust.com/detail.asp?product_id=14826

u guys think it'll look/perform/sound good?

if so i'm getting it as soon as i get the money

[JIBBBY]

Chase - Those mufflers will perform the best, however you will have a throaty very loud exhaust noise at higher rpms....Low rpms you should be ok...Those are straight thru mufflers like mine....

You can probably get similiar straight thru stainless steel circular mufflers off of Ebay for less then half that price....Just a suggestion if you want to save a few bucks...Most straight thru circular stainless steel mufflers like the ones in your link all perform similiar and are close to the same in looks...Like my Megan N1 racing mufflers...Very similiar to the ones in your link...I got my Megans for $40 each off of Ebay a few years ago new...

[Chase Croft]

sweetness, i guess i will just scan ebay for something similar

thanks guys, i'll let ya kno how it turns out :-)

[lexusalex]

WoW!! Great thread guys!!

I always thought SC might have a nice Hp potential if modified.

My car is a 1993 SC400 with 152,000 mi

I started out with a BFI completely sealed out from the engine bay with Aluminum foil tape, air is drawn from the chamber under the bumper, chamber is also opened up to allow rammed air at speeds.

I then replaced rear Exhaust mufflers and removed 2 resonators, car is still not very loud but has a nice deep tone.

Also I installed S-Afc 1 and had the car dyno tuned. Before S-AFC I made 200rwhp , after I made 207 but gains were better then that from 4 to 6k rpms I gained around 15 hp there and around 20lb of torque. as much as 15% of fuel was taken out at 5,000 rpm, car was definitely running rich. After tunning with S-AFC I could tell a niticable difference in power after 4000rpm.

end result I am making 207rwp and 230lb of torque at the moment. My estimate it’s around 275hp and around 300lb of torque.

My 0-60 times measure before and after with G-tech were 7.4-7.7 sec before and after im getting 6.4-6.7 almost

a full second difference. At speeds over 60 I think there is a huge improvement in acceleration.

Raced my friends 95 sc400 stock before intake and exhaust and after , difference was huge, before we were nearly identical, after he had no chance I would just pull away from him at highway speeds.

I raced many other cars

raced a manual WRX, it was pretty much dead even until 90mph thats when i started to slightly pull away from him.

I think my car would benefit a lot from headers if gains are what people claim.

here is a link to my dyno graphs http://www.dragtimes.com/Lexus-SC400-Timeslip-9719.html

[JIBBBY]

Lexusalex - That's a really good dyno for a 1993...You must have done a really good intake mod and ECU tune...207rwhp is very impressive on an older SC, without headers too....Headers and deleted down cats should bring you another 10whp or so....Get a torque converter and your cars 0-60mph times will greatly increase also....

That's one strong 93 you got, good job... ;)

[BlueSC400]

Lexusalex - That's a really good dyno for a 1993...You must have done a really good intake mod and ECU tune...207rwhp is very impressive on an older SC, without headers too....Headers and deleted down cats should bring you another 10whp or so....Get a torque converter and your cars 0-60mph times will greatly increase also....

That's one strong 93 you got, good job... ;)

I am on a bit of a budget right now, but I would like to really start Moding my car, I can get the money for just about anything I need it just might take a month or two of starvation =p

The first thing I was going to do was replace my exhaust manifold, and Mufflers and add a cold air intake.

Later I want to add a single turbo and nitros system but I want to get as much real power out of the car as possible first.

Are there any other changes I should consider doing before I begin working on getting a turbo in my car?

I have a 1993 SC400 right now I have done almost nothing to it aside from some lightening and straight through exhaust

Also I know nothng about ECUs, I just have never used or done anything in the computer area, is that something I should really consider?

[JIBBBY]

Lexusalex - That's a really good dyno for a 1993...You must have done a really good intake mod and ECU tune...207rwhp is very impressive on an older SC, without headers too....Headers and deleted down cats should bring you another 10whp or so....Get a torque converter and your cars 0-60mph times will greatly increase also....

That's one strong 93 you got, good job... ;)

I am on a bit of a budget right now, but I would like to really start Moding my car, I can get the money for just about anything I need it just might take a month or two of starvation =p

The first thing I was going to do was replace my exhaust manifold, and Mufflers and add a cold air intake.

Later I want to add a single turbo and nitros system but I want to get as much real power out of the car as possible first.

Are there any other changes I should consider doing before I begin working on getting a turbo in my car?

I have a 1993 SC400 right now I have done almost nothing to it aside from some lightening and straight through exhaust

Also I know nothng about ECUs, I just have never used or done anything in the computer area, is that something I should really consider?

You should maybe consider a "Piggy back ECU" maybe an Apexi SAFC piggy back ECU unit...This increases the air and fuel mixture that is being delivered to the motor..It is easily wired up to the stock ECU then you can fine tune the engines air/fuel mix and flow.....This Piggy-back ECU further advances the capabilities of the limited stock ECU...Gains in the 10-15hp range should be expected.....

[lexusalex]

Lexusalex - That's a really good dyno for a 1993...You must have done a really good intake mod and ECU tune...207rwhp is very impressive on an older SC, without headers too....Headers and deleted down cats should bring you another 10whp or so....Get a torque converter and your cars 0-60mph times will greatly increase also....

That's one strong 93 you got, good job... ;)

I am on a bit of a budget right now, but I would like to really start Moding my car, I can get the money for just about anything I need it just might take a month or two of starvation =p

The first thing I was going to do was replace my exhaust manifold, and Mufflers and add a cold air intake.

Later I want to add a single turbo and nitros system but I want to get as much real power out of the car as possible first.

Are there any other changes I should consider doing before I begin working on getting a turbo in my car?

I have a 1993 SC400 right now I have done almost nothing to it aside from some lightening and straight through exhaust

Also I know nothng about ECUs, I just have never used or done anything in the computer area, is that something I should really consider?

You should maybe consider a "Piggy back ECU" maybe an Apexi SAFC piggy back ECU unit...This increases the air and fuel mixture that is being delivered to the motor..It is easily wired up to the stock ECU then you can fine tune the engines air/fuel mix and flow.....This Piggy-back ECU further advances the capabilities of the limited stock ECU...Gains in the 10-15hp range should be expected.....

I would do exhaust ,headers,intake and do ecu or S-afc after since it would be adjusted according to new air flow resulting from those mods. I know i noticed a big improvent just from a BFI intake and Exhaust.

[BlueSC400]

Lexusalex - That's a really good dyno for a 1993...You must have done a really good intake mod and ECU tune...207rwhp is very impressive on an older SC, without headers too....Headers and deleted down cats should bring you another 10whp or so....Get a torque converter and your cars 0-60mph times will greatly increase also....

That's one strong 93 you got, good job... ;)

I am on a bit of a budget right now, but I would like to really start Moding my car, I can get the money for just about anything I need it just might take a month or two of starvation =p

The first thing I was going to do was replace my exhaust manifold, and Mufflers and add a cold air intake.

Later I want to add a single turbo and nitros system but I want to get as much real power out of the car as possible first.

Are there any other changes I should consider doing before I begin working on getting a turbo in my car?

I have a 1993 SC400 right now I have done almost nothing to it aside from some lightening and straight through exhaust

Also I know nothng about ECUs, I just have never used or done anything in the computer area, is that something I should really consider?

You should maybe consider a "Piggy back ECU" maybe an Apexi SAFC piggy back ECU unit...This increases the air and fuel mixture that is being delivered to the motor..It is easily wired up to the stock ECU then you can fine tune the engines air/fuel mix and flow.....This Piggy-back ECU further advances the capabilities of the limited stock ECU...Gains in the 10-15hp range should be expected.....

I would do exhaust ,headers,intake and do ecu or S-afc after since it would be adjusted according to new air flow resulting from those mods. I know i noticed a big improvent just from a BFI intake and Exhaust.

Geuss I will do that, I will keep you guy updated with the impovments I see

[lexus082]

I am planning on replacing my lower control arms. I am having a hard time deciding between the Lexus LCA or the supra lca. Its about a $300 price difference between the two control arms. I would like to maintain the lexus stock ride quality, I am just wondering how much stiffer the bushings are in the supra control arms? Can anyone put the two control arms on a scale from 1-10? Thanks

[JIBBBY]

I am planning on replacing my lower control arms. I am having a hard time deciding between the Lexus LCA or the supra lca. Its about a $300 price difference between the two control arms. I would like to maintain the lexus stock ride quality, I am just wondering how much stiffer the bushings are in the supra control arms? Can anyone put the two control arms on a scale from 1-10? Thanks

Supra LCA's gives you a firm stiff responsive feel, not too agressive, but much better then the Lexus arms in my opinion...Get the supra LCA's you won't regret it....Remember Supra is performance, Lexus is luxury...If you are running with the stock Lexus suspension the Supra arms are your best choice for performance and even probably luxury...I love my supra LCA arms and are night and day compared to my original SC400 arms....That's the best I can explain the change...The arms are basically the same but the Supra OEM bushings are much better all around bushings....

[Alex-us]

Cool thread. Lotta reading.

I was looking at the Lextreme site and the TC page says you don't have to send one in until AFTER you get theirs and install it. Then they give you a refund.

http://www.lextreme.com/tc.html

Also, has anyone looked into a locker/LS from Toyota Motorsports? Might be cheaper than buying a whole diff.

[JIBBBY]

Cool thread. Lotta reading.

I was looking at the Lextreme site and the TC page says you don't have to send one in until AFTER you get theirs and install it. Then they give you a refund.

http://www.lextreme.com/tc.html

Also, has anyone looked into a locker/LS from Toyota Motorsports? Might be cheaper than buying a whole diff.

Good info....I didn't know Lextreme did that exchange with the T.C.....That definetely helps and saves money..... I would definetely consider Lextreme as all their products are very good.... I know the owner personally and he is a straight up guy whom likes to deliver a good product....I am waiting for the high performance cam set to come out which is just about ready for resale from Lextreme.com....

[Dread]

just reading this and wondering.

would most of these mods work with a '92 manual sc300?

[JIBBBY]

just reading this and wondering.

would most of these mods work with a '92 manual sc300?

They all would if it were an automatic tranny...

Air intakes are the same "BFI Intake"

Headers and exhaust have to be purchased for the SC300...Not a problem

ECU piggyback is the same

Dragon Torque converter is great if your car is equiped with an automatic tranny...

Hope that clarifies things abit for you....THe clublexusforum.com is all about SC300 modifying, check it out..

[lexus082]

If I may ask what year supra control arms did you purchase. I see there's a difference I guess in toyota part numbers 93-94, 95-96, and then 97-98. There most be a difference at least in the bushing since they're all not the same part number for 93-98. The supra arms are all individually listed from what it appears at Hoy Fox Toyota. I have a 94 sc400 not sure which control arms to get?? The 93-94 arms, the 95-96 arms or the 97-98 arms.

[devir]

Not a bad Job Jibby, months later and the thread is going strong.

I just bought a 1998 SC400 and would like to mod the thing out. Currently it has 68k miles on it and is in great condition.

Exhaust - I'd like to work this first with stock pipes. for the Magnaflow Cats, The two front sizes are 2.25 inch and the back 2 in 1 is 2.25 in and 2.5 out? Any part numbers to use would be a help.

Once I replace the 3 cats, i'd like to replace the back 2 resonators, with a Straight through design, but I want to keep the ghost quiet sound the car currently has. People tend to get freaked when i suddenly floor it and disapear without a sound. I like that. What should I use for this?

LSD - I dont know what i've got for a differential. Going straight i've peeled out with both tires for a long while. HOw can I tell if I have stock or aftermarket LSD?

Breaks - They not bad, the rotors are ugly and semi rusty. I'd like to go slotted cross drilled for style.

Supra Control arms - Where can i get these and what year/model Supra would fit on a 98 SC? so far I've found front lower arms for 250-400 a pop. Do I need upper and lower or just one of them?

Seafoaming - Would you suggest I do this now? I found some old oil change reciepts and it was texaco station that did the work. Would putting in a high quality Synth oil be bad at this stage of the game?

Intake - What drop in filter and part number can i Use with the stock intake ?

[JIBBBY]

If I may ask what year supra control arms did you purchase. I see there's a difference I guess in toyota part numbers 93-94, 95-96, and then 97-98. There most be a difference at least in the bushing since they're all not the same part number for 93-98. The supra arms are all individually listed from what it appears at Hoy Fox Toyota. I have a 94 sc400 not sure which control arms to get?? The 93-94 arms, the 95-96 arms or the 97-98 arms.

93-94 Supra LCA arms will bolt on just fine to your 94...You will really notice the difference..Enjoy......

[JIBBBY]

Not a bad Job Jibby, months later and the thread is going strong.

I just bought a 1998 SC400 and would like to mod the thing out. Currently it has 68k miles on it and is in great condition.

Exhaust - I'd like to work this first with stock pipes. for the Magnaflow Cats, The two front sizes are 2.25 inch and the back 2 in 1 is 2.25 in and 2.5 out? Any part numbers to use would be a help.

Once I replace the 3 cats, i'd like to replace the back 2 resonators, with a Straight through design, but I want to keep the ghost quiet sound the car currently has. People tend to get freaked when i suddenly floor it and disapear without a sound. I like that. What should I use for this?

LSD - I dont know what i've got for a differential. Going straight i've peeled out with both tires for a long while. HOw can I tell if I have stock or aftermarket LSD?

Breaks - They not bad, the rotors are ugly and semi rusty. I'd like to go slotted cross drilled for style.

Supra Control arms - Where can i get these and what year/model Supra would fit on a 98 SC? so far I've found front lower arms for 250-400 a pop. Do I need upper and lower or just one of them?

Seafoaming - Would you suggest I do this now? I found some old oil change reciepts and it was texaco station that did the work. Would putting in a high quality Synth oil be bad at this stage of the game?

Intake - What drop in filter and part number can i Use with the stock intake ?

-----------------------------------------------------------------------------------------------------------------------

Well you have a very good SC to mod...For starters you are equiped with the VVti system which gives you a clear power advantage over the earlier model SC's...

Ok, to answer a few of your questions -

first off I don't have magna-flow part #'s for you..You do not need them, just ask for the right size cats 2 into 1 and order...There is only on part # for the fit...Magna-flow mufflers vary I believe but are one of the more quieter of the high flowing mufflers...Ad a few highflow resonators if the exhaust ends up being to noisy for you...That is what I did.....

LSD - Lexus does not equip any of their vehicles with LSD's...You may have traction control but that is not the same....You would need to look into a TRD LSD for your 98 model...It's a bolt on mod that any tranny shop should be able to mount up for you...You can also go with any 93-98 Supra TT automatic differential like I have..Those are your torsen LSD which are torque sensing and good to go....They all match and bolt up perfectly to the SC's....

Brakes - Drilled and slotted rotors, better looks and better braking power...You can't go wrong...

Lower Control Arms..On a 98 you should not need to replace them, as they are too new and are not worn out yet...Even with the 98 Supra Control Arms (New) I don't think you would notice that big of a difference..Uppers control arms you never need to replace, I am still running on my originals and I have a 92 Sc400...Wait another 5 years before considering the 98 Supra LCA's or 100,000 miles which ever comes first.. Save the cash...

Seafoaming is always a good idea once a year...Carbon build up occures aggressively with the EGR systems intact...I would seafoam....

K&N drop in filter if you wan't, however you won't notice anything....The BFI intake will yeild your best intake results...Right ups on that can be found on planetsoarer.com...

In reply to this on going thread - When I first wrote it on this forum I didn't think many would take the time to read it...I am glad there is interest..

[lexus082]

What about the 95-96 supra arms or the 97-98 arms? They should fit too right? Do you think I could talk to a toyota dealer and find out what the difference is between years of production.