The Ikon

For the SC should not we get greater h.p. gains from free flow exhaust/mufflers as would a V8 mustang or camaro??? I have a K&N cone filter and some free flow mufflers(from a local muffler shot), and I'm thinking of trying some Flowmaster Delta series (for optimum flow as well as a quieter muffler) vs. spending the cash on borla, greddy etc.., cat back systems (that only offer very minimal gains for big $$$). What do you think about flowmaster or dynomax on the SC4/3?

What type of exhaust/mufflers are you guys running?
I don't want a very loud exhaust note.(my exhaust now is only about 25% louder than stock but I feel that it's still too restrictive) What about removing the Cats would this help or hurt h.p. and the e.c.u.? I was told it would hurt but on my 300ZX it helped out and the car drivability was not affected.

Does any one have just the exhaust and intake dynoed or g-teched separately?

What do you guys think, I'm sure every one could benefit from everyone's reply...

The Ikon

FastSC300

I am considering removing my cats as well. I plan on making my own custom 3" exhaust as soon as I can.

It will be FULL exhaust, from header back to the muffler,
however mine will be just single type exhaust(like supra TT)

SH

ps. prep for turbo

The Ikon

Have you heard any thing about the effects on the car after removing the cats?

FastSC300

the only issues you might have is:

the car will be louder for sure

you might not pass emissions(?) ofcorse i have seen supra's pass emissions without any cats at all.

By removing the cats, you will feel a significant increase of top end power from stock.

I bet it would sound great

SH

mindflux

please go here for my setup:

http://www.geocities.com/SunsetStrip...t/exhaust.html

No catalytics noise level (1995 SC400):

Exhaust tone at idle very low and unnoticeable.

Exhaust noise in normal driving situations, stop and go traffic, 55mphs crusing barely noticeable.

At WOT and at load is loud enough to be heard inside the cabin with the radio on.

At WOT engine free reving (neutral) is loud enough to muffle any other car with a loud exhaust next to you.

Keep in mind about this when removing cats...if you already plan to remove rear mufflers and resonators the exhaust will be just TOO loud. Comparable exhaust tone (not note) Corvette, Z28.

note: race vehicles should not be driven on public "US" highways and mindflux90 should not be held responsible in any way. Perform this mod at your own risk. :eek:

Thanks

JBrady

Mindflux, cool mod. Good observation that gutted cats often flow worse than cats with guts. I don't know what the stock mufflers flow but a simple backpressure test would tell. As far as aftermarket the Dynomax Superturbos flow VERY well and have a good low sound. They are quieter than standard flowmasters and FLOW much better!! One concern for 96 and newer cars. In 96 automakers went to OBDII electronics. These are MUCH more sensitive and may run improperly without cats.

VeilsideRSPsc

i had a custom exhaust with two tanabe style mufflers made which removed the cats... didnt notice too much power... it was certainly louder than stock. after the turbo goes in, im going to have the exhaust taken out and replaced with 3" all the way through with A'PEXi N1 mufflers... should make some good power. lets hope so

-brian
team koncept racing
hyper racing
houston, tx

'92 veilside rsp sc300
'01 stock silver is300

The Ikon

Would I lose any bottom end torque with the cats removed with the additions of free flow mufflers???

Has any one heard from Lextech???

FastSC300

yes you would probably lose some low end torque, but you would probably gain some high end....

Scot Hail

The Ikon

Would the lost of torque (if any...) affect the 1/4 mile et. or just the 0-60 times... I don't want the 1/4 times affected...

FastSC300

I dont know if it would effect your 1/4 time but your trap may be higher.....1-2 mph faster through the traps, besides you usually try to stay high in the rpm range when dragging, you want to stay in the power band of the car, which is approx 6000-6500 rpms

Scot

mindflux

Ikon can't really tell if you will loose time in the 1/4 mile. I am sure that if you take out the cats and run free flow exhaust it will be too loud and you will loose a lot of low end torque.

Mind

LEXUSDOC

I really don't think that you are going to get any major gains out of freeing up the restriction in your exhaust.
I run the RMM exhaust in my sc400 and only noticed a very slight increase in HP. The problem with the sc v8 is that the throttle body is too small. I replaced the air intake with the RMM kit and could not even notice any gain. Mabie just a tiny bit on the top end. I have to tell you dollar for dollar the torque converter is the best add on for the buck. It made the car "Fun". I have tested the vehicle in the 1/4 mile after each one of the modifications I made. The exhaust took off .1 of a second. The air intake did not make a difference. But the torque converter eraced 1.1 seconds off the quarter mile. $900.00 for a full second is a bargan in my book. I have sold a few torque converters to customers and they simply love them. It turned the LS400 into a rocket ship. Nonetheless if you engine is basically stock, exhaust modifications will not give you the results you are looking for.

DOC

FastSC300

LexusDoc is right, on NA motors especially imports, dont expect to pick up more than 10-15hp from a full cat back system...if that. Now if you are turbocharged or supercharged then it's a different story a catback or removal of cats and straight downpipe makes a significant improvement.

bottom line though, this applies to MOST cases, when you increase flow you will gain power.

Scot Hail

Lance

LexusDoc,

What's the drivability like now that you have the upgraded torque converter? How is the shift quality? Is it significantly more jarring than stock? What are the drawbacks? Does it still "feel" like a luxery car? TIA--

Lance