KOKISF

Hi and thank you for your time , my question is simple is the stock isf exhaust is really crappy? My goal is to make my car a tad more faster but I dont want it to be loud by any means , being there done that!!! so I was wondering if I only install ppe or sikky to my ride will this make it much louder , and create good power? from what ive searched ive seen numbers from 30whp with the stock exhaust , but its not quite clear if this numbers are with cats or not , as for what ive seen a researched in the forum, I would like to do headers , joez intake and drop in filter, what kind of numbers you guys think ill hit?

darbs242

iTrader: (5)

You will pick up about 30 wheel with headers alone. The exhaust is worth 20 wheel by it self but it will allow the headers to make another 10... So headers & exhaust will almost get you 60 wheel. Joe z or hps intake are worth 5-6 whp

flowrider

iTrader: (9)

IMHO, the most restrictive part of the stock exhaust system is the crush bend in the axle back portion.

Lou

vbb

iTrader: (3)

The stock exhaust is not bad at all. I actually love the sound/tone of the car in its stock form. If you want maximum bolt-on power out of your IS-F, you will need to change the headers, exhaust and intake though.

BULLIT

Thanks for the info Lou. Is it possible to buy a piece to replace this section without buying a whole exhaust?

RCB

iTrader: (18)

Any axel back system will eliminate that restriction. Borla, etc.

aWorkOfArt

Not sure about the numbers with just the headers and an intake. But im running the PPE headers and a JoeZ intake and AFE Drop-in filter and you can tell the car gained significant amount of power. There is also the feeling I get from it being restricted from using the stock exhaust, its like the car is being held back by something... all the back pressure i guess. As far as sound wise, it sounds slightly raspy and loud at cold start, but after the car is warmed up, it tones down alot and has a nice little rumble to it. You can tell you got something under the hood. When driving, it has a nice deep tone to it and love it thus far... Hope this helps bro...

I wonder if eliminated the crush bend with an aftermarket axle back will allow for car to breath better? Like a Borla or an ISS when they release one. Experts chime in, this thread is informative to us all.

Rossi

iTrader: (4)

Here is thread on Borla axle back I started recently.....
https://www.clublexus.com/forums/is-...ck-thread.html

KOKISF

wow guys thanks for the replies , apparently Im not the only one wondering about this , after seing the pic posted by Mr. Lou I totally agree on the restriction there , but it is not something that you can fix with an experienced welder imo, and save a couple of hundreths!!!

1sexylexus i think whats holding you back is the cats and the segment just mentioned before just my opinion , im just courious if someone has tried this!!!

LegendGT1

Its still hard to tell how loud it will be in person but here is a video with just sikky headers.


Here's one with PPE headers, an intake, cat less mid-pipe and stock axle back

KOKISF

thanks for the vids, its so hard to tel the pc im using right now sucks lol speakers are blowned , all I know is that I dont want my car to sound like an american muscle car i rather leave it stock !!!I love the way it sounds now but would like more power!

JDMV8

iTrader: (6)

The most restrictive part of the exhaust is the catalytic converters.
You can get the most power gain by deleting them (there are 2 sets of cats, total of 4)
Subsequently, your car will get louder from a cat delete, it will be droney.
Check out Lou's page for modified mufflers and custom exhaust system, very interesting; and from what I understand, it is sound-suitable and gave him power gains.

I have the ISS QES system (no cats, high flow mufflers and x pipe)
It is very loud and droney, but I'm too young to appreciate luxury just yet!

Welcome to the F family!!

bnizzle87

I didn't think the stock exhaust was bad. I just preferred something that woke up the car and gave it an even more powerful note. The Joe Z does exactly that. Not much drone, and it's definitely an attention grabber.

BULLIT

Sorry I didn't realise which piece this was, I have an axle back Borla on my car now and was looking for a little more sound, from what I can tell the Borla catback is different so I wouldn't be able to just buy the centre section. Any idea where I could get a centre section from and do you think it would sound much different?

KOKISF

keep in mind ,what im looking for is more power , and i know that when you make power ,noise is a by product and i am willing to sacrifice in this case some of the power for lower levels of noise specially drone, and cabin noise!! Im 100% sure I dont want to spray my car , so i think the stocker should be find. 1sexylexus have you dyno that set up ? i will love to see the results on that one since It think thats what im looking for?Or anyone Dynoed this set up hps intake or joez drop in dry, just sikky or ppe ,bone stock exhaust no delete of any kind?