flowmaster

[lowrideraz]

Originally Posted by jbrady

Do you know or can you measure the stock pipe sizing? It is probably metric at 50mm, 55mm or 60mm. (1.97", 2.16", 2.36")


To the original thread... pass on the flowmasters. Stainless offerings from Magnaflow and Dynomax are much better choices.

According to Lexus the dimensions are:

"Supporting Systems
A true high-performance engine relies on outstanding support systems and thoughtful engineering that touches every detail. The Lexus IS F's unique stacked quad diffusers, for example, make more than a visual statement. They play an important role in a high-performance exhaust system by reducing backpressure. The stainless steel exhaust system starts with tubular exhaust manifolds and integrated catalysts. Next come dual 2.4-inch diameter front pipes that are joined before a pre-muffler and 2.7-inch single center pipe, after which the system splits into two 2.1-inch pipes and enters dual 16.8-liter mufflers."

Lou

[Damage]

Anyone have a soundclip of how the car would sound with straightpipes (no cats, no mufflers)?

[jbrady]

Originally Posted by lowrideraz

According to Lexus the dimensions are:

"Supporting Systems
A true high-performance engine relies on outstanding support systems and thoughtful engineering that touches every detail. The Lexus IS F's unique stacked quad diffusers, for example, make more than a visual statement. They play an important role in a high-performance exhaust system by reducing backpressure. The stainless steel exhaust system starts with tubular exhaust manifolds and integrated catalysts. Next come dual 2.4-inch diameter front pipes that are joined before a pre-muffler and 2.7-inch single center pipe, after which the system splits into two 2.1-inch pipes and enters dual 16.8-liter mufflers."

Lou

GREAT find... even went back looking on lexus.com and could not find the above. Maybe in a magazine?

Anyway, this gives:

Duals out of the cats at 60mm/2.4"
Single center pipe at 70mm/2.7"
Duals to mufflers at 55mm/2.1"

Would love to do a backpressure test at various points. Any Houston owners interested in some testing?

[lowrideraz]

^^^^The whole article is attached.

Lou

[MRxSLAYx]

Ok. Well here are the pics.

[LEXUSF]

Originally Posted by mrxslayx

ok. Well here are the pics.

ok now the sound clips! :d

[MRxSLAYx]

And here are the vids
Sound clip 1- http://videos.streetfire.net/video/I...ust_642011.htm
Sound clip 2- http://videos.streetfire.net/video/I...t-2_642015.htm
In car- http://videos.streetfire.net/video/I...Car_642013.htm

[LEXUSF]

Originally Posted by MRxSLAYx

And here are the vids
Sound clip 1- http://videos.streetfire.net/video/I...ust_642011.htm
Sound clip 2- http://videos.streetfire.net/video/I...t-2_642015.htm
In car- http://videos.streetfire.net/video/I...Car_642013.htm

thanks! lol yes the res is large!

[verals05]

That exhaust sounds great!! Way better than stock... I love the rumble it has at idle

lol now lets get a dyno! I wonder how that exhaust would affect the rwtq and rwhp

[MRxSLAYx]

Originally Posted by verals05

That exhaust sounds great!! Way better than stock... I love the rumble it has at idle

lol now lets get a dyno! I wonder how that exhaust would affect the rwtq and rwhp

Rumble at idle is the best.
I want to dyno the car but i probably wont get around to it until im done with the mods that i want. I plan on an intake and MHP tune within the next month or so. After that comes my Bday present

[Damage]

so no mufflers and no cats? just resonators left?

[ISFHAHA]

Isnt it illegal to drive without cat ?

[Damage]

Originally Posted by ISFHAHA

Isnt it illegal to drive without cat ?

Yes. I went without cats on my s2k for 2yrs. No problems.

[Joe Z]

I had Flowmasters on my 88' Stang... V8 American Muscle..


For the question regarding the secondary cats delete, not too big of a deal since the MAIN cats are still on the manifold.. But with out mufflers, it probably wont pass smog via the sniffer or visually.
Also, the exhaust flow right after the resonator is still restricted by the flat crushed piping.
In my honest opinion, modifying the oem exhaust piping or cutting it up can be costly down the road...

Technically, any exhaust modification made to the OEM Exhaust by removing parts of it, is "illegal".. Replacing it entirely with a modified system is also "illegal"...
Thats why lots of performance exhaust components are sold with the "For Off Road Use Only" disclaimer.


MRxSLAYx, nice work on the exhaust modification.. It sounds pretty mean!!
Hopefully, you got some before dyno runs in??
With out that, you really won't have a clear comparison as to what gains you may have achieved with your current mod or future mods.

Joe Z

[lowrideraz]

Originally Posted by ISFHAHA

Isnt it illegal to drive without cat ?

Yes, but stock came with four cats, the second two only are removed in this application. The primary cats are still there. But, yes, to remove any cat is illegal. But, I also have my secondaries removed and everyone with the JoeZ or SRT exhaust also has them removed.

Lou