EJ8VTECFTW

ok dont tell me to use the search function cuz i just sat here for an hour and searched and either im using the wrong keywords or theres no true comparison of 60mm vs 70mm, im looking into getting an exhaust and the only reason id go 70mm skunk2 would be if it was significant to a power gain on NA application otherwise a 60mm apexi n1 is just what ill buy, if someone can break it down to me on the difference between these piping sizes is going to greatly help me out on my purchase later on this week. btw is install the same on a 70mm application?

Zesti1

60mm = NA set up
70mm = forced induction set up

Installation process for 60 or 70 is exactly the same.

EJ8VTECFTW

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zesti1 &raquo;</TD></TR><TR><TD CLASS="quote">60mm = NA set up
70mm = forced induction set up

Installation process for 60 or 70 is exactly the same.

</TD></TR></TABLE>

would it be bad or good to use 70 on an NA application?

will_rex

There are people running 3in exhaust with all motor and it's supposed to be pretty good. 70mm is about 2.75". I'd say 70mm for performance, 60mm for less noise.

EJ8VTECFTW

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by will_rex &raquo;</TD></TR><TR><TD CLASS="quote">There are people running 3in exhaust with all motor and it's supposed to be pretty good. 70mm is about 2.75". I'd say 70mm for performance, 60mm for less noise. </TD></TR></TABLE>
yea ive seen some of those setups, and watched videos of them, they dont sound to bad..i could deal with the noise if the power increase is significant for a catback..

killyourscene

na means??

silentballer

naturally aspirated

i.e. all-motor, non-forced induction

blahstar

my friend is running 2.5 inch piping on his 2jz swapped lexus sc running 36pounds at 726 to the wheels.

he is using the smaller piping for more backpressure.

dont go over 2.5 on a n/a car. after that its just sound.....

sewelh2

Buy the 60mm because na engines need the extra back pressure. My friends a certified tech at a honda dealership and thats i have run on three of my hondas.

EJ8VTECFTW

can i use 60mm for a turbo as well? ik people say 70mm is better but how bad would it affect me if i have a 60mm when i turbo..?

Zesti1

Note: Im running the 70mm on my car now

EJ8VTECFTW

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zesti1 &raquo;</TD></TR><TR><TD CLASS="quote">Note: Im running the 70mm on my car now </TD></TR></TABLE>

but what if i were to install 60mm exhuast and turbo later on

I:_Drive

you are going to take exhaust advice from a canadian who has a toronto blue jays logo with an mac 10 replacing the blue jay?? mmmkay.

EJ8VTECFTW

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zesti1 &raquo;</TD></TR><TR><TD CLASS="quote">60mm = NA set up
70mm = forced induction set up

Installation process for 60 or 70 is exactly the same.

</TD></TR></TABLE>
old thread but sorry to tell u i wouldnt be using 70mm on a k20 FI setup, id be going with a 3 inch pipe

i dont think your reasoning makes sense because we used 60mm on d16y8 SOHC engines in the 90's..wake up. honda gave us a freaking k20, get the most out of it, dont throw a hairline spec upgrade catback (60mm) its been dyno proven that with 70mm there are NO losses, just gains OVER the 60mm

06siracer

ok this is just what i remember learning about different sized pipes. Anything smaller than a 2.5 in pipe can steal horse power and torque, anything bigger then 2.5 in on a na engine can gain power but you lose some low end torque because some back pressure is good for street cars. and yes u can use a 2.5 in pipe on a forced air engine but u'd be much better off using a 3in pipe because the point of forced is to push as much air in and out of the engine as u can and match that with fuel delivery and timing.

EFinawesomeman

I'd say go with the N1 cus I've put it on a few Honda's and they look and sound great. If you do end up going the forced induction route. I'd reccommend getting all new piping in the build up anyway and when that happens just get the bigger piping when you go turbo. Thats my .02

Aco512

i would go with the 70 only because its slightly larger, n/a or boosted
especially if they both sounded the same

WILD_WILL

I have the skunk2 70mm and it pulls like a **** and i only have the Injen sri you def feel the difference and can feel the bigger piping doing its job. It sounds very deep,back fires during down shifts and normal shifting you can beat it for sound after 4 k it sounds like thunder building i love it.

Paddy

nice so 70mmis the way to go

Blurry

60mm vs. 70mm isn't going to make that much difference in performance...just sound...if you are planning on adding a s/c or turbo then definately go with the 70mm..if you stay na then 60mm is plenty good enough...and the sound will be a little quieter so the popo don't hassle you...or maybe they will....I've heard 300hp or less 2.5" is plenty...then again a lot of people swear by the 70mm on na so unless someone has a dyno of both the 60 and 70mm exhaust I can't see there being that much of a hp difference...

formervendor

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blahstar &raquo;</TD></TR><TR><TD CLASS="quote">my friend is running 2.5 inch piping on his 2jz swapped lexus sc running 36pounds at 726 to the wheels.

he is using the smaller piping for more backpressure.

dont go over 2.5 on a n/a car. after that its just sound.....</TD></TR></TABLE>

Your buddy is not helping himself by creating "Back Pressure" in a turbo car...

Back Pressure in a turbo app means restriction. If you have back pressure that means the exhaust pulse is slowing the exhaust turbine... and seeing that the exhaust turbine is attached to the inducer by means of a solid shaft it is slowing down the compressor You want 0 back pressure Call the guys at Sound Performance in IL or WOTM in AZ to confirm.


Modified by Duckiller00 at 6:16 PM 8/24/2007

formervendor

For the record...

We (Skunk2) have tested the 70mm systems on several vehicles previously equipped w/ 60mm systems (Skunk2 as well). The tests had shown no major drop in power... only gains over the 60mm. This kinda shocked us as we thought there would have been a trade off.

K Series engines love the 70mm... we are seeing gains over the 70mm w/ our new Proto-Type 76mm in some high horespower situations.

WILD_WILL

Trust me i only have the Injen sri and it pulls like crazy when vtec hits its so addicting with this exhuast it will be very hard not to hit wot every 5 min's

blue_shtuff

old thread but was curious...i know that u guys are all talking about k series and such, but what about for a b18c5? would i benefit with a 70mm exhaust? i have a 60mm right now...i know my S2000 LOVES the T1R 70mm single on it, but what about for the type r?

Hellzcivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EJ8VTECFTW &raquo;</TD></TR><TR><TD CLASS="quote">
yea ive seen some of those setups, and watched videos of them, they dont sound to bad..i could deal with the noise if the power increase is significant for a catback..</TD></TR></TABLE>

It's not. Your flow is still restricted by a Catalitic Converter, unless you plan on removing that as well, which opens up a whole new set of problems.

I run 60mm with forced induction. When I spoke to my mechanics about changing the exhaust when I got the supercharger, he told me not to waste the money till I decided to remove the cat or install a high flow cat.