Big Mistake By Instaling 3" Xforce System In To My R33 Non Turbo

[SkyKC]

Gents ,

Please help asap,

as for the below (which is posted now in for sale section) I got a xforce 3" instaled in to my R33 non turbo and (im so stupid) loosing so much power, now

1)iIf i cant get this one sold, i wanna know how to modyfy this. can I still keep 3" inlet (4"tip) xforce mufler and connect it to 2.5" piping?

2.) This muffler has silencer installed, but will I llose power still if I use this one with 2.5" piping mild steel?

3. I still have the stock R33 2.5" piping with me, thinking of getting this muffler hooked up in to that....

Please can anyone sugget the best way out of this mess..............

FYI--

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(http://www.skylinesaustralia.com/forums/R33-3-Cat-Xforce-Exhaus-t206350.html&p=3650952#entry3650952)

Hi Guys,

Today I got a brand new Xforce 3" Exhaust Full system (3" Mild steel, with Xforce resenator with Xforce MF-LP08 4" tim muffler) installed in to my R33 non turbo - (Gosh im loosing so mcu power, so stupid I should have gone for a 2.5" system) This was installed in to my car today 16/02/2008. and I really want to sell it quickly and get a 2.5" system.

Please let me know if anyone wants to buy $600 (All orginall xforce system, Brand new)

My number is 0421 646 66, sms me or call me or PM me here....

or if anyone has a really good 2.5" system for a R33 non turbo, we can swap?

edit by eug.

search tags: 3" 3 inch exhaust cat back catback non turbo NA volumetric efficiency scavenging backpressure back pressure low power response

[SmittyR33]

Lost power from an exhaust upgrade??? An exhaust upgrade usually results in more power because of the extra flow. Well at least on the NA cars I have owned. Is it louder than the old exhaust? If not there may be a restriction somewhere and that could be the cause of your power loss?

[SkyKC]

Lost power from an exhaust upgrade??? An exhaust upgrade usually results in more power because of the extra flow. Well at least on the NA cars I have owned. Is it louder than the old exhaust? If not there may be a restriction somewhere and that could be the cause of your power loss?

It is definitly louder than stock, but I think im loosing BACK pressure? due to large 3" piping............when I baught the car 1.5 years agao, it came with 3.5" piping and car was so slow, once I put 2.5" it was good, now again its bad...

I dont know im confused now, should I upgrade the cat also then? have 3"inch one at the moment, the compliance one....

Note - Muffler has the silencer still on, I think if i remove the silencer im gona loose more power.............at least that what i learnd from several forums...please correct me if im wrong.

[Eug]

LOL... what's with selling in here lately?

Lost power from an exhaust upgrade??? An exhaust upgrade usually results in more power because of the extra flow. Well at least on the NA cars I have owned. Is it louder than the old exhaust? If not there may be a restriction somewhere and that could be the cause of your power loss?

i think, what SkyKC means by loss of power is in fact a loss of response or a feeling of gutless'ness.

an exhaust upgrade usually does net a power increase, but in mild NA applications too big of an exhaust will reduce the volumetric vacuum/scavenging efficiency.

an NA engine simply doesn't expel enough exhaust gases to fill a large exhaust (volume) at low-medium rpm to get any decent flow. this 'flow' creates a plunging (vacuum/scavenging) type effect which actually helps draw out new exhaust gases.

It is definitly louder than stock, but I think im loosing BACK pressure? due to large 3" piping............when I baught the car 1.5 years agao, it came with 3.5" piping and car was so slow, once I put 2.5" it was good, now again its bad...

I dont know im confused now, should I upgrade the cat also then? have 3"inch one at the moment, the compliance one....

Note - Muffler has the silencer still on, I think if i remove the silencer im gona loose more power.............at least that what i learnd from several forums...please correct me if im wrong.

i'm confused as to what you actually have in your exhaust system?

stock headers?

stock front pipe?

3" cat

3" catback with 4" tip.

stick with 2.5" as a maximal guide for daily/sedate driving and try to keep the rest of the system the same size.

i guess a search prior to buying/installing your cat back would have saved you time and money. i suggest you have a read through the forums on other people's feedback.

[SkyKC]

Hi EUG,

You are spot on mate "feeling of gutless'ness." exactly wht I feel. my system got stock headers and front pipe, 3" cat and 4"tip muffler. So I will go back to 2.5" cat back,

and the muffler inlet has to be 2.5" as you say...........(3" system sound soooooooooooo coooooooool though, got really nice beat hehe, was thinking to keep the 4"tip muffler)

I read so much about this before I got this system, my mech told me that since this system has a silencer fitted that I wont be loosing any back pressure, which is wrong

[SkyKC]

Should I get a high flow 2.5" cat? will it increase anything for better or to keep 3" cat (Dont think its a high flow, the one which comes with compliance)

[GTS4WD]

HAHAHAHAHA!..

I do remeber I wrote on a thread somewhere in the NA section:

"Dont buy X-FOrce!.. It will give you cancer of the ear!"

Get a hotdog/silencer/resonater..

Any/all will help quiet the biatch up!

[dori34]

you should've researched first before running out and buying a 3" Xforce exahust

stick with the 2.5 or 2.75 max!

last time i had a 3" on it lost heaps low down but gained more top end

[(OO)SKYLINE(OO)]

Becuz your car is NA, 3" is too big and you are loosing Back Pressure in the exhaust system. Right now its just a fart can all show / no go.

Take it back down to 2.25" or 2.5" but aftermarket if you want the noise and better flow.

[SkyKC]

Becuz your car is NA, 3" is too big and you are loosing Back Pressure in the exhaust system. Right now its just a fart can all show / no go.

Take it back down to 2.25" or 2.5" but aftermarket if you want the noise and better flow.

I cant find anywhere which has after market 2.25 or 2.5 system....only thing I can find is 2,5 inlet mufflers, so if im not buying some one else system, gota do a custom job maybe.....

have to sell my one first tho,, no money now...

by the way does r32 2.5 system goes in to r33 without drama or what kind of modification does it need?

and R33 gtr will go for sure I guess

Cheers

[SkyKC]

Becuz your car is NA, 3" is too big and you are loosing Back Pressure in the exhaust system. Right now its just a fart can all show / no go.

Take it back down to 2.25" or 2.5" but aftermarket if you want the noise and better flow.

HEHEHEHE you are rite, sounds nice but no go...................

[R34GTFOUR]

I cant find anywhere which has after market 2.25 or 2.5 system....only thing I can find is 2,5 inlet mufflers, so if im not buying some one else system, gota do a custom job maybe.....

have to sell my one first tho,, no money now...

by the way does r32 2.5 system goes in to r33 without drama or what kind of modification does it need?

and R33 gtr will go for sure I guess

Cheers

Just go to any exhaust shop and get them to make up a catback exhaust out of mild steel in 2.5inch, it shouldnt cost you any more than 300.

I would recommend selling your cat aswell and get a 2.5inch hiflow

Edited February 17, 2008 by R34GTFOUR

[SkyKC]

Just go to any exhaust shop and get them to make up a catback exhaust out of mild steel in 2.5inch, it shouldnt cost you any more than 300.

I would recommend selling your cat aswell and get a 2.5inch hiflow

I think thats the best way to do it then, did you mean 300 with the muffelr?

[SkyKC]

J

I would recommend selling your cat aswell and get a 2.5inch hiflow

Justjap has xforce 3in high flow for $200, is that the nirmal price or can I get it for cheaper?

edit- mmmmmmm u mean 2.5 cat,,,,,,,,,,,,,,ok let me see if they are same price, but justjap dont have them,

***when we say 3" cat does it mean it has 2.5" inlet then 3" outlet?

[(OO)SKYLINE(OO)]

I cant find anywhere which has after market 2.25 or 2.5 system....only thing I can find is 2,5 inlet mufflers, so if im not buying some one else system, gota do a custom job maybe.....

have to sell my one first tho,, no money now...

by the way does r32 2.5 system goes in to r33 without drama or what kind of modification does it need?

and R33 gtr will go for sure I guess

Cheers

Hey SkyKC!

Im sure an exhaust place can custom make one like what R34GTFOUR said. They can work out what size cat you need too.

They will know the exact size and you can buy just the muffler (The ones you see at Autobarn / Autopro)

probley cost less than $200 and get them to weld it on but make sure the In Pipe is 2.25" / 2.5" to match ya exhaust pipe of what ever size you choose

but you can have like a 4.5" outlet for the noise.

Edited February 17, 2008 by (00)SKYLINE(00)

[NFSR33]

i just got a exhaust put on my car..

non turbo, 2.25inch catback xforce system with a 4inch cannon

car is running slow due to lack of back pressure, but when silencer is in, it runs smooth and fast

diagnosis, match the piping size with the cannon size...

you will usually see non turbo r33's with twin 2" or 2.5" twin tipped canons...

good way to keep the grunt, and the power...as the air is being expelled through a pipe with the same diameter

eliminating the lack of back pressure theory....

so to the guy who started this post, reduce piping size...and if u want a large cannon, and god knows we all do, get use to the sound of a silencer...if not, do as im about to, coz i made the same mistake as you, get a twin tipped cannon

[SkyKC]

i just got a exhaust put on my car..

non turbo, 2.25inch catback xforce system with a 4inch cannon

car is running slow due to lack of back pressure, but when silencer is in, it runs smooth and fast

diagnosis, match the piping size with the cannon size...

you will usually see non turbo r33's with twin 2" or 2.5" twin tipped canons...

good way to keep the grunt, and the power...as the air is being expelled through a pipe with the same diameter

eliminating the lack of back pressure theory....

so to the guy who started this post, reduce piping size...and if u want a large cannon, and god knows we all do, get use to the sound of a silencer...if not, do as im about to, coz i made the same mistake as you, get a twin tipped cannon

Cool, its all clear to me now, custom is the way to go. tomorrow ill get some prices and see how it goes. will definitly get a 2.5inlet to 4.5out cannon muffler with silencer + centre resanator + 2.5 pipe + and 2.5 high flow cat.........

note - anyone knows a really good exhaust place near castle hill or blacktown area? thinking of going for xforce muffler again...

Thanks heaps guys, will let you know how it goes....

(please someone buy 3" xforce system from me........................)

[Eug]

it's not back pressure pharken!!

[SkyKC]

it's not back pressure pharken!!

Eug, what do you mean?

[Dicer]

Eug, what do you mean?

in mild NA applications too big of an exhaust will reduce the volumetric vacuum/scavenging efficiency.

He's said it many times in many threads now