2,5" vs. over 3" Exhaust
#1
Senior Member
Thread Starter
iTrader: (1)
Join Date: Sep 2004
Location: Germany
Posts: 337
Likes: 0
Received 0 Likes
on
0 Posts
2,5" vs. over 3" Exhaust
Hey Guys,
i want to buy a new cat-back system and dont know which one would be better.
Well, there are 2 cat-backs which have my interest.
APEXI GT Spec
HKS HiPower Silent
APEXI is 65mm at the flange to the cat, the piping diameter rises to 85mm at the muffler.. so you can upgrade your piping up to 80-85 mm.
HKS is 65mm at the flange to the cat, the piping diameter rises to 75mm (3inch) but then INSIDE the muffler it gets back to 2,5inch.. so you have no chance on building a full 3inch right?
since i live in germany, it will be difficult to ship the APEXI because of its oversice.. so i have to cut the piping to fit a box, and weld it together again as soon as it gets here, so this is a problem.. HKS can be shipped without any problems and would be a bolt-on system.
What do you think.. is it worth the 0,5inch bigger diameter for the APEXi?
What is the difference in performance between a 2,5inch and 3inch exhaust?
My car is supposed to produce ~ 350whp in future.. how big is the difference between 2,5 / 3,0inch? 10,20,30hp?? i really dont know
so please help me with my decision!
i want to buy a new cat-back system and dont know which one would be better.
Well, there are 2 cat-backs which have my interest.
APEXI GT Spec
HKS HiPower Silent
APEXI is 65mm at the flange to the cat, the piping diameter rises to 85mm at the muffler.. so you can upgrade your piping up to 80-85 mm.
HKS is 65mm at the flange to the cat, the piping diameter rises to 75mm (3inch) but then INSIDE the muffler it gets back to 2,5inch.. so you have no chance on building a full 3inch right?
since i live in germany, it will be difficult to ship the APEXI because of its oversice.. so i have to cut the piping to fit a box, and weld it together again as soon as it gets here, so this is a problem.. HKS can be shipped without any problems and would be a bolt-on system.
What do you think.. is it worth the 0,5inch bigger diameter for the APEXi?
What is the difference in performance between a 2,5inch and 3inch exhaust?
My car is supposed to produce ~ 350whp in future.. how big is the difference between 2,5 / 3,0inch? 10,20,30hp?? i really dont know
so please help me with my decision!
#4
F**K THE SYSTEM!!
Dont waste money on a cat back.
Buy a nice 3" downpipe and then gut out your stock cat. (with the broomstick)
I would for these reasons.
1. More overall exhaust flow(if u gut the cat)
2. Still have the sleeper/ stock look.
3. Probably a cheaper upgrade. Considering your looking at 500$ catbacks and the goodbrand downpipes dont go for more than 300$
Buy a nice 3" downpipe and then gut out your stock cat. (with the broomstick)
I would for these reasons.
1. More overall exhaust flow(if u gut the cat)
2. Still have the sleeper/ stock look.
3. Probably a cheaper upgrade. Considering your looking at 500$ catbacks and the goodbrand downpipes dont go for more than 300$
Trending Topics
#8
Senior Member
iTrader: (1)
Join Date: Oct 2007
Location: Nova Scotia, Canada
Posts: 568
Likes: 0
Received 0 Likes
on
0 Posts
For a turbo car 3 inch all the way or Y it off to dual 2.5 inch. I am in the same boat as you are, but I am beginning to make my own system because I want to stay dual and there is nothing available with a properly built Y-pipe.
If you can get the 304 stainless locally I would recomend buying a good muffler, some pipe, some bends and build it yourself!!!
If you can get the 304 stainless locally I would recomend buying a good muffler, some pipe, some bends and build it yourself!!!
#9
Just like the other guys said. turbo 3" n\a 2.5". But if I were you do a full back and after the cat, go to a slightly smaller pipe, then into your mufflers which woudl be bigger. This cause a hyperbola in your exhaust and makes air flow out faster which will probly give you a couple horse.
#10
Senior Member
Join Date: Nov 2005
Location: united states
Posts: 541
Likes: 0
Received 0 Likes
on
0 Posts
check out the for sale i picked up a corksport full 3 1/8 for 300 shipped. The bigger you go with your exhaust the more low end you lose due to the loss of scavaging. its more noticable on na vehicles, on turbos you want the turbo to be able to flow as much as possible
#13
rotorhead
iTrader: (3)
dude 2.5" is fine. I did 250 to the wheels on a 2.5" exhaust... how much power do you plan on? If you are keeping the stock turbo you will be fine with 2.5" . In fact, I think J-rat made over 400whp on the 2.5" racing beat catback. I'm not saying 3 inch won't net you some power, i'm just saying getting a 3 inch exhaust isn't critical.
#14
back from the land of v8s
Join Date: Aug 2007
Location: Burleson Tx
Posts: 585
Likes: 0
Received 0 Likes
on
0 Posts
Ive known a few people in the past the simply bought the mufflers they wanted then had a shop bend the piping to make theirs. SAVED HUNDREDS $$$$$$ I know one FC that had 3" down with a 3" single to a N1 was $125 installed.
#16
Senior Member
Thread Starter
iTrader: (1)
Join Date: Sep 2004
Location: Germany
Posts: 337
Likes: 0
Received 0 Likes
on
0 Posts
hey guys, do you know where i could get 85mm ID flanges? i need 4 pieces, it would be also awesome if the same shop would carry 85mm OD stainless steel pipes
i would take racingbeat flanges and pipes, but the biggest they carry is 75mm (3inch)
i would take racingbeat flanges and pipes, but the biggest they carry is 75mm (3inch)
#17
Play Well
Join Date: Feb 2005
Location: We're all fine here now, thank you. How are you?
Posts: 4,218
Likes: 0
Received 0 Likes
on
0 Posts
Thread
Thread Starter
Forum
Replies
Last Post
rgordon1979
3rd Generation Specific (1993-2002)
40
03-15-22 12:04 PM