Performance & Maintenance Engine, forced induction, intakes, exhausts, torque converters, transmissions, etc.

Exhaust sizing

Thread Tools
 
Search this Thread
 
Old 01-25-09, 09:25 PM
  #1  
supralative
Pole Position
Thread Starter
iTrader: (4)
 
supralative's Avatar
 
Join Date: Jan 2005
Posts: 390
Likes: 0
Received 1 Like on 1 Post
Default Exhaust sizing

GTE turbo swap down the road.
Would you guys do a single 4in DP to MP then go 3in duals or 2.5in duals?
Old 01-25-09, 09:43 PM
  #2  
OneJay
Lexus Champion
iTrader: (14)
 
OneJay's Avatar
 
Join Date: Feb 2008
Location: Denver
Posts: 4,263
Received 8 Likes on 8 Posts
Default

I have a 1jz with a stock dp with 3" mid to 2.5" duals and its fine for stock-ish power levels.
If youre going single, then get 3.5-4" dp and mp, and if you go dual maybe 3" duals.
Old 01-25-09, 10:30 PM
  #3  
supralative
Pole Position
Thread Starter
iTrader: (4)
 
supralative's Avatar
 
Join Date: Jan 2005
Posts: 390
Likes: 0
Received 1 Like on 1 Post
Default

Single 2JZGTE for sure makig 950WHP range.
Thats why was gonna do 4in DP/MP then buy a reducer to 3in then to 3in Y then 3in duals from there.
Old 01-25-09, 10:50 PM
  #4  
1sxyrxy
Lead Lap
 
1sxyrxy's Avatar
 
Join Date: Jan 2006
Location: Ronert Park, CA
Posts: 735
Likes: 0
Received 0 Likes on 0 Posts
Default

if you know how to make 950hp i would assume you would know what exhaust to use. go 4" all the way back single exit. but if you want dual. i would do 4" dp to 3 in all the way to duals
Old 01-26-09, 09:23 AM
  #5  
supralative
Pole Position
Thread Starter
iTrader: (4)
 
supralative's Avatar
 
Join Date: Jan 2005
Posts: 390
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by 1sxyrxy
if you know how to make 950hp i would assume you would know what exhaust to use. go 4" all the way back single exit. but if you want dual. i would do 4" dp to 3 in all the way to duals

Yes I do know what exhaust to use. As you can see in my original post I didnt post anything about a single side exhaust. I dont want a single side with the opening still there on the other side, and dont want to get an aftermarket lip and fill in the other hole either. Yes less back pressure is better in turbo applications, but was just seeing if anyone who ACTUALLY has done it, what they went with. I was hoping 2.5in would suffice, but yes 3in would still be better. A single 3in all the way back is good enough to trap 143MPH in the 1/4 also.
Old 01-26-09, 09:39 AM
  #6  
Biggu
Lexus Champion
iTrader: (12)
 
Biggu's Avatar
 
Join Date: Aug 2007
Location: Ohio
Posts: 2,001
Received 9 Likes on 9 Posts
Default

I have a 1jz in my car with stock twins and stock downpipe but a 4" mid to 3 inch duals.

plans are down the road to go to single setup with 4" downpipe, 4" mid and 3 inch duals but instead of having 2 exhaust made i just had the 4 inch made.

it fits in well but hangs down a tad but i have a really low car (IMO) if i would do it again id make the piping oval that way its got better clearance.

here are pictures for justice.




Old 01-26-09, 10:12 AM
  #7  
Gunnar
Lexus Champion
 
Gunnar's Avatar
 
Join Date: Sep 2006
Location: Kansas City
Posts: 1,626
Likes: 0
Received 7 Likes on 6 Posts
Default

Look into what LexusFTW has on his car (GTE 76mm I believe). I want to say it's 4" dp/mp and dual 4" straight pipes, looks good but is pretty radical.
Old 01-26-09, 02:02 PM
  #8  
supralative
Pole Position
Thread Starter
iTrader: (4)
 
supralative's Avatar
 
Join Date: Jan 2005
Posts: 390
Likes: 0
Received 1 Like on 1 Post
Default

Biggu
looks nice...but you said what I was thinking also. Ground clearance along with clearance underneath for the dual 3in

I know LexsFTW and I dont want to run straight pipes at all.
Old 01-26-09, 04:01 PM
  #9  
IMF
Former Sponsor
iTrader: (2)
 
IMF's Avatar
 
Join Date: Jul 2008
Location: CA
Posts: 188
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by supralative
GTE turbo swap down the road.
Would you guys do a single 4in DP to MP then go 3in duals or 2.5in duals?
It depends on what you want to achieve.

The bigger the piping the more lag you will experience. I personally like the feel of the 3 inch downpipe with 2 2.5 inch exhaust however that's just my personal preference. I like the feel of the quicker spool up, not a big fan of turbo lag that you get with the 4 inch DP. Then again, i dont care about making the most HP, i care more about the way it drives and feels.

What will be your main use with the car? daily driving, drag racing?

If you want a good combo of low speed responsiveness and a little extra edge at high speed go for the 3 inch DP and dual 3 inch exhaust. Again, it all depends on what you are trying to achieve.
Old 01-26-09, 10:18 PM
  #10  
supralative
Pole Position
Thread Starter
iTrader: (4)
 
supralative's Avatar
 
Join Date: Jan 2005
Posts: 390
Likes: 0
Received 1 Like on 1 Post
Default

The SC will run some 9.5's when done at least and I can daily drive it if need be.
Lag is kind of overated to me with a standard transmission. Just really concerned with the ground clearance with dual 3in back there.
If I ever found a decent looking rear lip with the single side opening then yes a single side 4in exhaust to simplify the job.
Old 01-27-09, 12:42 AM
  #11  
IMF
Former Sponsor
iTrader: (2)
 
IMF's Avatar
 
Join Date: Jul 2008
Location: CA
Posts: 188
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by supralative
The SC will run some 9.5's when done at least and I can daily drive it if need be.
Lag is kind of overated to me with a standard transmission. Just really concerned with the ground clearance with dual 3in back there.
If I ever found a decent looking rear lip with the single side opening then yes a single side 4in exhaust to simplify the job.

Clearance should not be an issue for a 3 inch exhaust unless the car is dropped. If that is your only concern then don't worry about it, you got more then enough room down there for a 3 inch exhaust as long as its a good design.
Old 01-27-09, 08:21 AM
  #12  
Toyboxx
Lead Lap
iTrader: (1)
 
Toyboxx's Avatar
 
Join Date: Jun 2008
Location: Az
Posts: 501
Likes: 0
Received 2 Likes on 2 Posts
Default

Why not go 4"Dp/MP as well as 4" Duals. Kinda what like LexusFTW has on his car.
Old 01-27-09, 09:00 AM
  #13  
supralative
Pole Position
Thread Starter
iTrader: (4)
 
supralative's Avatar
 
Join Date: Jan 2005
Posts: 390
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Toyboxx
Why not go 4"Dp/MP as well as 4" Duals. Kinda what like LexusFTW has on his car.
Cost is part of the concern also.
4in duals are alot more expensive then 3in duals then finding a nice set of 4in inlet mufflers too. I am pretty sure I can make the 950WHP mark with 4in DP/MP with 3in duals from there.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Ali y0
Performance
29
09-14-23 09:42 AM
4urxtc
SC- 1st Gen (1992-2000)
18
09-06-12 10:57 PM
scmaluco
Performance & Maintenance
3
08-13-12 06:16 AM
djrazr
SC- 1st Gen (1992-2000)
16
04-02-10 09:31 PM
fLEX-US
SC- 1st Gen (1992-2000)
10
11-04-07 05:49 PM



Quick Reply: Exhaust sizing



All times are GMT -7. The time now is 05:12 AM.