Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

402-worth switching from 1 3/4 to 1 7/8?

Thread Tools
 
Search this Thread
 
Old 03-11-2007, 10:07 AM
  #1  
TECH Addict
Thread Starter
iTrader: (27)
 
SVT THIS's Avatar
 
Join Date: May 2005
Location: Owasso, Ok
Posts: 2,238
Likes: 0
Received 1 Like on 1 Post

Default 402-worth switching from 1 3/4 to 1 7/8?

I have SLP LTs w/ 1 3/4in piping. I was planning on running a full custom 3in dual exhaust dumped over the axle out back. Are the power gains seen with 1 7/8th inch piping worth it? I am running the L92 heads so I believe I really need to go to the larger diameter to get the power our of it I want. What brand of 1 7/8th inch headers would you reccomend? Is it easier to have a shop custom make your true duals or should I go with TSP's kit?
Old 03-11-2007, 06:10 PM
  #2  
11 Second Club
iTrader: (38)
 
gman's Avatar
 
Join Date: Mar 2004
Location: ct.
Posts: 354
Likes: 0
Received 0 Likes on 0 Posts

Default

I went from kooks 1 3/4" to kooks 1 7/8" headers and the installation was pretty easy. I have heard of some people having fitment problems with the 1 7/8" headers but mine fit the same way as the 1 3/4" did. So far I haven't redynoed the car with the new headers on it so I don't know if it is worth the swap. Alot of people say you will gain some peak horsepower but lose some low end torque. Hope this helps.
Old 03-11-2007, 07:10 PM
  #3  
TECH Junkie
iTrader: (2)
 
WKMCD's Avatar
 
Join Date: Mar 2005
Location: Northern VA
Posts: 3,416
Likes: 0
Received 2 Likes on 2 Posts

Default

THe 402+ engines respond very well to 1 7/8 LT's..
Old 03-11-2007, 08:59 PM
  #4  
TECH Regular
iTrader: (5)
 
ssam98's Avatar
 
Join Date: Jan 2004
Location: nyc
Posts: 437
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by SVT THIS
I have SLP LTs w/ 1 3/4in piping. I was planning on running a full custom 3in dual exhaust dumped over the axle out back. Are the power gains seen with 1 7/8th inch piping worth it? I am running the L92 heads so I believe I really need to go to the larger diameter to get the power our of it I want. What brand of 1 7/8th inch headers would you reccomend? Is it easier to have a shop custom make your true duals or should I go with TSP's kit?
Go with kooks step 1 3/4 to 1 7/8,
Old 03-12-2007, 12:43 AM
  #5  
TECH Addict
Thread Starter
iTrader: (27)
 
SVT THIS's Avatar
 
Join Date: May 2005
Location: Owasso, Ok
Posts: 2,238
Likes: 0
Received 1 Like on 1 Post

Default

I have heard that the L92 heads love bigger exhaust. I have heard awesome things about the Kooks. What is the deal with the HVMC headers, or whatever the hell they're called, from QTP?
Old 03-12-2007, 07:31 AM
  #6  
Internet Mechanic
iTrader: (17)
 
BlackScreaminMachine's Avatar
 
Join Date: May 2005
Location: Wallingford CT
Posts: 9,831
Likes: 0
Received 2 Likes on 2 Posts

Default

I have a good friend with a 402, he is considering very much going from a QTP 1-3/4 to the stepped 1-7/8 kook, id like to have him see a gain, especially on juice
Old 03-12-2007, 11:16 AM
  #7  
11 Second Club
iTrader: (38)
 
gman's Avatar
 
Join Date: Mar 2004
Location: ct.
Posts: 354
Likes: 0
Received 0 Likes on 0 Posts

Default

Your friend will benefit alot with 1 7/8 headers on a 402 with juice.




All times are GMT -5. The time now is 09:49 PM.