Single Turbo RX-7's Questions about all aspects of single turbo setups.

1600cc top feed, need fuel rail?

Thread Tools
 
Search this Thread
 
Old 09-05-08, 01:45 PM
  #1  
dominican boost junkie
Thread Starter
 
janrx7's Avatar
 
Join Date: May 2008
Location: Dominican Republic
Posts: 325
Likes: 0
Received 0 Likes on 0 Posts
1600cc top feed, need fuel rail?

i plan to upgrade my top feed to 1600cc injectors, do i need a new fuel rail? lines and clips? i plan to move my 850cc injectors down, do i need fuel rail there as well?

i have a walbro 255 pump, i plan to have 400whp do i need 2 pumps?
Old 09-05-08, 04:03 PM
  #2  
Rotary Enthusiast

iTrader: (1)
 
1wide7's Avatar
 
Join Date: Jul 2003
Location: balto
Posts: 866
Likes: 0
Received 0 Likes on 0 Posts
the 1600 will need a new rail, the 850's fit in the stock primary rail but it has to be ground down a bit because the stock 550's are longer with these injectors your going to need a fuel pressure regulator.

If your only going for 400whp you can use 1300 in the stock secondary rail and save alot of money I made 400whp with 850's and 1300's on 1 supra fuel pump and no aftermarket lines or regulator
Old 09-05-08, 04:30 PM
  #3  
slo
registered user

iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
The cheapest easiest option to safely support 420WHP or less (but no more), would be 4 850's stock rails eliminate PD an run an aftermarket FPR bumped to 55 psi base pressure, with a supra pump, the single walbro may be enough for 400 depending on which version it is.

The 1300's can be unreliable, mine once stuck open (but didn't technically fail just left me stranded).

No need to go crazy for only 400 WHP, more info:

https://www.rx7club.com/showthread.p...tors+max+power

Last edited by slo; 09-05-08 at 04:35 PM.
Old 09-06-08, 10:46 AM
  #4  
dominican boost junkie
Thread Starter
 
janrx7's Avatar
 
Join Date: May 2008
Location: Dominican Republic
Posts: 325
Likes: 0
Received 0 Likes on 0 Posts
slo thanks alot. i used the calculator and with 850cc stock on both top and side feed i reach my goal of 400whp with about 75-80% duty cycle. is this safe? my walbro is the 255lph. do i need a upgrade?
Old 09-06-08, 11:10 AM
  #5  
Eye In The Sky

iTrader: (2)
 
cewrx7r1's Avatar
 
Join Date: Feb 2001
Location: In A Disfunctional World
Posts: 7,895
Likes: 0
Received 114 Likes on 66 Posts
If you only want about 400whp and if you will be using a PFC ECU, do not use 850 primaries as they are hard to idle tune.

I run 550/1600 at 15.8 psi boost with my almost stock port GT35R engine without any problems.
Old 09-06-08, 11:45 AM
  #6  
dominican boost junkie
Thread Starter
 
janrx7's Avatar
 
Join Date: May 2008
Location: Dominican Republic
Posts: 325
Likes: 0
Received 0 Likes on 0 Posts
do you have any stumble near 4000rpm when the secondaries comes in?
Old 09-06-08, 03:00 PM
  #7  
slo
registered user

iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
With regards to idle there is no substitute for good tuning.

I was able to get 1680CC primaries to idle good at 1K rpm with an E8 and I am far from a pro tuner yeah a PFC is a different beast, but I'm sure its possible.

There are a few different versions of the walbro 255, some of them are better than others.
Old 09-06-08, 06:39 PM
  #8  
Rotary Enthusiast

iTrader: (1)
 
1wide7's Avatar
 
Join Date: Jul 2003
Location: balto
Posts: 866
Likes: 0
Received 0 Likes on 0 Posts
my car idles fine with 850's and starts with ease
also I have a supra pump FS if you need it
Old 09-06-08, 06:42 PM
  #9  
Junior Member
 
Initial_D_Boi's Avatar
 
Join Date: Jan 2007
Location: Grande Prairie
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
oh
Old 09-07-08, 03:33 PM
  #10  
In the Garage

iTrader: (2)
 
oo7arkman's Avatar
 
Join Date: Mar 2006
Location: Central FL
Posts: 1,406
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by slo
With regards to idle there is no substitute for good tuning.

I was able to get 1680CC primaries to idle good at 1K rpm with an E8 and I am far from a pro tuner yeah a PFC is a different beast, but I'm sure its possible.
Unfortuneately the PFC has a few more limitations and although my idle is smooth with my 850/1680 setup my AFR at idle is pig-rich at 11.2. The 550/1680 will suppourt 400rwhp.

On your fuel pump, I think you will get some to say you can, and others say you cannot use it. Honestly I think it is borderline being able to feed that much fuel so I think it would be better to error on he safe side and get a bocsh or supra pump. Or I guess you could always get the drop-in dual walbro pump hanger from rx7store and just buy another walbro. That is another good option.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
astrum
2nd Generation Specific (1986-1992)
24
11-15-17 08:44 AM



Quick Reply: 1600cc top feed, need fuel rail?



All times are GMT -5. The time now is 12:51 PM.