Fitting Extra Injectors

1. Ste Saxperience Post Whore Joined: Mar 2007 Yorkshire Posts: 5415 Saxo

   #1 16th August 2007, 20:26

   Is it better to have a 5th injector or 4 bigger ones?
   
   
   
   Also if fitting a 5th how do you fit it?
2. Jay_uk Infrequent Poster Joined: May 2007 Kidderminster, Worcestershire Posts: 239 Black MK2 VTS

   #2 16th August 2007, 20:30

   4 suited injectors properly mapped obviously depending on n/a or boosted
3. Ste Saxperience Post Whore Joined: Mar 2007 Yorkshire Posts: 5415 Saxo

   #3 16th August 2007, 20:43

   Boosted, would a 5th injector put in before the throttle body be as good.
   This would give even distribution and correct fueling.
   
   And be cheaper than 4 bigger jets.
4. belly_VTS Frequent Poster Joined: Jan 2006 Co Durham(north east) Posts: 626 cammed vts, (rest in pieces) corsa vxr - 340bhp

   #4 16th August 2007, 20:43

   depends what management your running. to run 4bigger injectors youll need to be on standalone. if your just settling for a mf2, then a 5th injector is needed.
   the standalone with bigger injectors will be the better route like
   
   if im wrong im sure somebody will correct me
5. mallboy Saxperience Forum Bum Joined: Dec 2005 Wolverhampton Posts: 3000 MK1 VTR TURBO

   #5 16th August 2007, 20:56

   Quote:

   Originally Posted by belly_VTS depends what management your running. to run 4bigger injectors youll need to be on standalone. if your just settling for a mf2, then a 5th injector is needed. the standalone with bigger injectors will be the better route like if im wrong im sure somebody will correct me

   na you absolutely correct. best to put the 5/6th injector on the intake pipe as close as possible to the trotlle body and preferably facing it aswell. the 4 bigger injectors are the expensive way round but is not very cost effective due to the standalone managment required
6. Ste Saxperience Post Whore Joined: Mar 2007 Yorkshire Posts: 5415 Saxo

   #6 16th August 2007, 21:04

   Quote:

   Originally Posted by mallboy na you absolutely correct. best to put the 5/6th injector on the intake pipe as close as possible to the trotlle body and preferably facing it aswell. the 4 bigger injectors are the expensive way round but is not very cost effective due to the standalone managment required

   Rekon ill do that then. heheh nice
   
   All i need now is the pipes and i can start fitting..... Might get a chrome intercooler aswell as the one ive got now looks a bit travelled.
7. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

   #7 16th August 2007, 21:07

   wtf is a 5th injector and where do you put it?
8. user_15989 Saxperience Forum Bum Joined: May 2007 Posts: 4857

   #8 16th August 2007, 21:08

   Adding a 5th injector is easy for the DIY boost job. This is as you already have a well setup engine that runs perfect and all your doing is using another injector driver such as a MF2 to add the extra fuel when boost is seen. Normally the extra injector is fitted before the inlet as the air for all 4 cylinders is mixed there. Then when your extra fuel driver sees boost in the plenum it fires your injector to the desired amount.
   
   4 bigger injectors in theory better but is harder to get working as you have to completely remap the stock ECU to drive them correctly or you have to start all over again and go stand alone. However saying 4 bigger injectors is better is not totally true. They are said to be better as you have more control over the fuelling of individual cylinders. How you have no individual air metering or O2 exhaust detection for each cylinder.
   
   So unless you are spending a fortune on management systems and spending the time and cash to have the car mapped to the enth defined both end up much of a muchness and both can be used to great effect on the Saxo. Don’t forget cars like DPs 12.8sec 1/4 mile monster is only running one extra injector. Though it is a 1000cc item. But 4 bigger the way I would tend to go.
9. KamRacing Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)

   #9 16th August 2007, 21:10

   Properly mapped with an aftermarket ECU and 4 injectors would be my choice
10. Aron Saxperience Forum Bum Joined: Feb 2007 Nuneaton Posts: 3554 EP3 Civic

    #10 16th August 2007, 22:30

    yea id say its worth spendin the extra uprating the injectors first of all with the stand alone. All depends on how much your looking to spend,
11. Ste Saxperience Post Whore Joined: Mar 2007 Yorkshire Posts: 5415 Saxo

    #11 17th August 2007, 11:56

    Well its a budget build so im going for the MF2!.
    
    The MF2 you can do yourself if you've got a bit of patience and knowledge....Obviously not ideal but im not a racer so it would be perfect for me, im not against the clock so its soley for a bit more fun on track.
12. spencer_cammedvts Saxperience Forum Bum Joined: Nov 2005 MEASHAM United Kingdom (England) Posts: 3445 257bhp Ibiza Cupra Turbo

    #12 17th August 2007, 12:43

    how much are the 4 extra injectors gonna cost. what size would be needed to run say 7/8psi on a vts or vts on standard internals?
13. user_15989 Saxperience Forum Bum Joined: May 2007 Posts: 4857

    #13 17th August 2007, 13:56

    I would not run a stock VTS at 8psi. Unless you have great management and are very well setup with great fuel I would say lower the compression. But if you up the FP the stock injectors should see ok just for 7psi.
14. Ste Saxperience Post Whore Joined: Mar 2007 Yorkshire Posts: 5415 Saxo

    #14 17th August 2007, 14:11

    Ill be using forgies eventually.
    
    I rekon ill only be running 6psi at first, then ill start the tuning once im happy with the kit ive got.
    
    The main focus for me is to get the block tuned so i dont have to run silly boost to get good power. I aim for a good set of cams and headwork, once the heads in a good state and its all runing smooth ill start tweaking.