V8 EFi injectors/ECU

[SS069]

I want to get a few more horses out of my V8 fuel injected Manta GTE, been doing a bit of reading & as per usual I am now confused......I am asking the question in anticipation as the car aint running yet, but it'll be up n running in a couple of days now I've got the bits I need

I would like to know if I can replace the flapper type airflow meter with a hot wire or even a 4.2 Jag one & install higher flowing injectors such as GREEN, BLUE or BEIGE.....what power gains could I reasonably expect....if any...!!!

has anyone messed with their RV8 injected engine yet or not...???

Mine is a Vitesse fully rebuilt motor that has been bored +20 including new cam & lifters, but of an unknown spec

PS - I also fancy going down the LPG route too.........all advice much appreciated.........

[ramon alban]

I want to get a few more horses out of my V8 fuel injected Manta GTE

Hello Steve,

If you are already familiar with the RV8 Efi Flapper system, you wont want to read any further. On the other hand because the car has been stood/neglected for 14 years (your other post) you may have problems getting the injection system to perform at peak efficiency.

So, before you spend any money, try to get the best from your current system. See here:

http://www.vintagemodelairplane.com/pag ... wer01.html

Virtually everything suggested is cost free.

[ChrisJC]

The hotwire and flapper injection systems are quite different, you can't really swap any parts between them. Certainly not the injectors or AFM.

You can fit the AFM from the 4.2 Jag though (as long as it's the flapper style AFM). I don't know if there are injectors that flow more, that are interchangeable.

You would be advised to get an adjustable ECU if you are doing that, so you can tweak the map to work properly with the different AFM and injectors. Mark Adams is your man, although he ain't cheap!

Chris.

[katanaman]

impossible to say if you will see gains without knowing the spec of the engine. A pure guess with it being a 3.5 I would say no gains are to be had. What you cant do is just change the injectors without re-mapping the ecu as it will have no idea about the new mount of fuel going in. You also cant put a hotwire meter on without changing the rest of the system and in particular the ECU. You will also find it difficult to get different injectors for the flapper system as they are a different fitment. You would be better to change the whole system for a hotwire system which opens up getting new chips and injectors. Again though unless something quite special has been done to your engine it will be a waste of time and money as you wont have reached the limit of what you already have assuming what you have is working properly.

[SS069]

thanks guys & I really do appreciate what you're saying.

I am aware that I will need to change the whole injection system including the ECU to run a 'hot wire' system, but was wondering what power agaings cost gains there would be.

I have had a few Wedge TVR's in the past & can remember reading the 'Bible' somewhere that I can swap the flapper & injectors for a Jag 4.2 flapper/injectors to increase fuel flow, but that said I don't want to spit flames with unburned fuel.....

As stated previously the engine has not run in anger yet, that's if I can get it to run at all, but I'm pretty sure she will - here's hoping

[katanaman]

4.2 jag is flapper if I remember right but you have taken things a little out of context. The ECU will need to know your flowing more fuel and just changing those parts wont do that. You will have to re-chip or on the flapper I think it has to be a piggy back system. Just changing those parts alone the engine will most likely run like a dog and burn loads of fuel for nothing. As stated before though your most likely not on the edge of what your system can do (around 260 bhp) so it doesn't need changed. If all you wanted was more fuel then you could do it with an adjustable fuel pressure regulator but again if you don't need the fuel it will just run rough.