The V8 Owners Forum -

Just bought a twin plenum set up to use on my Twin Turbo'd TVr motor, a quick question, are all injectors for the RV8 and it's derivatives the same? Are 5.0 ltr TVR ones the same as 4.6 RR? Are the 4.6RR the same as 3.5?
Brief spec, 4.0 ltr bottom end, Blower cam, JE big heads, 12 psi boost, looking for around 400 hp, NoS, if the stock injectors won't do, what are the best ones to get?

Jeff

Hi Jeff,
Im afraid the original injectors wont be able to fuel that power, you will need around 36LB or bigger. I fitted 500cc injectors to fuel to around 450BHP, and these are near the limit,
Phil

Hi Phil,

Thanks for the reply, I'm under the impression that the twin plenum manifold has different injectors in than a hotwire manifold.
The flapper type are imperial and the hotwire are metric? Can anyone confirm this?
Can I use a P38 or disco inlet manifold and fit the twin plenum to the top of it?
Any help would be greatly appreciated

Jeff

I'm fairly certain there are larger injectors which are the same external size as the flapper ones - perhaps Jaguar? And likely others.

I have just done this myself, so have the answers 4 u.
I had the jag injectors which are 227cc in my twin plenum on a 5.0ltr tvr motor, Phil said to me they would be maxed out so i got 30lb pound injectors which are different style as u pointed out, same as hotwire though.
The twin plenum inlet manifold as bigger ports by 3mm so i wanted to keep this so adapting the manifold to take later style injectors was the answer.
U need a 14mm drill bit, drill out the manifold from the existing size to 14mm but dont break thru the end, it will break thru almost, look at the later hotwire manifold and try drill it as far as that. U will c what i mean when u do it,its hard to explain, it leaves a shroud over the side of the injector.
The fuel rail from the hotwire bolts on the same but fouls the temp sensor, as im running megasquirt i dont need the thermotime sensor so removed this and put coolant sensor in there with an adaptor because its smaller thread size.
Hope this helps.

If you upgrade the inlet manifold to the Lucas Hotwire style injector you have a lot more choice for inj's i.e Ford Mustang, Chevy, Saab Turbo, Motorsport sizes etc

But he does have smaller ports bu changing manifold, this is why i kept the twin plenum manifold and driiled it so u can fit other injectors like u mentioned. im running the ford 30lb red tops

Thanks guys, that's the answers I was looking for.
So I need to open out the manifold to accept the later hot wire injectors and use the hotwire fuel rail too. I'll be using either a megasquirt or a Motec ecu, all to do with price tho.
So 30lb injectors should suffice although if I'm going up in size I'm tempted to buy bigger ones so that I only have to buy them the once.
I read somewhere that SVO ford green injectors are supposed to be good, I'll have to go and do some research.

The 42lb Ford green's do work well and are keenly priced.

No real reason not to use them

Are the green injectors used on v6 st mundano's the same as 5.0 stang ones? I take it the colour donates the flow rate and apart from that, injectors are injectors?

Fozwanger wrote:Are the green injectors used on v6 st mundano's the same as 5.0 stang ones? I take it the colour donates the flow rate and apart from that, injectors are injectors?

NO, the colour does not generically denote anything.

And whilst injectors are all injectors in as much as they inject fuel, yes. But there are various kinds, they have varying spray patterns etc.
But that's getting into the realms of magic to know what spray pattern is best

Generally unless there is a very good reason to select a specific spray pattern, just buy ones that are known to work and are cheap.

It's very unlikely the green Ford items ( Bosch ) used on the US cars are the same ones as the Mondeo.

5.0 racing do a set of Bosch green injectors for £150. I have a mate in the states who can send them to me. I thought that was quite reasonable. I'll check the Mindel ones and see what the spec is just for research purposes

St mondeo one are 19 lb so no good :-/

Spent half the weekend trying to find someone that can supply any 42lb ford green injectors in the UK, can anyone point me in the right direction?

Jeff

Just buy them from America.