RScrew69

pretty much as above, spoke to a fellow who is using 8 dark greens for his 500bhp 4x4 cosworth.

or i'm thinking would it be better to use 4 big flowing injectors with decent spray pattern for 500bhp?

any idea?

cheeRS

Kelv

iTrader: (4)

you cold use the siemens (or similar) high impedance injectors!

Chip

iTrader: (3)

4 modern ones, not 8 crappy old greens.

Go for a set of 1000cc, they will do 500bhp in their sleep and still ideal fine.

Talk to stu@msd and he can supply you with everything you need, including mapping it.

Mike Rainbird

iTrader: (3)

I had eight x 803 on my 500bhp Sapphire. They give a fantatsic spray pattern despite what Chip says / thinks .

Chip

iTrader: (3)

They do indeed, and then when an injector plug comes off like happened on my friends harvey gibbs built motor, it goes into total meltdown and you end up with a bill of half a dozen grand to put it right again, where as on 4 big injectors you just lose power on one cylinder and no damage results generally.

Its a no brainer IMHO!

Chip

iTrader: (3)

PS

Plus as well as being potentially lethal to the engine, its also more expensive to implement due to needing a completely custom or rs500 plenum and a second fuel rail etc, where as 500bhp on 4 injectors just needs a couple of hundred quid of "yeovil" or "swedish" plenum and bobs your uncle!

Mike Rainbird

iTrader: (3)

If it comes off at high boost / high load, same effect even on a 4-injector car . Just like if a singe fuel pump fails in the same scenario . I do agree that there are certain scenarios where this can be beneficial (like if it came off at slow speed, you would soon know about it with plenty of warning on a 4-injector set-up).

Cost wise, there is no question that 4-injectors is best, but if you had the RS500 set-up, I would use this .

Dingy

Old hat...

New ecu, new plenum required....

Cheaper to buy 4 siemens injectors and have it mapped correctly, you will get much better fuel econmeny to

Chip

iTrader: (3)

Even at high boost high load I know of people who have had a single injector fail on a 4 injector setup and NOT had a meltdown, but I dont even know anyone who knows anyone who has got away with it on 8, carnage is more or less guarenteed.

Going out and spending a whole load of extra money just to make your car more likely to fail is completely stupid.

Fair enough if you have an rs500 plenum and rail already there is some logic in using it for originality's sake but personally I would leave 4 yellows in the back set and just run 1000cc on the front if I had to leave it in there for appearances sake!

Chip

iTrader: (3)

PS

Mike, after your 8 injector setup you mention, would I be right in thinking you then advanced onto a 4 injector setup with a swedish plenum like I am recomending here?

Mike Rainbird

iTrader: (3)

I run a Mountune roller barrell intake set-up . I tried to buy Martins old 8-injector one that he sold to Oscar in Holland, but at that time, he wouldn't sell it. Ian Sibbert put me on to another one, but unfortuantely it was a four-injector arrangement, and as beggers can't be choosers, I bought this.

I would have actually preferred the 8-injector set-up, but that is because Ahmed has always drummed into me the fact that the spray patterns for smaller injectors are always far superior to the larger injectors currently favoured.

Turbosystems

iTrader: (5)

it is hard to beat the rs500 manifold whether it be on four siemens or 8 X 803's,technically you gain more power firing the fuel in further away at higher rpm and 8 injectors on an rs500 plenum looks the bollox

foreigneRS

unlikely with sequential injection i would have thought

Turbosystems

iTrader: (5)

I would say mike is right

GARETH T

8 is great


ive never heard of an injector clip falling off anyway

Chip

iTrader: (3)

Not the fancy roller bearing setup you are on now, I was asking what did you move onto directly after the 8 injector setup, ie for exmaple what was in your car when you took me round the ring in it?

I know now that you are on a T6 and rollers and that T6 can detect an injector going down and hence you wont the get problems that people do like my friend who's harvey gibb 8 injector setup melted the piston as a result of an injector failure.

If you can afford to go the whole hogg and do 8 injectors properly, there are gains to be had, but the cost for a good 8 injector setup (including mapping and T6 etc) is 4 grand or so realistically IMHO

Chip

iTrader: (3)

Really?

Well II have, that is unless Harvey Gibbs simply forgot to fit an injector clip on one of the 8, and im sure Mike will tell you that isnt going to have happened, so it MUST have just fallen off.

Turbosystems

iTrader: (5)

the rs500 plenum is worth having even on a standard car I don't think the topic was about pectel t6 and roller barrels

GARETH T

your stuck in the past, with old technology

Chip

iTrader: (3)

Agreed, the 500 plenum is great, and if running on an L8 I would use it with 4 modern injectors presonally in the interests of reliability

Chip

iTrader: (3)

His engine morphing routine is obvioulsy slow to catch up.

This is my sierra bay now:


complete with 4 modern injectors

Turbosystems

iTrader: (5)

chip the engine is old

Chip

iTrader: (3)

Agreed, but luckily that doesnt mean you HAVE to fit old injectors to it, or use a 16 year old wiring loom, not if you dont want to

Turbosystems

iTrader: (5)

heres the topic for u chip you arguementavice cnt

Chip

iTrader: (3)

Something appears to be missing from my cunt there tony, and its U

GARETH T

Mike Rainbird

iTrader: (3)

Chip,
It was an eight-injector set up .

Dingy

Thats rubbish, the spray pattern on a modern large injector is fair superior to that of a 20 year old bosch one...

And can ahmed not map these and thats actually the reason ?

Nash

iTrader: (3)

Seeing as Ahmed built and engine and ran it on 8x 55lbs i am pretty sure he can map them Dingy.

Stavros

55lbs are about same as greys arnt they though?

mechanic28

iTrader: (5)

out of interest how much power can u get from 8 yellows?as this is what i would do if i had a rs500 is use 8 yellows got to be good for 400ishbhp

Stavros

Should be good for over 500 on 8 yellows.

Alan s1

Yes as Stu said to me when i asked about a set up using Greys ect he said about going 1 step better and use the "blacks" 55lbs

Nash

iTrader: (3)

Stavros I just replied that Ahmed can map modern type Injectors. When i asked Ahmed about newer Large injectors, he said he could map them but for the power i wanted it was totally useless.

Alan s1 55lb blacks are alot better than greys, better spray pattern and slightly bigger. The only reason i got Ahmed to map mine on Greys was because i already had a set ready to use.

Mark Shead

Chip

Then clearly the clip was either not put on or somebody had played with it, In all my years I have never had a injector clip come off ever,
8Inj are deff better than 4 for spray and placement if used further away i.e RS500,
The question is if it is worth the effort yes it is but the added cost and complexity makes it not realy worth the effort unless you are looking for the last HP,
I choose to run 4 but have no problem running 8inj if asked.

Mark

Alan s1

[quote="Nash"]Stavros I just replied that Ahmed can map modern type Injectors. When i asked Ahmed about newer Large injectors, he said he could map them but for the power i wanted it was totally useless.

Alan s1 55lb blacks are alot better than greys, better spray pattern and slightly bigger. The only reason i got Ahmed to map mine on Greys was because i already had a set ready to use.[/quote]

I was going to go from 803's to Greys and just wanted to check with Stu brfore hand as i had spoken about a chip for the 803's from him
Thats when he said about going for the 55lb if i had'nt got aset of Greys already
(Still not got around to getting a chip sorted or tho i have the "Blacks" thats about where my money ran out for the car

Chip

iTrader: (3)

Ive never had a clip come off myself either, but I can think of no other explanation as to why one was missing and allowed the injector to become unpowered.

Deleted by Request

...they just cant come off if it is on the plug...to have one fall off means either the plug had no clip or it had no clip..lol

...8 injectors looks the bollocks either in wrc siamese form or rs500 ...deffo get a better spray pattern...but personally id always go 4 bigguns as i know these can be mapped no probs...and i am tight ..unlike mikes anal passage

RScrew69

so rather than trying to source a 500inlet or going after another 8 injectors, it would be best if i just used 4 siemens black 83lbph injectors to supply enough fuel to push the car over the 500bhp bracket.

would the 83lbph black injectors be best all round to supply the fuel for 500bhp?

or is it best to use the 55lbph

scoooby slayer

iTrader: (4)

have to say when i enquired at grove for mapping they wernt sure if ahmed would map my car on l8 and siemens
definiteley wernt keen at all and thats a fact and only a few weeks ago to