I am thinking about getting bigger injectors. Looking at the RC Injectors worksheet, that says I should get injectors of over 650cc for power figures over 400bhp. Does this sound correct?

I have no idea what type of injectors I should be looking for, so any advice would be gratefully accepted. Once my Engine and Turbo are rebuilt, I'll be hoping for around 400 - 450 Bhp. I originally thought that 440cc's would be OK but not so sure now.

Given the current strength of the pound, buying injectors from US companies like RC seems like a good option. If other people are interested in injectors, I could open a trade account and organise a group buy.

I’m not a great believer in that calculation sheet. For instance, if you put in the standard figures for the 20VT, it says the standard 330cc injectors would need to run at 90% duty to get 220bhp. That’s not right.....

Anyway, Flea AFAIK runs 440cc so you should still be ok with them for 400-and-a-bit bhp.

I emailed barbz the other day about this and he said they were £75 each! didn't actually give me the specs though but guessing they will be the 440cc ones!

You're very unlikely to be able to go over 440cc/min and retain the standard ECU. as I recall it required more than a days worth of work to get flea's running right on 440cc/min and he has problems with fuelling in 5th (unless he has had that resolved since). It's pretty much fair to say it is a limiting factor as PT only change the data in the maps not the code and so they can only go so far.

john, What are your thoughts on the 384cc injectors from the 16VT? Nigel seems to have no problems with them. I know they are old technology, but is it worth using them?

What about using the 16VT with a 3.8bar FPR?

I have been trying to talk to Rob at PT all week but he's always too busy. I don't want to go to the hassle and expense of another ECU so I'm still undecided on what to do.

I have no idea how close Nigel is to maxing out his 16VT injectors but I know Fergie is having to move up to 440’s as he’s maxed his 16VT’s. He’s aiming for a similar sort of power figure as you are.

My 384cc are close to the limit, but there's still some more to come, especially if I use an adjustable FPR

I think a 3.8bar FPR would be too much, considering I'm running as much as 1.6 bar already, maybe 1.8 bar when remapped - total fuel pressure would therefore be 5.6 bar, which is excessive.

I'm considering 440s for my remap - at least Flea has suffered all the pain of getting a map sorted - should be able to use his maps with some tweaks

Why even think about 16vt injectors when there are much better compatible injectors out there. Don't forget unless you buy new they will be 10-12 years old. How many people on here have ever changed their fuel filter regularly in their 7+ year old coupe? I do but I bet I'm in a minority. So all sorts of cr*p will have probably gone through the injectors and no amount of cleaning will get them back to brand new flow.

I'll add more later but I don't think many people would want to go through what I have, spend the money I have and put up with ongoing problems. If I had the choice to do it again knowing what I do now... I wouldn't.

I am planning on using 16VT injectors but not ones from the 16VT (if that makes sense). I’m Just looking for a modern injector which is 384cc - 420cc. I didn't want to go down the 440cc as that is overkill for my spec but I don't want to run a duty cycle of above 85% and any more than 3Bar fuel pressure. Wheat injectors would you guys recommend that I use as I want to buy brand new injectors before the live mapping?

P.S. I found this site: http://www.fiveomotorsport.com/

Have a word with Barbz I think he can source some Bosch ones. The main things you need are high impedance (12-16 ohms) and a bosch type fitment. If it isn't a split pattern injector then you need to try to centre it as much as possible (the split pattern injectors have a special lump that holds them at the correct orientation)

Again im shocked at how people are having injector woes. Now i know that the big boys need more fuelling. But i have plenty of fuelling on stnd injectors for 335bhp and if my power figures are working out ok, i could probably have enough for 350bhp with still running rich.

Ross

fccuk off you ... you don't know what it's like to run lean

That maybe true but then you will be running 3.8Bar reg and the duty cycle will be in the 90+ mark which is what I don't want. It may work fine but i feel its pushing them too far.

@ John what cc injectors would you go for aiming at 380BHP MAX and keeping the reg to 3Bar?

400cc/min but WHY do you want a 3 bar FPR? Fuel atomises better at higher pressures so as long as the injectors are able to continue to provide a consistent flow at the higher pressure then its all good. I wouldn't go above 4 bar base pressure though just because depending on which Walbro 255lph pump you have you might start to get near to the capacity of that.

What spray pattern would be the best for the 20VT? Could you rearrange these into order of your preference?

1) 21 Degrees Twin
2) 3-Prong Cone
3) Split 20 Degrees 65% of delivery within 10 degrees
4) 4 Degree Pencil
5) Tri-Cone
6) Cone

don't know if it's of any help, but a few Greek 20vts are running 500cc and one is recently running 750cc injectors (managed 380bhp @0.9bar on the club dyno day last week with a half done program. OK it was a 2.4 conversion )

Have a look at the siemens deka injectors V.CHEAP from the states (probably be around 200euro for 5 of them for you guys)

V.

Vas, are the people with those big injectors still running with the standard Bosch ECU? If so, have they had any problems mapping them?

What injectors are you running with? Any problems?

That sounds very cheap for the Siemens deka injectors, where did they get them from?

i can sense another group buy

Squid, yes they're running standard Bosch ECU. Don't know much else other than two guys Dimitriadis & Papailias (both in Athens) are programming them. Don't know what tools they use, or how, just seen the results.

Regarding the Siemens Deka injectors I bought them new here:
http://www.sprayitracing.com/60lb%20Seimens%20Deka%20EV6%20Style%20High%20Impedance.htm
check out the price
And yes they were new (didn't believe it at first!) guy responded on my mails quickly, so I can definitely recommend them.

I'm on the Marelli ECU (16vt) and the only problems I had were a split vacuum that *I thought* was causing my crap idle, sorted it, car is idling fine

V.

You were reading my mind Mark! I can think of at least 6 people who would be very interested. Time for another trade account, I think....

before you start buying injectors, make sure that whoever is going to map them can get them running OK. I'm just reporting on what's happening with the Greek guys and that for sure the Siemens deka work on my 16vt, that's all!

V.

Vas, thanks for that. I realise the mapping is the most important part of the equation. I'm going to talk to the mapping company about this tomorrow.

I was looking at injectors the other day, stumbled across this place which has a fairly wide selection:

http://www.racetronix.com/

I also stumbled across racetronix but am undecided on which ones to buy for me:

http://www.racetronix.com/01D114x.html

http://www.racetronix.com/621010.html

http://www.racetronix.com/0280150967.html

Fiat's Data book says that the standard injectors’ forms two cones of 10˚ with an overall of 22˚ this is so that half of the fuel can go down one inlet port and the other half can go down the other port. Ideally I would what to stick to this spray pattern as close as possible. The only injector that resembles this pattern is discontinued:
http://www.racetronix.com/621010.html

What do you think I should choose now? Comments?

for 400 ps, 650cc should do the job perfectly on OEM fuel pump.

Anything more, you'll need to go for 9oo - 1.ooo cc just to be sure

Not sure where you've got your data, but its seriously inaccurate

I'm running over 400 bhp on 384cc injectors, with a 255 l/h pump

I'm not convinced that the OEM pump could ever allow 400bhp, as regardless of the injector size, it just can't deliver enough fuel to the rail.

Nigel,

should also mention the fpr you're using, I assume it's the 3.8bar not the stock 3.0 bar, right?

V.