how many people are using the new siemens injectors,closed loop set up on biggish power cars?

ive just got my rs500 up and running on 4 greys but need to get it to stu to get it set up one way or another.im feeling that the way to go is the above route,or could i stick with the greys and go closed loop,or just get it running right on the greys?im only asking on here as i keep mithering stu with different ideas so am looking to you guys for some advice so i can sum up the benefits/costs etc.

i wont be using the car too much so fuel economy isnt really an issue,but would like as much power as is reasonably possible.

im sure everyone now knows but here is my spec.
200 block,knife edged crank,low comp,multi layer head gasket,ported head,bd10 cams,verniers,bronze guides,double valve springs,air injectors,4 greys,t4,all cometic gaskets.l8 ecu with pectel board.but will have a standard board shortly.

the car is booked into stu on 26th april,so i need to know what i want by then

 

regardless of how often the car is used, go for the closed loop. it'll pay for itself it no time (obviously itll take longer to pay for itself if its only used once a month tho... lol )

as for the injectors, is your existing spec running the greys on the limit? is so go bigger, if not, keep the greys...

simple

 

The only issue with the greys is they will be on their knees after 400bhp.

Closed loop allows a level of fuel control the YB has previously only dreamt of on high flow injectors, and its not all about fuel economy. As well as hurting the pocket, excess fuel can hurt the whole engine by contaminating the lubricating oil, thus wearing the rest of the engine very fast, and shortening the life of your oil dramatically. The other issue is cold start and running performance.

Done properly, using my latest software, you will NOT be able to tell if your engine is hot or cold when you drive it or leave it idling (no daft hunting) unless you look at the temperature gauge. That is FAR harder to achieve on normal software as well as pectel, but with the latest software we can have virtual perfection.

The closed loop can be applied to any injector, so theres no reason not to go for it unless you dont actually plan on driving it anywhere, but engine issues aside, why do a 200mile round trip to a show at 15mpg iof you can do it at 32+mpg instead? lol

 

ah,i wasnt sure how much power the greys would take,hence the question about keeping them with closed loop.

clearly the set up you originally reccomended is what i need,stu.
ill either get the bits beforehand or leave it all until 26th.

 

All parts always in stock Jay, just let me know what you want to do mate.

 

Hi Stu...

This might be a silly question but are greys really on their knees after 400bhp? I am not questioning ur knowledge But I am getting really confused over the way to go above 400bhp. I know every tuner has thier own individual way but if a grey can't fuel it , it can't fuel it for anyone can it??

As I say I might be miles off but just need it clarified please...

Thks for your advice as always.

Cheers Malc

 

Hi, depends on your opinion of "On its Knees" i expect.
Given heavier fuel pressure they can literally fuel for 500bhp, but at standard fuel pressure, on a YB (The engine type and tune matters due to VE), they are usually almost flat out at 430. Given its not great practise to regularly exceed more than 80% injector on time, i would say around 420 is probably the safe limit, although greys are proven in excess on 90% injector on time... its a tricky one to call, but given Jays particular requirements, I.E. he has not yet chosen an injector, then my advice for anyone who wants a 400+bhp injector has to be that he buys injectors that are having a party at 400BHP, not a nightmare. Especially as there is no cost penalty whatsoever, they dont even need fitting kits.

 

Hi Stu

Thanks for explaining that... So upping the fuel pressure to get a greys to flow over 400ish is not really ideal, its much better to use a bigger injector. Have I read that right? What do you class standard fuel pressure, a factory fit fuel pump or a stage 3 upgraded item? I just want to make sure I understand what you are saying correctly...

Cheers Malc

 

Yes fitting bigger injectors is better as upping the fuel pressure has other knock on effects to the rest of the cars fuel and electrical systems...

IIRC the Cossie fuel pressure standard setting is 3.5 bar absolute (no vacuum pipe on the reg while you check the reading. Put it back on afterwards though).

 

its big injectors for me then....