LeeT Posted October 13, 2006 Share Posted October 13, 2006 You might want to put the FPR *after* the fuel rail -Ian It's already in;) Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 13, 2006 Share Posted October 13, 2006 If you've got spare enough cc's to be able to map out a significant pressure change then you've got the wrong injectors. If it's the injector is too big, it will make mapping for the subtleties of idle difficult. If you pick a pressure at the start of mapping and stick to it, I don't think this is an issue. Bigger injectors are easier to get an idle with at lower pressures anyway, as you need more duty to supply the fuel OK it's daft buying 1000cc injectors and running 20psi through them, but the stock pressure is 36 to 38psi and that's about 5% fuelling difference from 42psi. Plus once you've hit around 80% duty, then that's it, you either risk going static or raise the base pressure. You need to run the right size injectors at the right base pressure. No two ways about it. Considering the stock 440cc injectors on a Supra running over 1bar of boost and an FCD are at 100% duty, I think injector technology has come on a long way in this area. No, it's not a great idea to run like this, but has anyone heard of a stuck open injector or one failing, despite all the people running 100% duty when booting it? I haven't. I'm not advocating running 100%, far from it - I hate the idea of having no headroom left. But 90% duty isn't an issue IMO. I totally agree on the regulator side though, although I wouldn't start thinking that you need to start spending silly money, as Ian says the Aeromotive's have a good rep on here, but there are also several other's that produce reasonable kit (weldon for example) But definitely stay clear of the FSE range etc, as my personaly experience has found them to be lacking. I think the whole "avoid aftermarket FPRs as they are junk" argument is unfair because I reckon aftermarket FPRs have been dragged down by one brand only - the FSE. Avoid. -Ian Quote Link to comment Share on other sites More sharing options...
Wez Posted October 13, 2006 Share Posted October 13, 2006 Just a final thought - Is it really worth converting the rail to dual feed? Chris seems to think not, but then most people seem to think its required with larger injectors. I didnt bother and my AFRs are fine at 1.4bar right through the rev range. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 13, 2006 Share Posted October 13, 2006 I wouldn't bother with a dual feed rail. My 700 BHP capable Skyline engine is on a stock single feed rail, with just a bigger inlet connection TIG'd on. If I thought a bigger / different / dual feed rail was required the added cost is trivial, in the total expenditure, but I am happy to run the stock one. The X section of most EFI rails, even stock ones, is so vastly bigger, flow wise, than even six 1000cc injectors at 100% duty that it isn't an issue, IMO. But then again I don't make bright anodised rails in pretty colours and packaging Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 13, 2006 Share Posted October 13, 2006 But then again I don't make bright anodised rails in pretty colours and packaging Hey, don't knock that funky purple anodising, it's sexy -Ian Quote Link to comment Share on other sites More sharing options...
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