turbo fpr usable for n/a?
Turbo Mini Forums

Just wondering if I can buy the turbo fpr for my car so i can simply fit and forget, and not have to buy an n/a one and swap the the rising rate down the line when the turbo lump goes in. Couldn't really find anything on the net about it.

Just fit it and blank of the boost sense port on it. Set it to 3.5psi and you are off.

erm, leave the boost port open?

Why? A normal n/a carb'd mini doesn't adjust fuel pressure based on atmospheric changes so why would you do it in this scenario?

I think you'll find theres a little hole to vent to atmoshere on a normal FPR

The reason being I have the injection tank I'm fitting, and with that comes the fuel feed and return so I just thought I mayaswell fit the turbo fpr ready whilst I'm there. All done and plumbed up and bracket made and I won't need to touch it then except after the fpr when I fit the turbo lump. N/a 1275 is just to get me on the road sooner.

It will be fine either left open, or with a vac signal attached to it.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Lovely stuff, cheers guys!

Actually Stevie rasies a point I hadnt considered...

I asume your on carb so this is irrelevent, but.

injection systems, set to approx 3bar fuel pressure and the fuel pressure is feferenced to what the engine see's via the "boost port" connected to the manifold/plenum, so the FP can raise by boost pressure, or drop by manifold vacum to keep a fairly constant 3 bar across the injector so atomisation is not affected.

carb systems are set to approx 3-4 psi, and usually referenced to atmoshpere, obviously for boosted engines they need to be referenced to boost, If the feference is taken after the buterfly, you can have the situation where on over run the fuel to the float chamber is cut, also there may be a boost drop across the venturi which could cause issues, but may be fine.

I did think about the fact it would be under vac after the venturi, where as normally it would under atmosphere or higher coming from the plenum signal. I think I'll just leave it to atmosphere as that's exactly what it's always going to see as n/a.

I used it on my N/A 998 engine, with the boost port open to atmosphere. Had no fuelling issues.

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Yes vent it too air had my 998 like this for a while before fitting my first turbo aseries

Yes i moved to the darkside

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On it's own, it really makes no difference.

The reference to maintain a constant pressure across the injector is more to simplify tuning, and for consistency. Nothing more.

A lot of modern cars run a dead end rail setup, reg in tank, no pressure reference. Often these run a higher base pressure too.
Say 60psi. This is a constant 60psi at all times.

So even with boost, having a pressure reference still isnt essential ( fuel injection ). Even 60psi FP vs 20psi boost...would still leave you with 40psi to inject fuel.

Fuel mapping may look a little strange, but as long as everything is consistent, it doesnt matter that much.

For a low pressure carb setup, obviously it must have a pressure reference given the low pressures involved otherwise boost would blow fuel out of the carb instead of allowing it in.

But as far as a vac reference goes either under n/a or boosted usage. On a carb I see this as a good thing. At light throttle and cruise, idle etc, you've no need for FP to be right at the limit of what the needle valve can seal. So a reduction in pressure at these light loads is a good thing. Lots of flow wouldnt be needed anyway, so a low pressure supply wont be a problem.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will