Why more fuel pressure Toby?

[Gunni]

well nothing amazing, and they might not happen at all so i won't make myself look daft just yet.

more fuel pressure and more boost is obviously the most important upgrade

Why not get bigger injectors, are you running the stock fuel pump?
If so it hold up to 5bar pressure or 3bar absolute + 2bar boost,
but obviously the wear is alot at full use,

[Toby_Unna]

walbro 255 type pump

30lb/hr injectors

it's maxed out at the current state of tune, injectors open 99% at full throttle/high revs.

this is at 7psi.

i could buy some 42lb/hr greens but cannot afford it at present, that is the eventual plan. for now i have an adjustable regulator which i expect will work to similar effect.

[DRIFTBOY]

Toby - Is your engine running standard internals and compression?

How much boost / power do you think it can take ?

Have you quarter miled it yet ? If so what time did it run ?

Wow, that's a lot of questions!
Sorry, I love your car though!

[Toby_Unna]

all standard mate. a Ԛ£100 lump from an auto that has absorbed a lot of thrashing since i got it. seems to be fine so far. if it blows up i'll get another similar one, though in the longer term i'd like to build up a fresh engine. probably keep it standard other than better HG/head studs which everyone seems to think is a good idea.

with enough fuel i guess 12psi to 1 bar would be ok, it's a very big intercooler which will help keep the inlet charge cool (along with running on the rich side on boost). it's detonation from the inlet charge being too hot that's most likely to kill it rather than power output.

no quarter mile time as yet

[dazleeds]

no quarter mile time as yet

santa pod nov 4th

will we be seeing you there then

[Toby_Unna]

yes i should think so

would have made the last one, but didn't get the car back together the night before.

probably break the fcuking driveshafts, luckily i only live half an hour away lol

[Turbo-Brown]

Did you ever connect the signal line to the FPR in the end Toby?

[Toby_Unna]

no it's all as it was Alex, FPR signal line open to atmo. didn't want to bugger things up after Ant mapped it tbh

runs fine as it is, and doesn't seem to mind the high injector duty.

[gareth]

without the hose connected to the FPR, do you have a low fuel pressure? or am i being daft?

what's this thing at santa pod then? might pop up in the wifeywagon 16v corrado and give that a blat up the strip?

[Turbo-Brown]

Essentially, the FPR having signal keeps the fuel pressure at 3bar gauge pressure (or the FPR rating if not 3bar) above the manifold pressure.

So when you've got the throttle closed and the engine running quickly i.e. on the over run, there will be about -0.5bar of vacuum in the manifold and the fuel pressure will be 2.5bar gauge pressure.

Correspondingly it will increase the fuel pressure when there is positive pressure in the manifold so if you've got 0.5bar of boost, the fuel pressure will be 3.5bar gauge.

This is quite important as if you don't have the FPR signal line connected, your boost subtracts from the fuel pressure so without it attached, with 0.5bar boost you only get a 2.5bar pressure differential between the fuel rail and the manifold.

The higher the boost, the lower the effective fuel pressure, even though it's still at 3bar gauge pressure.

Simple eh?

[gareth]

so would toby not be better off getting th FPR connected to yield some more flow from the injectors (due to a higher fuel pressure)? obviouls this alone would need a full remap though but might save the cost of new injectors and maybe even allow a few more psi?

[Ant]

all comments true with regards to the FPR signal line, but given that Toby's car is essentially on a simplified basemap still, and runs with stable/safe AFRs, it was decided to be left as was @ the time, we had lots of fun still though, til the laptop bit the dust

Toby, get that pressure up dude, I'm due up your way to see mr chu(date TBA), double meet/map session maybe ?

[gareth]

loks like Ant is not happy with huge power on his own E30 and is heading for total world domination by the E30

good man!

[Toby_Unna]

Ant, sounds good

Gareth - there's (just) enough fuel to run the car as-is. i would doubt that adding the fpr signal line would give enough fuel for a significant boost increase as it's so near the wire anyway, and would need a re-map as you say, so it's not worth the hassle as there won't be a worthwhile gain.

better option is to install the adj reg i already have (thanks to Ant) and do one decent increase and a remap all together

[Gunni]

At 7psi or 0,46bar your 30lbs injectors are only working as 27,3lbs injectors (at 7psi only)

With a 30lbs injector you should be getting about 57hp per injector
With a 27,3lbs injcetor your getting about 54hp per injector
@ 100% duty