Turbo Experts, need some guidance...

I've tried other forums but most seems to have their heads stuck up their asses, soo i thought i'd ask the gurus of all things turbo....:)


Right. My little project alfa 147 is crawling along. The plan is: put a K03 turbo (K03 051) on to run at 5psi boost.
I have done a lot of maths. So much so that my head now hurts....

Using "street turbocharging" and " "turbocharging na cars on a budget" i have done the following equations....

Displacement: 96.9Cu/in or 1599cc
Want 5 psi, so Pressure ratio (PR) is 1.34
Volumetric Flow Rate (VFR@ 100%) = 197 Cu/ft min
VFR x Volumetric efficiency (85%) = 168 Cu/ft/min
Air fudge factor means i have 12.59Lbs of air a minute, using a density ratio of 1.7= 21.40Lbs min of air.
K03 seems ok to me, and as its only going to be ticking over, it'll last until i get bored!!

All good so far....

FUEL!!!!
OEM injectors; 0280 155 769: 182cc@3bar, 14.5 ohm EV6

Now.... ive found a formula that says that if you divide your required HP (200) by the amount of injectors you have (4) then multiply that by 5 (fudge factor) then that will give you your required cc of injector. Ie: 250cc. Mine are short, as you can see.

My question is this.....(first of many!!) Can the ecu cope if i put in injectors that are only 20% out of oem?
I'm looking at volvo 0280155832's @12ohm and 249cc.

LUBE:
My other question is regarding the oily stuff. I have a tapping on the end of the head, which can supply the oil (already been done and proven) but the restrictors have me confused! Do i restrict oil flow before the chra or after it? I'm looking at a 1mm or 1.5mm port but am a little fuzzy on where to put it!!

TIA.
Ian.

Can't help much but can tell you that the restrictor goes on the feed not the return. Return would build pressure in the chra and push past the seals causing smoking. You want free flow away from the turbo back to the sump. I don't know what or whether a restrictor is needed for a k03.
Regarding the injectors, you need higher capacity injectors to give the map headroom to put fuel in otherwise they won't be able to deliver the fuel the ECU asks for. This is separate and distinct from the issue of you requiring a custom map to say when and how much fuel to put in. The chances of the original ECU getting that right are quite slim I'd say.

Sent from my XT1032 using Tapatalk

Cheers dude.I couldn't work it out whether to restrict in or out!!

Deffo in. Bb turbos don't need much oil and don't like too much oil so restrictor makes sure it gets enough but not too much. You don't want to stop the used and heated oil getting away. If the k03 has a journal bearing I wouldn't expect it to need a restrictor.

Sent from my XT1032 using Tapatalk

Heres my other problem....

The turbo i have laying about, i discounted as i believed it too small.
But it came from a 1.9L vectra diesel. 112cu/in @4500 rpm x0.9ve = a lot less than i want!!!

How can this little thing create 17psi max? I only want 5psi. :(

What about the K03 from a 1.8t passat, or A4?

You know that moment when you know youre wrong. you just cant pinpoint why. or how you screwed it up?
Yup. just had one of those. joys.
dis rpm = fudge cfm lbs/min
97.5 800 78000 22.56944444 18.05555556 1.317923763
97.5 1000 97500 28.21180556 22.56944444 1.647404704
97.5 1500 146250 42.31770833 33.85416667 2.471107056
97.5 2000 195000 56.42361111 45.13888889 3.294809408
97.5 2500 243750 70.52951389 56.42361111 4.11851176
97.5 3000 292500 84.63541667 67.70833333 4.942214112
97.5 3500 341250 98.74131944 78.99305556 5.765916464
97.5 4000 390000 112.8472222 90.27777778 6.589618816
97.5 4500 438750 126.953125 101.5625 7.413321168
97.5 5000 487500 141.0590278 112.8472222 8.23702352
97.5 5500 536250 155.1649306 124.1319444 9.060725872
97.5 6000 585000 169.2708333 135.4166667 9.884428224
97.5 6500 633750 183.3767361 146.7013889 10.70813058
97.5 7000 682500 197.4826389 157.9861111 11.53183293


So as long as i keep to a 1.34 PR im only outside the choke lines for 500rpm at top end.(gt1544)

For 200hp you need 1 litre of fuel a minute. So 4 x 182cc = 728cc/min 728cc/1000cc x 200 = fuel for 146 hp.

Sounds about right. 2.0 engine uses the same injectors but is quoted at 150hp. :)
The Volvo injectors I'm looking at are 250cc. That should do the job. Until I blow it up and then build a monster!!!
:wack:

PM me an email address, I have a sheet that does all the calculations and will tell you injector flow rates, corrections for fuel rail pressure and some other bits.

It's not concerned with how much power you're aiming for, it's purely based on air mass from boost pressure and manifold conditions.

Cheers Zepp. :)
Makes perfect sense. I can live with those numbers. Might look at a walboro too, just as an insurance policy.
Looks like its the 250cc and a bit of ecu fiddling should make a silly car VERY daft.:)

Are you trying to fit all of this without doing a remap?
The stock ECU is going to throw a fit if you put 250's in and it's expecting 182cc, idle mixture will be totally shit and I doubt you'll ever pass an MOT.

You could try a raising rate auxiliary fuel pressure regulator, they bump the fuel pressure up depending on boost, something like a bar per psi.

You'll need to change the timing as well, like knocking the base timing back 14 degree's or so.

no, youre right, the ecu would be shouting in italian and german words that i dont understand :wack:
Thing is, its been done a few times without remapping (turbo, no remap) at 5psi, the only aggro thats been encountered is the VVT on the inlet cam needs disconnecting or it throws a proper wobbly.
The rising rate fuel pressure regulator is a great idea, if only it had a return type fuel supply. Its only got a single pipe from the tank to the fuel rail! (bloody italians!!) so thats not gonna be a starter (looked at a GTV fuel rail, which does have the fpr, but then needs a return to the tank). A walboro is a must by the looks of it, too.