Fueling questions turbo D16A7

[Franknstein]

I'm in the process of turbo'ing my D16A7 (1600cc, SOHC, non vtec). I've just had the engine management system installed (the system is a Gotech MFI, www.gotech.co.za for details).

now I'm ready to sort out the fuelling.

here are the specs:
D16A7 motor with a Garrett T25 turbo (off the Nissan 200sx)
Hoping for at least 180 wheel hp.
Running at 0.4 - 0.45bar
I would like to use pump fuel if possible as well.

Now I need to know what I need to get the fuelling running nicely. Do I need a new Fuel Pressure Regulator, if so what kind. Do I need bigger injectors, if so what flow rate will do the job. Do I need another fuel pump, also, if I do can I run one inline with the old one.... and what flow rated pump will I need?

-or- is the expected whp too low to require all these fuel parts?

Please help!

 

[posol]

with a small turbo like that, here's what i'd suggest:

inline booster pump. MSD makes a nice one.. there are tons of other inline-style pumps.
if you want a full intank replacement, you can, but its not necessary. the booster with your stock pump will support your power goal.

personally, i'd go with the intank- a walbro 255 is good, but the 190 might suit you better now-, that way if you want more later, you're ready to go.

stock FPR is fine.

I'm unfamiliar with that software, but with most standalone's, you need to run larger injectors (i'd recommend 440-450cc's), and then dyno your car with them and the computer to tune them right. look foer 12:1 a/fs across the board with mild total timing (like 16*) and you will be good to go.

 

[Franknstein]

Thanx Sol. A couple more questions though....

I got this neat little webpage at home for calculating required flow rates on injectors for turbo application. You put the following inputs in:

Fuel consumption index: I set it to 0.62
Required crank HP: 200hp
Fuel Pressure PSI: (stock on my honda is +-35psi with FPR vacuum connected) and
+-45psi with vacuum disconnected)
number of same size injectors: 4
Duty cycle: I set to 80

The result I got was: about 450cc with my stock fuel pressure at 35Psi
If I boosted the fuel pressure to about 50/60PSI (cant remember exactly) then I got 350cc injectors as a result.

Question: If my stock fuel pressure is 35psi and the output was 450cc injectors at 80%duty then surely I wont need another fuel pump? If I do, why?

Surely also based on these figures, if I boost the Fuel pressure with another pump to like 50/60Psi then will 350cc injectors be cool?

Another question is... The stock FPR:
Surely the stock FPR is set to open and release fuel to the tank as soon as the pressure in the fuel rail is 35PSI... therefore if I install another fuel pump, surely I will have to get a new FPR set at like 50/60PSI or it wont make any difference? HELP! I confused now!

 

[posol]

the big thing here is that PRESSURE is not VOLUME.

to an extent, a hgher pressure system can MAKE UP for a lack of volume- but in the long run, the volume at near-stock fuel pressure is the best goal to make.
Run the 450's. It's your best bet. Its better to go bigger, than not big enough.

As for "another pump"... you need help. the stock pump is good for about 225 whp on boost... thats about it. after that, it needs help.. a boost. intank pumps are cheap. walbro's are like $90 US.

as fro the FPR question....
the FPR keeps your rail at X pressure, regarless of what pump or injectors you have. it simply won't open till it reaches X psi, and won't close until it drops below it. how soon or slow it gets there, depends on the pump/consumption rates.

with a standalone, a good set of flowing injectors, and a pump to support them, there is zero need for a FPR

 

[Franknstein]

Thanks Sol, that clears up a lot of my questions. So I think I'll go for this setup then:

4 x 450cc Tunertoys injectors (new)
1 x walbro 255 intank pump
stock FPR
Standalone Management
Stock fuel rail, filter etc.

Question: Fitting that Walbro in my tank... is it a mission? What's involved? Redrilling... welding, making brackets? Do I just chuck the old pump?

Question: Think those tunertoys injectors will be cool?

Shot

 

[[Freemantle]]

I'm terrible with matching civic/crx engines to the right model, so I have no idea what chassis you're pulling the ninja setup in. On my Prelude dropping in the walbro was EASY. Ran out the fuel to near nothing, and there is a plate right between the trunk and the passenger compartment. Three phillips screws and lifting the plate reveals the interior of the fuel tank, and the removal is stupid easy as well. I did it in about 90 minutes.

Chilton's/Helms manual = helps.