Fatman

I'm having a full decat and Tek-2 remap done to my car soon. It's a UK MY00 Turbo. How important is getting an up-rated fuel pump? I've seen higher pressure fuel pumps and swirl pot kits available. Are these recommended, or necessary? The fuel system is totally stock right now. Only other relevant mod is an ITG filter. What thinks thee...?

Fatman

bttt

highlander68k

It seems that the standard pumps aren't always as good as they should be. Although your mods aren't mega, it might be an idea to uprate the pump and fuel pressure regulator.

I done both and the both the throttle response and boost spool up was much quicker. Now I've done more mods and I'm sure the standard kit wouldn't have coped.

FSE do both and you are looking at around £210 all in. You can also by the kit from here (scoobynet) or from Gecko Motorsport who do a good deal too.

jonny gav

iTrader: (1)

tsunami racing do the pump at £117, you can contact them on 0191-4781666

john banks

I would suggest not getting a fuel pump for your mods at this stage. The stock fuel pump should handle a Tek 2 and if you are worried fit a fuel pressure gauge and see that it does not handle it first I would say. The reason for this is that the mixture may well be a little richer with the fuel pump, and fitting one to a car with a Tek could slow it down. Ask T-uk what he thought of his car after I slipped his fuel pump in when he wasn't looking - he hated it, flat as anything and it did show a bit richer, but he will need it for the forthcoming power with other mods.

Fatman

An uprated fuel-pump would just increase the pressure in the lines that the injectors see, would it not? If the injectors release only the metered amount of fuel they're commanded to, where's the problem? What controls the injector behaviour? Are they open for a specified period of time? Please explain...

Bear in mind, I'm not an expert in this field. However, I'd have assumed that a higher-rated fuel pump would simply raise the upper threshold of fuel flow rate through the system.

Bob Rawle

The problem is more basic, the std fuel pressure reg can't flow the fuel that the uprated pump will deliver, hence it backs up and increases pressure running the car richer than mapped.

bob

Fatman

OK, so an uprated fuel regulator is used as well. Are they absurdly expensive - or does this introduce further complications?

rb5_336

intersting Dr Banks. After fitting a T75, your 2.5 and an uprated fuel pump, me exhaust pipe is black!

john banks

Seriously guys, unless you want to get the maps tweaked it is best to keep the standard fuel pump because this is what they are mapped for. I love recommending fuel pumps to people as it is a great mod, but at this level OTT and only gives you fuel pressure inconsistencies as Bob has highlighted here and previously. If you fitted a regulator as well, then you could work around it, but if the car is fine suggest don't fiddle unless good reason to.

The full load fuelling I use is very similar to the leanest standard ECUs (AE800 and AE801) with extra during spool up. So it should not be worse than any standard ECU with an uprated fuel pump for exhaust blackness.

Fatman

Thanks, John, that's good enough for me. I'll leave it as-is. For now...

The reason I asked is that I've read references to people claiming the stock fuel pump is barely adequate, and can excessively lean the engine under increased boost. Perhaps that was the biased opinion of those who would sell replacement kit(?). If you suggest it's not a realistic problem at this level then I'll consider it a few quid well saved.

john banks

On the STi new age things are different. I've don't map the WRX so don't know about that, but I've not heard of a UK MY99/00 having a fuel pump issue because of upgraded performance on the original turbo.

MelTypeR

iTrader: (4)

John and Bob, i have an STI 5 Type R which has a full decat and a panel filter with the snokel from the airbox removed and was looking to get the car remapped. Car runs fine but seems a little flat in the midrange, car is always run on Optimax and OB.

Would it be better to upgrade the fuel pump ang reg before i get this done or should i leave it standard.
I will be planning futher mods later in the year so would it also be better to get a link or get a custom tek map?


Mel.

[Edited by MelTypeR - 24/04/2003 11:07:29]

john banks

Whether you do it or not do it before the map, and from the sounds of things if you want to go further best to do it. The STis and P1s I've done have all been on standard turbos and intercoolers so I've not gone bonkers and the fuel maps seemed sensible on the standard pumps. However one standard STi5 Type R I logged was frighteningly lean from a dodgy pump. If you are mapping and that is where it ends - decat and map then perhaps stick with standard pump. If custom mapping there is certainly no reason not to get a pump and regulator.

MelTypeR

iTrader: (4)

Thanks John.

Do you think it would be better to get a Link ECU or go for a Tek as i will be planning futher mods so i need the scope for further mapping if necessary.


Mel.

[Edited by MelTypeR - 4/24/2003 4:09:35 PM]