gtr fuel pump in gtst

[netrati]

I was planning on putting a R32 GTR fuel pump in my GTSt. After I do this will it run really rich and I'd have to do tuning all over again?

[predator]

yes...

[DREMEN]

But I thought if you still had the stock regulator in you won't have to worry about the tuning ?

[JimX]

I put a Bosch 044 pump in my car and didn't notice as much difference in the mixture as I thought I would. It'd be less difference for a GTR pump (less pressure) so I don't think a re-tune is absolutely essential but would be recommended. The ECU will cope to a certain extent.

[BHDave]

I always thought that the reason cars are running rich at idle with bigger pumps is because the stock regulator couldn't flow enough to keep the pressure right. So higher pressure at idle and more fuel getting squirted in.

I don't think a mild upgrade to a GTR pump will cause that much of a problem. You can always take a little bit of fuel out with the SAFC if it runs rich, or fit a bigger regulator.

[rs73]

on the dyno, my car A/F ratio is a bit too lean, like around 12.5

will putting in a gt-r fuel pump solve the problem? or something else, what about fuel pressure regulator, does this thing helps?

[rs73]

oh, in the meantime that leaning out was fixed by safc rich setting, but i dun think it will solve 100% of the prob if I increase boost pressure. currently running 10psi only.

[MattyB]

if the fuel regulator doesnt give you a fuel restriction (causing pressure build up) then you shouldnt have any change from getting a bigger fuel pump. after all its the fuel regulator that controls the fuel pressure not the pump. unless of coarse your pump is worn out and at high rmp its not able to pump ennuff fuel.

[bigfella]

check your fuel filter had the same problem and found filter full of rust

[BHDave]

"on the dyno, my car A/F ratio is a bit too lean, like around 12.5 "

12.5 is the perfect number. Almost every street car tune ive seen aims for this number.

[rs73]

Well mine is a 93 model, which means if the 10-yr old pump is dying soon I wouldn't be surprised...

On the other hand, yea maybe the fuel filter is dirty and not allowing good flow of fuel.

However another Q: does a gts-t injectors up to the task if you use higher flowing gt-r fuel pump?

[JimX]

I've got a Bosch 044 pump which flows more than a GTR pump, and my injectors are fine.

[rs73]

sorry, read my dyno chart wrong.

on higher boost setting at 11 psi the A/F ratio ranges from around 12.6 to 13.4... only after reducing the boost to 10psi the car managed to maintain between 11.5-12.5 A/F ratio and achieved an extra 14rwkw.

Reducing my boost increase my engine power from 140rwkw @ 11psi to 154rwkw @ 10psi

[netrati]

When I do buy the pump how can I tell for sure it's off a gtr?