I'm currently tuning my nitrous setup (50 shot Dry NOS) and I was looking at my dyno plot from the weekend. With a 50 shot at about 800 psi (low bottle) I gained 24.8 fwhp and 45.2 tq over baseline. I'm pretty certain that these numbers had to do with 1)low pressure, 2) NOS overrates their jets and 3) drivetrain loss with my auto.

SLTi30t gained 60.9 fwhp 93.1 tq over baseline with a 70 shot Dry NOS in his 5 speed I30. He had about a 2/3 hp:tq ratio and I'm almost there meaning that my nitrous was working but for the above reasons, I was slightly lower than 2/3.

Im wondering what our stock fuel pump can sustain hp wise because most all documentation on this board says "I wouldn't run over a 60 shot" on a stock fuel pump. Well is that "60 shot" or 60 hp?

If it's 60 hp, then technically, couldnt I run about "80 shot" safely on a stock pump?

Any help is appreciated.

thanks

 

It all depends on the pump, and it's a 60 shot, not 60 HP. Some people can get away with running an 80 shot on a stock pump, some people have problems even running a 50 shot. It's just not worth it to blow your motor over a $100 fuel pump. Just upgrade it, youve already put so much effort into the rest of your car...

 

Good point. I was already planning on upgrading to the Walboro/SARD combo but I guess I thought I was onto one of those great ORG myth-buster type things.

I guess the stock pump relies indepently on fuel psi rather than hp.

thanks

 

The thing is nobody knows the spec of the OEM fuel pump. Liter per gallon flow at different level of pressure. I doubt the OEM fuel pump is high pressure. The flow rate will dramatcially decrease at anything above 70 psi. The OEM pump wasn't design to flow at such a high fuel pressure. I'm sure Stillen did their research with the SC kit. If the OEM pump was adequate, they wouldn't include that T-Rex external pump.

 

Let's say you get the Warlboro fuel pump, how do you keep from running way too rich when your not spraying. If I ever installed a N20 system I would only use it at the track, so I would like to keep a good air fuel ratio while NA. Is that possible with a upgraded fuel punp?


If this is a really stupid question please be kind

 

I second the question because I don't really know either.

The only thing I can think of is maybe a SAFC
-hype

 

The short answer is YES. Here's the long answer...Dry nitrous system raises fuel pressure via vacuum to the fuel pressure regulator. Most typical SC kit or turbo kit do the same thing for extra fuel. When you are off nitrous, the fuel system behaves normal. It's a known fact that the OEM fuel pressure regualtor can't regulate the pressure because the extra flow of the Walbro pumps. Most people are using aftermarket fuel pressure regulator along with Walbro pump. ie. Sard, AEM, Paxton.

 

When you install an aftermarket pump, do you bypass the stock fpr?

errr....how is an aftermarket fpr installed.

 

No. You don't bypass the OEM FPR. Fuel pump is just a direct replacement. Aftermarket FPR is also a direct replacement except it's too big to fit in the OEM location. You have to remote mount it.