Hello all,

I am looking to completely build up my fuel system and want to begin with upgrading my fuel pump. I was wondering if there would be any problems with running the DENSO competition pump with my stock injectors? Keep in mind that I would like to avoid buying parts twice if I can, and I don't feel that the Walbro will be able to handle the power that I may want to throw at this car in the future. I have an S-AFC on the way to help the cause for now, and injectors will more than likely be addressed shortly. I plan to log a little time on the dyno soon to tune the S-AFC as well.

All in all, my question is to wether or not it would be o.k. for me to run a hefty pump on the car in it's present state?

Thanks!

 

Don't quote me on this, but if your fuel pressure increases then you'll run rich. If you're hitting a Dyno anyway then you can tune it back to normal.

Maybe time it so you change the pump just before dynoing. Then there's no problem.

 

So with the S-AFC I will be able to tone down the richness that I will experience with this fuel pump?

 

yes

 

Could someone explain me the goal of putting a bigger fuel pump with stock injectors if you tune it to normal ? I don't understand. When you want to run more boost, say 9-10 psi, you don't have to tune it to normal right ? You have to tune it to have a properly a/f ratio ?

Thanks

 

I think he's just trying to get the fuel pump out of the way. Even if he installed aftermarket injectors he'd still have to tune it to "normal" until he started forcing more air into the engine.

 

Mykl is very right, he can go ahead and get some mods out of the way before he turns up the boost, or upgrades turbo. Plus each car should actually be tuned specifically for itself, and after 15 years a little tuning will most likely bring some power as well as adding to gas mileage and overall reliability.

- Steiner

 

The weak link in the fuel system is the fuel pump, and it needs to be replaced well before the injectors need do. Fuel rail pressure increases with manifold pressure, and past ~10psi the stock pump can't keep up with the boost and you run lean. It's not the injectors as many think. With a decent fuel pump and a fuel computer or programmable EMS, the stock injectors are good for ~300hp.
If you have a fuel computer like an S-AFC you can tune the A/F ratios to suit your mods. Even a stock car can benefit. The factory mixtures are conservatively rich (especially at full load), and as long as you keep intake air temps down you can safely lean out the mixtures and gain more power. As a bonus you'll use less gas too.

 

Thanks everyone!

 

Thanks guys! It's more clear now.

Alex

 

Why you wasting money with the ND fuel pump?&nbsp A Walbro is a much cheaper option.


-Ted

 

That is what I am afraid of. For some reason, a fuel pump that is that cheap scares me. Money is not an issue really. That aside, is the ND a good pump?

 

How about a Bosch "044" fuel pump?
I'd bet it'll outflow the ND, and priced about the same a little over $200?


-Ted

 

Ted I strongly recommend you go with a SX Fuel Pump with the liquid crystal filled gauge. That pump is the ****.
I have seen alot of cars that are flying low use that pump especially on 10-11 second turbo 2's. And I have seen it on other Rotary powered cars as well.

 

Well, the reason that I am thinking ND is because it is a direct replacement (I think) for the stocker. What about these other aforementioned pumps?

 

We don't like the SX fuel pumps cause they are not reliable.&nbsp I have seen too many of these things returned to get serviced, because they failed.


-Ted

 

The Bosch pumps are some of the best out there, and they are practically a drop in replacement. High flow, and Bosch OEM reliability.

 

[QUOTE]Originally posted by RETed
[B]We don't like the SX fuel pumps cause they are not reliable.&nbsp I have seen too many of these things returned to get serviced, because they failed.


Well thats pretty interesting, as I have never heard of this problem before with the SX F. Pump before. I also heard the Cosmo F. Pump is very good as well.

 

Most of the racers in the 80's and 90's that started the import racing scene know how bad the SX fuel pumps were back in the day.&nbsp SX could've stepped up the quality control, but it still leaves a bad taste in my mouth - I would never run an SX fuel pump in my cars.&nbsp I would rather run an Aeromotive, if I needed that kinda fuel flow.

The Cosmo pump just plain sux for the price.&nbsp The Walbro 255lph fuel pump blows away the Cosmo pump for a fraction of the cost.


-Ted