I am getting ready to upgrade my fuel pump so I will be able to run the 100-shot, now I was just goig to order the normal 255lph high pressure unit that everyone else runs, but then I came across this when I was searching today http://www.autoperformanceengineering.com/ , now will this new Walbro 190lph high pressure pump be able to flow enough fuel for the 100-shot? I am asking becasue I hear everyone say how rich they run NA with the 255lph, and I wanted to avoid that if I could.

 

"This pump is so new that Walbro hasn't published flow numbers from the production run. The pump will flow the same as the 190 ltr/hr pump up to about 60 psi. After that, the 190 high-pressure pump will push more fuel than the normal 190 pump. This pump is currently available for only on model of the 190 ltr/hr pump."

Chunger posted this about a week or so ago in the 4th gen forum. I'm interested in the pump as well, because (hopefully) you won't need a FPR to go with the pump. Until we get flow numbers though, we're just speculating.
-hype

 

The 190 will work if you are running a "wet" setup. If you are running a dry setup, it may not be enough. Many of us have run both and found that the 190 is best for wet setups and doesn't tend to drown/richen the mix too much as compared to the 255. On a dry setup, the 255 is best due to increased demands.

 

You're talking about the normal 190 ltr/hr fuel pump though right?
The new "190 high-pressure pump will push more fuel than the normal 190 pump" after 60 psi.
-hype

 

To my knowledge, there has always been two 190 pumps. A high pressure one and a high volume one. Neither is suggested for a dry setup because both are very difficult to tune on that setup.

I may be wrong though. Personally, I don't see any benefit to using a 190 over a 255 when they are both essentially the same price.

 

You may be right about the pumps, but based off of what was stated the high presure 190 is still new since it doesn't even have flow specs listed for it.

The benefit *could* be that a FPR might not be needed to regulate fuel flow at idle since the pump flows OEM levels below 60psi. I'm planning to run a 50 to possibly 70 or 80 shot, so I will probably upgrade my fuel pump. However, I'd rather not have to get a FPR if I don't need one. Saves time, money, and effort installing and tuning the FPR.
-hype

 

I follow what you're saying, but personally I wouldn't skimp on anything that has to do with nitrous. Here's why: If you try and save a little bit of money by not getting a FPR (at 70 shot and up), you run the risk of serious engine damage to the incorrect mix.

Personally, I set my system up to be redundant as far as safaties are concerned. I'd rather run rich than lean any day. I have a S-AFC that will be tuned this year before racing season and that's how I'm going to get near the edge. It is very hard to tune a nitrous system w/o the use of the proper equipment. You've been around long enough to know that.

Just buy the 255 for your dry setup and you'll know it's plenty up to 100+ shot. I don't think you want to be the guinea pig on this one, do you?

 

Of course there's always the inherent risk of running lean with nitrous, and this is no different. However, I see no reason to go overkill on the pump if it's not required. Running blind would be one thing, but having gauges in the car and flow rates on the 190lph HP pump should help determine whether this setup is possible. If the pump shows signs of not providing adequate flow based on the rates, then I won't even consider it. However, until then it's still on my list. I'm erring on the safe side with my setup as well, so that's why I'm even considering a pump for if/when I move up to above a 50 shot.

I'm sure you can tell from my posts that I don't plan to go crazy and bump up my shot. I do enjoy nitrous for the tuning aspect though
Do you have any idea how many lph our stock pump is?
-hype

 

I think if I'm not mistaken that our stocker is rated at 190lph but it's no where near what a walbro 190 does. I downsized from the 255 walbro to the stocker when I first put on my Direct Port setup because the 255 was totally drowning the system. BIG MISTAKE. The car literally died off the line when I first engaged the nitrous. Then it would run but always a little on the lean side. I put in the 190 walbro instead, no probs.

 

So basically the OEM pump dumped a ton of fuel at first, but leaned out in the top end (higher psi range)?
Also are you running the Walbro 190 pump that isn't listed as HP?
Finally, do you agree that IF the 190lph HP pump numbers show that the pump can adequately flow fuel at high psi it should be fine for a dry setup?

From my understanding the answer to the last question is yes, but I just want to make sure my logic isn't flawed Thanks again for your help Jaime.
-hype

 

Im interested in this as well............would be a great thing if it works good w/out a adjustabe fpr

 

Sorry for not being around for a while.

To answer your question: The oem 190 pump does not flow enough volume for my DPI setup. I'm not sure about a single wet setup, but probably the same. The reason for the problem is because when you engage the system, it needs additional fuel. The oem can not keep with that initial demand and thereby just chokes it, but then catches up but never enough.

A 255 is not really overkill and even if it was you can control it with either a bypass jet size or a FPR. Either way it's been a very reliable piece in the majority of dry setups. I personally would er to the side of rich (more fuel) than lean (less fuel).

 

Would the 190hp pump be good for my wet setup running 75 shot?