Engine/Transmission (1998.5 - 2002) Rasp

[TDIdog]

Has anybody had any experiance with the RASP fuel pump? I am thinking of upgrading the stock system , and thought maybe the RASP might be the way.

Any input would be welcome. Thanks guys

jack

 

[BLACKRAM]

Mine is currently being installed. Why did I go with RASP? It simply defies logic to put on yet another inferior electric pump, after four bad ones. No matter what the price, or the design, an electric pump is inferior. I am sure someone will try and tell me their XYZ design works, and their brother's friend's truck runs great with it. All the stories will sound that way until they fail, and they will fail.

 

[rmrc]

RASP vs other units.

This is a mod that I'm also going to do, hopefully in the near future. I would prefer the RASP mainly because it's completely mechanical! No electric pump to worry about. The only down side is the price for the entire system (hoses, ect. ). My finances at the time will tell which system I'll go with.

 

[R-N-R]

Rasp Search

 

[paulb]

I have about 22K on mine, and it has worked flawlessly. Great piece of mind...

 

[Graphic man]

All hi end racing use mec. pumps!!!!

IMO there the only way to go !!!

and i too will be adding one to my truck soon!

 

[TDIdog]

So how does it work? The stock pump is plumbed in parallel, how is it activated?

Does the stock lift pump just sit idle until needed? Thanks

jack

 

[Graphic man]

from what i under stand

the stock pump is used to start the truck and then the RASP takes over, turning off the stock L/P

someone that has one could tell you better, but i think thats how it works!

 

[BarryG]

Probably the people who could tell you best are Stephan up at DTT and or member Opoole ( I think that is his name cant believe I cant remember now after I have talked to him a couple times about the setup). Opoole sells a complete plumbing kit for it as well as the pump. It uses a Hobbs pressure switch to activate the stock pump when needed. I myself am leaning very heavily towards this setup.

 

[tractorface]

Thanks Dr. Spock

"Mine is currently being installed. Why did I go with RASP? It simply defies logic to put on yet another inferior electric pump, after four bad ones. No matter what the price, or the design, an electric pump is inferior. I am sure someone will try and tell me their XYZ design works, and their brother's friend's truck runs great with it. All the stories will sound that way until they fail, and they will fail. "



Mechanical pumps fail also, a well designed SYSTEM is what is needed. This includes pump, lines, fuel module etc. I think the RASP has merit and is a fantastic pump, there is more than one way to skin a cat however. I personally do not like the idea of adding a belt driven pump to my engine, I understand why many would do this, it's just not for me. Don't hate your electric pump too much, you'll need it to start the truck, and I would not **** off the "lectric" gods too much as the pressure switch etc. need lectrons to flow.

The funny thing is the failure I had with my XYZ electric pump was pure and simple a mechanical failure un related to the electric... ..... I would suggest that a person look into using a standpipe in lieu of the OEM fuel module. Addressing the entire system is the key

 

[RustyJC]

I would suggest that a person look into using a standpipe in lieu of the OEM fuel module.

I'm surprised some power plant guys with diesel engine experience haven't tried a DAY TANK arrangement to feed the stock lift pump. The unpressurized day tank is kept filled by a pump mounted at/near the stock fuel tank (easy service with minimal head), then the NPSH (net positive suction head) of the day tank outlet floods the inlet of the stock lift pump with plenty of fuel.



Rusty

 

[Stefan Kondolay]

DTT is working on a line kit as we speak, the 3rd Gen RASP should also be available with 2 weeks. IdahoCTD has been running it on his 3rd gen for several months now. I have sold several of these kit now and haven't had a single call for any problem at all.



On our race car we have been running methanol through a very similar set-up for over 4 years now without a single hitch. And a buddy that we race with has had his for over 11 years. On the flip side the car that I drove this last year had three high end electric pumps fail and every time costed me a round of eliminations. There should be a pic for anyone interested in what the car looked like. https://www.autoimagery.com/store/c...ile=tn_0409-0044.jpg&numtolist=12&sortfiles=2 If you click on go beside my name it should show 3 different cars that I have driven.

 

[tractorface]

Hey Rusty I work with diesel gensets all day long and was thinking the same thing. The problem I see is putting a suitably sized resorvoir close enough to the VP with out causing safety issues with spills and all. The gravity feed deal is as close as one can come to this idea as far as I can tell

 

[RustyJC]

Yeah, you'd have to find a mounting site high on the firewall to get sufficient NPSH. If you stop and think about it, why would more than a quart or two of capacity be required?



Rusty

 

[tractorface]

Maybe a Triple Racor with a bypass to let the pump just run all the time, that would be similar to a daytank sort of.



Listen I like the RASP idea, I think it is great, I was just making a point. If I went to one I would ditch the OEM filter deal and use a larger capacity Racor or something. I am very happy with my current setup but I am still going to add a low pressure warning light. The nice thing about the RASP is the OEM backup pump..... Come to think of it that could be incorporrated into and pump setup, mechanical or electric. It's good to have alternatives

 

[TDIdog]

Hey Stefan. Perhaps you could shed some light on how the stock lift pump works in conjunction with the RASP. Does it only run at start up? What if the stock lift pump packs it in? If the stock lift pump is needed at start up, then a person is still reliant on the POS stock pump. Any other info would be appreciated. Thanks for your help Stefan

jack

 

[TDIdog]

TTT Hey Stefan, We need your expertize. Thanks

 

[24V-DSL]

www.koengineering.com

 

[TDIdog]

Thanks 24v-DSL, but I've read that site at least 4 times, but I can't see how the stock pump fits in with the RASP. Can someone that knows enlighten me please. I'm not trying to be a jerk, I'm just interested in getting one of these systems & would like to know whats up before it's on my truck.

Thanks in advance

jack

 

[JR2]

The stock pump is left in place and is used to start the truck and prime the filter after a change. It works off a Hobbs pressure switch. That switch will turn on the lift pump anytime there is not X amount of fuel pressure (I think they use 8 psi). The stock pump is isolated with some check valves so that when the engine starts it does not back feed the stock lift pump. If you search for RASP you will find some diagrams of a fuel system using the Rasp. I think the posts where by Snowracer.



JR2