FASS vs. Preporator, same truck same day same dyno.

[RonA]

Well I still see posts from people saying " Were you expecting more hp from a fuel pump". I guess he doesn't read the adds. I was also jabbed about getting off the thread. Something about quitting and Texas and President Bush. Still haven't figured that one out. I just e-mailed Roger rodbolt for a price on the Blue one. If I can swing it I am going to buy one and try it. I'm not even going to read their add. This way I will know if there is any noticeable difference between the two. I'll try them both and then I'll know.

Pain in the backside way to have to get information.

 

[Murle]

Sometimes it is hard for people to read and comprehend what they read and then run and unsubscribe a thread.

 

[Cooker]

Well I still see posts from people saying " Were you expecting more hp from a fuel pump". I guess he doesn't read the adds.

I see exactly where you are coming from Ron. I can understand that some of the 24v guys want a reliable LP and could care less about the HP gain, whether advertised or not. But for some of us who acutally do look at these products and see an advertised HP gain and expect it, along with the reliability, it can be quite dissapointing and misleading if it is not there.



FTR - I have no idea whether the FASS lives up to it's promise of increased HP. I was just commenting on this topic as some support for Ron as I see what is is trying to say.

 

[Gary - K7GLD]

"Sometimes it is hard for people to read and comprehend what they read and then run and unsubscribe a thread. "



AMEN, brother, *AMEN!*

 

[RonA]

The guy who begged me to hold the Fass untill Saturday never showed up. So I ordered an Air Dog. I also have a mechanical pump coming from PDR. I am going to try all three. The FASS set at 26psi, The Air Dog set at 30 psi. and the mechanical at whatever it can do. I'll use the one I like the best. I'm curious how the two electric systems stack up to their claims . It will be funny if the cam driven mechanical performs the best. Never see the 12 valve guys complaining about lift pumps or air in the fuel.

Ron

 

[Wiredawg]

Just a few points...

First: I would be interested in seeing head to head tests on the Airdog, FASS and the mechanical Pump, although we should be albe to draw some conclusions from posts of folks who have installed each of the different types.



Second: $489 for my FASS is not much money compared to other investments on my truck: $500 exhaust, $600 DDIIs (won them), $600 TST, $500 gauges, $900 exhaust brake. If someone finds a $69 replacement that will push fuel like the FASS or Airdog and proves reliable, I'll be happy to see it.



Third: I never read any advertisments from any of the 3 listed lift pump replacements. Brad was the only one who attended May Madness and he had a really cool demonstration display.



Fourth: I had just lost an injection pump that my favorite Five Star replaced under warranty. Fuel pres gauge never showed below 8 PSI full throttle.



Fifth: I've been a TDR member since 2000 and had not read of a reliable replacement pump for the lift pump. I could be wrong, but I'm hoping a high flowing lift pump replacement might save me the cost of an injection pump.



Finally, I have what I have and it's working great so far. and I'm happy with it I'll still be interested in seeing how other pumps perform, so I'll keep looking at these threads.



Wiredawg

 

[KYLE4]

Pros and Cons I only found two difference's in the Fass and the airdog one is price Air dog is more expensive and secondly Fass has a 4 year warranty Airdog 2 year warranty. Almost forgot Fass can use any filter with crossreference part # Airdog you have to use their filter's

 

[ILIANBG]

Yep. I too saw both of those system at a show, looked as pretty much the same thing in different package, I can't understand the price difference though. It seems to me that one of them is making a lot more money from us, or I'm sorry if I'm wrong.

It is very helpful for everyone to read all thi information. Thanks TDR.

 

[GIT-R-DONE]

Even longer post

RonA, in your quest for the performance of our beloved CTD, I bet you will find that there is no gain in HP with EITHER one of these fuel systems. Personally, I believe that BOTH makers, FASS and AirDog/Preporator, should remove there HP claims from there web sites. Its just not there.



Here is the thread that I started almost a year ago.



https://www.turbodieselregister.com/forums/showthread.php?t=89707&highlight=FASS+Dyno+Results



Although the test were not done on the same day, I dont believe it would have mattered. We did have something like what you are taking about doing , comparing both systems to find the truth as the Preporator thread is here.....



https://www.turbodieselregister.com/forums/showthread.php?t=90652&highlight=FASS+Dyno+Results



Now ole Wade Patton was to have received his Preporator unit but we never found out if he ever got it or tested it, also on the east coast never got done either, but there was a few out in California that did the dyno test.....



https://www.turbodieselregister.com/forums/showthread.php?t=90652&page=2&pp=40



There, now you have about 3 weeks of reading to do... ... :-laf :-laf



Personally, I would buy the FASS again and I would consider the Air Dog as well. Either way, I doubt anyone can go wrong with either of these products. Sometimes its just how much money you have to spend on a product.

 

[RonA]

Thank you very much for the reading material. I have read most of this. I believe you are correct about the performance. I am going to see how this thing does with the 12valve lift pump and filter. If I don't see any difference in how it runs(not hp) as far as idle and low speed, I think I will go that route. I guess the pressure from the mechanical is probably too high for the vp44. Otherwise a guy could get a cam from PDR for the price of a fuel system, add the lift pump for 130 dollars and quit worrying. I was told the Air Dog was almost twice the price. When I got the quote I was surprised. It is only slightly higher than what I payed for my FASS. The FASS price is $100 less now than what I payed for it. All these threads take up space, but the competition may help control the price. And you guys thought all this was a waste of time.

Ron

 

[Joe G.]

Ron,



My 40 PSI fuel pressure gauge is pegged quite a bit with my mechanical lift pump. If I am running at freeway speeds and lift it pegs the gauge everytime. I don't know if a VP44 can stand that or not.

 

[Cooker]

Couldn't you play with the overflow valve on the P-Pump to adjust the fuel pressure supplied by the mechanical lift pump?

 

[Joe G.]

The pressure from the mechanical lift pump is NOT steady. I have my pressure gauge damped so that it barely works. The lift pump used with the P7100 pump has big pressure spikes. The gauge is showing the average pressure as far as I can tell. Even if you shorten the spring in the OF valve it still may be too much for the VP44 because of the pressure spikes. I don't know for sure, but thought I should bring it up.

 

[RonA]

What about a 2 or 3 inch diameter cylinder maybe a foot long that the fuel goes into between the lift pump and the injection pump with a bladder and a spring loaded overflow valve. Maybe having some volume to absorb the spikes with would help smooth it out.

 

[Joe G.]

I have no idea if that would work or not. The OF valve is spring loaded. People with good hearing can hear it clatter when the engine is running. From what I have been reading it seems like a better idea is just to put a P7100 pump on the 24 valve engine. I know that's expensive, but it sure solves the lift pump problems.

 

[GIT-R-DONE]

I have no idea if that would work or not. The OF valve is spring loaded. People with good hearing can hear it clatter when the engine is running. From what I have been reading it seems like a better idea is just to put a P7100 pump on the 24 valve engine. I know that's expensive, but it sure solves the lift pump problems.

From the cost of buying a P7100, how much money does it take to do the conversion on a 24 valve? Aside from the cure to the lift pump problems on the 24 valve, what other advantages are there to doing this conversion? Thanks

 

[Joe G.]

I don't know what all is involved with installing a P7100 pump on a 24 valve. I know that some of the big horse power guys have done it. Ask them.



It's a lot more reliable from what I'm reading on these forums. It's engine oil lubed. If the fuel supply system dies for some reason the engine quits or runs poorly with no damage to the injection pump. Cheap to get a LOT of power from it. No funny business with electronics. In fact, you can make it run just fine with no electricity to it at all. Tie up the fuel solenoid, start it, and you can throw the batteries overboard.

 

[RonA]

It doesn't exactly solve all your problems. By the time you get the stuff and new lines and a cam and buy new injectors, it is a little pricey. The plug and play is cheap.

 

[Jetpilot]

Converting a VP truck to a p-pump truck is a lot of work, tuning, and $$. Most that have tried have done so for HP and rpm reasons... ... And some of them have not been happy with the outcome either. You give up variable timing which is a nice feature when you go to the p-pump. Getting the cruise control to work well is an issue, you will always have a check engine light on, and you now own a unique vehicle that very few will be able to "just work on".



I would say the conversion could be done for around $3k in parts + p-pump + labor. When PDR was doing them they ran over $10K. Personally I feel this conversion is for BIG HP guys. The VP is not that prone to failure as to make the change worth while in my opinion. I have run a VP to over 750HP for a long time with no failure.



Doug

 

[RonA]

Looking back on what I have spent on mine, I'd say you're right on the money dollar wise. And it is difficult to find someone to work on it. But it does run well even if it isn't set up for big hp.