Now I'm confused over the confusion… Rereading the last 3 posts I'm getting:

Injuneer: I don't get it… why are you saying that X is better if it's not working in an application that the bosch pump would work fine in?

1LEThumper, I think that we're just seeing another case where the 'fancy aftermarket stuff' doesn't live up to the hype (assuming that I’m understanding the discussion).

Myself… I'm wondering why a 79 924 porsche, with an NA 2.0 I4 that made 100and some hp came from the factory with a good sized lift pump in the tank and this "monster" mounted inline (probably enough for 600+ hp total)?

I've also wondered for a long time what a good (read cheap) source is for the pump, since it appears to be difficult to get for under $200 anyway (for an aftermarket replacement that I you do not know flows as well, since a much smaller pump would work fine in the original application), and you should be able to get the 67gph Holley for ~$150 from summit or the 255lph inline walbro for under $140 from assorted places online. It seems to me that for as many people constantly bringing this pump up there should be a source for them in the $100 range (of course, ATI and a few others rebadge it and sell it as good for "over 800hp...")

I've also wondered with the easy/relatively cheap prices of the holley and walbro why do people waste their money on the aeromotive/sx pumps which have proven much less reliable and similar flowing? Is it just to have the pretty billet looking (probably just an extrusion) anodized housing?

 

Who said anything about the 924s? That isn't even close to a 930 turbo car. Do some research on those cars....they did, and can make a lot of power....especially the factory race cars...which is what that pump is out of.

I don't know if this link will work for all of you or not. But Speed Inc does sell it...I guess if I get some time I'll call them today and see if Jim has all of the specs on the pump.
http://www.ls1speed.com/catagory.cfm?catagory=fuel

 

I said something about that 924. If you cross-reference the bosch part number it was used on a bunch of imports like some rolls and other big cars as well as the 77-80 porsche 924 (as a matter of fact, that's the only specific car model that I was able to find, the rest of the applications were as replacements).

That link didn't work, maybe if you can tell us what model and year you chose to get there…

 

OK, I did some poking around on that site and found what you're talking about… the 420l/hr pump, which is not the bosch pump mentioned a few times earlier in this thread…

Along those lines I'm still somewhat surprised at that answer… you can save $60 over the 420 and get 2 of the inline 255's and get more flow…

Oh well…

 

I'm not sayihng anything is "better".... I'm simply pointing out that the post I quoted made no sense - it would not take a pair of 420LPH pumps to support a 700HP application. If a pump is rated at 420LPH@75psi as stated, I simply showed how it should support close to 1,000HP. Simple math, and since I realized I may have made a "tech" error that I might have overlooked, I was asking people for insight into anything I was missing.

My point here should have been that people seem to throw around an awful lot of numbers they really don't understand.... #/HR, LPH, GPM.... etc. This is not rocket science, this is basic mechanical engineering. A quoted flow means absolutely NOTHING unless it is coupled with a corresponding operating pressure.

As far as curves for the Bosch pumps... yes, they are hard to come by. But the NOS catalog has the curve in it for the pump that I mentioned. And the Kinsler catalog has flow vs. pressure for several Bosch pumps, which they conveniently relable with Kinsler part #'s. The Bosch pump I mentioned is also sold by Accel, who sells it as a "750HP pump".... it isn't.

I've seen 2 of the Bosch pumps support my lowly 800flywheel HP (dry nitrous) with ease. I've seen a bank of 4 of them support a Porsche twin-turbo running 30# boost and making "over 1,600HP". Yes.... that pump will support 500HP.

 

MSD and Holley injectors are Multec Series One and are not flow-matched.

 

Amen to that!

A single Walbro GSS340 or GSL392 255L/Hr pump will support 550RWHP (safely) and two will support 1000RWHP using proper wiring and plumbing.

Aeromotive, Weldon, Paxton etc... = big $, noise, major current draw, heat, MUST be gravity fed (PITA) and short life when compared to Walbro or Bosch.

 

And for that matter, they're not even close to flowmatched... I've seen 2-3x the difference in a set of them vs a set of oem injectors on my bench.

I think that Hot Rod or one of the rags just published an article raving about them where they took a set of injectors that they found in the JY and compared them to a set of holley's and found that there was about 8cc/min variation in the JY injectors (besides one that didn't work which I really believe that they did to sell their point), about 4cc/min after cleaning them and about 12cc/min variation in a set of out of the box holleys.

They also spent some time raving about the multec injectors more fan like spray pattern. FWIW, OEM's specify a more aimed pattern for many applications for a reason (look at the GM Lucas and Rochester injectors, which look like someone opened a garden hoses with a nozzle set to 'stream'). A more fan shaped spray just covers the port walls the way that they are aimed in a lot of cars (this is also the reason why SVO injectors can be a pain to tune right in some cars, they have a more fanlike spray pattern).

 

FWIW...
We have a auto electronics course here at Purdue (EET 499A) that covers a lot of the aspects of the systems on cars today and what could be done....

Anyway, we had a guest lecture by a fuel injection place that is down on Gasoline Alley and he has so far up to 175 different spray patterns, nozzle tips, and types of ways to get the fuel to come out of the tip of the injector. Like he had said...they always show you that nice fan pattern on TV and the one just shooting a stream to compare a dirty and clean injector when some where set up to spray like that. Some of them have lazer cut square holes to 'rip' the fuel apart on exit of the injector, some are round, some fan, some drip. Just depends on what was called for in the orginal specs.

Anyway....just found that kind of interesting.

 

Thanks for all the information guys. I cant say that I am any closer on a decision for a pump though I guess I am leaning towards a Bosch 420lph or Weldon.

I just need a good setup for 900ish flywheel HP without the worry of having the pump crap out. Its amazing how a simple concept is actually a hard to solve in reality. ???

Jason

 

*cough*

Racetronix dual intank setup - keep the stock lines, don't worry about keeping 1/2 a tank of gas in the tank to keep the sump topped, and its nice and neat.

*cough*

The external is nice for the bling factor tho .

Ryan

 

You know me, I dont really care too much about the bling

But I am a believer in buying stuff that actually has proven to work for others....I dont have the cash flow to be doing things 2 and 3 times!

I'll look into that setup Ryan.....is there any big hp guys actually using that setup?

Thanks, Jason

 

Racetronix
MSD and Holley injectors are Multec Series One and are not flow-matched..

...................

Sorry just going but what I have been told(by 8 different tuners) and found to work.

As far as them being flow matched out of the box? WHO is stupid enough to try that on a High HP motor.

Then again I am not looking for much. Just 750 N/A and a little over 1,000 N2O

I was leaning towards your pump system but you refuse to return E-mails so you lost out.

 

Most people do not factor in the plumbing restrictions, voltage variations etc. which are unique to the vehicle / application.
Unless you literally reconstruct what you are trying to do on the bench then nobody can give you an exact answer.
Just because a pump supplies 255l/hr @ 43.5PSI @ 13.5V at its outlet port with minimal restriction does not mean that is what you will end up with at the rails in your car.
This is why you should try to duplicate a combination that someone else has had success with.
The Racetronix single system has been proven to be reliable to 550RWHP in an LT1 F-body car using factory lines.
A double pump system is reliable upwards of 700RWHP using factory lines. Upgrade the lines and that number will increase dramatically.

We try to return all our emails but it is getting to the point where it is next to impossible as we receive upwards of 100+ tech questions per day on top of product inquiries, sales orders, and dealer correspondence. As a manufacture & distributor we are not set up to deal with this extreme level of end-user support.
Dealers really should be picking up the slack in this area and we are working to improve this. Up until spring ’03 we had ARE taking care of tech questions and orders exclusively on DP systems but it was not working out. We are looking into processing DP orders through a few US based dealers. Until we have a solution in place we are shying away from DP sales as we have limited time to process and support them in-house. All in all we try and do our best but it is inevitable that someone might get overlooked along the way so please be patient with us especially when dealing with custom product such as the DP systems.

 

Interesting comparison of INTANK performance fuel pumps used in Dodge Stealth's, Nissan 330zx/Skylines, Toyota Supras:http://www.stealth316.com/2-fuelpumpguide.htm

While the calculations are interesting, it seems to me that he (as well as a few here) might be overlooking one thing: WOT isn't idle

While L98/LT1 injectors run at 3 bar (43.5 - 45 psi) differential, that typically means ~45psi in the rails at idle... and 4 bar (58.8 psi) in the rails at WOT (while the manifold is at 1 bar, or 14.7 psi). I know it's a bit less for some restrictions, but in thoery, you need 1 bar more pressure ability at WOT, than you do at idle.

That same issue is why a N/A vehicle will never need more than 60 psi unless it's base pressure is more than 3 bar (like the LS1 set up that uses a base of 4 bar differential). The issue really gets interesting at high RPM's (say 80% duty cycle), when the engine is consuming fuel in the rails at the rate of:
Engine Consumption (in L/hr) = [8 injectors] * [0.80 duty cycle] x [?? pounds/hr] x [0.657 Liters/pound of gas]

Engine Consumption (in L/hr) = [4.205 Liters/pound] x [?? pounds/hr]

So if you're pulling 80% duty cycle on 42#/hr injectors you need a pump that can supply:
177 LPH to the rails

But... it has to do it at 58.8 psi (WOT conditions, if this is an LT1). To see what your pump flows at that level, you'll need a psi vs. volume graph... ran at 13.5 volts (assuming that's what your pump sees, although it probably isn't). If you alternator cuts out on you... or if your amp load overruns the alternators' you may want to ensure it can flow those numbers at 12 volts, at least.

Looking at the flow map for either Walbro pump, it looks as though both provide about 190 LPH at 3 par (in the link above he listed it as 15 psi boost, but in reality that's actually WOT conditions for L98/LT1 rail pressures in NA applications).

If you run ANY boost however, or if you have a 4-bar rail differiental as in the LS1, you can see the required rail pressures really require a high-pressure walbro.

For this same reason, running a 300 hp blower will require a high pressure pump, while a 300 hp shot of nitrous does not (which DOES increase fuel volume, but not the required rail pressure like boost would), as long as the LPH are met at the rail pressure nessesary.

This only gets worse when you factor in flow restrictions from stock lines. Fuel charts really end up being an "ideal" flow rate for this reason. How much restriction (flow volume hit) a specific fuel line set up provides is tough to call though.... which is why you should log fuel rail pressure AND manifold pressure (MAP) when on a dyno... even if you're running MAF mode (this will give you an indication if things arn't right... ie: fuel rails are less than 45psi above MAP).