Amount of safe boost with factory fuel system?

[forcefed3.8's]

You can't run the Deatschwerks pump on a turbo Buick with a stock fuel return line. The volume is too high at low pressure and you can't get the fuel pressure low enough at idle. Yes, I tried it, I have one on my car. :smile:

On the flow data, maybe I missed something, but Richard Clark's test shows it flows the same as a Walbro when in boost (~70psi). Did I read the data wrong? 58 gal/hr at 70psi

Eric

Selling this pump as a bolt in is going to have alot of pi$$ed of customers.

I asked about this months ago, when the talk about these pumps started. But as it goes, it is the latest and greatest, and your car ain't squat unless you have this pump.

 

[turbofabricator]

But as it goes, it is the latest and greatest, and your car ain't squat unless you have this pump.

OK.....OK....I'm gonna HAVE to order one NOW! Oh, how I wanna BE Squat!!:biggrin:


Nick, are there issues you are having with the return pressure using stock fuel lines? Not an issue for me, as I canfix that, but other guys may not want to or be able to easily? After all the stock return line is only 1/4" and it necks down real small at the forward saginaw fitting at the frame.

 

[Nick Micale]

You can't run the Deatschwerks pump on a turbo Buick with a stock fuel return line. The volume is too high at low pressure and you can't get the fuel pressure low enough at idle. Yes, I tried it, I have one on my car. :smile:

On the flow data, maybe I missed something, but Richard Clark's test shows it flows the same as a Walbro when in boost (~70psi). Did I read the data wrong? 58 gal/hr at 70psi

Eric

Maybe something is different here in the desert, I just installed a DW pump on a 12 sec. GN with a completely stock fuel system, and the pressure was at the same normal setting [44 psi] at idle?

There is no "issue" at boost either.

I do now know which Walbro you compared data, but data I received and also the conversation I had with Richard, was that the DW was much better performing than a Walbo?

Since I have replaced about 1/2 dozen Walbro pumps lately that were relatively new, I am done using them. It was easier to eat the replacement cost than deal with Walbro for any adjustment.

If a DW pump I sell has a problem within 3 years of purchase, I will replace with no hassle, no charge. :biggrin:

 

[87GNSteve]

I read on other forums the DW pump runs hot. Is best to keep the tank full so the pump is submerged.

 

[protracracing]

Maybe something is different here in the desert, I just installed a DW pump on a 12 sec. GN with a completely stock fuel system, and the pressure was at the same normal setting [44 psi] at idle?

There is no "issue" at boost either.

I do now know which Walbro you compared data, but data I received and also the conversation I had with Richard, was that the DW was much better performing than a Walbo?

Since I have replaced about 1/2 dozen Walbro pumps lately that were relatively new, I am done using them. It was easier to eat the replacement cost than deal with Walbro for any adjustment.

If a DW pump I sell has a problem within 3 years of purchase, I will replace with no hassle, no charge. :biggrin:

Nick what did the fuel pressure drop to after you hooked the vac line back up to the adj reg with the car running.


Dennis

 

[Nick Micale]

Nick what did the fuel pressure drop to after you hooked the vac line back up to the adj reg with the car running......Dennis

I checked pressure before I removed the old pump and it was showing 43 psi. replaced the pump and it was 44 psi.

Without the vac line it was 37-38 psi.

A local GN owner installed a DW pump in his stock T-Type, I do not know any readings, but there was no change in how it runs?

"I read on other forums the DW pump runs hot. Is best to keep the tank full so the pump is submerged."


All in-tank pumps should be covered in fuel to dissipate heat.

Most GM cars of the '60-80's had the same crappy fuel float for the gauge, and many would be empty at a 1/8 full reading. I can remember a few times a customer's car would run out of gas when it would read 1/4 full.

The moral of this story, keep plenty of gas in your tank, especially a turbo car.

 

[DaySleeper]

I had one that was totally stock back in '91 and we could get away with 18 psi with some kind of adjustable fuel pressure regulator and stock everything else and some kind of octane booster.

 

[Nick Micale]

..... back in '91 and we could get away with 18 psi with some kind of adjustable fuel pressure regulator and stock everything else and some kind of octane booster.

Hard to believe it is 20 years since the days of when REAL gasoline could be found at most gas stations!

The crap gas we pump now contains 15% alcohol and it is also "reformulated" with a shelf life of 3 weeks before the octane drops quickly.

So add in warm summer weather and worse summer blend gas, and locally we are lucky to hit 14 psi on a stock GN without the knock sensor going off.

Just something to ponder before turning up the boost as well, as my favorite statement that irritates Julio, "alcohol is NOT an octane booster"!

 

[lgonzalez_1986]

i would go tt chip and reds armstrong pump hotwired with good grounds!!!

 

[moooven6]

You need a scanmaster....and maybe a knock gauge/alarm as one of the basics. The knock sensor is a factory piece - detects knock, and the ECM attempts to pull timing (knock retard - KR). It can "hear' the knock long before you can. If you can hear it...NOT GOOD!

 

[turbot3.8]

What symptoms or what do you look for if there is on issue with the stock return fuel lines with the “Deatschwerks” pump.

I just installed mine and now my idle is at around 10psi. Disconnected the hotwire and plugged it back in to the stock connection and still the same.

About 3 other people in my area say their install of the "Deatschwerks" went just fine with no extra modifications just simply drop in and plug, no other issues with return lines or anything, so what am I missing or doing wrong?

 

[Ttype6]

I think that calling these new pumps the "answer" without proper feedback is going to cause problems.

And to answer the question, if you have pressure, you have volume.

I,m sure they are a fine pump,but they cause two problems. The first is that they move so much more volume that they overcome the stock return line's ability to accommodate the extra volume at idle/low fuel need. This problem gets worse with a volt booster. I would never run without a volt booster.

The second problem is that because it sends so much more fuel to the motor,that the motor doesn't need,it gets heated by the motor and gets sent back to the tank which,in turn,heats the fuel in the tank needlessly.

The lower and sufficient volume of the Walbro doesn't create these problems. When your fuel demand increases enough to overtax one Walbro,add a second Walbro. Better yet,use the DW as your second pump. It would shine as a second pump,but not as a single.

Is the DW the answer to a problem? What problem? It creates two problems that the Walbro never had.
More volume is good When the motor needs it,but not Before.

Yes,as long as your pump maintains the pressure it should,it doesn't have a volume problem.

 

[Ttype6]

What symptoms or what do you look for if there is on issue with the stock return fuel lines with the “Deatschwerks” pump.

I just installed mine and now my idle is at around 10psi.

The issue with the DW isn't that your pressure,at an idle will go down,it's that it will go up.

 

[Ttype6]

You can't run the Deatschwerks pump on a turbo Buick with a stock fuel return line. The volume is too high at low pressure and you can't get the fuel pressure low enough at idle. Yes, I tried it, I have one on my car. :smile:

Yes you can,if you dill out the lines where the Saginaw fittings are,on the return line or you run E85. See,it would still be the stock lines and no one would be able to tell they were modified. It's not necessarily a drop in situation and you would still be heating the fuel unnecessarily.

 

[Ttype6]

Noted for sure. So I've heard 12 to 15 as normal factory "safe settings " if I stay in that range then I should have no problems technically? Right now it can run about 15 but I like how 13 feels. Guess 13 is pretty safe??? Thanks again for the help!!!

With 93 octane you should be able to run 17 lbs of boost with no spark retard. You have to be able to monitor the spark retard,so you need a Scanmaster. Your pressure is good so we know you don't have a fuel delivery problem.

If it seems to run better at 13 lbs of boost than it does at 15,it's probably because it it knocking and the computer is retarding timing.

The stock chip is programed for X amount of fuel at WOT so,as you increase boost,the X amount of fuel stays the same. As boost gets higher you will become leaner but,as I said,you should be able to run 17 lbs if you have 93 in your area.

No mater what,you'll need more octane to run above that. A mixture of 25% xylene and 75 % gasoline will allow you to run 20 lbs of boost,but we need to get some more information from the Scanmaster.

A thorough visual inspection of vacuum lines is always a must.

 

[Ttype6]

BUT I am a bit (O.K. ALOT) nervous.

You're,definitely,at the upper limit of that pump's capability. As I said earlier The DW pump would be a good choice for the second pump in a double pump set-up.

 

[Dennis F]

I run 20 in 1st + 2nd and 18 in 3rd.

Car has a TE44, big fmic, wally 255hp and 42 pd injectors and this is on 93 only. The secret to high boost on pump is lots of fuel and lots of intercooler. Hell, I can run 31-32 psi on straight 93 in my Evo and that has a huge fmic and 1650cc injectors!

 

[Ttype6]

I run 20 in 1st + 2nd and 18 in 3rd.

Car has a TE44, big fmic, wally 255hp and 42 pd injectors and this is on 93 only. The secret to high boost on pump is lots of fuel and lots of intercooler. Hell, I can run 31-32 psi on straight 93 in my Evo and that has a huge fmic and 1650cc injectors!

I wouldn't add extra fuel ,to stop knock,at the expense of power. There would be no good reason for that.Yes,fuel quantity is the way to run more boost when you lack fuel quality. You get away with more boost in first and second gears because there is less load on the motor.

 

[turbofabricator]

We just dropped in the new Aeromotive pump. (single) No issues so far. Wait until we get the StageII 274 engine back in to tell the whole story. Mid tens are not an issue at all, though. I'd like him to try straight C-16 and no alcohol to see if the fuel volume is up to the task alone. Probably won't do it, though. He likes pump gas and methanol (dual nozzle) Though the last failure was compounded by methanol. Lean out (pump issue) wrong plugs (extended tip) and methanol pre-igniting and flame cutting the exust valve during valve over-lap. (pie cut the valve which in turn sent shrapnel into most cylinders which required an overbore to 4.040") Man! This is FUN!!!!

 

[highboostgn]

get a walbro 340, hotwire kit, Adjustable Fpr a set of 42lb injectors and a matching chip