Look Ma...no Pressure Line

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DOOBEEWHA

DOOBEEWHA

HPISF languist expert
Messages
1,332
Location
Petaluma,Ca,
Hey guys,
After anwering a Q about the tank return line, I remembered a racing setup that Adam Drake is known to run.

===============RUNNING WITHOUT A PRESSURE RETURN LINE================================

This, according to Adam Drake.

By doing this arrangement with the air fittings, the effect is discribed as getting your nitro to feel more like an
electric, providing a smoother power delivery to the drive train. This is said to provide better traction, as it
buffers the torque with some smoothness


It's very easy to setup and only requires a retuning of the engine for a zero pressure sinario.


As the carb will draw fuel on it own,
the pressure fitting on the pipe is capped off at the nipple, along with filtering the tank's pressure inlet with a
fuel filter.

The new fuel filter acts as air cleaner for the inlet on the tank.

======================= THIS IS A RACING SETUP.=========================


Here's how:
Bare in mind, after you done, you will need to re-tune the mill for this difference in pressure lose.
No pics needed.

1.) Just take a 1/2 inch piece of fuel tubing, and a spare bolt that fits the tube tightly.

2.) Insert the the bolt in the tube and blow in to it to verifiy a tight fit (no leaks) for a pressure check.

3.) Place this tube on the pipe fitting and use a baby zip-tie to seccure it.

4.) Now,.. get a new spare fuel filter and zip-tie it in a good spot like in the center of the rear shock tower.

5.) Cut a piece of fuel tubing long enough to reach between the tanks inlet and the new mounted filter, leaving
a bit of slack.

6.) Attatch this tubing to the new filter and the tank's inlet fitting.

Note:This tube is still your way of priming the engine. You need to removed it from the new filter everytime
your going to prime the engine with some applied air pressure to send fuel to the carb..

7.) After you've primed the engine, re-attatch the tube to the filter and start her up.

8,) Start the engine and re-tune the mill for this new setup.
Remember: With the tank pressure gone, the engine needs to be tuned richer to compensate for the pressure
loss.

This is just a guess: On the Savage's half tank lean factor, I would tune the mill with only a half tank of fuel.

Once tuned to the best setting, you can them fill the tank like normal. IMO


===============================Good luck with this, guys==================================
 
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Really!... Ok. the thing is, I don't run this setup myself, currently.
so I don't have pics at this time.


Let me see if I can explain in short form,..

1.) You plug the pipes pressure outlet.(the fitting) Like with an end cap.

2.) Attatch a new fuel filter to short piece of fuel tubing.

3.)Attatch the other end of the tubing to the inlet of the tank.

Now.. everything is basically connected.

The only thing left to do is mount the new fuel filter thats now acting as an air intake filter for the tank.
Place it in a spot where its seccure. Like the middle of the shock tower, for instance.
(leave the ixisting fuel filter (if you have one) and fuel line alone.)

Now.. the mod is in place.
Just tune the mill to a richer setting to compensate for the lack of fuel pressure that it once had.
Does this help, FX?
 
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DOOBEEWHA said:
Really!... Ok. the thing is, I don't run this setup myself, currently.
so I don't have pics at this time.


Let me see if I can explain in short form,..

1.) You plug the pipes pressure outlet.(the fitting) Like with an end cap.

2.) Attatch a new fuel filter to short piece of fuel tubing.

3.)Attatch the other end of the tubing to the inlet of the tank.

Now.. everything is basically connected.

The only thing left to do is mount the new fuel filter thats now acting as an air intake filter for the tank, to a spot where its seccure.

Like the middle of the shock tower, for instance. (leave the ixisting fuel filter (if you have one) and fuel line alone.)

Now.. the mod is in place.
Just tune the mill to a richer setting to compensate for the lack of fuel pressure that it once had.
Does this help, FX?
Click to expand...
I not trying to be a pain, I just honestly can't visualize what it would look like or how to set it up. I'm a visual learner, I'll wait for pictures.
 
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any pics of Drake using this mod? and on what type of truck?

also, how will this be affected by the carb pickup/fuel level on the savage (think back to the half tank lean thread)
 
I can't be quoted, but I believe it was in refference to the Losi LST 2 Truggy.
I would have to research it further to provide additional details.
Do I need pictures? Is there a question to the truth in this posting?
 
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If I followed what you described, does it look like this?

Plugged psi port on pipe
psiline003.jpg


Filtered tank inlet
psiline001.jpg


I have heard of this being used before, I have broken a pipe in the field before and wasnt able to attach a psi line to the pipe, I kept running with out pressure to the tank.

The truck was a midtank savage, yes it did run, it did need tuning, but didnt work all that great during bashing.
 
JT, Thats exactly what this thread is about.
Your pics here are a great help for those who want/need a better discription in pics, rather than in words.
Even if I had set up my own truck to discribe in pics this setup, it still wouldn't carry the wieght that your comfirmation provides.

For this, I sincerly thank you, Jerry.

To whom it may consern,
Out Of General Principal,.. I intend to produce and verify the source of this threads content (in so many words) so there is no doubt that Adam Drake himself, has endorsed in publication, the setup as I've indicated.

Doobeewha
 
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would be interesting to get some footage up of it working.

How much re-tuning will this set up require, as i know when my pressure line has fell off/ripped off my tank in the past my motor stalls, and will not start until reconnected.

also poses the question as to why do they put the pressure line on the pipe in the first place?
 
It stalls because the mill was able to recieve fuel under pressure.
When the tube is taken away, now the mill is way too lean to draw the fuel fast enough.
This why it requires a richer neddle setting as I discribed.
The engine, if allowed to recieve fuel, can draw on its own, enough fuel to run very well.
We are just acustom to pressure feeding the mill for higher proformance.
 
The irony here is with this setup being reffer to as a "racing setup".
The fact is, this mod actually reduces the proformance of the engine to gain a better advantage on certain track conditions.

This is done with a smoother transition of power to the drive train, providing an even traction condition that gets a better lap time.

Imagine that....
 
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Yeah, thanks Jt for the pics on that type of set-up. I might try it out one weekend and see how it works. If I do, I'll post it here so everyone will know.
 
DOOBEEWHA said:
The irony here is with this setup being reffer to as a "racing setup" and is in fact a mod that actually reduces the proformance of the engine to gain a better advantage on the track with a smoother transition of power to the drive train providing an even traction condition that gets a better lap time.

Imagine that....
Click to expand...

thats what venturi's are used for in engines aswell, to decrease top speed but increase run times, and add another option to tuning.

really depends on the track and the amount of laps/run time
 
It is an interresting mod for sure...

Will I ever use it? Can't really say.

I guess if I damage the pipe out in the field, It's very posible, now that I
know this can actually work to a degree.

I will have to expect a drop in proformance in the grunt dept.
This mod is really not for the basher in mind.

If I start racing on track conditions, I'll consider it a valuable trick up my sleeve, if it applies in the competition.

I can see how the venturi carb inserts can do a service here, but it's the smoothness in this setup, is what I think Drake was going for.
 
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just go out and try it, then let us know what you think.

i feel the engine will run very similar to having the pressure, as changing the initial tune anyway.

i would recommend a good guality fuel tube, as short as possible and even large bore (if it exists), all to reduce the effects of internal friction, which will reduce the carbs effectiveness at drawing fuel as rpm increase, thus reduceing top end performance.
 
Yes... those are good points, gzus11.
I guess the reason that I'm not that excited to do this is because I don't
drive or race on track-like conditions at this time.
Nor do I want to re-tune my truck's mill just to see.

As I said earlier, this is a racing setup.(for a specialized application)
Thats the funny part... Its for racing because it makes you go slower.

Bashers will find doing this to thier rides a likely disappointment.
This setup warrants a need.
I guess I need to be more curious about it.

I'm a Basher at heart, but find it interresting to know my options here.
Although gzus11,
your more than welcome to report back with your findings with this setup.
 
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i think i will try 2 night an di will post some new pics up that you can see and i will try 2 get some footage
 
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