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Hobbs switch

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Old 11-10-2015, 11:06 AM
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Default Hobbs switch

Are all created equal? I need to put one on the car and don't want to wind up with junk.
Old 11-10-2015, 11:36 AM
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You want the genuine HOBBS ones with the proper connector for automotive use.
http://www.racetronix.biz/itemdesc.a...S%2D15&eq=&Tp=
Old 11-10-2015, 01:06 PM
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I got my Hobbs switch from Lonnie about 5 years ago. Haven't had any issues with it.

http://www.lonniesperformance.com/
Old 11-10-2015, 01:16 PM
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Hobbs is a brand....and a good one. Never had an issue with one. Ebay usually has quite a few. Devils Own sells a decent adjustable pressure switch as well.

http://www.alcohol-injection.com/en/...re-switch.html
Old 11-10-2015, 02:10 PM
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I bought this one.
Attached Thumbnails Hobbs switch-photo36.jpg  
Old 11-10-2015, 02:22 PM
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http://www.racetronix.biz/items.asp?...TpStatus=1&Tp=
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Old 11-10-2015, 02:38 PM
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I almost bought it from you guys but $16 for shipping an item the size of a half dollar doesn't sit well with me.
Old 11-10-2015, 03:02 PM
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Originally Posted by oscs
I almost bought it from you guys but $16 for shipping an item the size of a half dollar doesn't sit well with me.
That is considered a decent SH price given where we ship from.
Most customers purchase numerous items such as harnesses, relays, fuse holders, pumps, etc. which offsets the SH.

We also have dealers who stock some of these items.

Cheers!
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Old 11-10-2015, 03:14 PM
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Yeah I understand. However on small item stuff like that it's just a personal pet peeve of mine.
Old 11-10-2015, 07:40 PM
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I've got a couple of the adjustable Nason switches I was going to use on one of the compound builds for the truck. If they'd work for you, let me know.
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Old 11-10-2015, 07:56 PM
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I'm using Honeywell 77029 2 N/O. It takes a automotive type connector.
Old 11-11-2015, 08:15 AM
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Originally Posted by RonA
I've got a couple of the adjustable Nason switches I was going to use on one of the compound builds for the truck. If they'd work for you, let me know.
RonA
Thanks Ron. I ended up using a Honeywell unit.
Old 11-11-2015, 03:51 PM
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Surely your ecu can switch whatever you're wanting to switch with such a switch ?
Old 11-11-2015, 04:50 PM
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Originally Posted by stevieturbo
Surely your ecu can switch whatever you're wanting to switch with such a switch ?
God damnit I didn't even think about that..
Old 11-12-2015, 06:12 PM
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I've been running a cheap HOBBS brand switch for years without issue. Cost me less than $10.
Old 11-13-2015, 10:47 AM
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I am using the honeywell brand version also. But I was hesitant also. I still don't like the idea of another point of failure for the engine. Any reason you went with a 15psi hobbs though? I went with a 2 psi, because the way I see it, at 15psi is the earliest the pumps can come on, and then it will still take a short time (probably milliseconds) for the secondary pumps to spin up and start producing a fuel flow. So I bought mine at a low psi turn on, just to be safe. That was just my thinking though.
Old 11-13-2015, 01:40 PM
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I dunno just what I saw working. I won't need that extra fuel until somewhere in the 25psi range anyways. Figured 10psi back was good enough. Honestly though I'm just going to return it. Stevie made a Good point.. I'm just going to use the Holley to trigger the second one.
Old 11-13-2015, 02:28 PM
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A pressure switch for fuel pump activation should be selected so that secondary pump activates at apx. 100HP shy of primary pump running out of fuel. Activating the secondary pump too early causes a pressure spike and unnecessary cycling of the pump (excessive wear/heat/electrical load). Activating it too late causes a pressure drop and a lean condition.

Running both pumps all the time is not recommended. This puts a substantial amount of heat into the fuel and extra load on the electrical system (typically 150-200 watts +).

There are no issues with delayed reaction or failures provided a quality pressure switch and proper wiring is used as in our DPK kits.

All our pressure switches are of the highest industrial quality and are equipped with sealed Delphi Metri-Pack connectors so no connections are exposed to the elements. We have NEVER had one fail in our DP kits for over 15 years. TB owners have been running DP systems using a HPS dating back to the late 1980's successfully.

Quite simply it is a proven solution when implemented properly.
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Last edited by Racetronix; 11-13-2015 at 09:03 PM.
Old 11-14-2015, 03:40 AM
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Originally Posted by Racetronix
Running both pumps all the time is not recommended. This puts a substantial amount of heat into the fuel
Having tested this and run my pumps for some time without the engine running I cans safely say a very minimal amount if heat is imparted to the fuel from the pumps.
Pretty much everyone saying they heat the fuel etc....have never actually logged fuel temps !

It isnt negligible, but it is close and certainly nothing at all to have any concerns about.

Unless the system is designed badly, uses low quality pumps or has other failings, the only downside to running the pumps all the time is the additional electrical load, which again comes back to having a system designed to cope.
I've run my own car with both pumps all the time for over 10 years now, and built many others the same way.

It works, it's simple, you dont need to **** about with check valves etc etc IMO there are far more positives to running them like this, than there are for staging the pumps.
Old 11-14-2015, 01:39 PM
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Our engineers have done much bench and field testing combined with feedback from our dealers and thousands of customers to come up with products that best suit the average customer with a daily-driven street-car.

The advice we offer on these forums is not opinion based on a single application / user's experience. It is for the masses. Our products are designed to be reliable and address many technical issues which can arise if not addressed properly by design.

FACTS:

- Electrical load of 150-200+ watts (apx. 12-16 amps) per pump on a street driven car with typical accessory loads at low engine RPM (idle/light cruise/stop-and-go traffic) is a major consideration. HP pumps typically draw twice as much power as a factory pump thereby increasing the electrical load to four times that of the factory system when both pumps are active. (This increases electrical system load from apx. 90 watts to as much as 400 watts+.) This can account for apx. 25-35% of an alternator’s output at idle / cruise speeds. Add to this the load of lighting systems, cooling fans, A/C, computers, ignition and entertainment systems a battery discharge (low voltage) condition ensues. Reducing unnecessary electrical load is very important to make sure there is healthy system voltage and battery charge status.

- Check-valves reduce crank-to-run time (as required in factory equipment) by keeping pressure in the lines when pumps shut down. They also isolate pumps to prevent back-feeding issues when a pump starts to fail.

- Heat is a major issue in today's non-return fuel systems with heat-retaining plastic components and non-recirculating fuel modules. New fuel pump modules use turbine pumps and other components to help reduce heating and gassing of the fuel. HP in-tank pumps spin considerably faster than factory pumps and use very powerful motors to produce flow that is many times that of a factory pump in a package of the same size. This translates to heat in the fuel system since fuel is used to cool and lubricate the pump. It is a fallacy often posted on these forums that fuel surrounding the outside of a pump contributes to cooling in any significant way.
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Last edited by Racetronix; 11-16-2015 at 12:22 PM.


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