Welcome to the North American Subaru Impreza Owners Club Friday April 18, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 01-06-2013, 11:01 AM   #351
AkumaMotorsports
NASIOC Vendor
 
Member#: 214570
Join Date: Jun 2009
Chapter/Region: Tri-State
Location: NJ/SLC
Vehicle:
2008

Default

Quote:
Originally Posted by lancelucas View Post
The theory is definitely legitimate, my experience just hasn't really shown it to be a practical risk and Subarus have shown themselves to have pretty robust electrical systems -- IE, they take enough precautions against circuit overloads. The same thing (significant amperage draw above design) can happen if the fuel pump is badly worn, the fuel filter is badly clogged, the pump jams on a foreign object, etc.

FWIW, my car was setup with an A340 on the stock FPC pinned to 100% for a prolonged period of time with no adverse affects noticed. I took a couple road trips that would have included 4+ hours of continuous on time, save for fuel and pee stops. While mostly cruising there was certainly some 3rd-4th-5th blasts at over 400whp on E85, so definitely "used" the pump during those trips as well.
The statement is based on two things....
-The AMP draw has a specific gauge requirement, the Stock power wire is not witin safe range...amperage will vary with load requiremnts on the pump
-Aeromotive is also emphatic that you change the power lead to the pump

It is just not worth the risk. However, it is completely up to the owner/operator. Fire is not a fun thing to mess around with.

John
* Registered users of the site do not see these ads.
AkumaMotorsports is offline   Reply With Quote
Old 01-06-2013, 11:21 AM   #352
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

^^^Agreed!! The other issue is why run the pump at 100% all the time when it's not needed. You just end up overheating the fuel which can bring on much bigger problems!
manitou is online now   Reply With Quote
Old 01-06-2013, 02:53 PM   #353
lancelucas
Scooby Specialist
 
Member#: 124282
Join Date: Aug 2006
Chapter/Region: NWIC
Location: 30000 ft
Vehicle:
04 WRX Wagon PSM
13 STI Sedan SWP

Default

Quote:
Originally Posted by manitou View Post
^^^Agreed!! The other issue is why run the pump at 100% all the time when it's not needed. You just end up overheating the fuel which can bring on much bigger problems!
Sorry man, also not a big practical concern from my observations. I've tested it as my car is one of the ones with an in-tank fuel temp sensor that can be monitored. It has a surge tank, so the fuel is pumped by at least 2 A340 pumps running 100% all of the time, and sometimes by a 3rd (Hobbs switched activated at 25psi). I drove the car from full to empty and the fuel simply didn't appreciably heat up. And by then, it was ready to be replaced by a fresh tank of fuel anyways. Heat conducted from the engine to the fuel as it cycles the engine bay is probably a larger factor.

I'd love to see more data on this. Perhaps its a bigger problem in warmer climates (average ambient is not very high in my parts).

Last edited by lancelucas; 01-06-2013 at 03:06 PM.
lancelucas is offline   Reply With Quote
Old 01-06-2013, 02:59 PM   #354
lancelucas
Scooby Specialist
 
Member#: 124282
Join Date: Aug 2006
Chapter/Region: NWIC
Location: 30000 ft
Vehicle:
04 WRX Wagon PSM
13 STI Sedan SWP

Default

Quote:
Originally Posted by AkumaMotorsports View Post
-Aeromotive is also emphatic that you change the power lead to the pump
They are indeed, but only for pump performance reasons that I can find. I cannot find a single mention of fire or wiring system risk within these docs, only mention of upgraded wiring being required to get the pumps advertised performance:

http://aeromotiveinc.com/tech-help/f...th-fuel-pumps/

http://aeromotiveinc.com/wp-content/...1141_11142.pdf

Agreed that it us up to each owner/operator and thank you for pointing out some of the factors that should be considered. I tell people they need upgraded wiring for pump performance, so the end recommendation is the same.
lancelucas is offline   Reply With Quote
Old 01-06-2013, 03:25 PM   #355
amalgrover
Scooby Specialist
 
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Location: Valdosta, GA
Vehicle:
2011 Audi A3 Quattro
2009 Forester XT

Default

Quote:
Originally Posted by lancelucas View Post
Heat conducted from the engine to the fuel as it cycles the engine bay is probably a larger factor.

I'd love to see more data on this. Perhaps its a bigger problem in warmer climates (average ambient is not very high in my parts).

I think your theory is spot on. I talked with Fuel Injector Clinic for a long time about this when issues were starting to show up in the 1600cc injectors from fuel temperature. They told me that their testing and research had shown that the issues showed up mostly in warmer climates and mostly on newer Lancers more than any other vehicles. They said that the Lancer's fuel lines for some reason receive more heat from the engine bay than other vehicle's, and this plus the warmer climates are likely causing the issues.

So, I think that you are definitely correct stating that fuel cycling the engine bay is more susceptible to an increase in temperature. This is also why I stated that the boost-a-pump is more likely to cause temperature issues during an extended road racing scenerio than it is on a street driven setup. The amount of time that the pump is operating at the higher voltage is very small compared to if it was road racing for an hour or two.
amalgrover is offline   Reply With Quote
Old 01-06-2013, 03:41 PM   #356
Phatron
Scooby Guru
 
Member#: 36033
Join Date: Apr 2003
Chapter/Region: SCIC
Location: Tuning Lab
Vehicle:
CEO PhatBottiTuning
2006 STi GTX3582 + Meth

Default

everyone I've ever talked to about putting these on has laughed at me

Phatron is offline   Reply With Quote
Old 01-06-2013, 04:28 PM   #357
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

Hey amalgrover,
The other thing with those bosch 1600's is that they all swell up from heat. It's inherent in the design of just the 1600's. that's why ID pulled production on theirs and do not offer them any longer. I wish someone had that size injector that works as well as the 1000's and 2000's. hopefully Bosch redesigns that size for us 4 banger guys!

The point I was trying to make is that if the FPC works well with the rewired pump and meets your goals than why not use it that way.

I was reading the Kenne Bell info on the boost a pump and they don't recommend th for the big Walbro's or Aeromotive pumps. Hy say to retire them!
manitou is online now   Reply With Quote
Old 01-06-2013, 06:25 PM   #358
kellygnsd
Scooby Guru
 
Member#: 32669
Join Date: Feb 2003
Chapter/Region: SCIC
Location: Rancho C
Vehicle:
2007 2.34LR, EFR7670
LINK G4 hybrid STi

Default

Quote:
Originally Posted by amalgrover View Post
...what bswilmington is trying to say is that the voltage isn't the biggest concern. the biggest concern is that when amperage is increased beyond the limit of the factory wiring it can cause the wires to heat up, melt their coating, and cause a fire.
We're a far ways away from overheating the wires to the point of fire. The main issue is the voltage drop in the wire to the pump which lowers the pumps terminal voltage and output.

Quote:
Originally Posted by lancelucas View Post
That's not how I am interpreting this conversation.

They are referring to the poor pump performance when run on factory wiring/controller, and the gain that can be had in pump performance by running a direct-to-battery positive lead. The terminology is somewhat irrelevant...and what's funny is many (including me) have actually tested this stuff and moved on. But yet there are threads of people TALKING for days and days about it. Backprobe the main fuel pump wiring after it leaves the controller with a DMM with the car idling and you'll have all of the evidence you need -- the voltage observed is well below alternator output. The FPC kills voltage/current even at 100%, yo.

The risk of fire via melted wires is a separate conversation and one that I personally think is overstated. The point of the circuit's fuse is to prevent just that. If the circuit is being overloaded to the point of creating a risk, that's one of the things the fuse is for. Otherwise we'd see cars with jammed power windows and sunroofs burning themselves down left and right. Does anyone know of this actually happening in a road-driven Subaru?
If the fuel pump controller is PWM controlled an RMS voltmeter won't be able to get an accurate measurement of peak voltage to the pump. What did you DMM read with the controller at 100%
kellygnsd is offline   Reply With Quote
Old 01-06-2013, 06:52 PM   #359
amalgrover
Scooby Specialist
 
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Location: Valdosta, GA
Vehicle:
2011 Audi A3 Quattro
2009 Forester XT

Default

Quote:
Originally Posted by kellygnsd View Post
We're a far ways away from overheating the wires to the point of fire. The main issue is the voltage drop in the wire to the pump which lowers the pumps terminal voltage and output.



If the fuel pump controller is PWM controlled an RMS voltmeter won't be able to get an accurate measurement of peak voltage to the pump. What did you DMM read with the controller at 100%

My post was incorrect because I only read the quote of bswilmington by lancelucas, which means what I read was taken out of context and wasn't the whole statement. I misunderstood what was being said.
amalgrover is offline   Reply With Quote
Old 01-06-2013, 06:58 PM   #360
amalgrover
Scooby Specialist
 
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Location: Valdosta, GA
Vehicle:
2011 Audi A3 Quattro
2009 Forester XT

Default

Quote:
Originally Posted by manitou View Post
Hey amalgrover,
The other thing with those bosch 1600's is that they all swell up from heat. It's inherent in the design of just the 1600's. that's why ID pulled production on theirs and do not offer them any longer. I wish someone had that size injector that works as well as the 1000's and 2000's. hopefully Bosch redesigns that size for us 4 banger guys!

The point I was trying to make is that if the FPC works well with the rewired pump and meets your goals than why not use it that way.

I was reading the Kenne Bell info on the boost a pump and they don't recommend th for the big Walbro's or Aeromotive pumps. Hy say to retire them!

The reason they do not recommend them for those pumps is because those pumps are not tested above 13.5v (or at least the companies do not release data proving otherwise), and also the amount of amperage drawn by running those bigger pumps at 17.5v or 21v is ALOT. I can tell you that it will work just fine on my DW300, and as long as the wiring is setup properly for the amperage, the bigger pumps should work just the same, although temps could be an issue on these bigger pumps...but then again, maybe not...I personally haven't run one on anything bigger than an Aero340 so...I couldn't say for sure yet.
amalgrover is offline   Reply With Quote
Old 01-06-2013, 10:20 PM   #361
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

The amperage drops as the voltage increases not the other way around. You are probably right about them not testing them but if you read Kenne Bell's info they say you do not need the boost a pump with a re-wire of the big pumps and or they are not as effective with the re-wired big pumps.
manitou is online now   Reply With Quote
Old 01-06-2013, 10:24 PM   #362
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

I'll tell you though, I'm gonna call them and here it from them directly.
manitou is online now   Reply With Quote
Old 01-06-2013, 10:56 PM   #363
amalgrover
Scooby Specialist
 
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Location: Valdosta, GA
Vehicle:
2011 Audi A3 Quattro
2009 Forester XT

Default

this image from dw's site says otherwise sir

amalgrover is offline   Reply With Quote
Old 01-06-2013, 11:37 PM   #364
kellygnsd
Scooby Guru
 
Member#: 32669
Join Date: Feb 2003
Chapter/Region: SCIC
Location: Rancho C
Vehicle:
2007 2.34LR, EFR7670
LINK G4 hybrid STi

Default

Quote:
Originally Posted by manitou View Post
The amperage drops as the voltage increases not the other way around. You are probably right about them not testing them but if you read Kenne Bell's info they say you do not need the boost a pump with a re-wire of the big pumps and or they are not as effective with the re-wired big pumps.
Still got it backwards. Its a simple DC motor. A DC motors speed and in turn its output is directly proportional to the armature current that flows through it. That armature current is a function of the pumps terminal voltage and nothing else.

With our batteries being up front you have a long run of wire of known resistivity that connecting the voltage source to the load (aka pump)

Being that we have smaller than optimal power wiring to our pumps, as current goes up so does the voltage drop in the undersized wire based on ohms law and while you had 12 V at the battery, you end up with 10V at the terminals of the pump instead of 12V. Now compare the pumps output at 10V to what it puts out at 12V or whatever the system runs at and that's what can be gained by eliminating that excessive voltage drop from the battery terminals of the pump by rewiring straight to the battery with ungraded wire.

The numbers and voltage drops are just to illustrate what's going on and aren't actual measured voltage drops.


The current limits in the NEC for wire sizes aren't the max current that the conductors can carry but recommended current values not to exceed to prevent excessive voltage drop and heating that can cause insulation breakdown, melting, and fire. The allowable temp rise is based on the type of wire insulation used. It seems that some people think that the smaller wire somehow throttles the current or clamps it when but all that really happens is you get a bigger voltage drop and temperature increase. The wire will pass as much current as it can up until failure.

Last edited by kellygnsd; 01-06-2013 at 11:49 PM.
kellygnsd is offline   Reply With Quote
Old 01-07-2013, 12:07 AM   #365
Phatron
Scooby Guru
 
Member#: 36033
Join Date: Apr 2003
Chapter/Region: SCIC
Location: Tuning Lab
Vehicle:
CEO PhatBottiTuning
2006 STi GTX3582 + Meth

Default

V=IR....volts up, current up
Phatron is offline   Reply With Quote
Old 01-07-2013, 12:56 AM   #366
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

Yes yes, so sorry, my bad! I had a brain fart, I was confusing the dc motor with a fixed speed ac motor's voltage and amperage requirements. Ooops!

I will call Kenne Bell about the application of the boost a pump with the bigger pumps like the walbro 400. I want to hear what they have to say, I will report back!
manitou is online now   Reply With Quote
Old 01-07-2013, 06:51 AM   #367
amalgrover
Scooby Specialist
 
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Location: Valdosta, GA
Vehicle:
2011 Audi A3 Quattro
2009 Forester XT

Default

please do...like i said before, a BAP with a walbro 400 is a possible 400lph@70psi!
amalgrover is offline   Reply With Quote
Old 01-07-2013, 06:56 AM   #368
KillerBMotorsport
NASIOC Vendor
 
Member#: 198281
Join Date: Dec 2008
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2005 WRX/STi
WRB of course

Default

Quote:
Originally Posted by manitou View Post
Yes yes, so sorry, my bad! I had a brain fart, I was confusing the dc motor with a fixed speed ac motor's voltage and amperage requirements. Ooops!

I will call Kenne Bell about the application of the boost a pump with the bigger pumps like the walbro 400. I want to hear what they have to say, I will report back!

^ In for answers on this as well as we've considering the boost-a-pump as a means to dyno test (only) different fuels.
KillerBMotorsport is offline   Reply With Quote
Old 01-07-2013, 01:53 PM   #369
lancelucas
Scooby Specialist
 
Member#: 124282
Join Date: Aug 2006
Chapter/Region: NWIC
Location: 30000 ft
Vehicle:
04 WRX Wagon PSM
13 STI Sedan SWP

Default

Quote:
Originally Posted by kellygnsd View Post
If the fuel pump controller is PWM controlled an RMS voltmeter won't be able to get an accurate measurement of peak voltage to the pump. What did you DMM read with the controller at 100%
13.2-13.3v at the main fuel pump cord connector under the backseat. Walked up to the engine bay and measured 14.2-14.3v at the alternator terminal.
lancelucas is offline   Reply With Quote
Old 01-07-2013, 06:36 PM   #370
maxpowr
Scooby Guru
 
Member#: 159243
Join Date: Sep 2007
Chapter/Region: Tri-State
Location: medford nj 08055
Vehicle:
sg3 Turbo Tek Tuned
Hakt Ecu e85 30r 6spd

Default

So loss at the wire length and FPC?
maxpowr is offline   Reply With Quote
Old 01-07-2013, 07:52 PM   #371
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

So, I talked to Kenne Bell's late this afternoon and mentioned that I had a 500+ WHP Subaru and described my fueling system with the 12 gauge re-wired Walbro E85 465 pump and 1000cc injectors.

I asked Matt at Kenne Bell's if the Boost a Pump would benefit those of us running the bigger Walbro's, DW's etc...even if we have already re-wired the pumps through the FPC with 12 ga. wire. He told me the BAP are controlled via a 5 detente switch that basically gives you 0-50% increase in voltage in 5@ 10% increments. The voltages are: 0=12v, 1=13.2v, 2=14.5v, 3=16v, 4=17.6v, 5=19.3v.

He said the larger 40 amp BAP (limited by a 30 amp fuse) will still benefit these big pumps by providing a rock steady voltage supply at the pump even if they are set at the 0 or 1 setting. Matt said to look at the amperage draw of the pump at a given voltage and psi setting at your FPR. You need to look at the maximum amperage draw for the system, which should be well under the 30 amp fuse. The Walbro 465 at 13.5v and 60 psi draws 15.64 amps.

Based on this info from KB it seems that the 40 amp BAP ($249 retail) would be a good match with the Walbro 465. Given a 50-60psi system fuel pressure we could most likely use the 1-3 setting of the BAP and be well within the limits of the wiring, fuses and using the stock Subabru FPC. The BAP kits come with enough wire to mount them in the engine compartment or the trunk or anywhere in between.

I hope this helps!
manitou is online now   Reply With Quote
Old 01-07-2013, 07:55 PM   #372
hjz420
Scooby Specialist
 
Member#: 265757
Join Date: Dec 2010
Location: jax
Default

It would have been alot easier to go back 5 pages and say buy 16volt battery and a step down module for the ecu. Next upgrade alternator and re locate battery in trunk. My .02
hjz420 is offline   Reply With Quote
Old 01-07-2013, 08:01 PM   #373
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

Quote:
Originally Posted by hjz420 View Post
It would have been alot easier to go back 5 pages and say buy 16volt battery and a step down module for the ecu. Next upgrade alternator and re locate battery in trunk. My .02
Not sure what that would gain you? $140 battery and $100+ step down transformer/ converter. I guess if you already needed the new battery but simpler......? IDK about that!
manitou is online now   Reply With Quote
Old 01-07-2013, 08:07 PM   #374
hjz420
Scooby Specialist
 
Member#: 265757
Join Date: Dec 2010
Location: jax
Default

Its actually very simple. Go look at any drag car. Didnt say it was gonna be cheap. You should know better. A battery that supplys the voltage and the amps in current is going to have a way better effect then running 12 gauge wire front to back across and side to side. Then adding a boost to pump. Then ita just like a capicitor for your ampzzz
hjz420 is offline   Reply With Quote
Old 01-07-2013, 08:19 PM   #375
manitou
Scooby Specialist
 
Member#: 193757
Join Date: Nov 2008
Chapter/Region: MWSOC
Location: Cedar, MI HP Techs MPS-SSLR2.5
Vehicle:
2006 XTI Limited
OBP, Junior tuned 573WHP

Default

Agreed! Definitely many ways to skin a cat! It's good to have options for sure!!
manitou is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
PhatBotti Tuning (merged thread) BoostinChick Vendor Reviews 96 12-19-2013 04:40 AM
PhatBotti Tuned - 205k Mile 02 WRX Wagon - 12.4 @ 111 benit0 Proven Power Bragging 14 11-04-2011 09:06 AM
Brake Fluid FAQ & Pedal Feel Info (the reference post) 8Complex Brakes, Steering & Suspension 37 06-06-2008 08:47 AM
PDX Tuning Dyno Day - Final Schedule & Payment Info - Standby folks read as well! Geoff Texas Impreza Club Forum -- TXIC 108 05-04-2006 07:26 PM
MWSOC/INR Event: July 7th Merrillville autoX - Full Event & Caravan Info 8Complex Mid West Subaru Owners Club Forum -- MWSOC 55 07-08-2001 11:08 PM


All times are GMT -4. The time now is 05:33 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.