follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
Speed By Design
Register Garage Members List Calendar Search Today's Posts Mark Forums Read

Go Back   Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB > Technical Topics > Engine Swaps

Engine Swaps Discussion of engine swaps.


User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-23-2021, 08:28 PM   #15
matt88
Member
 
Join Date: Oct 2019
Drives: 2017 Toyota 86 GTS Manual
Location: Australia
Posts: 28
Thanks: 0
Thanked 7 Times in 6 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by brzlegend View Post
I think a jeep and a chysler mini van has a heavy duty pwm fan controller, replacements are on ebay with the connector.
Great! Thanks for the tip!
matt88 is offline   Reply With Quote
Old 11-23-2021, 10:48 PM   #16
86TOYO2k17
Senior Member
 
Join Date: Jan 2018
Drives: 2017 toyota 86
Location: PNW
Posts: 2,102
Thanks: 333
Thanked 1,166 Times in 768 Posts
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Why not just install a fuel pump relay and not have to worry about it?
86TOYO2k17 is offline   Reply With Quote
Old 11-24-2021, 12:02 AM   #17
matt88
Member
 
Join Date: Oct 2019
Drives: 2017 Toyota 86 GTS Manual
Location: Australia
Posts: 28
Thanks: 0
Thanked 7 Times in 6 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by 86TOYO2k17 View Post
Why not just install a fuel pump relay and not have to worry about it?
Good point!

But, if I have the ability to drive it dynamically and not always slam it at full speed for its entire life, why not give that a go?
matt88 is offline   Reply With Quote
Old 11-25-2021, 12:09 AM   #18
brzlegend
Member
 
Join Date: Sep 2021
Drives: brz
Location: Tennessee
Posts: 55
Thanks: 4
Thanked 10 Times in 9 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by 86TOYO2k17 View Post
Why not just install a fuel pump relay and not have to worry about it?
You ever wonder why every OEM manufacturer uses pwm control plus the majority of standalones?
brzlegend is offline   Reply With Quote
Old 11-25-2021, 07:14 AM   #19
Ashikabi
Senior Member
 
Ashikabi's Avatar
 
Join Date: Aug 2014
Drives: 2013 FR-S
Location: Northwest Iowa
Posts: 7,322
Thanks: 454
Thanked 4,513 Times in 2,931 Posts
Mentioned: 59 Post(s)
Tagged: 5 Thread(s)
Quote:
Originally Posted by brzlegend View Post
You ever wonder why every OEM manufacturer uses pwm control plus the majority of standalones?
I'm gonna assume OEMs do it to simplify plumbing, reduce noise, possibly safety, computerized feedback for check engine lights, and surviving repeated exposures to being 99% empty. I'm sure there are some other reasons. But the point is, aftermarket/race applications don't have the same concerns as OEM. Standalones probably do it so they can mesh with OE systems

Sent from my ONEPLUS A5010 using Tapatalk
Ashikabi is offline   Reply With Quote
Old 11-25-2021, 08:18 AM   #20
brzlegend
Member
 
Join Date: Sep 2021
Drives: brz
Location: Tennessee
Posts: 55
Thanks: 4
Thanked 10 Times in 9 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Ashikabi View Post
I'm gonna assume OEMs do it to simplify plumbing, reduce noise, possibly safety, computerized feedback for check engine lights, and surviving repeated exposures to being 99% empty. I'm sure there are some other reasons. But the point is, aftermarket/race applications don't have the same concerns as OEM. Standalones probably do it so they can mesh with OE systems

Sent from my ONEPLUS A5010 using Tapatalk
Pwm is better in every way.
Two 285 Walbros push 4.5 gallons a minute hooked to a relay, why would you want that at idle? They also would use 35amps at 40psi base pressure at idle together.

Last edited by brzlegend; 11-25-2021 at 09:24 PM.
brzlegend is offline   Reply With Quote
Old 11-25-2021, 09:56 AM   #21
matt88
Member
 
Join Date: Oct 2019
Drives: 2017 Toyota 86 GTS Manual
Location: Australia
Posts: 28
Thanks: 0
Thanked 7 Times in 6 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Well I had some fun today doing fuel pump controller tests.

Disclaimer: I'm using the canbus translator from AGT engineering. I'm not sure of what effect this translator has on the waveform that drives the fuel control module outside of what a stock Subaru ecu would do, however I would like to assume that they've done their best at replicating stock Subaru behaviour.

So first, I scoped the output of the e38 x1 pin 50 "Fuel Pump Relay Control Primary". Just as per the work I've been doing on solving my radiator fans, the output is a nice 10 volts usually high, pulls to low style pwm square wave running at 128hz. Various fuel pump percentage settings, all the way from 1% to 100% produce the 128hz waveform with lowest duty cycle (1%) spending most amount of its time high at 10 volts and the least amount of its time at 0v. Enter 73% and 73% of the time the waveform is 0v and 27% of the waveform is 10v. All as expected.

But then scope the input to the fuel pump controller and things change. The biggest difference is that the controller is basically being driven with pulse frequency modulation at various frequencies to represent the percentage of fuel pump as controlled by the e38 (not by a varying duty cycle 128hz pwm as what's coming out of the e38). So for example the e38 punches out 128hz and 46% duty cycle, well the fuel pump controller, from the canbus translator, is now receiving a sync pulse at 48hz. Dial the e38 up to 85% and now the fuel pump controller is receiving a sync pulse of 85hz.

Another interesting find is that anywhere from 1% to 35% duty cycle as pumped out of the e38 does not produce any sync pulse from the canbus translator to the fuel pump controller. The e38 is happily pumping out its 128hz waveform at various duty cycles between 1 and 35% but lo and behold any of these numbers don't produce a result at the fuel pump controller input. It is only when you pump in 36% does the translator suddenly kick into life and what do you know, it's a 36hz pulse.

So does anyone know if A: the stock Subaru ecu also drives the fuel pump controller via a variable frequency sync pulse? And B: does the stock ecu have this "only starts driving the fuel pump" at 36hz or more issue?

Then I moved on to the output of the fuel pump controller. Basically all that is happening is that the controller is dumping out a DC level. At the lowest working frequency of input of 36% the voltage output was something like 8 volts. Push the controller to 100% and it is dumping out a good 12 volts. No matter where I set my scope for time scale, I cannot see any pulse width. It is honestly just pure DC driving the pump at a varying voltage.

So again, some of these behaviours may be from the canbus translator, however they could well be in line with the standard Subaru behaviour.

Does anyone else have the same experience as this?

For me, I want to drive my camaro pump with true pwm, something like 20khz. Also I want to be able to have the range from 1% to 100% as needed. Why? Because I want to. Maybe it's pointless or overkill but having this level of control will make me think I've done it "properly". So I am going to splice into the output of the e38 pin 50 directly and have that running the fuel pump controller instead of passing through the canbus translator. I will also find a controller that can take a 128hz in, variable duty cycle pwm and then dump out a 19/20khz pwm to the pump.

Much of the work I'm doing on solving the pwm radiator fans will end up applying here, I'm sure.
matt88 is offline   Reply With Quote
The Following 2 Users Say Thank You to matt88 For This Useful Post:
bcj (11-25-2021), brzlegend (11-25-2021)
Old 11-25-2021, 04:48 PM   #22
86TOYO2k17
Senior Member
 
Join Date: Jan 2018
Drives: 2017 toyota 86
Location: PNW
Posts: 2,102
Thanks: 333
Thanked 1,166 Times in 768 Posts
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by brzlegend View Post
You ever wonder why every OEM manufacturer uses pwm control plus the majority of standalones?
Most bigger aftermarket pumps use or highly recommend a relay, or use a hob switch triggered at set vacuum or boost to trigger higher volt/output or if a dual pump setup a hob switch to activate the second pump.

Most quality aftermarket pumps have no issues running at 100% all the time. They are designed to.

The reason oem use controller is probably for numerous reasons, heat being one,

in-tank pressure regulators probably canít regulate enough when pump is at 100% and fuel consumption is low IE at idle is another.

Cost and simplicity is another, and probably trying to use and design something that can run for 200k miles with no issues in an oem setup.

You can also get aftermarket controllers wired into the relay if you really wanted.
86TOYO2k17 is offline   Reply With Quote
Old 11-25-2021, 07:16 PM   #23
Ashikabi
Senior Member
 
Ashikabi's Avatar
 
Join Date: Aug 2014
Drives: 2013 FR-S
Location: Northwest Iowa
Posts: 7,322
Thanks: 454
Thanked 4,513 Times in 2,931 Posts
Mentioned: 59 Post(s)
Tagged: 5 Thread(s)
Quote:
Originally Posted by brzlegend View Post
Pwm is better in every way.
Two 285 Walbros push 4.5 gallons a minute hooked to a relay, why would you want that at idle? They also use 35amps at 40psi together.
I think you want that for more instantaneous and stable fuel pressures when you're using giant injectors. You don't need the computer to see dropping fuel pressure, then tell the pump to go faster, then get your pressure back. It's just always there. It surely can't be better in every way or people wouldn't switch away from it

Sent from my ONEPLUS A5010 using Tapatalk
Ashikabi is offline   Reply With Quote
Old 11-30-2021, 08:02 AM   #24
brzlegend
Member
 
Join Date: Sep 2021
Drives: brz
Location: Tennessee
Posts: 55
Thanks: 4
Thanked 10 Times in 9 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Ashikabi View Post
I think you want that for more instantaneous and stable fuel pressures when you're using giant injectors. You don't need the computer to see dropping fuel pressure, then tell the pump to go faster, then get your pressure back. It's just always there. It surely can't be better in every way or people wouldn't switch away from it

Sent from my ONEPLUS A5010 using Tapatalk
The ecu activates the injectors in milliseconds, i think it could up the fuel pump controller output before low fuel pressure.

Last edited by brzlegend; 11-30-2021 at 08:22 PM.
brzlegend is offline   Reply With Quote
Old 11-30-2021, 08:17 AM   #25
matt88
Member
 
Join Date: Oct 2019
Drives: 2017 Toyota 86 GTS Manual
Location: Australia
Posts: 28
Thanks: 0
Thanked 7 Times in 6 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
I had another play with the fuel pump PWM output of the e38 today.

As it was putting out 128hz and my fans were also set at 128Hz I gave it a long shot that perhaps changing the fan frequency may also change the fuel pump frequency.

There was no change though. No frequency I entered into the fan pwm frequency had an affect on the fuel pump pwm frequency. So it looks like the fuel pump pwm runs at a fixed 128 Hz.

I wonder if HPTuners has any ability to add a function to change the fuel pump pwm frequency? Fan frequency is available, so what would be so impossible to expect that fuel frequency could also be adjustable hiding somewhere in the e38?

On another note in my playing with the fan frequency I again tried my large frequencies and still hit a 9.33Khz ceiling. Interesting was the fact that at this frequency I noticed the square wave didn't seem to look as clean as the square wave coming out at 128 Hz. I didn't try a bunch of different frequencies to test my theory though.

If I end up using a fan controller that passes through the input frequency to the fans, well then I guess I'll have more work to do on that part because ultimately I would rather be running both the fans and the pump at high frequencies, less audible, hopefully more efficient etc etc...

At this stage I am expecting the Crown Vic clone fan controller I am going to try will not pass the frequency through and simply dump a DC level to the output. As for the fuel pump controller, I bought a Dorman 902-310 to have a play with that and see what I could do. I believe that will pass the pwm frequency through, but won't know for sure until I get my hands on it. If I can't get that to a useable solution then I think I will try a Cytron MD25HV as it uses a fixed 16Khz output and accepts a wide range of pwm input frequencies.
matt88 is offline   Reply With Quote
Old 11-30-2021, 09:38 AM   #26
Ashikabi
Senior Member
 
Ashikabi's Avatar
 
Join Date: Aug 2014
Drives: 2013 FR-S
Location: Northwest Iowa
Posts: 7,322
Thanks: 454
Thanked 4,513 Times in 2,931 Posts
Mentioned: 59 Post(s)
Tagged: 5 Thread(s)
Quote:
Originally Posted by brzlegend View Post
The ecu activated the injectors in milliseconds, i think it could up the fuel pump controller output before low fuel pressure.
Just read an article from onallcylinders. Stated more consistent pressure at the rail due to proximity of the regulator, and more consistent fuel temp as advantages.

https://www.onallcylinders.com/2017/...m-right-video/

Sent from my ONEPLUS A5010 using Tapatalk
Ashikabi is offline   Reply With Quote
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
WTB stock fuel pump Stevenduarte210 Want-To-Buy Requests 1 06-07-2018 08:08 AM
FS: stock injectors and fuel pump xsnapshot Engine, Exhaust, Bolt-Ons 2 01-06-2016 05:14 PM
Fuel system questions. Boost-A-pump/stock fuel lines for engine swap Toxicmilk45 Engine, Exhaust, Transmission 4 12-14-2015 03:52 PM
WTB: Stock injectors and fuel pump willharp360 Want-To-Buy Requests 3 12-10-2015 08:50 PM
FS: Stock Injectors and Fuel Pump carlossanchez89 Engine, Exhaust, Bolt-Ons 1 12-03-2014 03:28 PM


All times are GMT -4. The time now is 06:17 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2022 DragonByte Technologies Ltd.

Garage vBulletin Plugins by Drive Thru Online, Inc.