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The mkiv Supra Owners Club

Fuel Pressure


Jellybean

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3Bar static is a good starting point, an injectors spray pattern is affected by pressure so when using aftermarket units it would be good to check with the manufacturer what pressure they recommend, also the flow rating of the injector would be quoted for a certain pressure too as you can see on the injector sheet I posted below ;)

 

http://www.mkivsupra.net/vbb/attachment.php?attachmentid=211964&d=1463509494

 

Wez , How would I read the above sheet running BPU , what pressure should I set it at?

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Not wanting to sell these, they are too useful to me, sorry. But go here for Bosch Motorsport parts:

 

http://www.motorsport-systems.co.uk/

 

Thanks Chris , Rich got back and I asked Bosch , The unit does not have a Pulsation damper built in

 

Fuel Pressure Regulator Mini A

Pressure Range 2.2 to 3.5 bar

B 280 550 340-03 -- 148.44 +VAT

 

FPR Adaptor

Commercial Type No.: F 02U V00 735-02 153.78 + VAT

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Wez , How would I read the above sheet running BPU , what pressure should I set it at?

 

Not sure I follow, your fuel pressure has no baring on running BPU, stock or single. A cheap fix for getting more out of your injectors is to increase the static pressure using an upgraded or adjustable FPR, for example my 996 currently runs a 5bar FPR, I plan to reduce this and install bigger injectors ;)

 

The sheet is saying that the 900cc injectors are rated / tested at 900cc with 3bar pressure, which happens to be a common static pressure hence calling them 900cc, at 3.8bar they flow over 1000cc.

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Not sure I follow, your fuel pressure has no baring on running BPU, stock or single. A cheap fix for getting more out of your injectors is to increase the static pressure using an upgraded or adjustable FPR, for example my 996 currently runs a 5bar FPR, I plan to reduce this and install bigger injectors ;)

 

The sheet is saying that the 900cc injectors are rated / tested at 900cc with 3bar pressure, which happens to be a common static pressure hence calling them 900cc, at 3.8bar they flow over 1000cc.

 

Sorry , I must be misinterpreting what I am reading

 

I taught Fuel pressure has a bearing on

 

AFR's

Rate of flow is tied in with power levels / BHP / engine efficiency

Spray pattern

 

You set it accordingly , I am not too sure what pressure it is running (need to check with a gauge ); when I asked my mapper they indicated removing the pulsation damper will not affect it

 

I will throw up some logs :) But AFR's look good but to me a little rich on idle

 

I am a little confused why the mapper said to run them at oem pressure as opposed to Siemens 3 bar ? I taught it was do to my power levels , oem pressure is sufficient for bpu

 

Just curious if it has a bearing on the ticking noise I hear or is it just down to lack of a damper

Edited by Jellybean (see edit history)
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Motec log file

https://1drv.ms/u/s!Ao-FTTt3GMhrg4RF72PNqQPeKitomQ

 

Analysis software

http://www.motec.com/i2/i2downloads/

 

You will need to use m1 channels , by default it's mxxx series

 

M1 channel names

 

New Name (possible old name)

Engine Speed (Engine RPM)

Ambient Pressure (Baro Pres)

Inlet Manifold Pressure (Manifold Pressure)

Inlet Air Temperature (Air Temp Inlet)

Coolant Temperature (Engine Temp)

Ignition Timing (Ign Advance)

Exhaust Lambda (Lambda 1 or LA 1)

 

 

BTW, you can drag channels onto some of those graphic panels as well (so to change EngineRPM to show EngineSpeed).

 

Click on the graph to locate the data cursor (the value list on the right will show all the channels at that point in time). You can use the up and down arrow keys on your keyboard (or the scroll wheel on your mouse) to zoom in and out on the data. A short cut to zoom out to everything is "F2".

I

 

 

 

 

 

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I am a little confused why the mapper said to run them at oem pressure as opposed to Siemens 3 bar ? I taught it was do to my power levels , oem pressure is sufficient for bpu

 

Have you confirmed what the OEM pressure is, its prob around 3Bar :D

 

What are you calling a little rich at idle?

 

When cold it will run rich, as things warm up it can be leaned off and should idle nicely at around 14.7 to 15.0, this is for straight petrol, when you start adding meth etc the AFRs could be affected.

 

FWIW I still run stock reg, so stock pressures on my single with 650cc drop-ins with fuel pulsation dampener stock lines and a single Bosch 044 pump in tank :search:

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Just listen to your mapper, sounds like he's on the right lines. You really shouldn't need to tamper with fuel pressure settings on a BPU.

 

If it's a bit rich on idle then get him to adjust your cold start and fuel map. Just remember that as weather gets colder/warmer it will always throw the tune off a bit

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Have you confirmed what the OEM pressure is, its prob around 3Bar :D

 

What are you calling a little rich at idle?

 

When cold it will run rich, as things warm up it can be leaned off and should idle nicely at around 14.7 to 15.0, this is for straight petrol, when you start adding meth etc the AFRs could be affected.

 

FWIW I still run stock reg, so stock pressures on my single with 650cc drop-ins with fuel pulsation dampener stock lines and a single Bosch 044 pump in tank :search:

 

Spot on Wez , I think some of those rich readings are from cold , I am just doing some analysis on the data the last few days , just getting up to speed what I am looking at

 

I ordered up the Bosch unit , should be a reliable

 

I might put the OEM pulsation damper back in

 

I have the OEM readings in the thread, top end is 2.8 bar :)

 

Toyota GTE Service Specs...

 

Fuel Pressure at Idle w/vacuum hose disconnected is 33-40psi (2.3 - 2.8 kgf/cm)

 

Fuel Pressure at Idle w/vacuum hose connected is 24-31psi (1.7 - 2.2 kgf/cm)

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Off Topic , Chris do you know Ian Anderson ? , chief mechanic ’79 Williams F1 working in the prototype department developing semi-automatic gearbox

 

http://www.racecar-engineering.com/technology-explained/formula-1-sequential-gearboxes/#

 

No, sorry, heard his name many times, never knowingly met him. I think he worked on the Metro 6R4 rally car project, didn't he?

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  • 2 weeks later...

Just for anybody else who wants to install one

 

To fit the Reg,

 

***Buy /Borrow a Circlip pliers with the ability to fit them Internal

Remove the two E-Clips from the Adapter ,

Oil regulator seals,

Insert the Regulator until it clicks into place,

You only need to refit the retaining e-clip but you can fit the second clip , incase you ever needed it again

 

Still between two minds to remove the M14 IN male fittings ,they are on there tight, not too keen on using a vice to hold it !! the OUT fitting is cast in there , cylinder runs though it , I think you will damage it trying to remove the OUT fitting

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