Do I need an AFPR?

[Meiser]

Hi everyone,

I have an enquiry that I hope you can help me with. Basically, do I need an AFPR or will the stock one be more than sufficient?

I have an early 1UZ-FE and I am in the middle of fitting a Ford M112, along with 300cc injectors (up from 250cc), a water/methanol system and a Walbro GSS340 fuel pump. I will be running the M112 at approximately 9 PSI boost.

As this is all going in a MKIV Supra, I still have the stock NA Supra fuel control ECU in place, it's working fine, and I will be running my stock Soarer ECU too.

At the moment, the stock FPR is still on the fuel rail and I have an AEM AFPR fitted in the engine bay, but not connected to anything just yet.

I'm not chasing big power, I just don't want to run lean or far too rich.

Any advice would be greatly appreciated.

Thanks!

 

[dweinhart]

I would recommend this 0-30 PSI adjustable FMU | eBay
It is an adjustable rising rate FPR so you can adjust it from 1:1 all the way to 1:30. In theory, your 300cc should fine with a 1:1 and meth injection but the added safety and tuneability of an adjustable rising rate FPR/FMU coupled with a wide band will make tuning SOO much easier if you aren't running a piggyback or standalone

 

[dweinhart]

I would recommend this 0-30 PSI adjustable FMU | eBay
It is an adjustable rising rate FPR so you can adjust it from 1:1 all the way to 1:30. In theory, your 300cc should fine with a 1:1 and meth injection but the added safety and tuneability of an adjustable rising rate FPR/FMU coupled with a wide band will make tuning SOO much easier if you aren't running a piggyback or standalone

I am aware you have a FPR but unless it is a rising rate and you have the ability to change the rate at which it rises it will be difficult to keep the AFRs where you want them all across the board

 

[Meiser]

Thanks for the reply!

So, just to make sure that I'm on thr right track, remove the stock FPR and use an AFPR? I have this one with a gauge:

https://www.aemelectronics.com/products/fuel-delivery/adjustable-fuel-pressure-regulators/universal-adjustable-fuel-pressure-regulator

Will do the job?

 

[dweinhart]

Thanks for the reply!

So, just to make sure that I'm on thr right track, remove the stock FPR and use an AFPR? I have this one with a gauge:

https://www.aemelectronics.com/products/fuel-delivery/adjustable-fuel-pressure-regulators/universal-adjustable-fuel-pressure-regulator

A rising rate actually changes the psi as your boost increases. The one in this link does not have a vacuum feeding it so it could not increase your psi per lbs of boost. Ex . You adjust your FPR for extra 20psi over your stock 43.5 for a static psi of 63.5 at all boost levels. This will be rich at one boost level and lean at another. A rising rate or FMU like the one I suggested increase psi as your boost increases. Example : at 5:1 for ever pound of boost your fuel pressure increases by 5 (25psi fuel increase for 5lbs boost).The one I suggested lets you actually choose the rate of of increase from 1:1 all the way to 30:1. Most FMUs do not have this option without purchasing extra calibration disks