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Any benefit to new fuel pump w/ stock ECU

Old Mar 26, 2008 | 09:56 PM
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Any benefit to new fuel pump w/ stock ECU

Hi all-

My local rotary mechanic has recommended that I install an upgraded fuel pump to protect my engine - I usually run around 11 psi. I'm currently running the stock ECU. I primarily use the car for track days and autocross - it is not a daily driver. When I do drive it, I drive it hard. Do you think there is any benefit to an upgraded pump with the stock ECU (I was planning on the Denso)? Any drawbacks?

Eventually I will probably install a PowerFC, but I don't want to cause problems with the fuel pump on the stock ECU.

Mods:
Downpipe
Catback
Intake
AVC-R
Upgraded radiator, oil coolers, AST

Thanks much.

Emissions can kiss my ***.

Last edited by SixSigma; Mar 26, 2008 at 10:03 PM.
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Old Mar 27, 2008 | 02:50 AM
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It's not going to hurt if you run an upgraded pump - although it's benefits aren't really obvious until you manipulate it. I never ran an upgraded pump without other mods but I would assume you'll still get added line pressure from it. What the injectors will flow as a result I don't know. I'll bet Mahjik can help though.
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Old Mar 27, 2008 | 09:06 AM
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My daily driver has similar mods w/ the stock ecu and a Walbro and I haven't run into any problems, but I won't boost past 10 PSI until I get a PFC, old age should be the end of my engine, not boost creep.
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Old Mar 27, 2008 | 09:10 AM
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For the most part, it won't make a difference. When it can make a difference is when the fuel pump is too strong for the stock fuel pressure regulator. I don't believe the one you are looking at would fall into that category.

It will be a benefit when/if you upgrade your ECU and start boosting over stock levels.
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Old Mar 27, 2008 | 09:14 AM
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Yep. No benefit from a pump upgrade with what you have.
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Old Mar 27, 2008 | 01:55 PM
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other than a piece of mind that one is gonna flow more lph WHEN YOU NEED IT to. That means going over factory boost levels. I think it's a good investment regardless of ECU choice.

I keep refering people to this link.

http://www.stealth316.com/2-fuelpumpguide.htm

A worthwhile read.
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Old Mar 27, 2008 | 03:44 PM
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The stock pump is reliable to at least 300 rwhp. Since he isn't anywhere near that, his stock pump is plenty for his needs.
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Old Mar 27, 2008 | 06:10 PM
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At this point if I were you all I would do is rewire the stock pump for a consistent voltage read up about it
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Old Mar 28, 2008 | 02:51 AM
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Originally Posted by Mahjik
For the most part, it won't make a difference. When it can make a difference is when the fuel pump is too strong for the stock fuel pressure regulator. I don't believe the one you are looking at would fall into that category.

It will be a benefit when/if you upgrade your ECU and start boosting over stock levels.
eyy...im pretty much runnin the same mods he is what if i were to get the fuel pump n raise my boost to around 12 psi? im talkin on the stock ecu here...
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Old Mar 28, 2008 | 11:26 AM
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Originally Posted by ahad
eyy...im pretty much runnin the same mods he is what if i were to get the fuel pump n raise my boost to around 12 psi? im talkin on the stock ecu here...
Won't change anything as your FPR is still 1:1. The only way to increase more fuel in that situation would be to get a Rising Rate Fuel Pressure Regulator which could supply more fuel a the same boost level.
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Old Mar 28, 2008 | 12:25 PM
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yeah i kinda forgot to mention that but yeah im also gonna be gettin the fpr....my question was more towards whether its safe on the stock ecu n stuff...cuz a lot o ppl have freaked me out that going over 10psi on stock ecu is extremely risky...jus wanted to knw my limitations..thanks!
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Old Mar 28, 2008 | 12:29 PM
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Originally Posted by ahad
yeah i kinda forgot to mention that but yeah im also gonna be gettin the fpr....my question was more towards whether its safe on the stock ecu n stuff...cuz a lot o ppl have freaked me out that going over 10psi on stock ecu is extremely risky...jus wanted to knw my limitations..thanks!
Yes, it's still risky.

Keep in mind that simply "getting the fpr" still doesn't do anything. There are 1:1 RPF's and 1:X FPR's which are RRFPR's. With a RRFPR you can say for each PSI of boost, go 1.5 PSI in fuel pressure or something like that. With a 1:1 like the stock unit, nothing can change.

You can tune AFR's that way and then you are basically only limited (fuel wise) by the amount of fuel your fuel pump can supply. However, you are still limited by the stock ECU programming which will also include fuel cut.

That is basically the "old school" way of doing things before programmable ECU's for the FD were available and cost effective.
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