Smogrunner

iTrader: (5)

This thread is intended to provide a coherent guide to upgrading your fuel system as your modifications on your Evo go from mild to wild. When this thread is "finished," we'll clean it up and make decisions to rank competing approaches.

The single most amazing aspect of the Evo is how robust the system is to begin with. Most owners will never need more than a simple Walbro 255lph pump to meet their needs of up to 375+whp. Others will go to 525whp with just a Walbro and a set of bigger injectors. Pretty amazing.

If you would like to contribute to one of these stages, please copy the format I provided by quoting me, then remove the quote brackets, and edit what I, or others, have written.

One option that I am completely leaving out is methanol injection. Feel free to add a section on that if you want.

Here are some helpful links:
RC Engineering - good fuel injector worksheet and have tested many of the fuel pumps discussed in this thread.

Road Race Engineering tech pages: this one explains how important voltage is and explains how wire your pump to get a bit more voltage to it. This one compares different fuel pump flow rates, including the seldom used Denso Supra TT pump.

This website, Stealth 316, goes into incredible detail about a wide variety of in-tank fuel pumps and uses all kinds of objective data to support fuel pump choices.

ImportEvolution is a great company that claims they are about to become an official EvoM vendor. They feature lots more do-it-yourself parts than any vendor I could find on Evom. If there IS a vendor on Evom with as good or better selection of fuel-related parts, let me know and I will change this link to them. This is where I got my external Walbro and they shipped the next day. Very fast.

Aeromotive's website has a lot of good technical information to go along with pumps, and FPRs.

Smogrunner

iTrader: (5)

Upgrade #1: Walbro 342 in-tank 255lph fuel pump.



When is this recommended: As soon as you upgrade to a full 3 inch exhaust, add some sort of boost controller, and get a more aggressive tune via reflash or piggyback EMS device. At this point, it isn't absolutely necessary but most vendors/tuners recommend it here because it is so affordable and provides added headroom to your fuel system.

When is it a necessity: According to vendor/tuners on Evom, when you have parts listed above and add aftermarket camshaft/s.

Price: Around $100 bucks

Don't forget: you might want to make sure it comes with the little filter, which might add $10 to your order.

Where to buy: This is just my opinion, but please buy from Vendors on Evom that actually wrench on/tune Evos. AMS, Buschur, Gruppe-S, etc. Their financial health benefits us all.

Fuel system is safe with only this upgrade until?: On a typical dynojet, at about 385whp. On a properly calibrated DynoDynamics at about 345whp. At this point, it is time to add bigger fuel injectors.

More expensive alternative: Denso 1020 Supra Twin Turbo OEM fuel pump. It costs about $200 with the filter "tea bag" and has been tested to flow a bit more than the Walbro at 14 volts.

evo_08

iTrader: (1)

i have ams twinpump and so far so good

Smogrunner

iTrader: (5)

Upgrade #2:Larger capacity fuel injectors



When is this recommended:
1.) If you have one of those stock turboed monsters running 11sec/116+ 1/4 mile times, bigger injectors may be a good idea, although folks have gone as fast as 119+ in the 1/4 with the stock ones.
2.) If you have a highly tuned Evo with a modified stock turbo (White Rabbit, 20G-9) that is making over 380whp dynojet/340whp DynoDynamics. 3.)
3.) If you have done ANY full turbo upgrade (Garrett 30R on up).

Which injectors? Bigger isn't better! Go with the smallest capacity that you can absolutely rely upon to handle the power your car will make with its power upgrades.

Stock ECU: Use Denso 660cc or equivalent 680cc, or 720cc for stock, modified stock, GT3071 and 50trim turbos. Using the smallest effective injector will result in less adjustments being necessary to accomodate them and your stock ECU will be better able to make short and long term fuel trim adjusments that are easily within its adjustment range. With the stock ECU, it is rare that you can get anything bigger than 880cc injectors to work effectively.

AEM EMS: This EMS requires somewhat larger injectors due to less efficient injector drivers. (do a search for Evom Guru Ted B for more info on this). Since folks using this system may need to go with 880cc, 1000cc, or larger. This isn't a problem when using the Speed Density approach to metering air and fuel mixtures.

Price: Around $400 bucks

Don't forget: If you buy used injectors, it is a very good ideas to replace the rubber seals.

Where to buy: This is just my opinion, but please buy from Vendors on Evom that actually wrench on/tune Evos. AMS, Buschur, Gruppe-S, etc. Their financial health benefits us all.

Fuel system is safe with only this (and #1) upgrade until?: Assuming you have purchased the proper injectors, your fuel system is capable with these and the Walbro 255 to safely make between 520 to 550whp.

Note: After this it gets interesting...

Smogrunner

iTrader: (5)

Upgrade #3: The 525 to 550whp problem: Recommendations needed

Fuel rails are around $160


This FPR is good to 700whp and is $153


These cheap little $20 gauges bolt right up to your rail or FPR.


Bosch relay - couple of bucks


10 gauge wire - $10 bucks.


This upgrade should be geared for the MANY Evo owners with turbo upgrades that keep things relatively safe and sane (around 525 to 550whp max), but don't want to completely overhaul their fuel system.

Options:
1.) Rewire Walbro to run 14+ volts. This isn't really that effective on Evo's because they already see pretty good voltage at the pump. Our stock fuel pumps run at ~13.4 volts under load, this slight increase to 14 volts should yield about 5% more fuel delivery at most. Cost: about $20

2.) Buy the OEM Denso Supra TT pump to begin with and run the 14+ volt wiring. Depending on who you believe, this should be good for 10% more fuel than the Walbro at stock voltage.

3.) Add aftermarket fuel rail, fuel pressure regulator, fuel pressure gauge, and supporting under-hood fuel lines and fittings. Cost: about $380.

4.) ?

Vendors, gurus, etc. Please help here.

Smogrunner

iTrader: (5)

Upgrade #4: The 550 to 625whp problem: Recommendations/editing needed

This upgrade should be geared for Evo owners like me with large turbo upgrades and built 2.0 to 2.4 motors that want to push their big 30R, 35R or equivalent turbos at or close to their maximum output without going completely full monty.

Options based on cost:
1.) Take what you have done in steps 1-3 and just add an inline external walbro for $116


$10 dollar install kit:


2.) Modify your sending unit and install a single big external fuel pump like the Aeromotive A1000 or a Weldon unit. Includes an external filter, lots of fuel line, FPR, rail, gauge, etc.

3.) Break down and buy a complete big dollar fuel system like the Buschur one or the AMS one for $1400 and be done with it.

Vendors, Gurus, etc. Please help here.[/QUOTE]

Smogrunner

iTrader: (5)

Upgrade #5: The 625+whp system: Recommendations/editing needed

This upgrade should be geared for Evo owners with 35R and larger turbo upgrades and built 2.0 to 2.4 motors that want to push their cars "all the way." These are the big boys running their 35Rs to their absolute max, 37Rs, and 40Rs (or equivalent turbos).

First, you might get to 600whp (I'm trying) on the stock ECU, but not much further, this is standalone EMS territory - meaning you are looking at REALLY big injectors well over 1000cc and highly modified fuel systems. In addition to most of the stock fuel components being overtaxed, many other stock systems are completely taxed out: ignition, stock MAF, valvetrain, etc.

1.) Modify your sending unit and install a single big external fuel pump like the Aeromotive Eliminator, A1000, or a Weldon unit. Includes an external filter, lots of fuel line, FPR, rail, gauge, etc.

2.) Break down and buy a complete big dollar fuel system like the Buschur one or the AMS one for $1400 and be done with it: http://www.amsperformance.com/store/...roducts_id=148


Vendors, Gurus, etc. Please help here.

CO_VR4

iTrader: (83)

Here are some fuel system basics to assist in understanding the choices for upgrading and why upgrades become necessary:

1. Stock fuel pumps provide enough for perhaps 20% higher HP before they're marginal, and should be replaced.

2. With replacement (upgraded) fuel pumps, you get what you pay for. Walbros are not stock OEM quality fuel pumps. Why is that important? Because manufacturers of stock OEM quality pumps have to build them to last at least the warranty period. Denso and Bosch pumps ARE OEM pumps. The Denso 1020 is the Supra T.T. stock OEM pump, and outflows the Walbro, as well as being much quieter. I've never heard of a Denso 1020 pump failing; in contrast, Walbros fail regularly. The Bosch 044 inline pump is another high quality factory Porsche Turbo pump. Both flow substantially more than a Walbro, are quieter, and more reliable. They cost more than a Walbro, too, but you usually only have to buy them once. Concelli used to sell the Supra pumps for about $175. I've found them on E-Bay for that amount recently. The Bosch 044 inline pumps cost about $225-240, depending on where you find them. (Both of these pumps flow substantially more than the Walbros, and they can be used by themselves or together in a dual pump system if you want more reliable parts.)

3. With any replacement fuel pump, wiring to allow increased or constant voltage means increased pumping capacity. Why would you pay a significant amount of money for an upgraded pump and not give it the current it needs to perform? Rewiring is cheap in terms of performance gains. Under bigger load, the issues with lack of current make both factory and aftermarket pumps underperform. Rewire and get the stability and performance the pump is capable of. Make sure you read enough to know how to wire it safely, and use a relay to do it right.

4. Increased boost must be matched by increased fuel pressure in order for your injectors to spray the same amount of fuel that your ECU is calculating. In other words, the boost pressure in the manifold must be overcome by the pressure in the fuel injector in order for anything to come out. The higher the boost, the greater the manifold pressure the injectors must overcome. The fuel pump must be capable of delivering the amount of fuel your engine demands at the pressure that is necessary to compensate for the boost you're running. If your base pressure is 42 lbs. for example, and you run 20 lbs of boost, your pump needs to provide 62 lbs of pressure to "break even" and flow the fuel that your ECU is using for its computations. Make sure the pump you buy is rated for the flow you need at the pressure you're going to need it. See No. 5.

5. Fuel pumps pump LESS than their maximum flow as the pressure increases. You can have very high fuel pressure and VERY LOW flow at the far end of the boost curve. Run lean, buy a new motor. That's why it's useful to know what your fuel system is capable of flowing at the pressures you're going to run. That includes both fuel PRESSURE and fuel VOLUME.

6. Fuel lines from the pump to the rail are often a volume bottleneck. Too small ----> not enough volume of fuel. With high HP motors, go to an AN-6, AN-8, or AN-10 line from the pump to the rail, and the next size down for the return line.

7. Once you know your fuel lines are adequate for the fuel VOLUME your engine will demand, then install an electric fuel pressure gauge and you'll be able to monitor whether your fuel pressure is rising at a 1:1 ratio with your boost. If you have Defi BF gauges, the controller also has a mode where it will compare the two. That's cool! Now you know exactly what the fuel is doing compared to the boost... Fuel pressure gauges under the hood are used for setting and examining your base fuel pressure, but they are quite difficult to read while you're driving

8. Upgraded (in volume) fuel rails and Adjustable Fuel Pressure Regulators are recommended if you're making sure your fuel system is adequate for your engine's needs. As for the AFPR, see No. 4 above. While factory FPRs may suffice, why would you save $150 and risk your engine? Rails can be a limitation, too, and can also exacerbate fuel pulsing when you're using high volume fuel injectors. Bigger internal rail volume and cutting out the flow restrictions of the factory fittings are other (+) factors in replacing the rail. Not just the bling here, guys. Most of the major EVO vendors offer these parts for sale. There are threads on this board about various fuel rails, for example, and their pros and cons. Find the one that suits your needs the best -- they're all within $50 or so of each other.

8. Single pump systems can fail. If they do, your car stops running because it has no fuel, hopefully before your engine is damaged. Dual pump systems can fail, too. If only one pump fails, and the other keeps pumping, your motor can keep running. If you're not in it, you may be OK. If you are, the continuing fuel supply may cause you to run lean. That's not good.

Several vendors offer upgraded (and dual) pump systems. You can buy the parts themselves cheaper than their systems, but only if you (1) know what you need, and (2) want to take the time to shop around for the best prices on the parts. Summit, Jegs, and other major race parts vendors have most or all of the fuel line parts. Magnus has a huge fuel rail, anodized for methanol use. AMS offers their own rail. You get the idea -- pick and choose and you can select higher grade pumps and not spend as much, if you want to take the time to do so and you have the technical background to make sure you're getting what you need. Otherwise, rely on the shops that have done the testing and put together their own solution.

Ted B

iTrader: (6)

IIRC, Denso injectors are a pintle type (someone verify this pls, as my memory may not be correct), and are not what I would recommend for a high hp applications

A ball-type injector (e.g. Delphi) gives:

- Quicker response time (better idle quality with a large injector)
- Has typically 10X less moving mass (lasts longer
- Provides superior performance at high duty rates.

spyke

Is there a big external fuel pump that will supply 600whp and is as quiet as a walbro? Currently I have a bosch 044 and it is way too loud IMHO!

thanks
sven

CO_VR4

iTrader: (83)

Did you direct mount the Bosch 044 or did you use some isolation in the mounts, like rubber or similar? Is it the sound or vibration that you're hearing?

spyke

Hi,
it is the sound and it is mounted unter the car

sven

evo_08

iTrader: (1)

bg mighty sumo

CO_VR4

iTrader: (83)

Did you mount direct to the frame of the car or use isolation between the mount and the car? The Bosch 044 is a very good pump, and you should be able to tinker with the mounting method to minimize the noise that is conducted into the cabin of the car.

Spec'd

iTrader: (16)

Good post.

I think I'll bookmark it for a while.




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