E85 Fuel Setup

[s2d4]

If it's a circuitry fault then that applies to the twin pump set up too.

Now if it is an instant dead pump, then the reliability factor comes into play. Build quality and the level of wear if you are maxing out your pump. Are bosch 044's that unreliable? The stock pumps seem to last quite awhile and the specialised bosch motorsport line seems to be of better quality ?

What are the characteristics of the single pump on its way out that you would notice?

If a single pump dosn't switch on.... the car wont go- at all.

Depends how it fails... if you have one pump and it's on it's way out, you will notice it before you get into the top of the power curve.

J.

The two cases you saw, one of them is void since it was incorrectly set up. What was the other one?

I know of two well built (expensive) engines that have leaned out and gone boom using 2x 044's, because the failing pump was very hard to diagnose... One of the setups the failing pump locked up and started bleading fuel back from the high pressure side to the low pressure side... If you do go twin pumps, install a non return valve on the suction side of each pump.

Edited June 12, 2010 by s2d4

[180or200]

I had a std pump die gradually, only noticed when knock level's came up, also had a tomei and a 044 die, tomei would lean out when it was hot, 044 would lock up and give instant lean out (bang, key banger) luckily no damage, I figured in the case of the tomei and 044 I was over working them. Now I'm running 1 044 internal and 2 external, so far so good.

[XRATED]

If it's a circuitry fault then that applies to the twin pump set up too.

Now if it is an instant dead pump, then the reliability factor comes into play. Build quality and the level of wear if you are maxing out your pump. Are bosch 044's that unreliable? The stock pumps seem to last quite awhile and the specialised bosch motorsport line seems to be of better quality ?

What are the characteristics of the single pump on its way out that you would notice?

The two cases you saw, one of them is void since it was incorrectly set up. What was the other one?

By 'switching' I was refering to a second pump that is turned on at a preset parameter...

I have had 2 044's die for no apparent reason... There are alot of examples of them failing for various reasons... but not enough to be considered unreliable. High performance equipment isn't reliable as good oem generally- Bosch make good pumps for the money, but don't really compare to a weldon or fuel lab pump.

There are many many signs and symptoms of a faulty fuel pump. The bigest problem caused by a faulty fuel pump is leaning your engine out while under heavy load, wich may cause damage to your engine.

I had a std pump die gradually, only noticed when knock level's came up, also had a tomei and a 044 die, tomei would lean out when it was hot, 044 would lock up and give instant lean out (bang, key banger) luckily no damage, I figured in the case of the tomei and 044 I was over working them. Now I'm running 1 044 internal and 2 external, so far so good.

The other thing with large capacity fuel pump/s is the heat generated by circulating the fuel far to quickly... Large turbo combo's don't require alot of fuel untill they start to come onto boost... so you end up flowing a 1000hp worth of fuel constantly while driving around town using 0-400hp worth of fuel capacity... you end up warming the fuel and fuel pumps quite quickly.

180or200 I'm suprised you dont get some crazy heat issues using an 044 as a lift pump into a 3lt surge tank AND then 2 044's circulating around the rail. That's alot of juice going roundy roundy roundy. I'd also look at fitting a pair of these http://aeromotiveinc.com/products-page/acc...k-valve-orb-10/ to the suction side of your pumps to prevent backflow in the event of a failure.

At the end of the day there are plenty of big hp cars built by bigger workshops who use multiples of 044's as feed pumps... and mostly only in Aus? Most of the modified cars in the US and Europe use a single, large capacity fuel pumps.

Cheers

Justin

[s2d4]

Lol, my brain has been ticking all weekend. Interesting discussions indeed.

If a single pump dosn't switch on.... the car wont go- at all.

If it's a circuitry fault then that applies to the twin pump set up too.

By 'switching' I was refering to a second pump that is turned on at a preset parameter...

I am trying to established the difference between single and twins but this is kind of all over the place. As for the second pump turned on at a preset, that makes no sense as the second pump is there to eliminate surge so they are both on. I guess the top designs would be to shut the second pump off when its not in power range but doesn't seem to be necessary here.

The two cases you saw, one of them is void since it was incorrectly set up. What was the other one?

I have had 2 044's die for no apparent reason... There are alot of examples of them failing for various reasons... but not enough to be considered unreliable. High performance equipment isn't reliable as good oem generally- Bosch make good pumps for the money, but don't really compare to a weldon or fuel lab pump.

So what you are saying is that 044 is not as good as weldon or fuel lab pump. Thus the twin set up of 044 will not be as good as single set up of weldon or fuel lab pump.

btw, looking at the weldon inline pumps, as someone mentioned in the past. They do not cater to E85 so can not be used as a single external setup so not sure how you would push the inline so much in an e85 setup.

As for the in tank weldon pumps, they are all too big in size which require modification to factory tank or a gigantic surge tank, the smaller but still too big ones don't support enough (maxing out at 600hp/650hp) to eliminate surge, , massive dash fittings (one that can be chosen to safe guard fuel surge at 650hp, are -10 and above otherwise you are maxing out the pump and thus introduces reliabiity issues) which wouldn't work unless you use a reducer and thus reducing flow, this also means it won't work properly with any of the off the shelf fuel rail kits and costs of 700 USD +.

you didn't mention anything about the second twin 044 set up that failed?

What are the characteristics of the single pump on its way out that you would notice?

There are many many signs and symptoms of a faulty fuel pump. The bigest problem caused by a faulty fuel pump is leaning your engine out while under heavy load, wich may cause damage to your engine.

What I am trying to establish here is the difference with the single and twin if they are both set up correctly by taking care of precautions such as knock monitor/control in the ecu, wideband sensor, Fuel pressure drop ignition cut and check valves etc.

You've been saying that you wouldn't notice the single pump failure characteristics in a twin pump so the question was directed specifically at the single pump symptoms under the proposed setup. Please be specific here as the leaning out part is well established for both single and twins, under the possible failing types of scenarios mentioned previously.

More information is always good

Edited June 13, 2010 by s2d4

[rob82]

Bulkhead fittings will help, but the teflon hose isn't 100 at keeping the smell out... Teflon lined hose also has a very large bend radius compared to rubber, not to mention you need teflon/braided compatable end fittings... you cant use the regular rubber/braided fittings.

If your engine requires more fuel than one pump can supply and you run two pumps, then you run the risk of one pump not "switching on" or one pump failing... either way the other pump will support the flow rate right up untill the demand becomes to great (usually right near the top of your power curve) thus rail pressure drops and your AFR's head south very quickly.... this normally happens right around peak torque and nearly peak hp. You won't diagnose a shot fuel pump or notice the lack of fuel pressure untill it's to late.

I'd rather stop dead on the road/track and push the car off the road before I kill a 10/20k motor... easy to diagnose too.

I'd like you to explain why a correctly sized, inline, non return valve positioned at the low pressure/suction side of a pump is a "dumb idea"??? ... this is gonna be good.

AND why a ball valve??? is better...

Did you read the reason why you would put a non return valve on each pump running in paralell????

Cheers

Justin

First of all every twin pump setup I have done has switched the secondary pump, so it is imperative that there is a one way valve in front of the secondard pump so that the fuel system will even pressurize - so I fully understand the need for one way valves in fuel systems.

While putting a check valve on the suction side will work - it can however reduce the head at the input to the pump if the system is gravity fed from the surge tank. The problem also with larger pumps is the reduction in capillary action due to larger diameter intakes which means you need more head to aviod cavitation. So you really want minimal restriction before the pump.

Then there is also the electrical load issue of increased starting current due to the pump having to start with a pressuized fuel infront of the pump. May be enough to blow a fuse.

I've also never seen an OEM pump have a check valve on the suction side of the pump either.

[XRATED]

Lol, my brain has been ticking all weekend. Interesting discussions indeed.

Your all over the place like a mad womans s#it... ha ha ha

I am trying to established the difference between single and twins but this is kind of all over the place. As for the second pump turned on at a preset, that makes no sense as the second pump is there to eliminate surge so they are both on. I guess the top designs would be to shut the second pump off when its not in power range but doesn't seem to be necessary here.

At the end of the day the fuel rail and injectors dont know if there are 1 or 20 fuel pumps supplying the fuel- there is no difference if everything is working correctly.

You can set up a second pump in paralell that can be switched on when there is high demand and off when there is low demand.

"Surge" is a whole different thing... Fuel surge is when the fuel moves away from the fuel pump pickup and the pump starts sucking air rather than fuel, causing intermittant low pressure spikes at the fuel rail.

For a street car with a high flowing fuel pump set up, a "speed controller" is always recomended... it will slow down a pump/pumps when there is low demand then speed them up when the demand grows.

So what you are saying is that 044 is not as good as weldon or fuel lab pump. Thus the twin set up of 044 will not be as good as single set up of weldon or fuel lab pump.

An 044 is not as good as a more expensive weldon pump... not even close. but it's a 3rd of the price too.

btw, looking at the weldon inline pumps, as someone mentioned in the past. They do not cater to E85 so can not be used as a single external setup so not sure how you would push the inline so much in an e85 setup.

I provided the wrong link to the inline pump... I then gave the correct link in my next post.

As for the in tank weldon pumps, they are all too big in size which require modification to factory tank or a gigantic surge tank, the smaller but still too big ones don't support enough (maxing out at 600hp/650hp) to eliminate surge, , massive dash fittings (one that can be chosen to safe guard fuel surge at 650hp, are -10 and above otherwise you are maxing out the pump and thus introduces reliabiity issues) which wouldn't work unless you use a reducer and thus reducing flow, this also means it won't work properly with any of the off the shelf fuel rail kits and costs of 700 USD +.

....? your all over the place. None of the block weldon pumps are designed to be intank pumps... external use mostly. To maximise the pumps flow capacity you can use large fixtures and hose. Again "surge" has nothing to do with delivery and return lines.

you didn't mention anything about the second twin 044 set up that failed?

In both examples one pump died, while the other pump tried to keep up and couldn't supply enough fuel for the demand- resulting in a lean out.

What I am trying to establish here is the difference with the single and twin if they are both set up correctly by taking care of precautions such as knock monitor/control in the ecu, wideband sensor, Fuel pressure drop ignition cut and check valves etc.

You've been saying that you wouldn't notice the single pump failure characteristics in a twin pump so the question was directed specifically at the single pump symptoms under the proposed setup. Please be specific here as the leaning out part is well established for both single and twins, under the possible failing types of scenarios mentioned previously.

More information is always good

....? again I don't really know what your asking??

A single pump or 20 pumps set up correctly will all perform as required... exactily the same. Untill one breaks/fails. If you have one pump that fails you are more likely to diagnose/become aware of the failure well before you reach peak torque/hp.... multiple pumps will be harder to diagnose/recognise untill your reach peak torqu/hp- and by then it may be to late.

If you want me to give you the sign's and symptoms of a failing fuel pump, we will be here all night.

Here is my suggestion:

Get an under car surge tank arrangement. Use your stock intank pump as a feed pump. Plumb in a single fuel pump (choose one with a higher rated hp than you require) and wire it in with large guage wire and realy. Make shure you run a 40 mic filter before the fuel rail and a 100mic filter before the main feed pump.

The pump choice is entirly up to you. My preffrence is a single pump- but in my application it's the more expensive option... $1400 v's $750. Most people go for two pumps because it's cheaper.

Guages, alarms and AFR meter will all help you to recognise a lean out as it's happening.

Cheers

Justin

Edited June 13, 2010 by XRATED

[XRATED]

And like I said before... this is the internet... a public internet forum...

You really need to talk to a tuner/builder and ask them for advice... Who's going to tune the car? ask them...

Search through the forum and you'll find plenty of threads on fuel set ups.

J.

[s2d4]

I agree with you there. There are numerous fittings company that provide a special check valve specifically for bosch line of motorsport pumps and they all go on the feed side...

First of all every twin pump setup I have done has switched the secondary pump, so it is imperative that there is a one way valve in front of the secondard pump so that the fuel system will even pressurize - so I fully understand the need for one way valves in fuel systems.

While putting a check valve on the suction side will work - it can however reduce the head at the input to the pump if the system is gravity fed from the surge tank. The problem also with larger pumps is the reduction in capillary action due to larger diameter intakes which means you need more head to aviod cavitation. So you really want minimal restriction before the pump.

Then there is also the electrical load issue of increased starting current due to the pump having to start with a pressuized fuel infront of the pump. May be enough to blow a fuse.

I've also never seen an OEM pump have a check valve on the suction side of the pump either.

[s2d4]

So far you haven't answered the specific questions but rather start on something else that is already established or completely ignore the question to begin with. Your answers with regards to the evidence of what you've seen also vary from post to post without answering the actual question.

As for the weldon pumps, there are two inline pumps that are both e85 incompatible. The block mounted ones I did mistaken as the in tank set up, but the massive dash fittings requirement still stands which wouldn't work with any fuel rail kit out there without a reducer thus restricting flow, check valve on the suction side also restricts flow.. In addition the block mounted ones' orientation makes no sense for an under car design as the inline would be suitable. Last but not least, these are gigantic units which seems to rather inefficient for the weight and size.

And like I said before... this is the internet... a public internet forum...

You really need to talk to a tuner/builder and ask them for advice... Who's going to tune the car? ask them...

Search through the forum and you'll find plenty of threads on fuel set ups.

J.

Edited June 13, 2010 by s2d4

[Adriano]

How about an aeromotive pump, twin feeds for the rail(splitter then reducers)as most high hp rb's run. Are you satisfied with that.

IMO a wideband will not help, ive got one on my car, and it really is the last thing you are looking at under full throttle

[XRATED]

So far you haven't answered the specific questions but rather start on something else that is already established or completely ignore the question to begin with. Your answers with regards to the evidence of what you've seen also vary from post to post without answering the actual question.

As for the weldon pumps, there are two inline pumps that are both e85 incompatible. The block mounted ones I did mistaken as the in tank set up, but the massive dash fittings requirement still stands which wouldn't work with any fuel rail kit out there without a reducer thus restricting flow, check valve on the suction side also restricts flow.. In addition the block mounted ones' orientation makes no sense for an under car design as the inline would be suitable. Last but not least, these are gigantic units which seems to rather inefficient for the weight and size.

Please ask your question clearly then... What is your question?

My experience is by no means evidence.... In my experience- I have been involved with 2 twin pump set ups, where one pump failed and as a result the engine leaned out and damaged was the result.... I have also personally had an 044 sh@t out on me on two seperate ocassions- how dose that vary?

As i said before... I provided the wrong link to the inline pumps, in my next post I rectified the fault and provided the correct link- why are you still going on about it?

How could you possibly mistake a block Weldon pump as in tank? (I'm guessing you have had very limmited experience with fuel systems).

There are several weldon pumps with -8 in and out? these are by no means "huge"... Again as I said before, in order to maximise a pump's potential you can use a large feed line and return line- BUT YOU DONT HAVE TO..... JUST USE THE -8 IN AND OUT PUMP IF YOU WANT SMALLER LINES.

If you use the correctly sized check valve, it will not cause a noticable restriction- especially on the suction side/low pressure side of a pump.

Any threaded rail kit can be fitted with -8 fittings, or if going on a twin entry rail, just split the -8 line into 2x -6.

Turn the pump on it's side.... Daaaa... Who cares how big it is? If you don't like weldon buy somthing else? Whatever- How would you know how efficient the pump is? One weldon pump will take up the same or less space than 2x 044's... will do the same work as 2x 044's and last longer than 2x 044's How is than inefficient?

J.

Edited June 13, 2010 by XRATED

[JonnoHR31]

i think hes worries about some part of the fuel line or rail being smaller than the outlet of the pump and causing a restriction. have a look how small the standard steel lines on the car are, plenty of people flowing more fuel than you need through standard fuel lines. they wont be a problematic restriction and wont hurt the pump

[R31Nismoid]

Yer, plenty of people making 380-440rwkw through factory lines... They are not the worry point.

[180or200]

By 'switching' I was refering to a second pump that is turned on at a preset parameter...

I have had 2 044's die for no apparent reason... There are alot of examples of them failing for various reasons... but not enough to be considered unreliable. High performance equipment isn't reliable as good oem generally- Bosch make good pumps for the money, but don't really compare to a weldon or fuel lab pump.

There are many many signs and symptoms of a faulty fuel pump. The bigest problem caused by a faulty fuel pump is leaning your engine out while under heavy load, wich may cause damage to your engine.

The other thing with large capacity fuel pump/s is the heat generated by circulating the fuel far to quickly... Large turbo combo's don't require alot of fuel untill they start to come onto boost... so you end up flowing a 1000hp worth of fuel constantly while driving around town using 0-400hp worth of fuel capacity... you end up warming the fuel and fuel pumps quite quickly.

180or200 I'm suprised you dont get some crazy heat issues using an 044 as a lift pump into a 3lt surge tank AND then 2 044's circulating around the rail. That's alot of juice going roundy roundy roundy. I'd also look at fitting a pair of these http://aeromotiveinc.com/products-page/acc...k-valve-orb-10/ to the suction side of your pumps to prevent backflow in the event of a failure.

At the end of the day there are plenty of big hp cars built by bigger workshops who use multiples of 044's as feed pumps... and mostly only in Aus? Most of the modified cars in the US and Europe use a single, large capacity fuel pumps.

Cheers

Justin

doesnt seem to get hot running e85, will see what happens in summer, will fit a switch to turn one pump off if it becomes an issue!

as for a valve, whats wrong with the speedflow one's that I have fitted, works fine running one pump.

[XRATED]

Yeah the stock fuel lines are capable of flowing that volume of fuel... but they do create a restiction.

Especially with the extra volume needed for E85- I'd try and run larger lines. Large lines will reduce the fuel's velocity and reduce the required line pressure in order to maintain flow, also a larger return line will reduce back pressure and aid in re-circ or loop heating... You don't need to use braided lines either.

J.

[s2d4]

R31Nismoid and yourself are both right. There have been plenty of reports of the stock lines flowing enough to support those figures.

i think hes worries about some part of the fuel line or rail being smaller than the outlet of the pump and causing a restriction. have a look how small the standard steel lines on the car are, plenty of people flowing more fuel than you need through standard fuel lines. they wont be a problematic restriction and wont hurt the pump

[XRATED]

doesnt seem to get hot running e85, will see what happens in summer, will fit a switch to turn one pump off if it becomes an issue!

as for a valve, whats wrong with the speedflow one's that I have fitted, works fine running one pump.

If you start driving around town and the pumps start getting noisy... they're hot. also put your hand on the surge tank after an hr of slow driving. It seems to be alot of fuel movement... just my thoughts.

Personally I'd put them on the suction/low pressure side... but hey if it works.

The set up looks neat though.

Cheers

Justin

[s2d4]

You are right that I haven't had experience with the block pumps. But I think the size is a valid point as there is minimal space to place a big one outside of the car as suggested so it would have to be inside.

You've kind of just answered my concerns with the large dash fittings moving into small dash fittings. The 600hp-650hp ones are -8, anything over that goes up to -10 and -12. For the purpose of Flowing 660hp equivalent worth of 98 fuel due to e85, I wouldn't max out the 600hp-650hp range of pumps so I am left with either the -10 or -12 setup. Wouldn't perceived pressure at the outlet of the pump increase if the line is reduced down to -8 then distribute into 2x-6? You would have to pump harder (higher rate of wear and tear) to have the same flow through a small pipe so to speak if fluid mechanics is true. The manufacturer set those minimal requirements for obvious reasons? If the flow rating is based on the particular line size, the pressure increases when you reduce the line size and in this case, it is not actually flowing more so the flow rating would no longer be valid. You are effectively choking the pump so it would no longer run at its ratings. This principle applies to exhaust gases and the exhaust pipes since it will only flow as much as the smallest cross section area will allow, thus choking the turbos which results in the reduction of the turbo's efficiency.

As for the check valve placement, since the check valve would require a certain pressure before it'll open up, it'll place more restriction(higher ratio)on the low pressure side? On the high pressure side, say 3 bar (~44psi) would easily out flow the 0.5psi requirement for the check valves to open up?

I wanted to know what makes you so adamant that there would be a higher risk for twin pumps if precautions were taken care of so I would like to find out the cases. You mentioned one didn't use check valves so that's due to poor setup. I wanted to know under what conditions did the other one fail to figure out if its a set up fault or something else. But you never answered this question so no one knows how those fail at this stage. Did they use knock control/monitor? fuel pressure drop ignition cut? having the fuel pressure sensors/switches placed between the check valves and the pumps on the feed side?

Yeah the stock fuel lines are capable of flowing that volume of fuel... but they do create a restiction.

Especially with the extra volume needed for E85- I'd try and run larger lines. Large lines will reduce the fuel's velocity and reduce the required line pressure in order to maintain flow, also a larger return line will reduce back pressure and aid in re-circ or loop heating... You don't need to use braided lines either.

J.

Edited June 13, 2010 by s2d4

[s2d4]

The addition of 85% ethanol cools down the entire line as well as combustion due to its properties. Thus the heating effect will be dramatically less than for bp98.

If you start driving around town and the pumps start getting noisy... they're hot. also put your hand on the surge tank after an hr of slow driving. It seems to be alot of fuel movement... just my thoughts.

Personally I'd put them on the suction/low pressure side... but hey if it works.

The set up looks neat though.

Cheers

Justin

[XRATED]

You are right that I haven't had experience with the block pumps. But I think the size is a valid point as there is minimal space to place a big one outside of the car as suggested so it would have to be inside.

You've kind of just answered my concerns with the large dash fittings moving into small dash fittings. The 600hp-650hp ones are -8, anything over that goes up to -10 and -12. For the purpose of Flowing 660hp equivalent worth of 98 fuel due to e85, I wouldn't max out the 600hp-650hp range of pumps so I am left with either the -10 or -12 setup. Wouldn't perceived pressure at the outlet of the pump increase if the line is reduced down to -8 then distribute into 2x-6? You would have to pump harder (higher rate of wear and tear) to have the same flow through a small pipe so to speak if fluid mechanics is true. The manufacturer set those minimal requirements for obvious reasons? If the flow rating is based on the particular line size, the pressure increases when you reduce the line size and in this case, it is not actually flowing more so the flow rating would no longer be valid. You are effectively choking the pump so it would no longer run at its ratings. This principle applies to exhaust gases and the exhaust pipes since it will only flow as much as the smallest cross section area will allow, thus choking the turbos which results in the reduction of the turbo's efficiency.

As for the check valve placement, since the check valve would require a certain pressure before it'll open up, it'll place more restriction(higher ratio)on the low pressure side? On the high pressure side, say 3 bar (~44psi) would easily out flow the 0.5psi requirement for the check valves to open up?

I wanted to know what makes you so adamant that there would be a higher risk for twin pumps if precautions were taken care of so I would like to find out the cases. You mentioned one didn't use check valves so that's due to poor setup. I wanted to know under what conditions did the other one fail to figure out if its a set up fault or something else. But you never answered this question so no one knows how those fail at this stage. Did they use knock control/monitor? fuel pressure drop ignition cut? having the fuel pressure sensors/switches placed between the check valves and the pumps on the feed side?

Seriously, the phisical size is not an issue... if the weldon cant possibly fitt, then look at an aeromotive etc... i will garantee you can make a weldon fitt outside. http://www.weldonracing.com/product/16-6/D..._outlet%29.html is 8" long by 3.5" wide... how is that 'way to big' ??? an 044 is what- 7" by 2.5"???

There is no way your going to run out of flow with the above pump with 360rwkw on e85... the pump is rated at 700hp on methanol! and it has -8 in and out. So NO your not limmited to -10 or -12 choices....

If you necked down a -10 outlet on the outlet to -8 you would limmit the pumps full potential at a given pressure. But it is no different than running two smaller pumps of the same flow rate into the same -8 line... so what are you getting at? You might need to brush up a little on you 'fluid dynamics' too there little buddy..

If you choose the correct NRV there will be no issue with cracking pressure... for an application like this you would look for somthing with a .5-1 psi cracking pressure... hell most full bore NRV's dont even have a seat spring- thus 0 psi cracking pressure. Cracking pressure almost has no bearing on the restriction a NRV may create.... The suction side is low pressure and low velocity- the outlet side is high pressure high velosity... the same orriface under low pressure will flow more v's the under high pressure.

.... OK for the last time:

Example 1. On two occasions I've had a single 044 in a single pump configuration that has failed on be. Reason for pump failures are unknown.

Example 2. A High performance vehicle had two 044 pumps running in paralell as main feed pumps. One of the pumps failed and locked up. There were no NRV's fitted. The single remaining pump supported the engine to run at normal driving rpm. The vehicle was then driven aggressivly, leaned out and as a result the engine was damaged. Upon inspection of the fuel system, the faulty pump was found to be locked and also letting pressure bleed back through.

The vehicle was fitted with an accurate AFR guage with warning light and a fuel pressure guage with warning light. the engine was only held at peak load for a few seconds before it was damaged. Reason for pump failure is unknown

Example 3. A high performance vehicle has two 044 pumps running in paralell as main feed pumps. One pump failed. There were NRV's fitted. The single remaining pump supported the engine to run at normal driving rpm. The vehicle was then driven aggressivly, leaned out and as a result the engine was damaged. Upon inspection of the fuel system, the faulty pump was found to be weak/failing.

The damage was sustained over a relativly long period of time... 3 track days. The vehicle did not lean out untill right at peak hp at high speed. Lean AFR's and lowish fuel pressure at high speed was noticed by the driver however the condition could not be replicated on the dyno or from any other tests performed. It was difficlut to diagnose untill the whole fuel system was taken apart and tested. Reason for pump failure is unknown.

All set ups had correct filters in place, used correct fittings and correctly sized hose.

Any pump can break or fail... But you can limmit your exposure to failure by using less components.

I prefer to use one pump for a few reasons:

1. I don't need to save money on fuel system components

2. Less components= Less things to fail

3. Simpler to operate and controll

4. Easier to install and package

5. Less fittings and thus less points of failure/leaks

6. The one pump is of better quality than multiple cheaper pumps

7. Quicker to diagnose a problem with the fuel delivery

J.