quote Originally posted by ryan.hess: I believe that was the point... 3800SC = 58psi, NA engine = 45psi. The EP376 will support 325hp at 45psi, but only will flow 81% at 60psi what it does at 45psi. That means it supports 263hp. (actually I don't know, I'm using your numbers) The 376 puts out 188lbs/hr at 60psi. If someone knows of an AC delco that's QUIET, that flows 350-400lb/hr at 60psi, let me know...

Its easy to get lost in the all the math and ratings. That is one reason the consumer calls and says, " What works for you" .. "Sell it to me"... The rating is 207lbs per hour at 52PSI. This supports 325HP very 'safely'.

You dont look at 53-80PSI because you are not using it. Where do you get 58PSI for a 3800SC engine? Did you get that fuel pressure gauge and tape to the window and watch it under cruising and WOT conditions on a 3800SC? Did you just read it off someones website and assume this is the number a 3800SC engine gets to in a Grand Prix? Was it in a Fiero with a 3800SC? What fuel rails? What FPR? This all comes into play with testing and what works for one person, will not necessarily work for another when it comes to modified engines.

I can tell you that I have a stock fuel pump in my Grand Prix with the stock fuel rails. Its not hitting 58PSI under boost.

Loyde

quote Originally posted by Darth Fiero: On my buddy's lightly modded 99 Regal GSE L67, his fuel pressure at 10psi of boost is 58 psi, according to the gauge). Point here is the fuel pressure should hold steady under boost and should NOT drop off at higher RPMs. I have seen this happen on cars with failing or inadequate fuel punps.

I see.... Now, there is a problem here with the test instrument factor. This is really why I declined to tape a pressure gauge to the window and watch the readings to report to someone. Not one gauge is going to be the same unless it is a certified instrument. I can say that maybe my gauge is right to within + - 2 PSI... It really does not matter however. Its the same gauge I use every time I do a test. There are other readings that are important to support if the fuel system is right or wrong. Well, lets say in OBDII there is other supporting data that can be read to support AFR, KR, IPW, and MAF freq... that comes from the sensors that are calibrated to the OBDII code.

I should not say you are not going to use 53-58 actually. Saying this assumes everyones gauge would read the same, and this is not going to happen. It really goes back to, use a lot of data to determine your fuel system, performance, and overall, if you are happy with your install of your engine to your Fiero.

Loyde

[This message has been edited by FastFieros (edited 01-26-2006).]

Isnt the real question " Does a N/A engine require a different flow rate than a turbo or sc engine of the same cubic inch?
I won't think that the pump knows what it is connected to, of course not, but it should care (if it had feelings). What role does the fuel pressure regulator play in the equation? Does the N/A engine and the boosted engine have the same pressure setting. I would think that the pump is designed for a range of parameters.

Just asking

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quote Originally posted by ohio86se: Isnt the real question " Does a N/A engine require a different flow rate than a turbo or sc engine of the same cubic inch? I won't think that the pump knows what it is connected to, of course not, but it should care (if it had feelings). What role does the fuel pressure regulator play in the equation? Does the N/A engine and the boosted engine have the same pressure setting. I would think that the pump is designed for a range of parameters. Just asking

OK, I had to borrow this chart to answer this. Flow and PSI are going to cross at some point in the test. One goes up, the other goes down.

In most cases a naturally aspirated engine will have a B.S.F.C of .50. This means that the engine will use .50 lbs. of fuel per hour for each horsepower it produces. Turbocharged engines will want to be at .60 lbs. per hour or higher.

Now... we have to discuss these ratings on the injectors. GM rates different than the typical performance flow shop. Matter of fact, I have never really seen someone agree on what GM real rating formula is on injectors. Ryan is right to mention that 3800SC injectors are 36 lb, however, it is really 36.6, or 38 depending on who you ask. This was debated on CGP one time about when the 04 Series III was released because everyone was saying the new injectors in it were the 36 lb , and the S2 was 38. Then you have all this static flow differences based on what fluid you flow in an injector during a test. I asked KFI one time what chemical they used, and humm, I forgot.. it was not gasoline or alcohol however. You have to use something with the specific gravity very close to gasoline, but non-flameable..

OK, so now you can be really lost and read this website http://www.rceng.com/technical.htm .. it even has a calculator.

So, as you can see, it does not matter if… NA, SC, or Turbo is the factor… Only when doing the math. The injector does not know if it is in a 3800SC, 3800NA, LS1, or whatever.. The injector does not know it is getting 45PSI, or 52PSI. Its all about math, and then tuning the PCM, to the selection of parameters you come up with. Now the injector has PSI limits of function. There are several types of injectors. Disc, pintle, …. You can bind an injector up with to much pressure behind it. Then you have the atomatization being inconsistent with too low a pressure. Lots of variables to this stuff.

We did this at HalTech Racing. Call KFI. Order flowed and matched injectors based on HP and PSI/Flow of target pump. KFI supplies us also with the calibrated fuel pump, and regulator, all matched and flowed on the bench to work with XXX HP in mind… Install in race car and tune PCM with WideBand O2 AFR and adjust per race car performance. It takes an extremely talented driver to take a race car and make lap after lap of testing to keep a controlled and consistent test platform. I was the race car driver, and tuner. I carried a laptop inside my firesuit to collect the data.

Loyde

Ive read information on that site and here is a direct copy and past

"In most cases a naturally aspirated engine will have a B.S.F.C of .50. This means that the engine will use .50 lbs. of fuel per hour for each horsepower it produces. Turbocharged engines will want to be at .60 lbs. per hour or higher."

Can someone explain this statement?

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" DRIVE IT LIKE YOU LOVE IT"

quote Originally posted by ohio86se: Ive read information on that site and here is a direct copy and past "In most cases a naturally aspirated engine will have a B.S.F.C of .50. This means that the engine will use .50 lbs. of fuel per hour for each horsepower it produces. Turbocharged engines will want to be at .60 lbs. per hour or higher." Can someone explain this statement?

Well, B.S.F.C is brake specific fuel consumption - How much fuel you are using per horsepower per hour

Now you have to read this website http://www.web-cars.com/math/horsepower.html

You learn one area, you have to find out it time to read and learn another area.

We could get into wear of the engine, supercharger, the temperature, the humidity, and many other variables when talking about what goes into tuning a PCM to a fuel system.

Once again, people as consumers pick up the phone, email, or whatever someone that they trust is going to provide the correct calibrations and information. No one person knows everything right off the top of there head. You get a book, a website, and read, read, and read... Then you test, test, and test some more. Its alot of work.

Loyde

I as an average consumer don't have time or the resources to do a search to learn everything. We just rely on you and others like you who have already done the leg work and research many sources to get the answers.

I guess I like to simplify things. If the stock 3800sc pump would fit the Fiero fuel pump unit we would use it. If we were going to to mods to the stock 3800sc engine we would use the recommended pump for a modded engine along with other recommened changes to support the mods.

What pump can we purchase that will produce the same pressure and flow numbers as the stock 3800sc pump ?

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" DRIVE IT LIKE YOU LOVE IT"

[This message has been edited by ohio86se (edited 01-26-2006).]

quote Originally posted by ohio86se: I as an average consumer don't have time or the resources to do a search to learn everything. We just rely on you and others like you who have already done the leg work and research many sources to get the answers. I guess I like to simplify things. If the stock 3800sc pump would fit the Fiero fuel pump unit we would use it. If we were going to to mods to the stock 3800sc engine we would use the recommended pump for a modded engine along with other recommened changes to support the mods. What pump can we purchase that will produce the same pressure and flow numbers as the stock 3800sc pump ?

Well now, that is a very good question. I dont believe you will find any information from anyone on what the Grand Prix AC Delco pump flows. Even if you do find someone, then we have to decide if the test conditions were "right" enough to compare data.

My position with this...

KFI already flowed and tested 6 models of the EFI Walbro 255 pumps
Loyde buys brand new EP376 and sends to KFI for testing, gets and compares results. Posts results to website for others to have.
Loyde buys brand new Grand Prix OEM pump and sends to KFI for testing. (this was just done today) ... I was going to do it last week, but got side tracked on wiring harness work.

Now, back to the math however. It has already been agreed on that 207 lbs per hour will work for a 3800SC with stock injectors (based on 36-38lbs/hr) and 48-52PSI on the pump and fuel rails, supporting 325HP max.... Do you fall in this range? Buy EP376... its works. 330HP plus... buy Walbro 255...it will work without any problem. ... Dont want to worry or care what it sounds like inside the car... Buy Walbro period...

Loyde

quote Originally posted by FastFieros: Now, back to the math however. It has already been agreed on that 207 lbs per hour will work for a 3800SC with stock injectors (based on 36-38lbs/hr) and 48-52PSI on the pump and fuel rails, supporting 325HP max.... Do you fall in this range? Buy EP376... its works. 330HP plus... buy Walbro 255...it will work without any problem. ... Dont want to worry or care what it sounds like inside the car... Buy Walbro period... Loyde

Is the Walbro THAT loud that you can hear it inside the car with the engine running?

The testing results should prove to be interesting

As far as the noise factor. I really don't know about the kind of noise Im going to experience with using the TTA pump but I will be adding some sound deading panels between the fule tank and the hump just in case. Ive had noisy fuel pump before and I drove me crazy. Although I dont think Ill be able to hear the pump of the exhaust. There already should be like rubbery pad on top of the fiero tanks as is ...i think.

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[This message has been edited by ohio86se (edited 01-27-2006).]

quote Originally posted by 3800GMCC: Is the Walbro THAT loud that you can hear it inside the car with the engine running?

depends on how loud your engine is

i use a walbro and i don't believe it is any louder than stock

Is the walbro a plug and play pump or do you have to wire in a different connector?

quote Originally posted by 3800GMCC: Is the walbro a plug and play pump or do you have to wire in a different connector?

as long as your order the one for the fiero its plug and play

Who says you can not use the stock GM 3800SC fuel pump I have used one many times in my swaps, Out of 13 swaps in the last three years only four used walbro 255 pump the rest used stock 3800SC pump's. None have had problems and as far as noise goes the stock one is only slightly quiter. You can argue back and forth forever and still get no where, every one has an opinion and most will not change it no matter what they are told or shown. Do what you want I do not force my opinion on others I give advice if wanted if not so be it, I am also not trying to sell any thing so I do not feel the need to insult other things so people will buy what I sell or buy from me. Every swap I do is slightly different I give the decisions on what is to be done and what to buy to the owner of the car I am working on. Not every one can afford the top of the line fancy parts some just want a simple well built car with a nice strong safe swap. Dan

quote Originally posted by FIEROFLYER: Who says you can not use the stock GM 3800SC fuel pump I have used one many times in my swaps, Out of 13 swaps in the last three years only four used walbro 255 pump the rest used stock 3800SC pump's. None have had problems and as far as noise goes the stock one is only slightly quiter. You can argue back and forth forever and still get no where, every one has an opinion and most will not change it no matter what they are told or shown. Do what you want I do not force my opinion on others I give advice if wanted if not so be it, I am also not trying to sell any thing so I do not feel the need to insult other things so people will buy what I sell or buy from me. Every swap I do is slightly different I give the decisions on what is to be done and what to buy to the owner of the car I am working on. Not every one can afford the top of the line fancy parts some just want a simple well built car with a nice strong safe swap. Dan

I dont see in this thread anywhere that someone has indicated that the 3800SC Grand Prix fuel pump could not be used. I made mention that the Fiero V6 2.8 fuel pump should not, and I really will say, cannot, be used with a 3800SC. I have tried to use this 2.8 pump on a completely stock engine twice, and it just does not cut it at anything around 50% and above on throttle. The Grand Prix pump has the jet pump port. What did you do with this port? Just crimp the hose and leave it hanging? I had thought about it, but the pump is not cheap. The 2001 + is $300 at the dealer, then the 97-99 is $340.... It only comes in that pump casing according to my dealer. Walbro part numbers for the replacement of this OEM pump. Walbro 340 Fuel Pump - $125.00 from ZZPerformance.

Loyde

I dont think I would ever consider using the Fiero pump. It just doesn't seem reasonable that it could deliver the needed fuel for the additional cc's let alone being sc or turbo. So why not just use the pump that is called out for the 3800sc on ZZP site?

Sounds cut and dry to me.

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[This message has been edited by ohio86se (edited 01-28-2006).]

I have an update to the stock fuel pressure debate for 96-up 3800 Series II SC engines...

I have done some research to find bone stock fuel pressure specs for this engine which has also revealed that the answer was right under our noses the entire time. Printed on the stock fuel pressure regulator found on 96-up 3800 Series II Supercharged engines is the fuel pressure rating - 3.5bar. This is what the fuel pressure is supposed to be at with no vacuum or pressure being supplied to the vacuum port on the regulator. 3.5 bar is approx 50.7 psi. Fuel pressure is supposed to increase approx 1psi per 1psi of boost applied to the regulator. I also performed some real-world checks on my latest bone-stock L67 Fiero swap using a calibrated fuel pressure gauge:

No vac/pressure at vac port on regulator: approx 50 psi.
Normal idle vacuum at port on regulator: approx 45 psi.
WOT / 9psi boost at port on regulator: approx 59 psi.

Now, to find out exactly what volume of flow a given set of injectors can flow at different pressures, use the following formula:

new flow rate = old flow rate X square root of (new pressure / old pressure)

I had a set of bone stock L67 injectors flow tested. They flowed approx 34 lb/hr @ 43.5 psi @ 100% duty cycle. Here are the various flow rates for these same injectors at the pressures I supplied earlier:

45 psi = 34.6 lb/hr
50 psi = 36.5 lb/hr
59 psi = 39.6 lb/hr

-ryan

www.treperformance.com has walbro clones available for $70, I just ordered 2.