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Some supercharger ?'s

Old 11-13-2006, 09:23 AM
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Default Some supercharger ?'s

I am in the process of getting ready to do a centrifigul charger for my 500 efi. I have seen a couple of ways people do it...Namely the debate over keeping the recirc pump and not. I see that Vortec keeps it and procharger gets rid of it and installs a crossover...I did run across on e installed ( pro Charger ) ona 500 efi that they kept the recirc pump and he stated the owner of the rig that it ran great that way..... so what is the real deal here? Is it possible to keep it or what?

With that said I am going to install 50 lb injectors at the time of install. neither really says you need it but I would rather get rid of the 37lb stock injectors and go with the bigger ones and keep a from getting flow from merely upping the preassure....where can I get a deal on a set of 50 lb injectors for a 500 efi.


enlighten me........needing help.....

Bryan
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Old 11-13-2006, 10:13 AM
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Default Re: Some supercharger ?'s

The problem with using steady fuel pressure instead of raising it is you need really big injectors. For example,at .55 bsfc (about as lean as your going to run a sc motor) lets say you want to make 700 peak hp,you would need 60 lb injectors at 43 psi,80% cycle duty and .55bsfc. The problem with that is once you go past 62 lb injectors you will need a different computer to drive them as they are low impedance vs high impedance and mefi 3's and 4's won't drive them. A 50 lb injector will only support 580 hp at .55 bsfc,80 % duty cycle at 43 psi,probably short of what your trying to achieve. The next problem is lets say you set your fuel pressure to 60 psi all the time to make the smaller injectors work,your tuning guy is going to be pizzing around forever on the dyno trying to get the lower rpm ranges clean,it can be done though. Just some input to help you,Smitty
go to the posted link and you can substitute your numbers and hit calculate and see what size you will need,remember to use at least .55 bsfc for your calculations
http://www.rceng.com/technical.htm
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Old 11-13-2006, 01:03 PM
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Default Re: Some supercharger ?'s

Originally Posted by articfriends
The problem with using steady fuel pressure instead of raising it is you need really big injectors. For example,at .55 bsfc (about as lean as your going to run a sc motor) lets say you want to make 700 peak hp,you would need 60 lb injectors at 43 psi,80% cycle duty and .55bsfc. The problem with that is once you go past 62 lb injectors you will need a different computer to drive them as they are low impedance vs high impedance and mefi 3's and 4's won't drive them. A 50 lb injector will only support 580 hp at .55 bsfc,80 % duty cycle at 43 psi,probably short of what your trying to achieve. The next problem is lets say you set your fuel pressure to 60 psi all the time to make the smaller injectors work,your tuning guy is going to be pizzing around forever on the dyno trying to get the lower rpm ranges clean,it can be done though. Just some input to help you,Smitty
go to the posted link and you can substitute your numbers and hit calculate and see what size you will need,remember to use at least .55 bsfc for your calculations
http://www.rceng.com/technical.htm
Helps a little bit.......maybe just a bit more confused now. WHat are you running in your motor and did you install a crosover?

ATI is telling me I do not need to upgrade the injectors.....
I m trying to make 700 hp with an M-3 set up on a stock 500 efi......Make sense?
Bryan
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Old 11-13-2006, 06:28 PM
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Default Re: Some supercharger ?'s

Originally Posted by Bryan Rose
Helps a little bit.......maybe just a bit more confused now. WHat are you running in your motor and did you install a crosover?

ATI is telling me I do not need to upgrade the injectors.....
I m trying to make 700 hp with an M-3 set up on a stock 500 efi......Make sense?
Bryan
Bryan, if you actually have 37 lb injectors you will have a hard time reaching 700 hp unless the bsfc is fairly low,you will be better off with bigger injectors but you will still have to raise the fuel pressure under boost unless you get REAL big injectors.
As far as the crossover/thermostat housing,most blower motors do not use them so you can run lower temperatures which allows you to run more timing,boost and fuel. If you built a procharged motor but wanted it to run 160 you could but if it was tuned right you would make less power.I have read where Ford did block durability testing years ago and blocks that were ran too cold had accelerated cylinder wear but after 170 hours of running 100 degrees in my old 502 w/procharger on it there was no real measureable cylinder wear or ridge so I think it would be something you would need to worry about if you had plans of running a motor a few thousand hours,not a few hundred.
I'm currently running 63 lb injectors in my 540 at near 80 psi of fuel pressure at 80% duty cycle,I unfortunately don't know what my actual bsfc is because the dyno I used didn't have the correct plumbing for measuring it. The motor runs between 100 to 110 degrees most of the time with just a crossover and no t-stat. Make sure whoever does your programming lowers the setpoint to around 90 degrees or less for the cold enrichment or your motor will run in the warm up mode all the time,Smitty
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Old 11-13-2006, 07:38 PM
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Default Re: Some supercharger ?'s

Thanks for the info....so I guess 50 lb injectors would fit the bill? As far as recirc pump goes could I just run a 120 degree thermostat and get the same relative result? I want to do this as correct as possible givin the circumstances.... I will not be pulling the motor and will be re-flashing the ecm to get it as close as possible until next winter with the freshen up and dyno tuning ....I have friends running a 502 mag w/ an m3 and it runs great thus far installed a crossover and had the ECM done by Mark @ precision marine.


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Old 11-14-2006, 03:28 PM
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Default Re: Some supercharger ?'s

Just got off the phone with ATI..... For the 500 EFI kit they do not eliminate the recirc pump inany way.....just put a 120 degree thermostat in the stock system.....sounds strange huh........guess that answers my previous ? maybe. It is strange because on the 502 mag kit they send a crossover to replace it.


Typical in the marine industry i guess.

Bryan
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