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rizalhoo
01-16-2004, 08:04 PM
Hello,

I got a question for those who got a boost controller and raising the boost level higher than the stock level, do you need a fuel pump such as the walbro 255 fuel pump?

I mean is it true that we need that so let say if I got like boost set at 20-21psi?


Quote from lancershop's description on the fuel pump

"...If you are running higher then factory boost a fuel pump is a MUST to prevent detonation..."

By the way whats a detonation? :oops: sorry for asking :oops:

NRG
01-16-2004, 08:38 PM
20 to 21psi, i think a fuel pump is not needed......after 24-25 is where you will start to need it.......Not to mention a fuel cut defender........

rizalhoo
01-16-2004, 08:46 PM
Anyhow what does the fuel pump do by the way? I mean what is the job of a fuel pump?

NRG: so 20-21psi is safe without fuelpump eh bro?

anyone ? thanks a lot in advance.

gt40
01-16-2004, 10:48 PM
From: Wrenching with Rob--Chemical Soup: The Mystery of Detonation
By Dr. Robin Tuluie, Ph.D.

http://www.motorcycle.com/mo/mcrob/rt-fuel2.html


Detonation is the result of an amplification of pressure waves, such as sound waves, occurring during the combustion process when the piston is near top dead center (TDC). The actual "knocking" or "ringing" sound of detonation is due to these pressure waves pounding against the insides of the combustion chamber and the piston top, and is not due to 'colliding flame fronts' or 'flame fronts hitting the piston or combustion chamber walls.' ... Detonation is commonly referred to as "knock," and is a very serious and detrimental problem that results in high shock loading of the piston, rod, crankshaft and bearings. It is quite destructive.

The above is a reasonably clear explanation.

BTW, When first put the big turbo on, I ran 1.6 bar on the stock fuel pump and injectors. Even with the fuel cut defender i ran out a few times on long uphill boost etc...

Put a bigger pump on if you plan on doing anything significant. Next will be bigger injectors when you get to 23 + psi and some tuning...

Hope that helps

rizalhoo
01-17-2004, 12:43 AM
wow! thanks for explaining the detonation thing up to me gt40 :)

anyhow i have no idea whether I need to get the fuel pump or not but for sure for now my target is gonna make my car like touching 300+whp and very soon making an attempt to do so and also thinking of running like 20-21 psi or most maybe 22 but I heard thats really not a good and healthy idea for the car and the turbo especially....so I need advices and suggestion whether to go for the fuel pump or not with my plan above :D

Thanks a lot :P

rizalhoo
01-17-2004, 12:44 AM
sorry but 1.6bar is how many psi?

gt40
01-17-2004, 02:15 AM
14.57 psi= 1 bar so 1.6 bar is 1.6x 14.57=23.32 psi...

rizalhoo
01-17-2004, 02:20 AM
gt40: Thanks a lot man! That gives me a clearer idea on should I get the fuel pump now or it can wait...so since you are running like 23.32psi and putting like 400+hp(is that right? sorry if im wrong bro) with the stock fuel pump and fuel injector then I think the pump n injector can wait then :)

rizalhoo
01-17-2004, 02:24 AM
one other thing, so when replacing the stock fuel pump with an aftermarket fuel pump, then I have to get a fuel injector too? or the fuel injector can wait?

fourg63_gst
01-17-2004, 03:06 AM
Fuel injector can suerly wait.

Coolguy949
01-17-2004, 09:37 AM
That quote fails to mentions the key point about knock/detonation. Knock is when there is pre-ignition. The piston has reached TDC (top dead center) position but the crank hasnt fully turned over past it. The combustion either occurs when the crank is exactly at TDC or slightly before (cause the pressure to want to push the crank backwards). Too severe knock and you can literally have the rod pushed into the piston head.

Rob

Coolguy949
01-17-2004, 09:39 AM
one other thing, so when replacing the stock fuel pump with an aftermarket fuel pump, then I have to get a fuel injector too? or the fuel injector can wait?

At 19psi, the stock injectors (560CC) are already at around 97 - 98% capacity. There's not much room to turn up the boost before you start fuel cutting. You can get a lot more power out of the stock turbo just by adding 660CC injectors.

rizalhoo
01-17-2004, 10:29 AM
Rob so you are saying that I should get the fuel injector when im running like 20-21psi? do I need the fuel pump too? or fuel pump can wait?

Coolguy949
01-17-2004, 10:35 AM
you'll know when your fuel injectors are starving if you start hitting fuel cut. You'll also notice that you will hit fuel cut easier at night because the air density is higher and the injectors cant match the fuel because they are already maxed out.

rizalhoo
01-17-2004, 10:45 AM
is it possible to get just the fuel pump w/o the fuel injector and prevent from hitting the fuel cut?

coz i dont really have enough cash for the fuel injector....dont even ask about the money for labor :oops:

Coolguy949
01-17-2004, 10:49 AM
possibly. I dont know if RRE flow tested the stock fuel pump, but yeah, it might raise the bar a bit if the fuel pump is dying off due to other factors.

Fuel pump is easy to install from what i hear, and they are around $100. I think I have them in stock if you need one.

Injectors arent that expensive if you sell your stock inkectors. Many DSM owners want 550CC injectors for their 16G turbos. The Stock 560CC injectors can easily be sold in the low $300's. You;ll be spending about $100 - $125 on your new injectors this way.

Dr. Evo
01-18-2004, 07:15 PM
That is a beautiful idea!! God I didn't even think of selling my stock injectors to DSM'ers! :D

robi
01-18-2004, 08:50 PM
I did my pump in 15 minutes first time Prob only take ten from now on.

OT Coolguy I need som 264's have any in stock???
Check your PM's @ evom.net reg... brakes let.s make it a package deal...