TD05 on Ebay

vrg3 · Post by **vrg3** » Tue Feb 17, 2004 10:10 pm

Nico, dude, that can't be right. The stock fuel pump can't support 350hp.

The stock pump moves 150 liters per hour at 43.4 psi. That is, at 7.1 psi of boost. Under higher boost it will flow less. With the return line pinched to increase pressure more it'll flow even less. And you have to allow some fuel to return back through the return line; a typical bare minimum is 20%.

Let's make some generous guesses:

flow = 130 L/hr
usable flow = 120 L/hour * 80% = 104 L/hr
fuel density = 0.73 g/mL = 0.0016 lb/mL = 1.6 lb/L
brake specific fuel consumption = 0.55 lb/hp/hr

104 L/hr * 1.6 lb/L / 0.55 lb/hp/hr = 300 hp

So 300 hp is an extremely loose upper bound on the highest power the stock fuel pump can support.

ciper · Post by **ciper** » Wed Feb 18, 2004 1:16 am

Has anyone calculated a the flow rate for the 2.2 at different pressures, if so please post it so we dont end up doing the same work over and over again.

vrg3: In your calculation you also assume that the pump is still working at peak performance. After so many years I wouldnt doubt its quite a bit weaker than that.

NICO I WRX U, I dont like you. You messed up a good thread.

Matt Monson: I forgot about the intercooler pressure drop! Ill have to recalculate for that.

MY92 · Post by **MY92** » Wed Feb 18, 2004 3:19 am

Haha, nice one

Matt Monson · Post by **Matt Monson** » Wed Feb 18, 2004 3:38 am

vrg3 wrote:Nico, dude, that can't be right. The stock fuel pump can't support 350hp.

The stock pump moves 150 liters per hour at 43.4 psi. That is, at 7.1 psi of boost. Under higher boost it will flow less. With the return line pinched to increase pressure more it'll flow even less. And you have to allow some fuel to return back through the return line; a typical bare minimum is 20%.

Let's make some generous guesses:

flow = 130 L/hr
usable flow = 120 L/hour * 80% = 104 L/hr
fuel density = 0.73 g/mL = 0.0016 lb/mL = 1.6 lb/L
brake specific fuel consumption = 0.55 lb/hp/hr

104 L/hr * 1.6 lb/L / 0.55 lb/hp/hr = 300 hp

So 300 hp is an extremely loose upper bound on the highest power the stock fuel pump can support.

Damnit VRG

You beat me to the punch. This math was the whole reason I asked my question in the first place. I so wanted to call BS. But then I can't complain since I spent the afternoon working on my RS installing my new Cobb headers. I bet I now have 240hp NA!!!

NICO · Post by **NICO** » Wed Feb 18, 2004 8:35 pm

i dont whant to have a battle on this fine site. when i put my motor back in, i am going to drive to miami and along the way i would love to race all u guys just to say i have the fastest legacy.

ciper · Post by **ciper** » Wed Feb 18, 2004 8:41 pm

You may have the fastest Legacy now, but your days are numbered.

boostjunkie · Post by **boostjunkie** » Wed Feb 18, 2004 8:45 pm

NICO I WRX U wrote:i dont whant to have a battle on this fine site. when i put my motor back in, i am going to drive to miami and along the way i would love to race all u guys just to say i have the fastest legacy.

I'm in Olney, MD. On the way down to Miami. I'd love to have a run with another legacy!! I'm not sayin mine's any faster than your's, but I'd like to have something to compare my car to. Not to mention, I'd like to see how you have your front mount intercooler setup!!

vrg3 · Post by **vrg3** » Wed Feb 18, 2004 9:05 pm

Nico's got a monster intercooler:

http://www.legacycentral.org/images/members/nico/1.jpg

That's probably what keeps the superheated plasma coming out of his compressor from killing the motor immediately.

Oh, and Nico, I'm not trying to fight with you... I'm just sayin' that something's not right with the situation you describe. Math proves it.

boostjunkie · Post by **boostjunkie** » Wed Feb 18, 2004 10:17 pm

Yeah, I heard it was a diesel truck intercooler but I'd never seen pics of it. Hey Nico, any more shots of the piping?

ciper · Post by **ciper** » Wed Feb 18, 2004 10:36 pm

Nico, please run your car at a drag strip. It may be quick but I doubt its as fast as you think.

The pressure drop across that intercooler is probably ginormous.

evolutionmovement · Post by **evolutionmovement** » Thu Feb 19, 2004 12:10 am

What would that IC do for the efficiency of the radiator behind it?

Steve

vrg3 · Post by **vrg3** » Thu Feb 19, 2004 12:12 am

It would hurt radiator efficiency. Just like so many other front-mount intercoolers. Our radiators have plenty of safety margin.

ciper · Post by **ciper** » Thu Feb 19, 2004 12:12 am

Ive boiled over my NA radiator on uphill canyon runs...

vrg3 · Post by **vrg3** » Thu Feb 19, 2004 12:26 am

Really? Wow. With everything in good shape (no bent fins, bugs/leaves clogging passages, good coolant and thermostat)? How hot was the weather?

ciper · Post by **ciper** » Thu Feb 19, 2004 12:29 am

It was about 80 Id guess. I was racing another subaru (and beat him) up the hill. Nothing wrong with the car besides tired hydro lifters and a sway bar clunk I couldnt track down.

On the way down I was killing a WRX but my brakes started to fade, then smoke so I slowed down

Eastbaysubaru was at the event, some observatory I cant remember the name of.

It was the worst case scenario though, many miles of hard driving with two feet

eastbaysubaru · Post by **eastbaysubaru** » Thu Feb 19, 2004 4:42 am

LOL! That was fun as hell. It was at the Mt. Hamilton meet last year. Good times

-Brian

NICO · Post by **NICO** » Thu Feb 19, 2004 11:26 pm

i no i no i got to take my baby to a drag strip this year i will, my cuzin dino host the NORTH OF THE BORDER BASH and its going to be at a drag strip. i will have lots of time to race so i dont mess up.
http://www.northoftheborderbash.com/home/home.html

hear are some old pics so u can see the piping http://www.legacycentral.org/centric/members/nico.htm

my radiator is perfect no over heating at all. some times i dont get heat, cuz the car stays so cold. i cant make the tempature gauge pass the half mark, no matter the heat of the day or how hard i rev the shit out of it.

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