SELLSZ06

iTrader: (12)

For A Phamspeed Turbo Ls1 With Ported Heads And Cam And A Goal Of About 600rwhp What Is Best Injector Size 42 Or 60's? What Changes Needs To Be Done To The Fuel Sytem For 60lb'ers.?

smokinHawk

iTrader: (48)

42's will be at the edge so id use the 60's.
to swap out injectors your going to need some computer programming ofcoarse.
also you need a pump that can support it to.

the stock lines should be alright, but if you go up further then that id upgrade.

kcshaner

I'd say at least 60's and no less....65's or 75's would be a safer bet from what I have learned. As long as you get hi impedence injectors, all you have to do is install them, and have your car tuned for the larger injectors.

I personally am at about the same power level as you, and upgraded from 50's to 60's and I wish I went larger...better to big then to small IMO.

furiouSS99

iTrader: (-1)

I'm convinced to use 60's on a FI setup I'm working on too...but I'm curious about the computer tuning...you would have to adjust your flow rates, obviously, for the bigger injectors-but what about the offset and other related injector tables? The 60's (mototron I assume were talking here) wouldn't have exactly the same charateristics as stock injectors (like response time, etc) would they? I have heard alot of people say they idle and run well, but I can't get any tuning details...any info would be appreciated.

*not trying to steal the thread, but it is related info

Boostaholic

iTrader: (4)

From the Turbo FAQ

How do I select fuel injectors for a forced induction application?


First you need to figure out what BSFC (Brake Specific Fuel Consumption) value you will use, BSFC is the pounds of fuel the engine burns per HP per hour.

Here are some BSFC guidelines.
.45 for N/A motors
.55 for supercharged
.65 for turbo

Injector Size in LB/HR = ((Desired Flywheel HP) * BSFC) / (# of cyls * Duty Cycle % / 100)

These simplified versions can be used for V8 motors with 80% duty cycle
Turbos : LB/HR = (Desired HP * .65) / 6.4
Superchargers : LB/HR = (Desired HP * .55) / 6.4

Example
600 * .65 / 8 * .80

Gives me
390 / 6.4

Result : 60LB/HR

Boostaholic

iTrader: (4)

1bad2k2ta

iTrader: (3)

Boostaholic,

Are those supercharged/turbo number fwhp or rwhp? Looks like fwhp.

Thanks

KissMySSo1

iTrader: (2)

Those #'s are way off.

Boostaholic

iTrader: (4)

How do you figure?

They are supposed to be at the flywheel

If you have a better formula for finding that data then let me know.

MelloYellow

The 60# rating is at 3 BAR, you need to convert them to LS1 4 BAR 58psi then run the formulas for FWHP.

SINISTER

iTrader: (16)

motron 60# cant go wrong!!

HUGGER ORANGE SS

iTrader: (2)

MelloTellow.. You're right.. I was looking at the figures and they seemed a little low, IE a lot of injector to hit a certain FWHP level.. I am running 50lb Holley injectors, and I'm pushing about 700RWHP and my injectors have not hit 100% duty cycle as yet. However I am pushing about 70psi of fuel pressure with my dual 340m's intank pumps, and my new aeromotive fuel controler for my 2nd pump.. But at my power levels and 50 lb injectors I can't go much farther..

Clint

disassembled

iTrader: (3)

I need to start planning my fuel system. I plan on using a weldon pump with controller, and an injector to support 1300 fwhp with the stock computer (crossing fingers). Would it be ok to run a 75lb injector and then use alky or meth when i want to hit 1000 rwhp? Should i run dual intank pumps? Should i run low impedance injectors with an impedance convertor? What would be best for my situation? I obviously don't want to have a 1000 hp car all the time so what do you guys think? I plan to do a sumped tank, rails, lines, boost referenced FPR, and any other little things that go with the fuel system. How would a high lb per hour injector do when run at an extremely low duty cycle? I don't think i would want to run more than 600 hp on the street.


Greg

LSs1Power

iTrader: (5)

It should be the other way around. SC usually need more fuel to give the same HP as turbo because they have prastic loss which is not accounted for. So a Turbo car might need 42's to get 550rwhp, but a SC will need 57 or 60lbs injectors.

NA$TY-TA

iTrader: (21)

I agree with you there and those figures were 3 bar fuel pressure 43.5psi and we run a base of 4 bar 58.03psi...... and with a rate rise FP reg. we can puh them farther... look at Mightey Mouse he made over 800rwhp with 60# Motrons... and Meth injection (wich helped) BTW Im selling my motron 60"s... time to go bigger
Kyle

MelloYellow

Agree also that cylinder fuel requirements are higher for SC cars than turbo also. Not sure how cylinder power relates to BSFC. But it takes 75-100 Cyl HP more to drive the blower (and the fuel to make that).

But I think Cyl HP and BSFC are calculated differently.
Bottom line, takes more fuel/inj for SC's.

KissMySSo1

iTrader: (2)

60#rs at 60 psi will support 1000fwhp

LSs1Power

iTrader: (5)

I doubt it... Im running 60lbs injectors with 60-61psi of fuel pressure and seeing around 75% DC at 550rwhp. That is around 650 FWHP and im at 75% Duty Cycle. From what im seeing with the 60lbs i think they are good up to 650rwhp on a SC'd LS1 or 750rwhp on a Turbo running 60psi of FP and over 100% DC.

Boostaholic

iTrader: (4)

This sounds a little off to me, seems like you should have been closer to 65% duty cycle.

01Blackerado

iTrader: (4)

The only known calculation I've seen for inector size and power is the:

Lbs/hr= HP/16 and then add a little for the SC'rs and with this, those numbers are pretty far off. Correct me if I'm wrong