Hermosa

Just wondering how hard it is to replace the fuel injectors on a SC400. And while we are at it what are very high quality ones to replace them with? Cost? Where to buy?

007lexus

Why do you wish to change them? Did you find out their defective? if so, how?

007

Hermosa

Not defective. I don't think they would be sufficient if I had 8 lbs of boost.

007lexus

For a stock SC, can changing the FI to a larger size increase any kind of performance? Keep in mind, no booster.

007

Lex Luthor

No, they're plenty large for the stock motor. For a boosted 1UZ, any of the major brands will do, i.e. RC Engineering, Bosch, Siemens, Rochester, Accel, FMS, HKS, etc. When you say 8lbs. boost, how 'bout some details?

Hermosa

SRT was supposed to give me 8.5lbs with the Stage 3 SC they promised to do for me the third week of May. They have ignored all my mail since. I have been looking into turbos lately. I am not a car expert but have always been able to figure things out real quickly.

Since I have ties to the CNC industry fabricating some parts should not be a problem since I have dozens of machines and one of the best programmers in the West Coast on my side. I would like to run some simulations on air flow on a computer to determine what I consider to be the first step, an exhaust manifold. I am hoping to use high quality materials and as perfectly smooth interior as you can between parts.

I am wondering what size turbos I should use and how many, single or twin.

I ask about the fuel injectors since those would be the first to get changed out and I want to get things done to the motor so why not do it all at once. It will save on labor.

Lex Luthor

Twins would work out better, something like two maxed-out T28's with internal wastegates and an FMIC. Have you spoken to Eric at E.L. Prototypes? He's in your neck of the woods and is perfectly willing to TT a 1UZ for reasonable funds. I have a guy near me that's willing to do it as well. How much rwhp are you looking for? As of right now, still easier and cheaper to do a 2JZ motor.
- Jon

808state

you may or may not need to change the injectors (depending on the amount of hp you're expecting..not boost). according to corky bells "maximum boost" you can use this formula to get a figure:

to convert cc/min to lb/hr:

(cubic centimeters/minute) = (pounds/hour) x 10.5

the 1uz-fe oem injectors are 251cc/min which converts to 23.9 lbs/hr.

a simple calc to figure out the properly sized injector is:

pounds of fuel per hour per injector = (expected bhp x 0.55)/number of injectors

if you expect say 350 horsepower then:
pounds of fuel per hour per injector = (350 bhp x 0.55)/8
pounds of fuel per hour per injector = 24.06

***calcs above assume i did calculations correctly and inputted the correct numbers, i'm not a turboligists!***

although it seems adequte, you could size it one size larger for future improvements. also, 10 year old injectors may or may not flow at 251cc/min. not sure if the 251 rating is a worst case scenario or perfect conditions.

if you do a search for 4/12/01, michael kilty changed his stock injectors with 400cc ones on his gs400. stock gs400 ones are 275cc/min. also, someone called up rc engineering and they quoted him with 310cc/min injectors for $85 each.

mindflux90@hotmail.com might still have plug and play injector info.

lets not forget about the fuel pump...either. oh yeah, never changed my fuel injectors, so wouldn't know. maybe a lex tech would know.