550cc Injectors...

nsngarage

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Jan 24, 2009
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Does anyone know (im sure you do.. lol) what cc the injectors out of the early 90's lexus V8's were? I've heard they were 550 but they seem a lot easier to get and wayyy cheaper than the RC injectors and others that are advertised as 550s..

any help would be appreciated :)
 

suprahilux

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Jun 12, 2007
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not sure about the exact rating, but I know that they are not 550s.

If you think about it, each cylinder in a 4.0L V8 is only .5 liters. Each cylinder in a I6 3.0L is .5 liters. Seeing that the V8 is not turbo and there is one injector per cyl. also the air flow per cylinder would be similar to that of the N/A supra (per cylinder). So there is no reason for toyota to have put in anything bigger than the N/A supra injectors. 295 to 315cc? Possibly up to 380cc.
 

nsngarage

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Jan 24, 2009
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quite a good point.. someone was talking to me saying they would sell me 550's from a 91 Lexus LS400.. which didn't sound right to me... So i decided to check lol

appreciate the post ;-)
 

suprahilux

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Jun 12, 2007
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Total airflow into the 1uz is greater so they made the afm bigger.

1uz afm allows about 25% more unmetered air through than stock 7m. So with this swap, you can get 550cc injectors(from something else) which are 25% greater flow than stock injectors so the fuel maps on the stock ecu are still accurate.
 

suprahilux

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I really doubt that they were upgraded to 550s. It is very difficult to use much more fuel in the same motor without forced induction. Now if he put a turbo or supercharger on it then maybe he would need injectors that big.
 

supraguy@aol

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Dec 30, 2005
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You also want to make sure you choose the right impedance injectors for your car. You didn't say what year your is, but I know that the 87-88 turbos are low impedance injectors.
 

cjsupra90

previously chris90na-t
Jun 11, 2005
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suprahilux;1268387 said:
Total airflow into the 1uz is greater so they made the afm bigger.

1uz afm allows about 25% more unmetered air through than stock 7m. So with this swap, you can get 550cc injectors(from something else) which are 25% greater flow than stock injectors so the fuel maps on the stock ecu are still accurate.


This is pretty much exactly why the Lex AFM setup works...

For those wanting to know, NO, The 1UZ V8's did not ever come with 550's... The stock 1UZ injectors are only 250's... Who ever told who ever that they came with 550's does not know what they are talking about and dont listen to them. And Yes, this is fact, they were 250's, not 550's
 

frontierguy25

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Mar 26, 2007
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Yup bunch of crap they fed you! If you look at domestic cars, like the GTO, Vette, they only come with 38lb injectors that's like a 400cc injector!!