Questions on Lex/550 upgrade

[goliath]

I just read through Reg Riemer's Tech notes on the Lex/550 upgrade and JSeaman's guide to installation.

Any way...

Will the stock FPR and 02 sensor allow the fuel system to opperate properly?

Or is an AFPR and widband 02 sensor required for proper opperation?


Thanks

 

[goliath]

anyone?:1zhelp:

 

[Nick M]

Are you sure you read it? Becuase he covered that. A small tuning device might help a little, but isn't needed. The tuning device, such as an airflow device is used to bring the car into Vf specs, before the computer changes what it might view as incorrect.

It should go right in with out trouble if everything is working correctly.

 

[goliath]

thanks Nick

But I'm not understanding your statement. Could you be more specific.

The artical I read from SONIC only discussed The AFM and 550"s.

 

[Nick M]

The larger airflow meter will send a slower signal to the ECU. The ECU would try to richen the mixture. The larger injectors will cover the slower signal. An AFM scaling device can help bring Vf back if needed.

The Lexus flow meter causes the TCCS to see a slower square wave signal from the air flow meter than the stock air flow meter would send to the TCCS. This tells the TCCS that there is less air than there actually is coming into the engine but in reality there is not less air coming in. The air flow meters function is to measure the air coming into your engine. When we change the size of the air flow meter body we are in actual fact changing the scale of the air reading that is sent to the TCCS.

This second fib is a small one, changing the fuel injector size to a larger injector so the TCCS will no longer need make the short and long fuel trim corrections. The increased injector size allows more fuel to be injected at any given pulse width. (Remember that the TCCS leaned out the mixture because we caused a fib about the actual air volume coming into the engine.) By increasing the injector size to a larger injector we are allowing the correct amount of fuel to be injected into the engine with the short injector pulse width caused by the Lexus air flow meters false reading.

The only modified parts were:

HKS Sport Turbo upgrade HKS EVC II HKS Super Power Flow HKS MA-67 turbo exhaust system

 

[Bishop92t]

AFPR and wideband are not required but highly recommended. It's a great idea to have some sort of tuning, and I would consider an EGT or wideband to be required for safe operation.

 

[goliath]

AFPR and wideband are not required but highly recommended. It's a great idea to have some sort of tuning, and I would consider an EGT or wideband to be required for safe operation.

Thanks Bishop:bigthumb:

 

[tte]

thanks Nick

But I'm not understanding your statement. Could you be more specific.

The artical I read from SONIC only discussed The AFM and 550"s.

But if you read it more carefully I think they also modified the stock AFR to make it adjustable.

cheers,
Roy

 

[goliath]

Thanks tte

I will read it again.

 

[MRSUPRA]

I think an AFC is needed just as much as anything. Most people will run very rich with the Lex/550 combo. I gained lots of of power in the topend by pulling fuel with my AFC. I made 511rwhp with Lex, 550's, AFPR, Walbro,(old)AFC, FCD. A wideband is good to have, but a dyno tune will work too.

 

[goliath]

Thanks MRSUPRA.