'99 Mods For Miles

[rx3hundred]

Whats up

Just picked up a '99 rx300 and I would like to know what all modifications are out there for me? I will be going with the K&N kit to be starting. I am not going to be doing appearnce mods, looking more for power and some improved gas mileage.

Are there any programmers for these cars that re-flash the computer?

What are my options?

Thanks

RX3HUNDRED

[wwest]

That K&N "mod" will quickly result in an MAF/IAT sensor failure ($167 DIY) due to oil and dirt contamination. Oil wicked from the K&N filter, and dirt because the K&N is a lot less efficient, 100% of the time, at cleaning the incoming air than is the OEM filter.

And just how often at you are WOT and max engine RPM?

That's the only situation in which the OEM filter provides the 3-5% restriction in airflow that the K&N might not.

Racing teams use K&N, first, because they are PAID to do so, and secondarily because a LOT of time is spent at the top end of engine performance and racing engines are only expected to last maybe 2 or 3 races, not the 150-200,000 miles most of us expect out of todays vehicle engines.

[bartkat]

Don't listen to the alarmist. Go ahead and get the K&N. Properly maintained, it won't give you any problems.

[riwyle]

He may be an alarmist, but I am more interested in the facts than name calling. If you understand the physics of the air flowing through the filter and then the throttle valve, you will realize WW is absolutely correct. So why add something that is totally valueless unless you are running at a drag strip?

[TunedRX300]

He may be an alarmist, but I am more interested in the facts than name calling. If you understand the physics of the air flowing through the filter and then the throttle valve, you will realize WW is absolutely correct. So why add something that is totally valueless unless you are running at a drag strip?

←

It depends on usage and what is important to each individual owner. Do you realize even OEM paper filter does not filter out all dirt particles? Sure K&N increase air flow not much and at the expense of filtering fewer particles. But if that is the tradeoff rx3hundred is willing to make, I would say go ahead.

MAF can be cleaned easily under 5 minutes, K&N's pre-oiled filter for the RX is not over-oiled to the point of coming off. I have K&N on my RX for over one year, no error code ever. Had one for my 94 Altima for over 80K, no problem.

[rx3hundred]

Alright, well scratch the k&n idea....

what can i do for mileage??? And Are there any programmers out there??/

thanks

[TunedRX300]

Alright, well scratch the k&n idea....

what can i do for mileage??? And Are there any programmers out there??/

thanks

←

If your sole purpose is to increase mpg, increase tire pressure, remove spare tire, remove mud guards, remove roof rack, remove trunk cover, remove all rear seat head rests if you never have any passenger in the rear. Take out all necessary weight.

If you don't believe poor aero dynamic increase drag, just watch those flaps when a jumbo airplane is trying to land. Another example, after you remove mud guards, see how freeway wind has made plastic edges into knives and make them cut into the paint underneath.

[wwest]

You can easily modify the MAF/IAT module's IAT, intake air temperature, signal so the mixture runs to the lean side during acceleration. But during cruise, relatively constant speed, the front oxgen sensor determines (primarily) the proper A/F mixture ratio and I don't know of any easy way to defeat that.

Prior to the C-best ability becoming available for me to manually disable the A/C indefinitely I always disconnected the A/C compressor clutch during the winter months, otherwise most modern day vehicles with automatic climate control run the A/C all the time.

With the c-best option I typically disable the A/C if the OAT is consistently below 65F.

Don't know just how much this helps MPG ratings.

[bartkat]

He may be an alarmist, but I am more interested in the facts than name calling. If you understand the physics of the air flowing through the filter and then the throttle valve, you will realize WW is absolutely correct. So why add something that is totally valueless unless you are running at a drag strip?

←

I do, however, know that I've been running K&N and the similar TRD filters in cars for over 10 years now and never ever had oil come off the filter and contaminate anything, or any other air filter related problems. It doesn't hurt a thing in normal operation and it's there when you want it at WOT. So why not put one on? It is user preference after all.

[rx3hundred]

wow so really i have two options here,

1. put on a K&N and see no differnce, and possible see a CEL.... maybe 1 or 2 hp at WOT gain, doing so by a lean a/f anyways which isnt very good...

2. start making the rx look ugly by stripping it down to a civic dx model and hopeing for no headwind....

Guess the rx300 will be staying stock ... prob like it should. :chairshot:

wwest- I dont see how cuting out the A/C compressor would really gain too much, considering they are very efficiant and have little drag at speeds over 35mph (2000rpm) anyways, so i dont see myself hackin wires to disconnect it.... thanks though. And by OAT, were you meaning ambient temp?

-dan

[wwest]

OAT..Outside Air Temperature.

I can't verify this but I have heard that the A/C compressor uses up to 1/3 of the engine HP at cruise speeds. Some posters have reported a 10% improvement in MPG, 22 to 24+.

And yes, today's A/C systems are outstandingly efficient. But not when used in the way they are in these automatic climate control systems.

In these systems ALL of the airflow is first routed through the A/C cooling evaporator which is kept as close to 32F as is possible. In order not to discomfort you with such COLD airflow a portion of the chilled air is then routed through the heater. The two portions are then remixed to achieve a reasonable comfort level of airflow to your face and upper body via the dash outlets.

Sort of equivelent to using your furnace at home to reheat the cooled A/C output.

Running the A/C when the OAT is below 65F only benefits you if you have need of the dehumidification aspects of its operation.

[monarch]

I agree with wwest. Walmart now carry's pre-oiled, drop in K&N filters. Next time you visit a Walmart take one out of the package and hold it high in the air against a store light. You'll see thousands of specs of light through the filter media - those are all thouands of holes where dirt can get through the filter media directly into your engine.