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Tsbs For 2004 Rx 330


doncapecod

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Shared love(rs).....

Don,

I just took my 01 AWD RX300 out to North Bend and did wheelies in the discount mall (not Kittery) parking lot o test the AWD, VSC, etc.

Didn't have the guts to take the C4.

What is you overall opinion of the RX330?

Re: Climate control, fogged windshield and foul A/C odor.

Re: AWD, open center diff'l, braking for engine torque apportioning, etc.

Screw the nav, its useless.

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wwest, I don't have a 330 yet. Turning in a leased car (not my Porsche) and looking for a mid-size SUV. Started looking at a whole bunch of them and narrowed down to the 330 and the Cad. SRX, but can't find any TSBs on either model.

BTW, were you talking about North Bend, WA. Spent 7 years in Seattle area. <_<

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Yes, WA, Came to work for Boeing in 61, fresh out of the USAF at Pease. Hung out our own shingle in 72, Strobe Data Inc.

All things being equal I would recommend the RX330. I had an 00 AWD RX and traded up to the 01 AWD RX to get HID, VSC/Trac, etc. You may already know some of this but IMMHO the RX has (had?) two major flaws.

Prior to the 330 the RX used an always flaccid viscous clutch across the center diff'l supposedly to apportion engine torque to the rear if/when needed. On a 4 wheel dyno mine measured 95/5 F/R "native" torque distribution and only got up to ~75/25 F/R with disparate F/R rotational rates.

I'm not enough of a mechanical engineer to know/understand how the torque is "natively" apportioned but I suspect it has something to do with the different final drive ratios used in the front vs the rear.

But I do think I know why the viscous clutch is always flaccid and never "stiffens" up to the point of routing a significant level of engine torque to the rear. During hard or severe braking the rear axle MUST be uncoupled from the front to prevent loss of control due to rear wheel lockup. The majority of the braking effort is always at the front so the front wheels always turn much slower than the rear in this circumstance. The AWD Chrysler T&C solves this problem by providing an over-running clutch around the viscous coupling.

With no over-running clutch on the RX to provide this capability the engineers dare not provide a true viscous coupling capability.

The New RX330 has dropped the viscous clutch entirely in favor of a completely open center diff'l and the Trac system's use of the brakes to prevent a tire or tires from slipping and thereby apportion engine torque. This system has a couple of short-comings also. With all four tires slipping the system will quickly dethrottle the engine. Actually it will quickly dethrottle the engine, to prevent brake over-heating and the rotors warping, anytime the driver persists in using the throttle to "gain" traction. To prevent the smallish ABS pumpmotor from over-heating during extended Trac activity it will be automatically disabled after about 45 seconds of continuous use.

The RX series, the 330 included, cannot have snowchains used on the rear due to poor suspension clearance and while the manual recommends use of snowchains ONLY on the front Lexus has admitted in writing that this can be very hazardous and will oftentimes lead to loss of control. Oh, the 330 also uses differing F/R final drive ratios so I suspect that the "native" torque distribution ratio is still bias toward the front.

I put 1.2" wheel spacers all around on my 01 so as to accept 17X8 wheels, wider tires, and to get the ability for rear snowchains ONLY.

The MAJOR problem with the automatic climate control is the fact that the designers do not understand human metabolism as it relates to radiant heating (or lack threof).

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Thanks for all the detailed info on the 330. Since we'll be in Naples in winter and Cape in summer, I don't think what you describe will be too much of a problem. Problem is I hate FWD cars of any type. Re Seattle...I used to own Griffin Envelope on East Marginal Way (close to the old Boeing HQ bldg) and next to the State liquor commission bldg. Sold out in 98 and came back to Cape. New owners moved to Kent, so I think bldg is MT now. I loved WA..there was so much to do, but our family is all in New England. Thanks again for the info. :)

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We'll be at Daytona the last of the month for the 24 hour race then over to Tampa, palm Harbor, to visit two of my sisters. The West Family Foundation sponsors the TeamSeattle cars so as to benefit Seattle childrens hospital. How far is Naples from Tampa?

If you don't have to rely on the AWD aspects of the RX then it would be an excellemnt choice.

To avoid the horrid mold and mildew odor while in Florida see:

http://www.airsept.com/eed.html

A problem for almost all cars since the beginning of the use of the new less efficient refrigernant.

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Yes, WA, Came to work for Boeing in 61, fresh out of the USAF at Pease. Hung out our own shingle in 72, Strobe Data Inc.

All things being equal I would recommend the RX330. I had an 00 AWD RX and traded up to the 01 AWD RX to get HID, VSC/Trac, etc. You may already know some of this but IMMHO the RX has (had?) two major flaws.

Prior to the 330 the RX used an always flaccid viscous clutch across the center diff'l supposedly to apportion engine torque to the rear if/when needed. On a 4 wheel dyno mine measured 95/5 F/R "native" torque distribution and only got up to ~75/25 F/R with disparate F/R rotational rates.

I'm not enough of a mechanical engineer to know/understand how the torque is "natively" apportioned but I suspect it has something to do with the different final drive ratios used in the front vs the rear.

But I do think I know why the viscous clutch is always flaccid and never "stiffens" up to the point of routing a significant level of engine torque to the rear. During hard or severe braking the rear axle MUST be uncoupled from the front to prevent loss of control due to rear wheel lockup. The majority of the braking effort is always at the front so the front wheels always turn much slower than the rear in this circumstance. The AWD Chrysler T&C solves this problem by providing an over-running clutch around the viscous coupling.

With no over-running clutch on the RX to provide this capability the engineers dare not provide a true viscous coupling capability.

The New RX330 has dropped the viscous clutch entirely in favor of a completely open center diff'l and the Trac system's use of the brakes to prevent a tire or tires from slipping and thereby apportion engine torque. This system has a couple of short-comings also. With all four tires slipping the system will quickly dethrottle the engine. Actually it will quickly dethrottle the engine, to prevent brake over-heating and the rotors warping, anytime the driver persists in using the throttle to "gain" traction. To prevent the smallish ABS pumpmotor from over-heating during extended Trac activity it will be automatically disabled after about 45 seconds of continuous use.

The RX series, the 330 included, cannot have snowchains used on the rear due to poor suspension clearance and while the manual recommends use of snowchains ONLY on the front Lexus has admitted in writing that this can be very hazardous and will oftentimes lead to loss of control. Oh, the 330 also uses differing F/R final drive ratios so I suspect that the "native" torque distribution ratio is still bias toward the front.

I put 1.2" wheel spacers all around on my 01 so as to accept 17X8 wheels, wider tires, and to get the ability for rear snowchains ONLY.

The MAJOR problem with the automatic climate control is the fact that the designers do not understand human metabolism as it relates to radiant heating (or lack threof).

wait...

u mean, the older generation of RX has 95:5 normal distribution of power?

i thought it's constant 50:50

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If the RX300 or 330 had equal final drive ratios front and rear then I would have no basis for arguing against a 50/50 F/R rear torque split. But the fact of the matter is that both have differing F/R final drive ratios, the RX330 more disparate than the RX300. Does that mean the RX330 starts out at something closer 98/2 F/R? Maybe.

Can't say for sure except something causes the RX300 to be 95/5 and it is NOT its open center diff'l nor the VC, viscous coupling across that diff'l. Obviously it is the VC in the RX300 that stiffens up, partially locks the center diff'l, and routes the 25% level to the rear but only after several minutes of front slippage vs the rear.

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