Redline at high altitude?

[Nero]

My wife and I are planning to take a road trip this summer to spend time with family in California. On our way, we planned on driving some of the more scenic routes through the Rockies. My question is, how well does the RL handle the steep grades and thin air? I have never been in high altitude with a super or turbo charged engine.

Anyone out that way have any insight?

Any favorite scenic routes?

Thanks in advance.

[Sp00ner]

Super/turbo cars are supposed to be able to deal with the thin air alot better than N/A cars. Or so I've been told, never been through the mountains in one before.

[Tom01SC2]

I've climbed from 1000ft to 6500ft. Car didn't have a problem, still plenty of power, but the loss of power is noticeable. In two weeks I plan on taking a trip where I'll climb well over 7500ft in elevation...

Tom

[Hawflake]

Theoretically, thin air would not matter as much to our RLs because the supercharger decides how much air the engine gets and what pressure the air comes in at. However, it does have to work much harder at compressing the air (i.e. spin faster) in order to achieve the same boost, at peak level, it cannot possibly generate as much boost as it could as sea level. Still your advantage over a normal aspirated car up there would be obvious, it might be interesting to take on a few V-8 up there.

[Sp00ner]

We drove through the Telluride area, up to Stony Pass on jeep trails, that was around 13,000 feet. We used a Trailblazer with the inline 6, and you could feel it losing power quick. It never seemed to lose the bottom end torque though, it took 4 of us, all of our stuff, and drove right up the side. The higher we got though, the worse and worse the top end got. Near the top, it was having trouble getting high enough into the Rpms to shift to the next gear, it made it, but you could feel it breathing hard.

[Nero]

Originally Posted by Tom01SC2

I've climbed from 1000ft to 6500ft. Car didn't have a problem, still plenty of power, but the loss of power is noticeable. In two weeks I plan on taking a trip where I'll climb well over 7500ft in elevation...

Tom

Cool. Good to hear that the superchgarger handles the lower amount of Oxygen well enough. Good luck on you coming road trip. Let us know how the RL takes 7500+.

[MotorMouth]

Originally Posted by Hawflake

Theoretically, thin air would not matter as much to our RLs because the supercharger decides how much air the engine gets and what pressure the air comes in at. However, it does have to work much harder at compressing the air (i.e. spin faster) in order to achieve the same boost, at peak level, it cannot possibly generate as much boost as it could as sea level. Still your advantage over a normal aspirated car up there would be obvious, it might be interesting to take on a few V-8 up there.

Actually, no... The rotors cannot "spin faster".

The roots supercharger can only move a fixed volume of air per revoloution, in the case of the M62 1 liter per revoloution. Now if the air becomes thinner the supercharger still moves the fixed volume but the density of the charge gose down in relation to the atmospheric change.

Turbo motors on the other hand are not as easily affected because the wastegate actuator still wants to see 15 spi for example so the turbo contunues to spool until that pressure is met. The danger for turbo motors starts to come at very high altitudes where shaft speeds on smaller turbos can get very high, as I recall some can see in the 150,000 rpm range.

[Hawflake]

Originally Posted by MotorMouth

Actually, no... The rotors cannot "spin faster".

The roots supercharger can only move a fixed volume of air per revoloution, in the case of the M62 1 liter per revoloution. Now if the air becomes thinner the supercharger still moves the fixed volume but the density of the charge gose down in relation to the atmospheric change.

Valid point, we do have a roots type instead of centrifugal type.

[rip_vw32]

Guys..........I LIVE at 6350ft......This thing does great!!!! Taken it over Vail pass and up to Frisco, still no problems. Passing on the left, right, center.....This thing won't quit. Besides, the MAF and MAP sensors handle the air and fuel charge when going to higher altitudes. YES you will experience some change, BUT not as bad on non-computer controlled, N/A engines.......You'll have no problems.......