Horsepower vs. elevation.

D

Dongbeiren

New member
Guys,

I'm just curious, how much has the horsepower left of the 4Runner at 7300 ft above sea level, in the good old Wyoming?

I love my truck, but really wish it had a turbo charger. Mountain road driving at this elevation is .... Not so enjoyable .....

Cheers, :cheers:
 
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You've lost 59.13 horsepower (uncompensated by the engine) at that elevation. Actually probably a bit less if you're staying there for a while and your ECU compensates for the change.
 
limamike said:
You've lost 59.13 horsepower (uncompensated by the engine) at that elevation. Actually probably a bit less if you're staying there for a while and your ECU compensates for the change.
Click to expand...

You will also lose HP if it is really hot or really moist atmosphere. Here are the rules:

The relative horsepower calculations are made in accordance with SAE J1349. The standard reference conditions for SAE J1349 are: Air temp 77 deg F (25 deg C), 29.235 Inches- Hg (990 mb) actual pressure and 0% relative humidity.
 
Yep, living at elevation equals much slower cars. Forced induction however really helps. Wait a year and supposedly the TRD supercharger will be out.

I figure I'll be at around 15k miles then and everything will be broken in and I'll be ready for a SC. Save $13 a day and you should have a good fund ready for the SC when it is released.

The upside to being at elevation is that we do get better gas mileage. Thinner air (less drag) and less oxygen to fuel combustion leads to less gas used.
 
A trd supercharger at your elevation will put you back about even with a NA 3.4 at sea level. You could throw on a smaller pulley and get a little more out of it.
I'm in heber ut at 5500 with a 2.2" pulley and it runs great.
 
FancyPantsMcGee said:
A trd supercharger at your elevation will put you back about even with a NA 3.4 at sea level. You could throw on a smaller pulley and get a little more out of it.
I'm in heber ut at 5500 with a 2.2" pulley and it runs great.
Click to expand...

What?

You know this isn't the 3rd gen forum right?
 
Except it wasn't.

A stock 3.4 (from a 3rd gen) has 183 hp and 217 ft-lbs at sea level.
A stock 5th gen motor is still ahead of that even at the stated altitude. Adding a SC to a 5th gen would most certainly not be even with a 3.4 at sea level.
 
Crit Rat said:
Except it wasn't.

A stock 3.4 (from a 3rd gen) has 183 hp and 217 ft-lbs at sea level.
A stock 5th gen motor is still ahead of that even at the stated altitude. Adding a SC to a 5th gen would most certainly not be even with a 3.4 at sea level.
Click to expand...

So you could not port that info over and substitute 4.0 for the 5th gen. The concept is the same, he just stated it as it was in his experience.
 
SC do help get alot of the horsepower back but you won't build the same amount of boost that you would at sea level but more ponies does help up here period.
 
Crit Rat said:
Yep, living at elevation equals much slower cars. Forced induction however really helps. Wait a year and supposedly the TRD supercharger will be out.

I figure I'll be at around 15k miles then and everything will be broken in and I'll be ready for a SC. Save $13 a day and you should have a good fund ready for the SC when it is released.

The upside to being at elevation is that we do get better gas mileage. Thinner air (less drag) and less oxygen to fuel combustion leads to less gas used.
Click to expand...

The throttle response is sometimes really annoying, especially when going uphill, you really need to floor it to get the truck up to speed. Also when in cruise control, it just keeps shifting between 4th and 5th gear (occasionally 3rd) every 10 second. I don't know how it feels when in 2WD mode since I got the LE with AWD all the time...

I'm interested in the SC also, don't know how much would it cost when it's out. I didn't find the gas mileage to be better than lower altitude, I'm averaging at 19 MPG combined, I think that's lower than average, is it?
 
limamike said:
You've lost 59.13 horsepower (uncompensated by the engine) at that elevation. Actually probably a bit less if you're staying there for a while and your ECU compensates for the change.
Click to expand...

I use to follow a Youtube car review channel, those guys are in Denver and when they brought the cars to a dyno, most of the naturally aspirated engines lost 1/3 hp at wheels, if that's the real case, I can't imagine how much do I have left at 7000+ ft... :jaw drop:
 
If the OP question was leading to "Will my T4R do well at elevation?", then I'd have to say, yes.

I took mine up the Telluride side of Imogene Pass (13,000'+) in June and had no complaints. I'd add that my GVW was north of 6,000 at the time.

Several other members just got back from the Summit (same area), and they didn't seem too disappointed about power at altitude.

Happy trails.
 
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