Engine/Transmission (1998.5 - 2002) Boost PSI & Mountains

[JesseJ]

Altitude here at home is approx. 1200ft. I'm going to Denver for a week then over the mountains to western Co for a few days. Mostly will be around 5000-6000ft. minus going over the top and coming back. I have a stock HX-35 w/ boost elbow set at 34PSI and I'm wondering if I should adjust the boost down some while out there so I don't overwork or blow up the turbo. Maybe down to 26-28PSI. Anyone from high altitude w/ suggestions?

 

[PC12Driver]

I don't think you'll have anything to worry about. I've done that run a couple of times with a trailer in tow. The first time, I was still running the stock turbo with a boost elbow. I probalby lost about 1 psi for every 2,000' of elevation. Peak EGTs did increase with altitude, but there was no 2nd rise as you would see with a turbo running off its map. After about 8,000' I was EGT temp limited on the hills anyway, so I couldn't fuel it anymore to overdrive the turbo.



Long story short, it sort of takes care of itself. You have nothing to worry about.

 

[JesseJ]

So basically I'll just need to keep my foot out of it and keep the EGT down then? I guess I'm just a little worried since I know the turbo has to spin faster to get the same PSI boost at higher altitude and since it already has a lot of miles on it. Don't really want to shell it out and send pieces into the motor. Although it would give me a good excuse to get a new turbo.

 

[johncameron]

It's quite amazing how much abuse these HX35 turbos will take. I've held mind at ~34lbs of boost for an easy 10 munutes towing uphill. At that time I was running a SMARTY and DDII's IF I were you I'd use SW3 and just watch your EGT's, you should be able to control them with the ammount of fuel you're running.



John

 

[HookMeUp]

You don't have anything to worry about. I did that run empty last spring (Eishenhower Tunnel) and never saw anything above 1100° and I was hammering it pretty hard just to see what it would do.

 

[JesseJ]

Well I usually use the fuel saver setting just trying to save some money on road trips and I know the fuel saver mode cuts the fuel back quite a bit. My boost is also running higher than 34PSI currently because the outside temp. is so cold giving me denser air. Thanks for the input guys, you have put my mind at ease.

 

[johncameron]

Well I usually use the fuel saver setting just trying to save some money on road trips and I know the fuel saver mode cuts the fuel back quite a bit. My boost is also running higher than 34PSI currently because the outside temp. is so cold giving me denser air. Thanks for the input guys, you have put my mind at ease.

I thought you were towing, ya for sure SW1 works alot better with Cruise control.

 

[JesseJ]

Yeah no towing for me. I rarely get to tow anything with it. My buddy is too stubborn. I don't think he likes it when I can walk all over his 454 and not have to stop at every gas station along the way so we usally end up taking his truck, probably just to spite me. :-laf