Engine/Transmission (1994 - 1998) High Altitude Driving

[Vaughn MacKenzie]

Yesterday was warm and I went for a long drive in the '98 and ended up in the NE Oregon mountains between 4000 -4600 feet. Remembering this thread I decided to mess around for a bit seeing how the truck drove compared to home (400 feet elev). Air temps were 66-68 degrees at that elevation. The turbo definitely spools slower but if I don't roll into the throttle hard it spools up fine with very little smoke. Get into it more aggressively and it gives a decent puff, more that at home, but clears right up. Stomp on it and it smokes good, seems to bog and takes longer for the smoke to clear.

Power was definitely down, felt flat compared to home. Truck is totally stock except for marine 300 4-hole injectors. It would be interesting to see how it runs at 6-7,000 feet or higher.

Vaughn

 

[Forrest Nearing]

Yes, water/methanol injection is the same on gas and diesel engines.

well, on a diesel it can really increase cylinder pressure due to increased "timing"



on a gasser, there are generally only positive benefits.

 

[rosebunch]

Well I have found a couple of inexpensive modifications I can make to my 95 that will help the air flow for 2nd Gen trucks. I am going to get a 'Cowl Cold Air Intake" from PSM (Performance Systems Mfg. ) which will add extra positive air flow into the stock air box; and a TAG (Turbo Air Guide) from DPP (Diesel Power Products) to straighten the air flow into my turbo to prevent air cavitation which should help. These are supposed to help for heavy towing (which I do) and racing (which I do not do).

Bob

 

[arthr31]

hi rosebunch,
i'm interested in these products you've written about, can you provide some links? tia.

 

[rosebunch]

You can get Both Items from Bryan at DPP (1 866-379-8685)

www.DieselPowerProducts.com



If you prefer, the PSM website is:



Pete Tomka

Performance Systems MFG

303-279-7193

www.psmbuick.com

 

[rosebunch]

Hi all.
well I am back in Colorado Springs pulling my 32ft 5th wheel. The TAG and and cold air intake have made the truck much more responsive. I came in via highway 50 over MONARC Pass. The truck has plenty of power to clime the grades and I am getting better milage, less smoke and quicker turbo spoolup.

My pulling mpg increased by 2mpg IE I am now getting 13mpg with RV, 18 city without RV. Do not know about highway truck only as I have not had opportunity to run any distance solo.

Hope this helps. I am very happy with the results with the TAG and Cool air intake.

 

[Vaughn MacKenzie]

That is where the TAG is most beneficial, when towing. Whose cold air intake did you install, Diesel Power Products'?

 

[Champane Flight]

Right foot.

I have almost the same setup you do. First turn that ole starwheel back to stock, then begin to use the right foot to ease into boost before you turn her loose. Go to the stock setting on the plate also if you have not yet. Without turbo and exhaust mods you can get real toasty on the pulls you find just west of CS pulling a load. I run a custom AFE setup and a four inch diamond eye exhaust, run around 900 post and 1200 pre on long hard pulls, but this is at 80, can't quite run this fast and make the corners on Monarch... . :-laf

 

[rosebunch]

Vaughn,
I installed the PSM cool air intake, and the DPP TAG. My EGTs ran cooler with these mods, also.
Champane, I do have the star wheel in the stock position. I have learned to be gentle with my right foot when first starting, which gives much better results than the LEAD rt foot at beginning acceleration at this altitude - but then she goes!!!.
Bob

 

[MMcCallie]

I've got my plate and AFC full forward with an open intake and 5" exhaust. Around 5,000 feet i can peg over 1,500 EGTs if i'm going around 90 mph. If i lug around or below 1,000 RPMs with too much pedal, i can roll enormous amounts of coal. When over 8,000 feet i've seen my EGTs over 900 while making less than 1 psi boost just lightly cruising uphill.

With my water injection i'm seeing almost no smoke at all and the highest my EGTs have spiked is a bit over 1,350. My boost is now being limited from over 42 psi down to 27 psi. I have yet to try it in the mountains. There is so little air at altitude.

 

[Vaughn MacKenzie]

Vaughn,

I have learned to be gentle with my right foot when first starting, which gives much better results than the LEAD rt foot at beginning acceleration at this altitude - but then she goes!!!.

Bob

Bob that's what I did with my '98 when driving to the 4-corners area late last March with the flatbed. The elevation varied between 5000 - 7700 feet. If I tromp it I'd make a nice cloud and the truck would bog. Roll into it easier and let it spool then it pulled strong with barely any smoke.

 

[Champane Flight]

Yeap

Once they spool, you can go around all those pesky naturally aspirated four wheelers, and under charged Pfords. It is toooo much fun. . I had a intercooler boot slip off the other day though, the wife was laughing at me, said I was showing off when it happened. I guess a set of Mr Bobs is in order... :-laf Sounded like a giant balloon popped! Knew what it was when it happened though, was just hoping it wasn't blown...

 

[rosebunch]

Yes, it sure is amazing how much further you get with a gentle touch! Ease in gently then watch her take off. Some times it is hard to stay gentle in a tense situation like trying to pull into heavy traffic. However as all ways a little self control pays off in the long run!