Upgrades to my Avalanche

Tim M

Tim M

PRESIDENT, Member # 015
GCC Member
Location (City)
St. Charles
First Name
Tim
Last Name
Mauldin
So the added weight to my trailer + the trip to Oklahoma proved one thing - I need to upgrade the performance on my Avalanche. A couple of things I've been looking at are cold air intakes and exhaust. Two Guys Garage added a Volant CAI to a 6.0 litre Chevy and saw 23rwhp gain. So, I think I will go with that. Exhaust, lot's of claims out there, but I can't find really any dyno results for exhaust. So, I think I will go with Gibson here. I'm hoping to get 30 add'l rwhp and torque, thoughts?

Exhaust - http://www.summitracing.com/parts/GIB-65574/

CAI - http://www.summitracing.com/parts/VNT-152536/
 
I have not heard of Gibson. But, most Mineke Shops will do a custom Magnaflow system for the same price - installed.
 
Forget about focusing on increasing maximum rwhp. Focus solely on rear wheel torque...

To improve towing ability try to increase torque at the RPM where your engine is generally working hardest when towing. If your current torque peak is higher in the rpm band than where you engine is running when towing...consider changes that will lower the torque peak to the rpm it is needed most. That may mean a lower maximum torque peak but you will have more torque where you need it most.

A low boost turbocharger would be a good idea as a turbo will build more boost under load....providing more torque where and when it is needed. One of the reason so many diesel trucks use turbos for hauling heavy loads.

Kerry
 
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Purple Venom said:
And that would equate to a cam change, right?
Click to expand...

More than likely... if you plan to keep it naturally aspirated...used in conjunction with a RV/towing style intake manifold change and perhaps small diameter, long primary tube equal length exhaust headers.

What you are hoping to achieve is maximum fuel efficiency at the RPM where you are towing. A shorter duration cam with decreased overlap will help. Smaller / longer intake runners and smaller exhaust tube diameter all serve to increase port velocity which helps efficiency.

All the traditional changes that increase HP at higher RPM and raise the RPM where you achieve peak torque...work against you if the goal is to increase torque at lower RPM.

However with a turbo you could keep your cam and intake manifold and change just the exhaust to accommodate the turbo. Re-degreeing the stock cam for use with the turbo and a lower torque peak would also help.
 
I'm fairly sure most of those mods would void the warranty.

Another alternative - new F150 V6 Ecoboost - 22 MPG, 11,600 lbs towing capacity.
 
Tim, If you are going to be pulling your trailer alot just trade your truck for a new diesel pick-up. You won't be sorry, my Dodge runs 300 hp and 600 ft/lbs torque pull anything you got and will get 18mpg most of the time. I know its a BIG investment at frist but I am on my second diesel pick-up and loved them both. IMHO

Rick:)
 
Rick, that is my last option. With the price of diesel, I'm not sure the investment would pay for itself unless I would get better than 8 MPG with a diesel. We'll see how this goes and figure it out from there, you may be right.
 
Tim, When I'm towing my fifth wheel about 9000 lbs I'll run 65 to 70 mph it will get 11mpg. Have not towed my boat by itself with the new truck but old blue got 16mpg boat and trailer goes about 3500lbs.

Rick:)
 
Fully loaded, I'm figuring my trailer is in the 6500 lb range. So, the math would be on a 400 mile trip:
Gas - 400 miles/8mpg = 50 gallons of fuel @ $3.70/gallon = $185 in fuel

Diesel - 400 miles/11mpg = 36 gallons of fuel @ $3.91/gallon = $140 in fuel

Savings - $45 per 400 mile trip. I would typically do 4 - 6 trips per year over 400 miles or less, so that would be about $300/year savings. That doesn't justify purchasing a diesel, assuming the new payment and the expensive repair costs that go with it. If it were a savings of $2,000 - $3,000 per year, then yeah, I would seriously consider it.

What were your mpg's without towing? I'm currently getting 18 - 21 on the highway and 14 - 16 in the city.
 
STL Mark said:
I'm fairly sure most of those mods would void the warranty.

Another alternative - new F150 V6 Ecoboost - 22 MPG, 11,600 lbs towing capacity.
Click to expand...

I looked at one at Pundman,$42000 4x4 was all they had, seemed over priced to me. 2 turbos on a small engine pulling alot of weight scares me!
 
Tim, I'm getting around 17mpg around town and 19 to 20mpg highway. I didn't buy a NEW diesel because of the new DPF on the new diesel exhaust so I only look at early 2007 and older trucks. looking at around 50,000mi for 30.000.00 $. A diesel truck is just starting to get broke in at that milage my last truck had 160,000 on it and still ran great just wanted to up grade to the new trucks, ride and noise. But I had very good service out of the old truck replaced lift pump and a power steering pump. You know diesel fuel used to be cheaper than gas I don't know why all of a sudden it went higher and they are not bring it back down. That is a bite but WTF.

Rick:)
 
Cai installed today. Started on the exhaust, decided I didn't have enough time, changed spark plugs instead. Wish I would have stuck with the exhaust, would have been easier. Anyway, will get the exhaust on tomorrow night, then off to Omers to get results :D
 
Hey Tim, If your trailer is only 6500lbs I would think with the upgrades you are doing the Avalanche would do a fine job. A diesel truck might be a little on the over kill, but why do we own a COBRA.

Rick:)

P.S. Did Paul get my post on the generator?
 
thanks rich. Rick, maybe, I appreciate your feedback, good to have hard numbers for comparison.
 
Tim, Anytime if you ever want to just hook your trailer up to see what the different truck tows like I'm sure we can get together maybe if I borrow your trailer for inspection you can go with me.

Rick:)
 
Sounds like a plan! :D Upgrades completed. Volant Cold Air Intake completed yesterday, took me a little over 45 minutes, changed the spark plugs to some that Omer gave me at the dyno day, and completed the exhaust today :D The exhaust is quieter than most performance exhaust, which is what I wanted since I drive this thing on long trips. Wanted to get it to Omer's tomorrow, but Rich says he is out of town, so will have to wait until next week to see if these upgrades did any good. Pics below.
 
Headed to Omer's tomorrow morning. Any bets on what new HP and tq numbers will be?
 
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