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Discussion Starter · #1 ·
Just wondering if I should add on:

POWER TOWER
K&N filter

Any thoughts? I'm hearing the increase in power is well worth it.
 

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May not hurt. You should check in to Airaide and others. I am using an Airaide intake and a Flo master system. They seem to help getting 19.5 mpg at 65 (not towing) out of a 99, 350 in a Z71. I am using a single not dual exaust system (did not want to mess with spare tire removal).
 

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K&N is on the list of mods, but from other Av owners I know I won't see a major improvment in mileage no matter what I do.
 

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Hi jman, I do have the helix power tower on my tahoe as well as flowmaster exhaust,k&n air system. Here is something else I have been looking at> www.vararam.com <, I have read some good things about it, also going to put up a set of headers when the budget allows. Kirk
 

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Discussion Starter · #5 ·
Kirk
I think I'm going to get the POWER TOWER. Did you yank out the factory intake/filter or did you just add a K&N filter to the existing box?
Did you get the performance increase they all claim? How about MPG?

That Vararam looks very simple. Wonder how true the performance claim is?
 

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Jman, Yes I did remove the existing air box and the bracket that held it into place. I then installed the heat shield and tube and tower to the throttle body, yours may be different my throttle body is on the front of the manifold, some earlier years were on top of the manifold. By taking the mounting bracket out this allows a direct passage to the under side of the tahoe and you get max air flow. I also made a couple of sheet metal plates to completely seal off the motor compartment and glued foam strips to the inside of the hood so I only get cool outside air. I think all mods to the motor have a adding effect expectually with intake and exhaust you have to do them both to see any advances in HP or MPG. This is why I will do the headers when the budget allows. I also use a superchip tunier to optimize the performance when towing and around town. Yes I do think it has helped with MPG and HP, every little bit helps, Kirk

PS I may just add a whipple supercharger to this thing as well, have been considering it, What a boost 275 hp to 375 hp with a single bolt on item, wow
 

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Discussion Starter · #7 ·
Excellent. I'll get all these mods soon. I don't think I'll be getting a super charger though. I have a teenage son, and I'd never get to drive my 'Ho!

Thanks for the info!
 

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Yea I know what you mean about the teenage son. Mine is still on his permit and about 2 month away from his lisence. Maybe thats why he is so for doing the s-charger
. Good luck with your mods,Kirk
 

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NDJollyMon said:
Any thoughts? I'm hearing the increase in power is well worth it.
Probably the most noticeable increase will be engine noise, not power. Both of your suggested upgrades have a tendency to increase the intake sounds, to the point that you can start to hear them in the cab under certain circumstances. Some, like the throttle body spacer, also have a propensity to make a whistling sound under load. That can get old fast.

There's one other thing to consider; since your increasing your trucks ability to "inhale" you'd really need to make the corresponding changes in it's ability to "exhale" (read: exhaust system) in order to take full advantage of those mods. But either way, the difference won't be significant.
 

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Discussion Starter · #10 ·
Jim...
Thanks for your thoughts. I never really thought about the engine noise. Then again, my FLOWMASTER MUFFLER is loud enough to where I may not hear it!


I'm going to my brother in laws for Easter, and I'll listen to his 'Burb engine. He just did the mod.
 

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Here is my list in the order that they will be installed:

Rancho adjustable shocks - Installed
4.10 Eaton positraction rear end - going in on Thursday
Thorley long tube headers & Gibson cat-back exhaust - next month
k&N FIPK intake - month after that
Hypertech Power-programer III - month after that

So in about 90 days I'll be done.

I subscribe to Sport Truck magazine and they do alot of dyno tests on these items. I saw in a past issue that they got 5hp to the rear tires on a Chevy 5.3 with the K&N FIPK system. On another test they got about 10hp out of a cat-back exhaust. The biggest bang-for-the-buck was the smog legal headers which put 35-40hp the the ground. Most numbers had a similar boost in torque as well.

I figure by doing the whole program I should wake up my 5.7 nicely
 

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Hi Jim, that is also on my list. Why did you choose the eaton and if you don't mind how much did it cost to install. I have a price of $1200.00 to put in a 4:10 posi but I did not check on the brand? Does eaton hold up better then other makes? Kirk
 

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Hey Kirk:

The Eaton brand is a very heavy duty unit and is a far better system than what Chevy installed. Also, Eaton has a long reputation for handling really BIG horsepower and torque in the racing industry, and is very popular amongst that crowd because of this. One last Eaton benefit is that in the event of a failure you can rebulid it. Not so with Auburn (Eaton's largest competitor).

The total cost out the door including 8.25% sales tax was $1098. This total was about $100 higher because I had them replace all the central bearings while they were in there. Of course $225 of the cost was for new gears because I switched from 3.73 to 4.10. For those of you who want to keep your ratio the same the cost will be less. $395 for the Eaton unit and about $200-300 for labor.

They also did a really nice job flushing out the pumpkin and axel tubes with some special solvent that gets into all the crevices and leaves the system totally clean. Make sure your installer does this.

One last note, after getting much advice to do so, I had them fill the system with Mobil 1 75-90 synthetic gear oil which is suppposed to run about 20 degrees cooler and will not foam in the event of a severe overheat. They also insisted on putting in one bottle (about 4 ounces) of a GM Positraction additive.

I'm going on a weekend road trip to Las Vegas today (without the trailer) that will put me over the 500 mile break-in needed before towing. Although after dropping $1000 in the rear end I'll be playing nickel slots!
 

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$700 is a lot to spend if there is nothing wrong. I guess I will wait until the GM factory limited slip fails, and the truck is no longer in warranty before I upgrade to that. I'd be interested in hearing what your non-towing mileage changes are though. I have the 3.73's, and would be interested in knowing the everyday difference with the 4.10's

Tim
 

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Most of these mods sound good. Some better than others, here is what I found out from experiance and from research. Hope this helps some of you all.

Throttle body spacers: Do there best work for those with Throttle bodies or carbs, when the spacer goes between where the fuel & air mix. The newer vehicles that have fuel injectors in the intake manifold or the direct injection to the cylinder there is very little to no gain. Because the fuel & air mix after the spacer.

Air Intake system: Improve air intake, improve mpg, and horse power but cost versus price is important to keep in mind! K&N system $200-300 for 1 or 2 mpg. Average HP increase of 10 or less. Slight increase in noise, rarely noticed by anyone but primary driver. Replacement K&N or other high flow filter is better, and cheaper choice.

Exhaust: Probly the best bang for the buck. More HP and better mpg on average 3-4. With just a muffler change. But, with good comes bad. In the form of noise! More than likely... alot.

I have done these upgrades, mods or what ever you want to call them on 2 of my own vehicles 5.7 and 5.3 suburbans. Remember an engine is a big air pump the faster it goes in, the faster it needs to come out to get good returns.

My 2 cents worth, hope this helps.
 

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Discussion Starter · #18 ·
Dern...
Thanks for your info! You sound like you've done what I'd like to do!

I think I'll do the Throttle Body Spacer & the K&N filter. I have a FLOWMASTER already. Air in...air out!
 

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Discussion Starter · #20 ·
True or False?

I have heard that the K & N type filters can foul up some GM sensor? (the filter oil)
Any truth to that, in anyone's experience?
 
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