2001 Yukon/Tahoe 5.3 Towing sucks. Help

Had this Yukon for a while has about 70k miles, but it just seems gutless. I've heard the 6.0 is better, but I'm wondering what people have done to powerup their Chevy/GMC 5.3's

Check your gear ratio in the differential. That's the easiet way to improve it's towing ability, just like a lower pitch prop.
The alternative is getting more air in through internal changes like a cam or head porting, or external like cold air induction and exhaust, or turbo or supercharging.

I actually drove one that had a whipple charger, it was awesome, of course those are like $6k.

#1 trick is the axle gear ratios!

Get a new PCM at PCM For Less. Ask them to remove torque management, but it will be at the cost of the driveline.

Do not put a K&N into it. Instead open up the air box with the factory filter and you will get the same power, for less cost and keep the MAF in good shape. Many will run a dryer duct to the fog light area and gain substantial power.

When I got my PCM from Wester's Garage, he said the dyno pulls showed the exhaust would not make a different unless headers and everything back were replaced. Cats are darn expensive and therefore it becomes a loss of power in the low end for little to no gains in the high end by just putting mufflers, to make a nice quite vehicle loud.

I have an 05 Avalanche with the 5.3 & 4.10 rear. It pulls my 4500 lb Vride without much trouble. It'll gear down to 3rd going up a mountain pass but still pulls 50+ mph without any trouble.

what kind of mileage you guys getting with the 5.3 ?

I have a stock 2006 4.8LT GMC. Pulls the B52 just fine. Quite suprising to be honest.

15 mpg in town, 20 mpg at 60 mph, drops a bit at 75 mph. 11 - 12 mpg towing the boat.

I have a '07 Sierra 1500 crewcab w/ the 5.3L and it pulled the Moomba's 4100 lbs just fine. And that was before i opened it up w/ a Airaid cold air kit, Airaid powerAid throttle body spacer and had a local muffler shop dump the stock muffler & cat and install a fairly quiet performance muffler along with a legal performance open cat. It's only slightly louder inside and all this DID increase noticeable power & torque in the mid-high range as well as i gained almost 5 mpg.

Rob, I'd love a Whipple but my wife would cut off my ... well you know if i did that!

Bill K ~ Do you have a special ed. V-ride??
4,500lbs??? Here is the specs on a V-ride:


Overall Length: 21' Beam: 93.5"
Capacity: 10 persons Weight: 3000 lbs.
Hull Design:

"Bill K ~ Do you have a special ed. V-ride??
4,500lbs??? Here is the specs on a V-ride:


Overall Length: 21' Beam: 93.5"
Capacity: 10 persons Weight: 3000 lbs.
Hull Design:"

4,500#'s sounds pretty close when you add in the trailer, which i'm sure he uses when he tows it, fuel, gear, etc.

buguru, with trailer, rims, and all the gear I would think that could easily get up to 4500...especially if he happened to have some lead or other ballast that you can't drain. I mean if you think about it if you had a big cooler full of ice and beer...I mean non-alcoholic beverages...that itself can be 100lbs. plus I'm sure that was a rough estimate on the weight by him anyway.

By the way I have an 05 Z71 tahoe with the 5.3. I put a K&N FIPK cold air intake in it (removed the bottom plate that the stock box sits on) and also a 1 in 2 out flowmaster with turn downs and I noticed considerable gains both driving and towing. But what helped the most was getting a custom Tune done to the pcm by Justin at BlackBear Performance. Go to Z71Tahoe-suburban.com and look under the blackbear performance section and there will be contact info for him. Basically he sends you a cable to hook up...drive around for a while then send that cable back to him...he'll custom tune a new pcm to what you want it to do and send it to you and you send him your old pcm. He can tune it a lot better and in a lot more areas than just a bullydog or the other tuners you can buy.

Yea Rocky,
4500 is probably pretty high. I believe the boat specs out at 2900, and the trailer around 1200 lbs. But add the additional weight of the 18s Dan put on the trailer, a full tank of gas, a pair of SkySkis, and a full cooler & I'd bet I'm not far off.

I just looked it up I have the 3.73 axles but I also have 20" rims. Pulling the boat is pretty bad, but in the winter towing a 4 place snowmobile trailer it gets really weak. Pulling up the canyon near our cabin I'm down to 1st gear for a lot of it and can't hold above 35 even.

Let's hear some more about the airbox modification.

and Sippi, what did the pcm cost?

Any benefits to just a K&N filter?

Peter, that's been my experience with cat back exhaust, you gain a little towing but really suffer on the bottom end.

By the way, the minimum elevation I ever tow at is 4000' and I tow up to 10K'

You're losing 15-25% of your available power due to altitude. Turbo works very well at high altitude. Your gear ratio should be 4.10:1 or higher.

Cold Air Intake will help. that with a good exhaust (borla, magnaflow, flowmaster) and then get a custom tune from justin and that's the best mods you can do with out a supercharger/turbo. as far as the intakes...go to that forum I posted above and do a search for intakes...Justin did a test of all the most popular intakes like K&N FIPK, AEM Brute Force, and a few more..as well as just a K&N drop in filter to the stock box. basically the AEM had the highest Improvements with the K&N a very close 2nd. the reason being with the AEM the instructions call for the removal of the bottom plate that the stock box sits on. I have the FIPK and I took off that plate so mine would get the max it could just like the aem. if you take the top off the stock box with a drop in filter its not the same and you wont see the same improvements because its pullin air from a small space between the top of that box and the hood. a cai with the bottom plate is the next step up from that because it has more area to pull the air from as well as not pullin hot air from around your engine due to the shield. when you remove that bottom plate you can see all the way to the ground from there. what this does...when your driving and air comes through your bumper and in front of your wheel well it gets pushed up through that hole you created and forces it into the filter allow more and colder air into your manifold. the MAF will not get messed up and fits perfectly in there. you will not throw any codes or anything.

as far as justin's prices. I'm not sure that he wants me to post them but I will say its cheaper than buying a tuner (like a bullydog) and you get much better gains in whatever area you want them since he can change things the tuners can not. also if you sign up on the Z71tahoe-suburban site you get a nice discount!

All of you who think K$N type filters are so great read this article. It is a scientific ISO test so there is no disputing the results. If they are saying the stock air filter is good enough for a modded 500 HP diesel then they are good enough for a small 5.3L gasser. http://duramax-diesel.com/spicer/index.htm

Subscribe to a couple of the GM forums and do a search for "dryer" or "air box" and I am sure you can find many articles like this one http://www.gm-trucks.com/forums/index.php?showtopic=21077&hl=dryer+vent

You will actually gain more power than an AEM or other type intake system as you are forcing air into the motor at speed. Ram air does work. Many will pull the tow hook or the fog lights to install the tubing. You do have to be careful or water intrusion.

Call PCM for Less and find out what they charge. My PCM was around $400, and $50 for any additional reflashes.

I would still say gears will make the biggest difference, and lose the 20's. 20's also affect braking substantially.

"the MAF will not get messed up and fits perfectly in there. you will not throw any codes or anything."

So how much experience do you have with these things and automotive diagnostics? Tell my co-worker that one as his Chevy was throwing a code for the MAF before he cleaned it. And yes he used a lightly oiled K$N.

I'm not talking about closed air boxes I'm talking about the the stock air box which is more constrictive than a closed box system like a voltant. the study that justin did actually did include the voltant system. an the aem had higher numbers than it. what you are talking about is a ram air which does force air into the intake...when you take the bottom plate off it basically makes the ram air system.

and I have enough experience to where I've put the FIPK system on 4 of my trucks and a few of my friends trucks and have never thrown a code with them. I also worked in a shop through high school where I put countless fipk systems on and never though codes.

The two things you can do that are reletively inexpensive and will provide about a 10% combined increase in peak hp are 1) reprogram and 2) cold air intake.

Superchips Cortex (~$400)
http://www.superchips.com/categories.php?p_cat=99&cname=Cortex+Programmer

Volant CAI (~$400)
http://www.volant.com/cai_kit.asp

Re-gearing on a 4WD will be expensive as you will have to do it on the front and the rear differential, but will provide about the same 10% gain (if going from 3.73 to 4.10)

Supercharging would also do it, but i would guess it would be overkill spending $6k to have it pull your boat better.

I can tell you getting your pcm custom done is somewhere around 1/2 of that superchip programmer and he'll be able to do more than the programmer will. Also you can get a K&N FIPK or AEM cai and remove the bottom plate that the stock box sits on and it'll run you about 1/2 of what a voltant will. and from justin's study i do believe the aem had higher increases than the voltant.

I have an 07 yukon xl with the 5.3 man that thing is gutless when I tow it not only has no power but it also surges. I had it back at the dealer and they said it was the size of my boat 06 supreme v232 causing this so I went back with my bass boat in tow with the same problem and the service mngr. said it is just a design flaw and I had to live with it so we tow with the duramax. But it sucks having an oversize station wagon that wont tow

I know this comment is adding absolutely nothing...

but I have a stock '03 Avalanche with the 5.3L and 100k miles, and it pulls my boat just fine. I drive up and over mountain passes almost every weekend. I use the tow/haul mode and run in 3rd gear on the flats at 70 mph and up hills in 2nd gear at 55 mph (I believe 3500 rpm's). My boat weighs about 5k.

Silverado 5.3 w/4.10's and Tahoe 5.3 w/3.73's.

My silverado tows pretty well, stronger up hills, but I prefer the Tahoe because it rides so well. It's not quite as strong up hills but not too bad.

Here's the important part; both vehicles have stock Z71 275/70x17 tires. I would bet most of you guys complaining about power are running oversize tires??? Or worse, oversize tires and lift kits?

If you want to instantly kill the performance of your tow vehicle put a lift kit and big tires on it. It will surely be gutless and malhandling.

Not running the stock wheels and tires does not automatically causes power loss. This is only true if you increase the overall height of your tire. For example a 275/70x17 is 32.16" tall. If you run a 285/50x20 you are only at 31.22" tall, which would actually slightly increase your power at the wheel (more rotations/mile). I run 315/50x20 All Terrains on my 07 Avalanche. I think once you get to 33" on the tahoe/yukon/avalanche body you need to get a lift to accommadate them.

do you have the tow/haul button on?