BIG DECISION HERE!!!

Okay so a buddy of mine is about to start up a speed shop and specializing in GM trucks. I am trying to decide if I should go the lifted big tire route or get more power with a set of long tubes, y pipe, water-meth injection, tune, intake, and tranny cooler and say gain another 100 horse or so
What about my tranny?? He said most transmission failures are due to heat anyways so a cooler would just help that much more
What yall think?

I've never understood the lifted route. Unless you are seriously into offroading I don't see the point. All you do is increase your fuel usage, restrict underground parking access and increase your possibility of a roll over ( not sure if you saw the thread about the guy doing a 360 on the interstate.)

Now horsepower is the universal language for fun! Giddy up. I'd recommend a blower as that is the best bang for the buck. I'm not sure how water/meth injection works but I question the 100hp you think you'll gain. I'm running 6psi of boost and only got 100rwhp. Granted I went with a conservative tune.

JohnnieMo said:

I've never understood the lifted route.

Now horsepower is the universal language for fun!

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I agree with JohnnieMo, I never understood a huge lift, especially on a 2wd truck.
(I own a 4x4 and I wanna do a 2/3 drop! I would go lower but Canadian winters force me to not turn my Avy into an expensive snow plow.)

Also for the money dropped for a quality lift kit, gears, and big rim and tire set-up you can add a blower (or other go fast goodies/power adders) and beef up the trans for lots of fun, while attracting a lot less attention from the PoPo.

P.S. since you have a 2wd, you are the perfect candidate for making a true street sleeper! Without the transfer case as a weak link, all you have to do is a quick tranny build (Vette servos, input sprag, stage 1 kit, etc.) and put some added horsepower in front of it, for some tire twisting fun!

I agree to the extent of your AV being a 2wd, like DO said, it doesn't make much sense. And personally IMO the newer body style AVs don't belong offroad.

No no no 09chevyavy, these guys have it all wrong. LIFT IT!!!! You know were my 2 cents is coming from because I think you and I have bounced some threads back and forth, and they were regarding "Lift". Do it and make that sumFEMALEDOG look like the factory SHOULD'VE made it look!   I had an 05 lifted 6" on 35's that I traded for the new 13 lifted 6" with 34's(I think you've heard my story, so won't bore ya beyond that). So I've never had the "luxury"(saying that sarcastically) of owning a stock hieght Avalanche. But i DID log a couple hundred miles on a friends 07 back when it was new in 07 and its WHY i got into Avalanches!!!! Got my lifted 05 shortly thereafter driving his new 07 cause i just loved it, and my 05 was just as comfy with the lift!! They are SOOOOO the perfect rig to lift!!!! The "weight/balance/ride" of that whole setup is just PERFECT to lift and still have a "soccer mom rig" feel.(yeah that's right, i said it, and not afraid to admit it either!) As far as parking garages, I haven't found one I don't fit in yet with a 6" lift(tho, you'll wanna take it slow on some of em, hahaha) And the BIGGEST bonus for "us city folk" is that I get to see brake lights 4-5 cars ahead instead of 1 car ahead..... As far as gas milage, I'm getting 13 from the start of the life of the rig(new, out the dealership lot with lift) and noticed that its just getting better and better(was 9.8 in the first few days).... If ya bought an Avalanche for superb milage, ya bought the wrong rig!!!!(in my humble opinion) And coupled with that 6 speed tanny(vs my old 05 with a 4 speed) I only see mileage getting BETTER as we go.....

Sorry for the long post, but make it look like the Factory should've made it look man!!!!

And oh yeah, I almost forgot, I GARANTEE that my lifted Avalabnche rides nicer than a lowered Avalanche!!! I just don't see how you could get one to ride BETTER than this, I really don't..... Kinda goes against the "laws of lift", but its not 1986 anymore and we're not just dealing with blocks and lead springs for lifts anymore..... Just sayin'.

Let me know if I convinced ya!

Whichever way you decide I think a tranny cooler is one of the best mods you can do.

The cool thing is there is no wrong answer 

... just a variety of opinions. 

I think I am gonna go ahead and do performance followed by lift. Best of both worlds right!!!
Now these stats I got from my buddy, without a tune on a 5.3 like mine
He said and I quote
"Long tubes and a y pipe will give you 25-30 horse because of better flow
Intake will give right at 20 (he does custom intakes with drag racing filters and such)
Water meth injection will put my right around 35-40 horse and 1-3 mpg increase as well, this is because the water/methanol mixture (51% h2o 49%methanol) shoots directly before the throttle body and cools down the combustion and keeps it burning longer so it will burn more fuel in the chamber, it also makes intake air temp go down 5-15% and gives a 20-25 point fuel octane jump up. So from 87 up to 107-112
Add a tune on that such as diablo sport that says 15 horses stock, which it won't be because of the mods.
He also said adding a tranny cooler would make that okay and maybe a servo to tighten things up


Then I talked to him about lifting it and he said "hey why not go for both of them!" So I'll do that!!!! Sounds good to me!
So I will be still doing the 7.5 lift kit and 35s and 18 inch rims (level 8 trackers to be exact- because of cheap price- $500, right back spacing, and I love the Mickey Thompson classic locks but they are too small. I need 18s or knuckle on kit will rub!!) and swap my gears out to a set of 4.10s

Sounds like a plan guys thanks for the input

Also, Johnniemo, the water meth works even better with boosted applications. They've been know to add around $100 horse alone. And also, if this is wrong, don't kill the messenger!! Unless its with kindness or free money.  everyone can use some of those

Moe02 said:

Whichever way you decide I think a tranny cooler is one of the best mods you can do.

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I think your buddy is a good salesman, LOL! 

I'd put money that before and after rwhp increase with those mods would be less than 60.

You don't need anywhere near that much octane without forced induction or increased compression.

Why not a cam?  Why not a custom tune?  Why not a torque converter?  Why not forced induction?  Why not non-dished 4.8 pistons to get the increased compression to make use of all of that octane?

The skeptic in me says it's because he's only doing bolt-ons. 

Okay that all makes sense I know but here it the research that I have done
Also, I am trying to spend as little money as possible because I am 16, so its not as though I have a steady paycheck
Cam- the cam isnt the problem, he said that the biggest thing is the labor involved and then after that the tune and computer mods, after all that it would end up being around $2,000 which I dont have

Custom tune- I will probably end up doing that from another shop in my local are so thanks for that inspiration!! 

Torque converter- I have no clue what goes on with those and maybe you guys can enlighten me on that

Forced induction- Same problem as the cam, too much money for me

Pistons- I could check that out but it seems like it would also be good chunk of change and also take lots of time.


Also, this is my daily driver and need it to be driven everyday because I share it with my mom at home because she only has a work car for to and from work so I'm looking at bolt on stuff because I need the truck on the weekends unless I pay for my moms rental car which I would do technically because its only about $35 for the weekend

Also, where can I find someone to talk to about a custom tune on the site here? Anyone? And whats the piston thing you're talking about? And I'm still confused about the torque converter

Nelson Performance has a good rep for custom tuning - do a search and you can find them on the web.  I do my own tuning but have purchased and used for many years a wiring harness from Nelson for my radiator efans.

4.8 and 5.3 engines have the same bore.  The 5.3 is a low compression engine, due in part to the dished pistons.  (Dished pistons have a carved out section in the middle of the piston giving a little extra combustion chamber volume.)  This makes it a really good candidate for forced induction.  The 4.8 pistons are not dished, giving that engine a compression boost.  Since the engines have the same bore, one can put the 4.8 pistons into the 5.3.  In general more compression equals more power up until you get detonation, with that point being dependent upon how much octane you are running in your fuel.  Given your situation, changing pistons isn't probably something you want to do now as it would be more invovled than a cam swap.

A higher stall torque converter will allow the engine to rev higher taking off from a dead stop.  If you floor your truck from a dead stop you'll probably see the tach jump up to 1500-1900 rpm or so I'm guessing.  A higher stall speed torque converter would let the engine rpm jump higher and more into the engine's power band coming off the line.  Depending upon how high you go the more you would really need a tranny cooler as extra heat is an unwanted by-product of the high stall torque converter.  Given that you have to drop the tranny to install the torque converter you're probably looking at about at least $600 in labor plus about $400 for a new converter.  That may be a bit much for your situation.

I didn't mean to rain on your enthusiasm.  I just wanted you to have some realistic expectations.  That said your tires and wheels will probably set you back more than $2000 and doing a gear change will probably cost you close to $1000.

I'm glad to see you are excited about your truck.  That is the best part!

I also don't want to rain on your parade - just want to tell you what I know.  The more you know the more informed your decision will be.

I get funds are tight.  At your age I dropped $6500 into a stereo in my Chevy Lumina.  So you are starting well ahead of me 

Before you do anything, drop your truck on a dyno and get a baseline run.  My truck put out a paltry 233rwhp and 272rwtq.  There is just no way adding exhaust is going to bring that up 25rwhp.  To make power you need more air and more fuel.  The water/meth is something I just don't understand....  is it like nitrous at all?  Does it add extra oxygen?  If not, nitrous might be a better route for you.  Cheap and big power gains.  You also only use it when you want to.

I did the magnacharger, cat-back exhaust and cold air intake, and only got 100rwhp.  These engines just don't start with much.  My Trans Am with the LS1 added 200rwhp with a similar setup.  But it was starting near where my truck is at now. 

As for long tube headers, there is a lot of debate on those on this site.  Take a read.  Generally, longer tubes are meant for very high horsepower (i.e. very high RPM).  Off the line, where you need the grunt to move the truck, you might want short tube headers.  Or you could just leave the stock ones.  That is what I did. 

Gone are the days where bolting on a few new parts made big power.  The manufacturers are learning to squeeze every bit of "safe" power out of these engines.  To get big power, you need to take big steps. 

I was looking at intake, exhaust and gears and my shop said "don't waste your money"

When you are done your mods, get another dyno run and see where you are at.  Then let your buddy see it and you'll know whether or not he sold you snake oil.

I think that is the bad thing about engines these days!! My dad was saying when he was in high school on his first truck he put in a new cam himself along with a carb and exhaust and made the tires chirp between 1-2, 2-3 and if it was wet 3-4. Like that is insane!!! Why cant that happen anymore?? Either way I think I am gonna go ahead and do all these upgrades. And hey, if it doesnt work out, no sweat really. Just money lost and a big lesson learned. Better to learn now when I am still big into research and all that and take that experience and use it later. Thanks for the advice guys!!! How much did you guys throw down for a new supercharger? It seems like around $5,000 and like I said I don't have that laying around but it's cool just to know for the future if I am in the situation to be able to spend it

Also I would be swapping out spark plugs as well. Would a tune be fine or am I looking at bigger injectors as well?

09chevyavy said:

Also I would be swapping out spark plugs as well. Would a tune be fine or am I looking at bigger injectors as well?

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I was about to suggest at an extra 100hp you'd need to do some fueling mods but I'm not sure on the Gen IIs and if its a flex fuel vehicle to begin with it's already set up to flow some extra fuel.

Also depends upon if you want to up your WOT shift points.

09chevyavy said:

I think that is the bad thing about engines these days!! My dad was saying when he was in high school on his first truck he put in a new cam himself along with a carb and exhaust and made the tires chirp between 1-2, 2-3 and if it was wet 3-4. Like that is insane!!! Why cant that happen anymore?? Either way I think I am gonna go ahead and do all these upgrades. And hey, if it doesnt work out, no sweat really. Just money lost and a big lesson learned. Better to learn now when I am still big into research and all that and take that experience and use it later. Thanks for the advice guys!!! How much did you guys throw down for a new supercharger? It seems like around $5,000 and like I said I don't have that laying around but it's cool just to know for the future if I am in the situation to be able to spend it

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I helped someone install a cam in their 5.3 AV and with some tranny and other mods he did on his own he was chirping his AV's tires on the 1-2 and 2-3 shifts.  Given that 3-4 in these at WOT would probably be somewhere around 150 mph I don't think he ever tried that - especially if it was wet!  I managed to shatter the output shaft of my tranny when the tires hooked instead of chirped on one 1-2 shift.... 

A magnacharger kit comes with everything you need and it sells for around $5500 - $6000.  You could likely find a used one as well.  They install fairly easily.  If you have the flex-fuel system you already have a larger fuel pump.  However I don't think it matters either way for the blower.  100HP will work under the current pump, but I'm not sure for injectors.

Spark plugs are like changing oil.  Do it when it is needed, but don't expect anything to change performance wise.  Wires are good too.

Yeah I heard wires are a good thing to swap out for a little more spark.

At this point my plan is a custom intake from my buddy, maybe a throttle body spacer, pacesetter long tube headers and catless y pipe, and either a diablo sport or custom tune. Water meth injection would come later on because the kit is $830 and other stuff like the solution itself as well as adapters to run into a plastic intake tube and such would bring it up around $1000 so I don't think that will happen

Then I will save up this spring and summer and probably next fall with birthday money and get the rough country 7.5" lift, new 4.10 gears, 35x12.50R18 Mud grapplers, and 18x9 level 8 tracker rims or 18x9 xd cranks in flat black

After that, phew I have no idea!!!
I would be looking at either dropping a 6.6 in there or a supercharger hahaha

Either way eventually I want to be sitting on 40x15.50s, rolling coal out the back, and sitting up high and protected by some bumpers and custom rock sliders

I was thinking at that point with that lift I would contact my fiberwerx to talk to them about a set of fiberglass fenders front and back to fit them

I am thinking it would be sweet to run some 38s on basically a 6 inch lift with some fab work on the saddle bags and I would make some custom wheel well liners just to try and keep it somewhat clean. Also would upgrade axles and maybe drop in 2500 front and rear axle assemblies and just end up spending some ungodly amount of money on the thing but hey it's like we all say on here......... Once the mod bug takes over, nobody is stopping that freight train!!!!!

Save your money on the throttle body spacer they don't help anything.

Yeah I know, but they do make it whistle a lot so it sounds really really cool!!!

09chevyavy said:

Yeah I know, but they do make it whistle a lot so it sounds really really cool!!!

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So does my Vortech Supercharger and it definitely does something! 

Bought it used for a fraction of the new price. 

Where did you find a used supercharger?!?!?! Why would anyone take it off after putting it on