Make it run faster with stock everything..

Taylorboy · June 24, 2020

Just bought a 2015 gmc 1500 crew cab 4x4 and was wondering how to make it faster? Any ideas

CamGTP · June 24, 2020

Remove all the seats, doors and bed, it'll be way faster now.

You are basically pretty limited here. Getting a tune is your best bet for picking up a little bit of power. Also installing a flex fuel sensor to run E85 will help pick up a little power over regular unleaded 87 or 93 octane. We aren't talking a ton of power either, maybe 15-25hp.

Actual changes to parts needs to happen to really make it faster. Like a camshaft swap, headers, gear ratio changes, supercharger etc etc etc.

Edited June 24, 2020 by CamGTP

michigan2500hd · June 25, 2020

Seems with modern day naturally aspirated vehicles there's isn't a lot of power left to unlock. Like it's been said before a custom tune will wake it up some.

I been going to lighter wheels and tires. Had 20's with heavy tires and wheels with mud tires, etc over the years.

I just bought some stock 2020 18" wheels yesterday with stock 265/65/18 Michelin primacy LTX tires and immediately felt the difference .

My stock 17" with 285/70/17 Duratracs weighed 76# each. Similar to some of the stock 20" wheels and tires. Now my set up weighs 62#, that's a unsprung savings of 14# per wheel and tire.

My point is I probably gained more "power" by doing that then I did with my Magnaflow exhaust or intake.

Taylorboy · June 25, 2020

I Understand on the weight of the tires etc.. I’m not trying to break the bank and definitely not trying to dig into the motor as far and cams and stuff what I’m asking is?.. What would be best for better gas mileage (tuner or programmer) and still have enough power to get up and go when I need it to. Really would like to go faster than 99mph what could I do to turn that function off?

CamGTP · June 25, 2020

Your foot and how well you follow speed limits is going to the biggest factor in fuel mileage. I drive 95% city so my avg mileage is between 10-16 depending on what fuel I am using. When I go to the cabin about 100 miles away getting low 20's is very easy to do even with the active fuel mngt disabled on my truck.

If your drives are a lot mix of city and highway you will probably always be around what the truck is rated for. Roughly 17-20mpg or so.

I've tuned many trucks over the years and just changing some stuff then getting 2-3 mpg isn't going to happen. If that was the case then they would have done that from the factory.

The 5.3's have plenty of power, there is no worry there. A good engine and transmission tune can make it feel like a whole different truck. Removing the 99 mph speed limiter isn't a good idea unless you fix the reason why first. For one your tires need to be speed rated to go above that and the biggest reason is the rear driveshaft. They are not rated for going that fast and it could explode at speeds above 100mph. There are many pictures and even dyno video's of stock GM aluminum driveshafts going boom and causing thousands of dollars of damage to the sheet metal, fuel tank and transmission/transfer case housings.

xSHIFTxNASTYx · June 25, 2020

9 hours ago, Taylorboy said:

I Understand on the weight of the tires etc.. I’m not trying to break the bank and definitely not trying to dig into the motor as far and cams and stuff what I’m asking is?.. What would be best for better gas mileage (tuner or programmer) and still have enough power to get up and go when I need it to. Really would like to go faster than 99mph what could I do to turn that function off?

Not picking on you but I do agree with @CamGTP, fix the reason why you feel the need to go faster than 99mph. He's right that there is a reason why the limiter is set there. Plenty of vehicles can reach top speeds higher than 100mph if they're built for it; engine, drive train, axles, wheels rated for it, etc.

But I digress because I've done the same thing before long trip up north on back country roads, pushed it to see how fast I can go on a long 5 mile straight stretch of highway, actually broke 100mph and hit 105mph before I backed off knowing that it isn't safe to be driving like that (must not have the limiter set on my truck?) - just wanted to see it for fun but with heavy Duratracs.....them things were humming like a bumblebee!

8 hours ago, CamGTP said:

~~ ..... rear driveshaft. They are not rated for going that fast and it could explode at speeds above 100mph. There are many pictures and even dyno video's of stock GM aluminum driveshafts going boom and causing thousands of dollars of damage to the sheet metal, fuel tank and transmission/transfer case housings.

The thought of a driveshaft going boom reminds me of watching pulling trucks in person have their drive shaft and u-joints explode.....you would never realize the kind of destruction that causes until you see it in person..... Also the main reason why they require heavy thick metal shields around front and rear u-joints when racing. Yikes, it is NOT a pretty sight. Think about it, it's dangerous for pit crews if that happens, imagine driving 100mph and having it explode vs a pulling truck at high torque only moving 10-20mph and having it explode under full load and extreme stress.

Donstar · June 25, 2020

18 hours ago, Taylorboy said:

Just bought a 2015 gmc 1500 crew cab 4x4 and was wondering how to make it faster? Any ideas

Welcome to this forum! you will find a lot of good information on this site. I've owned a stock '15 with the base powertrain for 5 years and never needed or wanted it to go faster. This prompts me to wonder why you are finding your truck needs more speed. Is the speedometer set on kmh's or is there a mechanical issue? If you are going 99mph on the fastest Interstate and not passing everyone in sight, then your truck is not in proper working order, imo.

Grumpy Bear · June 25, 2020

4 hours ago, Donstar said:

I've owned a stock '15 with the base powertrain for 5 years and never needed or wanted it to go faster.

If you are going 99mph on the fastest Interstate and not passing everyone in sight, then your truck is not in proper working order, imo.

X2 and X2

:thumbs:

flyingfool · June 25, 2020

I would buy a used AMG from 2006-2014 , they are designed to go over 140mph on the street

dgstarr63 · June 25, 2020

If you have a 3.08 axle ratio, changing to a 3.42 or a 3.73 will make it much faster accelerating and make a considerable difference in towing ability.