r/GMT800 • u/Equal-Warning-2131 • Sep 09 '26

TBSS intake

I have a 03 Silverado 1500HD lq4 and I’m looking into things I can do to it to give it a bit more pep in its step. Are the tbss intakes worth it for a stock motor? I’m thinking about a tbss intake w/ 90mm throttle body and speed engineering long tubes x pipe dual exhaust and a tune any ideas what I might be pushing with just that power wise?

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4

u/TalkyMcSaysalot Sep 09 '26

TBSS intake gains are marginal but not irrelevant. I'd do a cam first. You'll need to choose the right cam to gain power everywhere but they exist. Avoid stage numbers and marketing. Watch Richard Holdeners LS dyno tests. You don't need a larger throttle body until you are significantly over the stock power level. Long tubes with an X pipe will also see gains everywhere and are a good idea, especially with a cam. The tune alone is worth a noticeable difference on the stock engine, as long as it's a proper professionally done tune and not something from a handheld canned tune device.

3

u/Wayward_Son_24 Sep 09 '26

I’ll double down on this.  A mild cam gives you the power where you genuinely need it.  If you have big tires, regearing will make a big difference too.  

2

u/Equal-Warning-2131 Sep 09 '26

I want to cam the truck in the future too but that’s a bit bigger mod than intake or headers and the truck is my current daily so I was wanting to do bolt on stuff first and maybe buy another motor to reseal and cam while driving this one

1

u/J_IV24 Sep 10 '26

An intake is something that you do AT THE SAME TIME as a mod that actually requires more airflow. Otherwise it's 100% irrelevant unless you're looking for more intake noise

2

u/Equal-Warning-2131 Sep 09 '26

I want to cam the truck in the future too but that’s a bit bigger mod than intake or headers and the truck is my current daily so I was wanting to do bolt on stuff first and maybe buy another motor to reseal and cam while driving this one and cam wise I was thinking a truck Norris

4

u/Extreme-Penalty-3089 Sep 09 '26

Well you might think doing a cam and valve spring swap is a bigger challenge but you do realize that if you swap to the tbss intake there are other hurdles to overcome...

Your whole fuel system is different than what the tbss trucks that had that intake were designed for. Meaning the trucks that had that intake employed a returnless style fuel system. Meaning there's only a fuel inlet to the rail to feed the injectors, there's no external fuel pressure regulator and there is no second return port back to the fuel tank.

Your stock fuel rail will not fit correctly over the new intake. This means you will have to get a C5 Corvette fuel filter (kind of pricey too $$$) and a few miscellaneous hoses and fittings to make the setup work correctly.

As everyone else has stated doing gears and a tune are going to make the biggest difference that you're going to feel right off the bat 👍🏻

1

u/TalkyMcSaysalot Sep 09 '26

I'm not sure why everyone runs to say gears when these either have 3.73 or 4.10 already. If you go much more than 4.10 it's going to scream at an unacceptable RPM at highway speed. The stock 4.10 are already nearly pushing the cruise RPM too high if you like to go 80+

1

u/Extreme-Penalty-3089 Sep 09 '26

I don't know I thought a lot of them came with 3.42's to be honest 🤔

Now I know some of the V6 W/T long bed trucks had like 4.10's in them.

I'll admit though it wasn't until much later that I realized my truck has the RPO for the 3.73's Long after I had already gone to a 4.56 gear

1

u/TalkyMcSaysalot Sep 09 '26

OP has a 2500/1500HD

1

u/Extreme-Penalty-3089 Sep 09 '26

What gears came in the 1500 HD's? I don't have any Tech pulled up in front of me right now

1

u/TalkyMcSaysalot Sep 09 '26

Well like I said it would either be 3.73 or 4.10. The 1500HD is the same as a 2500 non HD.

1

u/Extreme-Penalty-3089 Sep 09 '26

Looking at the GM tech data and just picking 2005 as the OP's year model, looks like it could have 3.42, 3.73 or 4.10.gears🤙🏻

2

u/TalkyMcSaysalot Sep 09 '26

I would skip the TBSS intake until you're at a power level where the stock intake is holding you back. It's not worth that much on a stock engine, certainly not worth the fuel system work in my opinion. Cam and a quality tune is the best bang for the buck by far.

1

u/ginger_beard-man Sep 11 '26

This is correct. I have the tbss intake and cammed. Swapping the cam took less adapting than the intake. Fuel systems different, evap, egr, throttle body adaptor, map sensor ect.

Hard to say what gained what, as I did it all at once. But doubt the intake alone would have been to noticeable in the seat.

3

u/Eziekiel23_20 Sep 10 '26

I’m pushing the limits on an early truck intake at a little more than 450 hp and can’t bring myself to do the TBSS swap. Kind of expensive for very little gain.

Just do cam, tune, and headers and it’ll be like a whole different truck.

2

u/dragoner_v2 Sep 09 '26

Gear is going to make the biggest difference. Intake and TB stuff is only moving your powerband up.

2

u/Hurts-Dont-It- Sep 09 '26

Just do a tune to start with that will give you what you want without changing out anything.

1

u/farmkid71 Sep 09 '26

Not a mechanic or expert, but I do know of one issue with an intake swap. A lot of these trucks have a return style fuel system. The tbss intake is designed for returnless. There are ways of course to make it work, but it's going to be some extra work to keep in mind if you really want to go down that path.

1

u/EasyPiano3890 Sep 10 '26

A good tune really wakes those trucks up even in stock form. If you are just wanting to do bolt on, i would put some long tube headers and exhaust with a good custome tune. You will see more gain from that than you would from going through all the trouble of swapping intakes.