Fellow Silverado friends,

I have a 2005 Silverado Z71 with 6L motor. I've had the following upgrades already done:
- Truck racing CAM (I cannot tell you the model info, don't think it's too aggressive)
- Upgraded air intake (large cone / cannister type)
- Headers & true dual exhaust with MagnaFlow mufflers
- 3.90 gears (front & rear)

I'm not "racing" the truck, but I do want the most performance I can get out of it, within reason. A friend suggested that the next step would be a turbo. However, I understand that while increasing power, the result is also stress on other drivetrain components. Since I know the turbo upgrade can easily run 2,500 and higher, this is a bit above my budget, not to mention other components I may need to consider upgrading due to the stress from the added power.

Any suggestions of other upgrades I can make without breaking the bank? I could presently throw perhaps up to $1,500 at it. Appreciate your thoughts in advance.

Joe

 

Let me add - also deleted the catalytic converter.

 

FWIW. I've built and had built some LS6s in a pair of C5 Z06s and a 1st gen CTS-V. Also helped friends build LS1s. The LS motors and I'm assuming the truck motors aren't that far off like ceretain upgrades a lot. So here goes some basic ideas.

* Starting with the air filter and replacing with a K&N in the stock box or modify it to get more air or buy an aftermarket cone filter setup. Only caveat with the wide open cone setups is protecting it from water and keep it away from the radiator. Simple and fairly cheap.
*Best bang for the buck and provides consistently good performance. Headers, long tube only, forget shorties. With that also go to high flow cats or none. An X-pipe is a good idea to help balance it and reduce drone. High flow mufflers are required but don't need to be obnoxious.
*Get it dyno tuned to squeeze out the most power safely. Be careful of too lean tunes and don't mess with the rev limiter.

Now you're moving as much air in/out as the factory TB and possibly intake manifold can handle. You also might be close to the limit of the fuel injectors.
*Intake.
Starting with the TB. A larger flow preferably polished. The larger stock GM ones polished up can handle quite a bit of air.
Intake Manifold. Again a larger flow stock GM fully polished is cheaper. I really like FAST LSx intakes but they're more expensive.
Dyno tune it again.
This may be time to bump up fuel injectors depending on where you are running out.

Cam and more.
*Mild - This really needs to be mated to what the stock heads, intake, fuel injectors can handle. Going mild will also keep the upper end more stable. On LS engines you need to protect against valve train float. Again very mild cam should be ok. Pick one that lends more to the torque/horsepower/rpm curve you want. Dyno tune it.
*NOT Mild - Wild or Race - You need a big budget. You really need to do the whole top of the motor. This also assumes that bottom end can take a big bump. Needs a lot of research and good builder. I've had one of these done for me and I spent $5K with no bottom end changes about 10 years ago.

This is just a short rambling on how I go about adding power. I've always been pleased with a header upgrade. Improving the TB and intake has been a good choice to further push the header upgrade. After that it always ends up getting expensive.

I would strongly suggest you go back to the builder and get very detail specs on your cam and research how much air/fuel you can move with it. That way you can verify whether the TB, intake, fuel injectors, and valve train are working together and whatare the limiting factors instead of just buying stuff. You want a clean and stable build.

I don't use power adders as my cars are all built for road racing and they are too prone to overheat with those. If you look at turbo/super charging understand all the issues above are still important. Just slapping a turbo on a motor with no improvements elsewhere usually ends up with bad news.

Good luck. Your truck sounds like it already has some fun added in.