F8L Z71

Remember that dyno's are different as well as the correciton factors used, the shape of the HP/TQ curve etc.... I about slipped my lid when I saw what the first 5.3L STS equipt truck put down at 15psi. It read 512rwhp or somethng but looking at the curve you could almost puke it was so sloppy. Also the tuning can make a hell of a difference. If you wanna run on the ragged edge of detonation or pour some race gas in you can easily pick up 50rwhp on a FI car/truck.... I just like to play it safe and have low dyno #s but run well at the track.

J's, truck is pretty quick though

diamondd2

So, what is the max boost that can be run safely on a stock 5.3 with an intercooler, a tune, and NO meth?

=Dave

F8L Z71

Not sure yet.... I have ran 14psi with just the intercooler and the meth turned off but I wasn't happy with the tuning on it and I kept blowing my intake tube off. My injectors were getting close to maxing out in duty cycle so we decided to turn down the boost a tad bit and start using the meth to ease the injectors a bit.

So IMO 14psi was ok but I never tried to max out power at that point. Keep in mind that I am running almost 8.5:1CR.. I htink 12psi is cutting it close on a stock 5.3L at 9.5CR because your effective CR is near 18:0.1 and they say that is the limit for a daily driven street car and be safe.. Not sure if that is accurate or not though.

diamondd2

Excellent. I am only looking for 9-10psi to make me happy.

BTW how did you lower your CR to 8.5?

=Dave

F8L Z71

I slapped a set of stock 6.0L heads (8.7:1) on it and used the 6.0L gaskets (.1-.2CR drop).

I had a bent valve on my 5.3L heads from the engine fire and rocks in the motor so figured might as well upgrade since I'll be doing a 6.0l shortly anyway.

8-10psi would be piece of cake on a stock 5.3L as long as your tune is good

Flyer

iTrader: (1)

Wow .. I can't believe I missed this one.

RADIX .. hands down. The drivability is awsome. The performance is awsome. There's nothing like the instant boost. With a little bit more modding, it's insanely fin to drive.

I should have a video up soon of mine. It looks slower than it is cause I was next to an 11 second race truck.

diamondd2

So, the 6.0 heads just slap right on there with no problem; NICE!

I think the STS turbo is the way I am going to go. Now to just figure out what turbo I need.

Thanks,
=Dave

Flyer

iTrader: (1)

Yes ... I think the RADIX is more worth checking out a little closer.

The STS leaves a lot on the table in 'stock' form. You should replace the injectors with bigger ones, it doesn't come with an intercooler, and you still have to get tuning done.

diamondd2

Yes, you are right. But I don't plan to get the stock option. I plan on an upgraded turbo, injectors, intercooler, and tuning. This should keep me in the same price range as the radix + LT headers and a cat-back (option 2).

I like the turbo because of the ease of installation, future potential, and the cool factor. But I think the thing I like the most is the way the boost comes on, with a supercharger the boost is constant and gradual , with a turbo full boost comes on early and fast and it feels violent. I like that.

=Dave

Flyer

iTrader: (1)

I think you have those backwards. I can't speak for installation of the STS kit, but the RADIX is more than simple.

The turbo has the lag ... the RADIX has the instant boost and stays at full boost the whole time. The turbo will have a little bit of a lag, especially if you start upgrading the turbo.