I get that there's many variables.

In reference to the OP, it does not take much for the backend to step out in 3rd (ZF) with 285 rears if that helps for comparison.

 

33 minutes ago, El Andrew said:

Are you still running the factory dump or cat?

Full XForce setup. The usual mods done to support that level of power though still original turbo (on borrowed time?)

Ported wastegate? If not 20psi is probably minimum it can run, and it's tuned accordingly

Yep, ported along with Turbosmart actuator

On 08/06/2020 at 6:20 PM, Puffwagon said:

A restriction can drastically change how much power is made from 20psi. Some tunes will push the parts way outside their efficiency zone which is ok to a degree, but will give lower numbers compared to a higher efficiency part. Examples: Stock cooler vs large tube and fin front mount, stock exhaust/cat vs turbo back 4 inch, stock crossover vs turboside cai, etc etc.

 

A dyno readout can also vary quite a bit.

 

At the end of the day it's running 20psi and providing the tune is safe/ballpark, the number doesn't matter.

 

Fwiw, imho 20 psi is too much for a stock motor. It might be fine for years...or not.

Dunno, my G6ET ran 20psi boost, stock motor with valve springs, made 511rwkw on E85. Did around 20k with it before I reverted it back to stock and sold it.

 

A BA running 20psi through a build 4 speed (I assume) would make 350-380rwkw on U98 with supporting modifications. 

why would a G6ET make 20psi and 511 on E85 but a BA only make 350-380 (161-131 less kW at the wheels) on 98? that's some weird figures.

3 minutes ago, Romulus said:

Dunno, my G6ET ran 20psi boost, stock motor with valve springs, made 511rwkw on E85. Did around 20k with it before I reverted it back to stock and sold it.

You quoted my whole thing so it's hard to accurately respond.

 

I'm guessing it's about my opinion about 20psi on a stock engine so I'll talk about that.

 

I still wouldn't recommend pushing a stock engine there if care is given for the engines health. Sure you can do it but I wouldn't recommend it. 

why would a G6ET make 20psi and 511 on E85 but a BA only make 350-380 (161-131 less kW at the wheels) on 98? that's some weird figures.

Manifolds
Motor health
Tune at its limit vs safe cause rods going bang bang.
Zf vs btr

still don't think that accounts for the difference, but yes, those things could contribute.