So lets say I want to do a really budget build on my 99 z28 A4... My engine has stock internals. So my question is how long should it go with 8 lbs of boost? I was thinking of putting forged internals in, but that really makes things add up quick. So if I could run it on 8lbs of boost until I got the money to go forged internals how long could I expect the engine to last? And also what would the hp gain with 8 lbs of boost?

 

8 psi on pump gas, maybe add a little meth injection should live a LONG time if the tune up is good. the "old rule" is 14.7 psi (1 bar) should theoretically double your N/A hp, so 8 psi would add about ~50% more power (theoretically)

 

loaded question is loaded.

 

Forged rotating assymbly would be the best thing you could do cheap way is the bad way.

 

With a good tune and assuming the engine is in good shape, it should last for years.

 

Definitely go with the meth injection and an intercooler and a conservative tune. It's cheap insurance. I'm running 9.5 psi and making 550 rwhp (with meth and LS9 cam swap). Otherwise, stock internals and 91 octane.
(3 months now, but I rarely see the full 9 psi boost on the street, (rear mount) and I hate to admit it, but it scares me when I get to full boost!). Hoping to get it on the track soon for an ET. I'm keeping mine under 10 psi as well until I can go forged. I'm taking the same approach.

I'll let you know if/when it goes BOOM!

 

9999999999999999999999999999999 miles

 

So what should the power gains be compared to a 100 shot? I am currently running a 100 shot, but I really would like to go procharger soon

 

The biggest thing to remember is that your factory motor was never meant to run at 9psi of boost. Power is heat, and the factory rings get mighty tight at power levels over 500hp.

Definitely run a methanol/water injection setup to help keep the piston temperature in check and it will help your cause.

 

Its all on the tune...check the reliability list above.

 

If done right years won't be an issue, if done wrong about 3 hits.

 

my twin turbo stock ls1 at 8 psi started to get bad blowby at around 25000kms driven pretty hard plenty of passes making 460rwhp thru a4!!!!! stock 4l60e lasted 1 day and 50kms haha!!!!