How many miles should I be able to get out of a stock S4 turbo?
I have :
a streetported motor
3" dp and 3" single exhaust
BOV
T-Rex FP
TB mod
RB FCD
I was getting a solid 7psi before the exhaust and TB mod, now I'm seeing about 11-12 pretty constant.
But, I've noticed some oil on the top of the turbo housing. I'm trying to track down the leak now. I have about 15k on the motor, but I don't know if the turbo was ever rebuilt ( doubt it ). I am seriously considering dumping it now and start the T04 upgrades. But, I dont know what all I need on that end either. If the stocker will last and be able to get me 250-275rwhp I will be content.
Please let me know guys!

 

Mine has about 105,000 miles on it.

 

Run it till it starts to whine or puff blue, then go for a rebuild/hybrid.

Stock will support 250-260ish rwhp, but it runs out of top flow and boost will start to drop at 5500-6000ish and at those boost levels and will die much quicker also.

 

Well of course running at higher boost will lower its life, but I think they are good for 80-100K miles (stock pressure anyway).

 

The stock turbine is very strong and ususally run trouble free. You said a Street Ported motor. How big is your port? Was the exhaust ported as well? This will determine how long the turbine will last. I have had a High flow turbine(stock back half) last 6 months on a fairly large SidePort The increased exhaust pressure kills the turbine. The ported engine is not going to do much for you horsepower with the stock turbine.

Since you car is a S4 there aren't many computer options out there for you so with a larger fuel pump and regulator and probably some larger injectors you could get to 270-280HP range.

I suggest you get some guages to see what is going on with your car before going too deep with trying to extrapolate the most power.

 

My stock one lasted 220,000km till she started blowing blue between shifts. Last 40k was at 14psi also.

 

Well properly taken care of they will last a lot longer but I didnt want him to count on it lasting forever so I gave him a "worst case scenario" figure. BTW 220,000 KM is like 150K miles right?

 

The chassis has 132k on it now. I do have a boost and AF gauge installed. I have an upgraded Fp also. The T-Rex Fp is from the vortech SC kit for LS1's and is rated at 125psi. or 50gph@75psi. New they're pretty pricey but I picked it up for $50. I'm waiting on my mallory FP reg, and then I was going to drop at least 720 secondaries in.

 

mine has 111,000 on the turbo s4

 

hmm... I think I have more problems or a bad gauge now. I was getting 10-12psi pretty easily. Now, even if I wind it out, all I see is 5-7psi. The car still feels pretty good though.

 

I think you already know that its time to upgrade your turbo... you just don't want to admit it!!!! if you want to retain your present DP, for 750 bucks you can get a stage 3 BNR modified stock turbo from RX-7 store and be good ta go for about 350HP.....

However, from your mods, you don't list any additional injection controllers.. after you upgrade your turbo your going to need at least an SAFC, better a REBIC and add additional injectors, or blow your wad and go haltech....

As far as turbo life... oil conditions and heat are the biggest factors in longevity.... dirty oil and hot running engines will chew them up.

As a rule of thumb, I will never increase the HP on ANY car by more than 20% without upgrading the radiator... the heat generated by the power upgrades does not increase in a linear fashion, its more like am exponential curve!!!

As for the boost drop.... check your lines for cracks, and then all you hoses and manifold gasketts before doing anything else