S4 or S5 uprade?
 

Hello. I have an 88 T2 with 109k miles on it. Im rebuilding the engine shortly, but i am still contemplating what i would like to do for power modifications. My goal is around 250-300whp on the stock turbo. Now my question is, should i stick with my S4 and send it out to BNR, or should i upgrade to an S5 and then send that out to BNR? I WANT to run the stock turbo, i just have a thing for fast boost :icon_tup:

Thanks, Ryan!

S5's win for response. How much boost are you wanting to run to achieve your HP goal?

Bryan@BNR

10-12

you will be in the 300-320 RWHP range at that boost level with a stage 2. I get 15 psi of boost with my FC on a stage 2 at 3100 RPM in 4th gear. You will be plenty happy with that set up.

Bryan@BNR
205 640 1193

Will i be seeing the same power levels from an equivalent stage 2 s4 and s5 turbo? I'll stick with s4 if i am going to hit my goal of over 250whp, saves me some money buy not buying an s5. But my goal also consists of an extremely fast boosting, torquey powerband. Whichever turbo would give me a better result in terms of responsiveness than i might just sway that way.

You can get a little more peak power from a S4 over a S5. The manifold is less restrictive, but the S5 is fully devided and has the best response. If you wanted to stay S4, if you keep your twin scroll and the switching actuator in the exhaust manifold, it will make the S4 turbo more lively down low, but will restrict a bit up top. Either turbo you will enjoy...

Bryan@BNR

I just got a s5 jdm motor the turbo on it is in awesome shape no shaft paly what so ever exept for the normal. My goal for the car is in the 300whp range it will be used as a spirited driver for the most part so the less lag the better what would you suggest on doing as far as rebuild stage 2 or 3. Also what other mods should I consider to get to my goal.

Thanks Mindaugas

Stage 2 will do 300 RWHP with ease. You will need intake, Full 3" exhaust, chipped ECU, clutch, injectors, pump and a healthy engine :D.

Bryan@BNR
205 640 1193

you have stated a chiped ECU where can I get that done becouse rteck only does S4 turbo and NA S5 also someone told me that S5 ecu will not work by itself that it need to see the remainder of the wiring or it goes into limp mode is that true.

A stock ECU will work good. You will need to pull around 6 degrees out of the timing and then get some 720s with a Super AFC 2 along with a FCD. Then with all the other mods, you should be good for 12-13 psi of boost. I would definatly install an EGT gauge to monitor those exhaust temps, then you will see how much room you have to adjust your timing up or down with the crank angle sensor. Also just as crutial is your AFR's. Make damn sure to keep the engine running pig rich and don't run more than 11.4 AFR at full boost. You may be able to run more boost, but definately keep an eye on that tuning b/c you can ruin the engine in a second if you dont know what you are doing...

There was more factual wisdom in this paragraph than you will ever know. I think all TII owners should memorize this before modifying their cars.