Turbo questions

[PrinceCaspian42]

Hey guys so ive decided to get a winter beater and park the speed so i can collect parts for a new turbo build. currently have the stock k04 with catless DP, TMIC and JBR powerpath Stage2 intake HPFP freektuned. car pulls great but since i need to replace the k04 i might as well go for more power. i plan on getting cx racing piping and a tr8 core. also i want to only run 93 oct no meth and theres no e85 near me so thats out of the question. so basically im debating between the BNR S3 and S4, i know most people say just get the s4 but heres the thing, i dont want to build my engine, i want to stay within the limits of the stock block. goals being around 350whp, so what my question is: should i try and max out an s3 or get an s4 and have it conservatively tuned. also is there anything else i should look at getting for these power numbers besides the obvious ebcs and 3.5bar and 3.5in intake? thank you for any input.

[CWP_MS3]

Well you won't likely make 350 whp on a BNR S3. As far as I know, they're only good for about 330 on pump alone. I don't know the spool characteristics of a S4 but I'd probably go S4. Goals may change later and you'll have the turbo to do it.

[xorphanx]

CS turbo

[PrinceCaspian42]

Originally Posted by xorphanx CS turbo

i dont want a CS turbo because of their boost creep issues.

Originally Posted by CWP_MS3 Well you won't likely make 350 whp on a BNR S3. As far as I know, they're only good for about 330 on pump alone. I don't know the spool characteristics of a S4 but I'd probably go S4. Goals may change later and you'll have the turbo to do it.

yeah thats probably what i will go for, mainly wanted to see if the s3 would be better to preserve the stock block.

[CWP_MS3]

Originally Posted by PrinceCaspian42 yeah thats probably what i will go for, mainly wanted to see if the s3 would be better to preserve the stock block.

Get yer tune right. That's gonna be what preserves the block. lol

Typically speaking you want less lower end torque, so the s4 will probably push torque further out than an s3. With that said, you may still end up with ring issues down the road from a more aggressive setup as it is.

Trouble comes with the turf of modding. Don't want problems, don't create them.

[xorphanx]

difference between the s3 and s4 is ~150$... is 150 really breaking your bank?

[PrinceCaspian42]

Originally Posted by CWP_MS3 Get yer tune right. That's gonna be what preserves the block. lol Typically speaking you want less lower end torque, so the s4 will probably push torque further out than an s3. With that said, you may still end up with ring issues down the road from a more aggressive setup as it is. Trouble comes with the turf of modding. Don't want problems, don't create them.

as far as the tune goes i would either stay with freektune or since im 2 hours away try and get dynoed by nishan.

Originally Posted by xorphanx difference between the s3 and s4 is ~150$... is 150 really breaking your bank?

no the cost difference between the two turbos isnt what im worried about, more or so the cost and aggravation of rebuilding the motor

[CWP_MS3]

I was referring more to the structure of your tune. Not who did it.

[PrinceCaspian42]

Originally Posted by CWP_MS3 I was referring more to the structure of your tune. Not who did it.

ahh gotchya

[MS3Shadow]

S4 is the best even for an stock motor.
All it goes down to us the tune.
That'll save or break your motor.

Sent from my Pixel XL

[PrinceCaspian42]

Originally Posted by MS3Shadow S4 is the best even for an stock motor. All it goes down to us the tune. That'll save or break your motor. Sent from my Pixel XL

sounds like ill be getting an S4 then. BTW im super jelly you have the Pixel XL

[TheSixthSpeed]

Originally Posted by MS3Shadow S4 is the best even for an stock motor. All it goes down to us the tune. That'll save or break your motor. Sent from my Pixel XL

Just out of curiosity, If one were to run 23psi on the S4, would the torque be too much for the stock motor?

Well I saw a video of an S4 running 24psi on an Mazadspeed 3 and the guy was putting down more than 400 wheel torque. So I assume the engine is build and forged unless it's not and is on the verge of throwing a rod?

[MS3Shadow]

Originally Posted by TheSixthSpeed Just out of curiosity, If one were to run 23psi on the S4, would the torque be too much for the stock motor? Well I saw a video of an S4 running 24psi on an Mazadspeed 3 and the guy was putting down more than 400 wheel torque. So I assume the engine is build and forged unless it's not and is on the verge of throwing a rod?

Like i said earlier, your tuner can tone down the torque for your stock motor.

380-400TQ is basically the border for the stock motor. Having meth/E85 would help it last longer.

Sent from my Pixel XL

[Fstrnyou]

Originally Posted by MS3Shadow Like i said earlier, your tuner can tone down the torque for your stock motor.

^this^
That's the thing with tuning, you can turn it up, turn it down, move it up or down the rpm range, etc. My peak load isn't targeted until 3500 with the K04 in an effort to reduce low end torque. I don't need a crap load of torque below that when putting around town. 4000+ is where I run hard...relatively speaking considering my car is stock. You could have a GTX3582R and keep it under 300ftlbs if it was tuned to do that.

[TheSixthSpeed]

Originally Posted by Fstrnyou ^this^ That's the thing with tuning, you can turn it up, turn it down, move it up or down the rpm range, etc. My peak load isn't targeted until 3500 with the K04 in an effort to reduce low end torque. I don't need a crap load of torque below that when putting around town. 4000+ is where I run hard...relatively speaking considering my car is stock. You could have a GTX3582R and keep it under 300ftlbs if it was tuned to do that.

Oh, ok. Well I guess that means lowering the ignition timing or rich AFR I guess, but most obviously is less boost where you don't want it like down low.

I self tune and I currently have my K04 set up to 22psi at 3000 - 4000 RPM and then 18psi till 5,500 and above that the throttle is open till redline but running like 11psi. Everything below 3,000 is stock. Only reason I run more psi down low is because my stock intercooler is limiting me in the middle. I'm backordered on CP-E TMIC. I'm also set up 12.5 AFR and an ignition timing table I got from this forum where I compared the ethanol ignition maps and set up the minimum with the lowest map setting and then setup the max with the highest map setting.

What I guess I'll do is set 3,000 to 20psi then at 4000 RPM I'm hoping to run 24psi(or a bit more if possible). I'm running methanol injection of course.