Modifying my TO4S bb to a 67mm yay or nay
 

Current setup

Hks to4s 44mm tial open wg, 3 inch exhaust
1680/850
Water Meth 70/30
Blitz fmic
Aem
SP REW w RA super seals

Car made 440rwhp 368tq at 18psi. Tuned by ray wilson pfs.


Long story short, sucked in plastic and trashed compressor wheel.

Its being rebuilt now. I am given thr option to go with a 67mm wheel, over the previous 63mm

Turbo previously maxes around 61lbs of aair and around 460rwhp.

67mm should allow me to near 500rwhp higher boost.


My question, do you guys believe if I can upgrade the wheel and gain efficiency to 20-25psi, is it reasonable to retune at this level on pump and water/meth? Or do I need straight meth? Or am I simply just asking for damger above 20lbs without race gas?

In otherwords, if I have enough efficiency to push high boost, what's the limitation of water meth 93?

Lots of threads about this, on pump 93 with AI the recommended max is around 22-23psi.

put the thing back the way it was. Drive it and enjoy. When Ray comes back down you can get it ready for a bigger turbo. 440hp is plenty fun to drive.

i have been trying to sell a new s400sx FMW. 67.7mm and @ 90+ lbs of air.... it might get you into the 500s lol

That or he should just buy my gt4094r. Thats my old turbo that took me to 6.3's in the 1/8th mile. Badass turbo! You know you want it Zach!

Has to be! I am having fun with 100rwhp less :lol:

I have a similar setup but without the SP, and was also tuned by Ray on the previous ECU. My car made 34X hp at 11psi wastegate spring, and would love to see somewhere around 420hp at OPs psi :drool:

It sounds mighty perfect

Yes you are def right, but I just hate to buy a new compressor wheel and re balance etc and not get something good out of it :lol:

I need 500!:scratch:

Power corrupts lol.
I'm currently running 25psi on preturbo water/meth and 93oct...well I should say WAS running that until my clutch really started crapping out lol. Either way, knock was extremely low for me under boost...I believe it was around 9 or so on the PFC knock scale (just for reference regular noise cruising around out of boost with my car is around 35 to 40...and thats mostly due to driving on crappy roads or hitting a bump lol)

Wow, whats your setup?

6766 dbb precision turbo, 850 prim 2200 secondary, ngk 11 heat range plug, hks twin power, stock coils, streetport, power fc, wannspeed preturbo injection kit 50/50 water/meth, large smic. I plan on changing to a vmount though because I don't like the higher intake temps in this hot weather, its getting close to 50c after a 1-4 pull but instantly goes back down once I cruise.

yes, yes you do !! :egrin:

50c is ok.

Well, bit the bullet and went with the new options on the turbo rebuild:

60-1 wheel upgraded to a 67mm
exhaust wheel upgraded to T04R/Z wheel
Ported Compressor Shroud
1.32 AR Exhaust Housing Swap.

Should be enough for 500+ ~20-24psi!

Do you ever run beyond 17psi on pump with your water/meth?

I'd like to put down your numbers with a 67mm at 20-23psi on pump. But I'm also very weary of going beyond 20psi without race fuel :/

I run 50/50, 93 pump with 100 race up to 20 psi. Above this, just for safety, I'll use
fuel of 110, or Q16. I rarely run the car over 19 psi.
Just make sure your AI is working correctly, and all will be good.

Question for you guys:

My current AR is a 1.0,

While the turbo is being upgraded to the T04Z size, should I move up the exhaust housing to a 1.15 or 1.32? Is it really noticeable? I have a large streeport