RX80JOE

iTrader: (4)

I was wondering if there is a "guideline" on using water/meth injection on a 13b unpinned. I plan on going to the dyno with my newly built S4 s366 build (after 500 mile break in), and was wondering if water meth would help in achieving higher hp/torque #'s on an unpinned engine. Max boost/hp? I was always told not to exceed 15psi boost, and/or 400hp on a unpinned 13b.

rx7jocke

I ran mine stock block s4 @387rwhp (400++ in engine) very very hard for many miles, this at about 15psi on a t04s 60-1. No water no meth no nothing.....the car just kept asking for more, i even drove it 300miles to the track, raced all weekend both drag and track and then drove home. So thats what i know is safe if everything works as intended. My tuner also delayed my max boost by about 500rpm to aid in durability. I dont think water/meth will get you much higher unless you are detonating or have very high iat's, but that shouldnt be a problem at 400-450hp in a low comp s4 engine. The s4 is a weak engine thou so even hitting the rev limiter in those power levels can break the dowel lands.
My advice, stay below 400rwhp or pinn it. Use water/meth depending on your setup and what quality fuel you have access to. We are spoiled with the quality of the fuel here in sweden and it is also not very hot so AI or wi is not as necessary here as it might be for you :-)

RX80JOE

iTrader: (4)

Thanks for the reply. I appreciate it and clears up my questions and what my tuner and building are telling me. Was just trying to get other opinions.