In general, can the fast spooling .68 housing make a motor more sensitive to detonation by having the boost come on so hard near peak torque? On the other side, would a .96 housing be more forgiving with a more gradual spool?

 

There's no easy answer to your question as its too vague. Tuning has a VERY big say on whether or not an engine detonates. Also another HUGE factor is the engine design. If you taking an engine designed for normal aspiration and you add a turbo on it, regardless of turbine A/R side your going to increase the chances of detonation. Generally a lower A/R turbine will spool quicker which will make the engine reach peak torque a lot sooner then it might reach when not turbo'd. Again, this is where tuning comes into play.

 

^^^ Alot of that can be played with using Cam Timing, But a 96 ar over a 63 would have alot more punch and probably would never really want to spool off a Beta. Unless your built and spinning more Revs than 6.5k.





I had a 63 and is it okay but not great for playing on the street, first would basically never spool, 2 gear was really late in the revs 3rd pulled good after about 4k.



48 ar is FUN, great street car and is a great turbo and will pull hard and not drop off at stock redline. I would suggest a 57trim 48ar to anyone turboing a Beta!