If you go with a 66, make sure you get a Q trim, as I'm sure Larry will recommend taht as well. I tried the 66 P trim and it did not perform as well as the 63, even on the top end. It was also very laggy.Supreme said:This is continued from the "rev limiter" thread. I am thinking about going with the SP-66 instead of the SP-63 for a little more top end power when I get a single turbo..
Would you mind briefly comparing the turbos and your experience with them? What size A/R is SP recommending for the SP-66 and in what trim? What is the lag difference and does it produce signifigantly more power? Any info is much appreciated.
The 66 Q trim has quite a but more power and spools quicker than the P trim too. I still haven't had a real opportunity to track test it yet. The one time I did it to the track I was having boost problems. To little off the line, then too much once it spooled. I replaced my wastegate and that seems to have cured the problem.
I am taking the car to get dyno tuned next Friday and then plan to go straight from the dyno to the track for some real word testing. So, by next weekend I should have all kinds of good information to post.
All this being said, I still feel the 63 is a better turbo for street driving. Quick spool and plenty of power. When you have a turbo that will do 1.4 60' times and very low 10s in the 1/4 on drag radials and no NOS, it doesn't get much better than that.
I have been using a .81 A/R on both turbos.