Originally Posted by Super Werty

When you go stage 2 is the only difference the larger -91 trim Rotrex?

Reason I ask is because...

I was the first to run the -91 on my Toyota Tacoma. Underdog Racing Development made the kit with a -81 but I asked for a -91 with a larger pulley.

What we ended up finding out was that I was making way more midrange power and a peak of about 450rwhp on a less aggreesive timing map on only 9.7 psi. While the guys running the -81 trim made less midrange and took a whopping 15 psi to hit 450rwhp.

The -91 trim also provided significantly lower boost temps

Wonder if GTM has tried the -91 with a larger pulley.