I think that a BB Red configured with a 9.8 would be just plain nasty especially on E-85, along with a well designed dump, speed density, etc.

The 9.8 should spool it about 200-400 RPM sooner and the BB center will cut another 300 RPM off the spool. So, between the two you can expect about a 600-700 RPM reduction in spool compared to a JB Red/10.5, plus similar improvements in transient response. I figure it'll outspool a JB 73 HTA Green.

How do you see it yourself? It oughta be nasty on the street or a road course. It would be interesting to do a dyno comparo vs a Green.

 

I'm contemplating it.

A friend of mine has a 2.3/JBRed10.5 and it makes 27 psi at 3800. I tuned a 2.0/BBRed10.5 and it was 26psi at like 44-4500.

My bbk full makes 28 psi at ~41-4200. If I could get the bbred(when I switch to it) close to that, and be able to still have the power gains over the full, I'd be happy as hell.

I'll be tuning a built 2.0/JBGreen here soon, so I should have some comparo data there too...

 

Hmm. I am guessing that all three of the above setups are running extremely low waste gate spring pressure levels. I am not seeing the type of spool that I would expect on any one single example.