[areasix]

Guys

I've just upgraded from a Stage 3 (in a 0.63) to a Stage 5 (in a new 0.63). The engine is a 2.0 litre. I expected a loss of spool of approx 4-500 rpm, but I've gone from a spool at 3400 to 4600. Both are on a T3 flange

My engine runs conservative cams, so expected the spool to remain strong.

I've checked for air leaks on the compressed side, and we're air tight

Can anyone confirm if this is the common situation for this swap?

I've also tried a P trim on a 0.58 (T4) and found it spooled at 4200, which I really didn't expect after the Stage 5's response!
Thanks

Ian

[Robert]

Originally Posted by areasix

Guys

I've just upgraded from a Stage 3 (in a 0.63) to a Stage 5 (in a new 0.63). The engine is a 2.0 litre. I expected a loss of spool of approx 4-500 rpm, but I've gone from a spool at 3400 to 4600. Both are on a T3 flange

My engine runs conservative cams, so expected the spool to remain strong.

I've checked for air leaks on the compressed side, and we're air tight

Can anyone confirm if this is the common situation for this swap?

I've also tried a P trim on a 0.58 (T4) and found it spooled at 4200, which I really didn't expect after the Stage 5's response!
Thanks

Ian

The Stage 5 is a significantly larger turbine than the Stage 3. The Stage 5 is almost as large as the P trim so the change in boost threshold isn't really out of line with what I would have expected and the P trim results sound about right too. You might consider moving down the A/R for the Stage 5 turbine to help bring it back in a bit.