guesstimated BUILT B20B BOOST LEVELS ??


Senior Member
i just finished rebuilding my b20b built with a blockgirdle and a blockgaurd. i also upgraded to eagle rods (with stock rod length) and arias low comp pistons (8.8:1) im still using my stock B20b crank and stock b20b sleeves (84mm monosleeve). im running a t3/t4 hybrid garret turbo with an internal wastegate set at 8 psi. I'm still in the process of breaking in the new clutch so i havnt turned up the boost yet but my question is for when im finished breaking in the clutch. I was wondering what a knowledgable honda motor builder out there would guesstimate how much boost my motor could safely handle. I dont want to pump it up to 15 psi at the track next week if its gona blow.

so how far can i safely push it ?

Import Builders

Senior Member
hey wait a second!

I think this guy pissedoffdelSLOW may be on to something!


If your run good octane, and have like 12.5:1 air fuel ratio, I think personally I might try 1 bar, and if it blows up, you know thats too much.

Honestly, the real answer to your question is this.

When it blows up, its too much, because as long as it doesn't blow up, its reliable right?

I had a customer on a STOCK GSR block, 81.5 MM JE pistons, rods, etc, boost 19 PSI at the track on the well tuned motor. It took away to blow up, but it was reliable for quite some time.




Senior Member
:werd: on the tunning, also remember b20 sleeves are weaker than other other b series so that will drop you down a bit...


Admin with a big stick
Geez.. enough with the "oh shit B20 sleeves are made out of glass and will break if you just blow a fart at them" crap. They're NOT made from paper! You can take that T3/T4 up to 14-16 psi easy on that B20 as long as you have good engine management and be just fine.