I've noticed that my turbo takes a FULL 5-6 seconds from 0 psi to 16 psi to build. Is this expected? That's cruising at 4k rpms in 2nd gear, going WOT and watching my gauge. Just doesn't seem right to me..my friends MasterPower T70 has quicker spool than that. Any ideas as to why my turbo spools so slow?

My car:
streetported S4 motor, 3mm apex seals, port matched uim and lim
2.5" intercooler piping to a semi large fmic
BNR stage 3, stock S4 manifold with egr blocked off
Microtech Lt8s, 3" no cat
all emissions gone, etc etc blah blah

 

Maybe add an additional external spring to the turbo? It may be that the wastegate spring is opening a big during boost causing it to take longer to get to 16psi.

 

The BNR stage 3 is a slower spooling model. The stage 2 is where you get that instant spool action, at the cost of a turbo that has to work itself harder to get more power out of it.

 

Never used a BNR hybrid, but as Hondahater said I'd check the wastegate actuator/spring and make sure its loading up the valve properly. Beyond that, it may just be the way it runs.

On the "friends T70 spools faster" comment - Larger turbines work well on the rotary. From the looks of the specs on the stage 3 BNR, it uses a clipped stock wheel? To run a 60-1 compressor?? Small turbine area no?

 

i have a stage 3, and it takes about 1-2 seconds for 15psi above 4krpm. It takes longer at lower rpm, like if i floor it from 2krpm. how are you controlling boost? One of the things i noticed when i was running my fmic, i had to add an extra spring to the wastegate arm to be able to make more than 10psi. I believe there is so much backpressure in the stock turbine, that it opens the wastegate from behind prematurely. an extra spring should keep it closed.

 

Are you just running 16psi on boost creep?

get an electronic boost controller and it'll spool much faster.

PS - if you already have a boost controller, try getting an upgraded wastegate actuator.

 

i believe it has an adjustable wastegate spring. make sure the tension is set properly for that. also pressure test for boost leaks.

 

on a side note (sorry to jack the thread)... how do those work? I have an HKS wastegate actuator that I got and the only adjustable part of it seems to be the threaded arm... and all the instructions are in Japanese

can anyone shed some light on this?

 

i have some jdm hybrid but, i ran the vacuum source for the wastegate actuator to the intake manifold instead of the turbo outlet, it made quite a differance with boost response

my theory is that it surges in the turbo outlet and will pop the wg open like it was previously stated, but its all around better spoolin when its goin right from the IM vacuum

 

Generally speaking, the more pressure an internal wastegate actuator sees (regular single port design like the stock turbo), the lower the boost will be. Taking the pressure source from before the intercooler's pressure drop can make the wastegate open sooner then, because the wastegate 'sees' more actual boost.

 

i use to see 12 psi with it hooked up to the turbo compand would be alot more laggy, and i would get the full 13psi and it was alot more responsive when it was hooked up to the manifold

 

I have a BNR Stage 4, I had a similar problem, I wasn't getting full boost until about 5500rpm. BNR uses a larger wastegate flapper which they weld on. Turns out that the weld melted meaning the flapper door would sit partially ajar. I'm asking them to replace the flapper door, I'll let you know how it goes.