I tried asking bryan from bnr but didn't get a response. Does anyone know what spring pressure on the wastegate actuators he provides? My goal is 14psi at most so I am hoping for the wastegates to open at less.

 

In my experience, the wastegate actuator is supplied with an 8 PSI spring.

The "upgraded" adjustable wastegate a friend received also had an 8 PSI spring.

Numerous calls and emails to Brian had him supply an "upgraded upgraded" actuator with a higher rate spring but it didn't make much difference. Even with the vacuum line disconnected, the car made about 8 - 10 PSI.

Ultimately the solution was to install a ghetto helper spring on the wastegate arm. Terrible, ugly, but it worked reasonably well.

 

Ah, thanks! I should probably use the actuator I got form kinagawa then, I already bought it and purchased a 10psi spring

 

I am curious, what boost levels were you trying to achieve? I'm looking for 12-14psi

 

The turbo (stage 3) is efficient on a 13B around 15 PSI. Actually on the engine I was tuning it seemed to have a power peak just above 8 PSI, then a linear increase to about 14 PSI, then another decent bump around 15 PSI.

We eventually did get 15 PSI in the midrange with the helper spring and the boost controller but it would taper off as the RPM increased simply due to a combination of weak springs and small turbine.

For the time we spent messing with the thing getting it working, we could have knocked up a decent mild steel manifold and upgraded the turbo with better results.

 

I'm interested to see how the kinagawa wastegate works out.

I just installed a discontinued HKS actuator on mine. Hopefully it works out, though all my issues thus far have been creep issues. I would love to not be able to make 15 psi

 

I'll keep you updated. I sent them an e-mail with pictures of how the diaphragm was not going back together properly, and they said they would e-mail me with instructions, which they did not. I tried calling them 2 times during business hours with no answer.

I will try again tomorrow.

 

I have recently had BNR stage 3 installed full sequential they attempted to tune to 14psi but it creeps to 16psi and also starts to drop off at 6500rpm

 

What boost levels does a stage 1 bnr have efficiency up to ? That's what I was going to go with since my goal is 275-320whp

 

You can always raise boost pressure, not lower, so fuel octane would be your limit

 

I couldn't get my BNR stage 3 to boost more than 6psi. With the MBC on I couldn't get it past 8psi. I ended up adding a helper spring to it and now it boosts to 10psi and stays steady to redline. 272rwhp at 10 psi.

 

i think i was the first to recommend the kinugawa universal WG actuator so i might have the most input on it, so far it has worked quite well in the original build i put it on.

i first tried helper springs but the springs even with the "upgraded" BNR actuator just distorted with the heat from the snail and it lost boost over time, usually quite quickly because most springs do not do well in the area of an abundance of heat.

fairly sure this was the kit I used for an S4 stage 3 BNR:
http://shopping.kinugawaturbo.com/ki...plication.aspx

fits kind of tight against the compressor(mount the bracket loosely then the actuator over the bracket and tighten everything down equally) but everything else worked perfectly. on the 6 port high compression engine we wound up using the 14.7psi spring and the net was still about 10psi with the boost controller at the lowest setting and came up to 13psi with about 30% duty cycle(about perfect if you ask me, a fair bit of room for more boost adjustment), but results may vary so be prepared to try a few different spring rates, a 4 port turbo engine will probably need a softer rate spring(10psi) to prevent overboost depending on your goal.


the largest factor to these hybrids and not getting the desired boost level is/was the stock intercooler. if you're running it and are having issues with boost even an upgraded actuator may only help to a degree. at high revs nothing helped keep boost up until it was ripped off and replaced. the wastegate actuator can only do its job if the airflow through the intake can match the exhaust, the larger the turbo is the more it will struggle with this especially with the stock intercooler. note: this issue was mostly noticed on the 6 port s4 n/a block, the 4 port turbo engines seemed to manage airflow on their own. 6k RPM with the 6 port and top mount was the point where boost went into the toilet, added a front mount and the kinugawa WG and everything went smoothly as i could adjust gain to bring the turbo up quickly and hold boost to redline perfectly.

for the price i would go with the rebuildable and adjustable kinugawa over the BNR actuator.

 

Anyone have info on helper spring specs or pics of install? Got a Stage 2 S4 w/13 psi springed actuator on my project. No boost controler either. Haven't been able to boost passed 6.7psi

 

The helper spring we used was just a random spring we had in the shop with a hook on each end. Drilled a tiny hole in the wastegate arm and another in the wastegate mounting bracket and hooked it between.

But as mentioned above, the spring could be a temporary measure. The absolute best way to fix this is with a much stiffer wastegate actuator or one with two ports. ATP Turbo sells them with a universal bracket to fit almost every turbo. The 2nd port backs up the diaphragm with boost pressure so that the wastegate isn't pushing just against the spring.