Jump to content
SAU Community

Recommended Posts

I have a R33 GT-R with a Greddy Profec B Spec II Boost Controller installed and I was wondering if anyone could help me to understand the settings.

I had my car dyno tuned and the boost controller set for 14 psi in high mode and 12 psi in low mode on the standard turbos. I initially didn't want to set the boost too high as I wanted to make sure that the turbo's would last.

However, I have decided on a turbo upgrade in the new year as I really want more power (HKS 2530's or HKS GTRS's).

I have read here that someone has the standard turbo's running at 15 psi...

http://www.skylinesaustralia.com/forums/in...t&p=1773956

Is this safe? Is it safe to push them any harder?

It was also mentioned in this post that after a month or two power dropped. I also feel this but I am not sure if I am just used to the extra power now. About 10 weeks ago I had a Haltech Platinum Pro ECU installed and it was dyno tuned at the same time. When I first got it back, it felt like a rocket. Now it still feels quick but it just doesn't give me the same experience. Keeping in mind that I have only owned this car for 3 months, it is definitely possible that I have simply grown used to the power. Any way to check for this or anything else that could be stopping the car from producing optimum power?

I would like to know how to set my boost to 15 psi without the help of a tuning workshop. Is this possible without any extra equipment like a dyno? If so, could anyone explain the process?

1 bar (14.7psi) is the most you want to run safely through ceramic turbos in bursts (ie. not at the track), the stock ceramic turbos are just handgrenades waiting to happen and can take an engine with them with ceramic dust.

Never used a jap boost controller, but you want to modify the duty cycle option slightly (leave gain alone as it's already tuned).

1 bar (14.7psi) is the most you want to run safely through ceramic turbos in bursts (ie. not at the track), the stock ceramic turbos are just handgrenades waiting to happen and can take an engine with them with ceramic dust.

Never used a jap boost controller, but you want to modify the duty cycle option slightly (leave gain alone as it's already tuned).

Didn't think of that... I was thinking that if I am going to upgrade turbo's soon, it wouldn't bother me if the standard turbo's died but I definitely don't want my engine going with it.

I think I might just leave it as is for now. I might just get the shop to have a look at it to determine if the power has dropped or not... I will give it a minor service soon anyway.

if its only 1psi more just turn the knob from the main screen whilst in hi boost mode and increase the value a couple % then press the knob. load it up and watch the boost gauge, if its too much drop it back a %, if its not enough keep turning it up. gain adjusts how hard it comes onto boost, too much and it'll spike. set gain is how much boost is needed before the solenoid lets the actuator see any pressure, best to have it set 2-4psi below your target boost, depending on how well your wastegate controls boost. personally i'd just leave it how it is until you get new turbos

Yes, I know it's only 1psi more but that's still 7% more boost. I was just thinking if it was easy to do, it might mildly satisfy my hunger for more power over the next month or two while I plan out/save up for the power upgrade.

I'm getting a minor service done soon, I might just get them to look into it for me.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yes, while being... strictly unnecessary. Tuning is a bit like quantum physics. You don't need to understand what Schroedinger's equation actually means. You just need to run the computation and accept the answers. With tuning, you just push page up/down until the exhaust tells you that you've got the fuel right. The VE can stay hidden behind the curtain like the Wizard of Oz and you'll never need to know what he looked like.
    • The second part yes, the first part about easy VE calculation is something I've seen a few people talk about online.
    • You 100% could do that, would save money on a gym membership lol. But yeah, getting a cordless orbital sander will feel priceless coming from doing it manually.  Good luck with it mate
    • I initially was going to do the whole car with a block then realised, it would be a bigger monster of the job 😂 I guess that's all part of the learning process. I appreciate all that advice, I think I got a good idea on how to tackle this whole job.
    • I admire your efforts with the scuff pad.  As a mere mortal, I use this for the baulk of my sanding work- https://sydneytools.com.au/product/milwaukee-m18bos125-0-18v-li-ion-cordless-125mm-5-random-orbital-sander-skin-only Yes you can easily create a low spot while sanding. There are 2 types of filler, 1 part of 2 part. The 2 part filler will get used for large corrections and the 1 part filler will get used for pin holes and areas that only need slight filling.  Depending on how zealous you are with the sander (very easy to do with a power tool) or if you are chasing rust etc, yes those low spots will need to get filled or you will end up with a very obvious defects in the paint.  Using the guide coat and large sanding block, high and low areas will be revealed (watch youtube videos for a good visual on this). Its up to you if you think its worth the effort to make the car completely flat before you spray it (you make it flat by filling the low areas).  At the end of the day, it comes down to time. The end result comes from the level of prep put in to the car. If you want a perfect result, you have to put in the time during the prep stage or else it will be impossible to achieve a perfect result during the spraying process. 
×
×
  • Create New...