Profec B Spec II - Your boost settings required.

OZ-Racing

New Member
Just helped a friend fit a Greddy Profec B Spec II to his R 8)

I ran a few searches in the forum, but couldn't quite find what I'm after.

Could anybody using one of these on their R, please post up your settings along with the boost that it runs at (doesn't matter what boost you're running), so that I can get a feeler for the the correct values. :)

I was hoping to find settings for 0.85 bar and 1 bar (if it's safe to run at such a phenomenal pressure :wink: ). I know the settings will vary from vehicle to vehicle, but when I put the settings in for 0.9 bar that I saw somebody else on here was using, the boost was surging up to about 1 bar then down to 0.5 bar then up again and down again etc. etc.
We tinkered with all the gain setting to no avail, I even tried reading the Japanese section, which made a bit more sense than the english :x

So please post up your setting and state what pressure they are for.

Thanks, James :D
 

Paul20

Member
alrite mate, im using a profec b spec 2 but with hks cams n standard tubby. was set up at hiteq but can only run 0.9 bar max because i have no fueling control and it starts pinking. i'l post my settings up when i get the chance if you like
Paul
 

Paul20

Member
dont know if this helps because i dont realy know how to set it up but heres some settings i managed to get out of it:

LOW HI
0.6 bar i think 0.9 bar
GAIN 10% GAIN 10%
SET GAIN 32% SET GAIN 24%
 

geetee

Active Member
You need the SET value too :D

When you're in the normal display mode turn the little knob one click and it will show the SET for the current mode (LO / HI).

So you should have:

SET (in %)
(duty cycle of the valve - higher for more boost)

GAIN (in %)
(sensitivity of the valve. too high and you'll get a boost spike, too low and either the boost will fall off at high rpm or you'll see the boost gradually increasing with rpm - NB.... raising the GAIN will raise your peak boost also)

SET GAIN (in kPa)
(actually Start Boost. Sets what boost pressure to start opening the wastegate. Too low and the spool up will be slow, too high and you'll get boost spike. NB - this does not affect your peak boost unless you set it too high and get a spike)


So I'm not sure where Paul is getting his SET GAIN in % from :?


I'm still trying to get mine right - stabilising the boost without overshooting is a pain. Just lots of trial and error.

James - sounds like your GAIN is too high if you're seeing that kind of fluctuation. Or it could be that your SET is too high and the boost is increasing up to the WARNING level and being cut by the LIMITER.

Start low and work up gradually seems to be the key. Keep your SET GAIN low (but not zero) whilst you mess about with SET and GAIN to get the right boost and it is consistent. Once you have that then slowly increase SET GAIN to improve the spool up until it starts to spike then knock it back a little.

Let us know what settings you end up with :wink:

Cheers
Graham
 

nismoboy

New Member
im also experiencing the same problem as u, mine spikes like fook, it goes to 1 bar then drops off midrange then rises to 1 bar again :? ive pissed about with the setting but it doesent seem to help to much,

when u get the setting for 1 bar and it holds it accuratly please post up your results thanks nis.
 

OZ-Racing

New Member
Thanks for the replies, I will pass the info on.

Once we have figured it out :? and assuming we don't cripple the poor car in the process, I will post the final settings and probably get one for my R :p
 

Paul20

Member
yeh, probably not a good idea to try use my values as i dont realy know how to use the thing, i leave it to the experts. just hi and low, thats all i need. ha
 

OZ-Racing

New Member
nismoboy said:
anyone got the setting for 1 bar sorted yet?
Apparently the car was holding 1 bar well, just before he took it to the garage, to fix the broken piston rings :roll:
Unfortunately I don't know what the settings were.
I'll let you know how it runs when all is fixed :lol:
 

geetee

Active Member
Nearly got mine dialled in.

It is hitting and holding about 14psi in 3rd gear upwards no probs with no overboost and no fall off.

Still got a problem with it going over slightly in 1st and 2nd then dropping off and waving about for a bit before settling down. Just a case of moving the Gain and Start Boost 1 click at a time now to sort it out.

God it's tedious :roll:

Get there eventually I suppose.

I'll post up what settings I'm currently on next time I've been out.

Cheers
Graham
 
S

smcnairn

Guest
just thought i would wake this post up again im going to Star performance on friday for a R/R and want my controller sep up the best it an be. mines still not set up properly want to run 1 bar. geetee did u get that settings?
 

geetee

Active Member
I ended up at

SET 32%
GAIN 32%
SET GAIN 0.05 x100 kPa
WARN 1.30 x100 kPa
WARN L.50%

Still have the problem in 1st and 2nd.

From talking with other people, I think this setup is totally wrong. Apparently the start boost (SET GAIN) should usually be set at about 0.95 x100 kPa to get decent spool up.

That said I'm hitting 1 bar by about 3.5k rpm on the settings above.

I've just started again, this time with SET GAIN at 0.95 x100 kPa and brought my SET right down. Now I've got massive spiking all over the place but haven't had time to mess with it much since :(

Not sure that helps really!

Let us know how you get on.

Cheers
Graham
 

OZ-Racing

New Member
Just fitted one to my car:-D

Let the fun and games begin:doh:

If I ever get a stable setting I'll post up my figures:thumbsup:
 

Fusion Ed

Active Member
There shouldn't really be an problem. From memory:

Set = ~30
Gain = ~20
Setgain = 70 to 80% of boost pressure wanted so for one bar set at 0.8

You shouldn't need to change the gain much as the std turbos are so slow to respond. The SET should be changed until you have the boost you want, and if your getting high spikes reduce Setgain.

Ed
 

OZ-Racing

New Member
Thanks Ed :thumbsup:

I'm now happily set at 1 bar with the following settings:

Set: 36%
Gain: 10%
Set Gain: 0.78
Warning: 1.10
Warning Lower: 10%

Very nice 8)
 
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