Profec-B II Boost // problems - Page 2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

cc4usmc · 04-10-2006, 07:15 PM

Quote:

Originally Posted by slider2828

I would probably just suggest reading the above post and not get settings as everyone's settings are different with a different setup. The above post should give you ideas on how to tune your turbo.

Just run
34 - Set
23 - Gain
8.3 - Start Boost....

But in order to get perfect efficiency, read the above posts and tweak it a little.

thanks....all that shit is to hard for me to understand...

TurK · 04-10-2006, 08:50 PM

Quote:

Originally Posted by cc4usmc

thanks....all that shit is to hard for me to understand...

goodluck then...

slider2828 · 04-11-2006, 01:01 AM

There are only 3 settings. 1st one is SET Boost, 2nd one is Gain, 3rd one is start boost. Easy as pie?

TurK · 04-11-2006, 05:46 AM

haha we all know how diffucult it can get....

Ess14 · 04-21-2006, 07:45 AM

Slider I'm no newb but I thought I'd bring up the boost fall off once more for my sake.

I'm running a T25
My settings have been fooled with from
SET: 38-42%
GAIN: 18-22%
Set Gain: ~.74 KPA Or ~ 10.5 lbs boost.

I'm going for ~ 12 lbs boost.

I hit about .70-.74 kpa very nicely, it doesn't spike higher - however if I keep it up it falls to freakin .20 kpa or something close.
also depending on what gear I'm in it may drop faster or slower...

I've been tweaking with this for some time now in between leaving it be and not caring - but let me know what you think.

Later

slider2828 · 04-21-2006, 10:10 AM

I think around 12lbs of boost, it would be on the upper end of your set and gain range. About 42% set and 22% gain. That is about where I have it. But a T25 will have that sort of boost curve because you are pretty much running close to its efficiency and secondly, the T25 with std actuator will not manage a flat boost curve at this level. The exhaust backpressure is rising at higher revs, causing the boost pressure to drop. The only way to combat this is to use the Profec-E01. The difference is that with the profec e-01, you can actually increase the SET% based on RPM. So if you know that your boost is dropping off, you can increase the SET% at the RPM that the boost starts falling off. This feature is called RPM offset. Not really much you can do..... Screw it increase boost to 13.5 which is around 46% SET. Other than that either a profec-e01 or bust. Wouldn't even bother changing the actuator. Good Luck

Ess14 · 04-21-2006, 02:39 PM

thanks, what bothers me is how fast I spool. I will hit .74 at >3000 Rpm and then as I get up there I really can't feel it at all. I'm going to keep messing with it. I had thought that -as you said- increasing my SET value will give me higher boost but it also would make me spool even faster...
We'll see how it goes, if any1 has more info please contribute.
If anyones running a T25 profecII and doesn't have fall off or minimal - chime in.

slider2828 · 04-21-2006, 02:50 PM

Nah man... please re-read, GAIN value is the boost response. Set value is how high it goes.... The Start boost is also how well it holds... Try playing around with the start boost. trying lowering your start boost.... see if that helps your boost fall off....

So keep set at 42% around 12psi
then gain around 23%
and lower your start boost around 9 psi and play around with the start boost.... See how this works for you....

Ess14 · 04-21-2006, 02:57 PM

Will do. Thanks much

ripnbst · 07-11-2007, 11:13 AM

Bump for this thread having assloads of information for people having difficulty with their profecs.

viscid240 · 07-11-2007, 11:55 AM

No need to bump a year old thread. That's why there is a search feature to find this info.

07-11-2007, 11:13 AM	#40
ripnbst Zilvia Addict Join Date: Jan 2007 Location: Tulsa, OK Age: 38 Posts: 814 Trader Rating: (0) Feedback Score: 0 reviews	Bump for this thread having assloads of information for people having difficulty with their profecs. __________________ In the market for a Clean Coupe

04-11-2006, 01:01 AM	#33
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	There are only 3 settings. 1st one is SET Boost, 2nd one is Gain, 3rd one is start boost. Easy as pie?

04-11-2006, 05:46 AM	#34
TurK Zilvia Addict Join Date: Mar 2004 Location: FL Posts: 966 Trader Rating: (0) Feedback Score: 0 reviews	haha we all know how diffucult it can get....

04-21-2006, 07:45 AM	#35
Ess14 Zilvia Member Join Date: Aug 2005 Location: Maryland Posts: 186 Trader Rating: (0) Feedback Score: 0 reviews	Slider I'm no newb but I thought I'd bring up the boost fall off once more for my sake. I'm running a T25 My settings have been fooled with from SET: 38-42% GAIN: 18-22% Set Gain: ~.74 KPA Or ~ 10.5 lbs boost. I'm going for ~ 12 lbs boost. I hit about .70-.74 kpa very nicely, it doesn't spike higher - however if I keep it up it falls to freakin .20 kpa or something close. also depending on what gear I'm in it may drop faster or slower... I've been tweaking with this for some time now in between leaving it be and not caring - but let me know what you think. Later

04-21-2006, 10:10 AM	#36
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	I think around 12lbs of boost, it would be on the upper end of your set and gain range. About 42% set and 22% gain. That is about where I have it. But a T25 will have that sort of boost curve because you are pretty much running close to its efficiency and secondly, the T25 with std actuator will not manage a flat boost curve at this level. The exhaust backpressure is rising at higher revs, causing the boost pressure to drop. The only way to combat this is to use the Profec-E01. The difference is that with the profec e-01, you can actually increase the SET% based on RPM. So if you know that your boost is dropping off, you can increase the SET% at the RPM that the boost starts falling off. This feature is called RPM offset. Not really much you can do..... Screw it increase boost to 13.5 which is around 46% SET. Other than that either a profec-e01 or bust. Wouldn't even bother changing the actuator. Good Luck

04-21-2006, 02:39 PM	#37
Ess14 Zilvia Member Join Date: Aug 2005 Location: Maryland Posts: 186 Trader Rating: (0) Feedback Score: 0 reviews	thanks, what bothers me is how fast I spool. I will hit .74 at >3000 Rpm and then as I get up there I really can't feel it at all. I'm going to keep messing with it. I had thought that -as you said- increasing my SET value will give me higher boost but it also would make me spool even faster... We'll see how it goes, if any1 has more info please contribute. If anyones running a T25 profecII and doesn't have fall off or minimal - chime in.

04-21-2006, 02:50 PM	#38
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	Nah man... please re-read, GAIN value is the boost response. Set value is how high it goes.... The Start boost is also how well it holds... Try playing around with the start boost. trying lowering your start boost.... see if that helps your boost fall off.... So keep set at 42% around 12psi then gain around 23% and lower your start boost around 9 psi and play around with the start boost.... See how this works for you....

04-21-2006, 02:57 PM	#39
Ess14 Zilvia Member Join Date: Aug 2005 Location: Maryland Posts: 186 Trader Rating: (0) Feedback Score: 0 reviews	Will do. Thanks much

07-11-2007, 11:55 AM	#41
viscid240 Zilvia Junkie Join Date: Dec 2004 Location: Only where the cactus strikes! Age: 42 Posts: 516 Trader Rating: (0) Feedback Score: 0 reviews	No need to bump a year old thread. That's why there is a search feature to find this info.