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-   -   Profec B spec II install and review (https://www.rx7club.com/3rd-gen-archives-73/profec-b-spec-ii-install-review-192249/)

overkill 09-30-04 11:11 AM


Originally Posted by speeddemon7
ever since I installed the profec b spec 2 ive had horrible primary boost response.
Im thinking theres something not right with the profec installation.
I followed the instruction manual to a tee. I just cant see what the problem is.Ive tried and tried to find the issue with no luck.

Which version install did you you go with?

Bad_Karma7 09-30-04 11:14 AM

Ok, I was buying a boost controller and the guy I talked to said that it would be a waste of money. His explaination was that it is used to gain pressure, not keep it at stock levels. I told him that I had the basic mods and that I have read that I'm ok with stock ECU if I maintain boost level at 10psi. Is this guy on crack?

overkill 09-30-04 11:32 AM

Yes you can use a Greddy profec b spec a to keep your boost at 10psi. The only thing a boost controller cannot do is limit boost UNDER stock level's or exceed the boost capabilities of the turbos.
Also, with the profec b, if the unit is installed and turned off f boost levels automatically are set to 7psi. That would make one think that it could hold boost at 10psi.

On a side note, it's somewhat pointless to mod your car if you are keeping stock boost levels. You are better off buying a tuned ecu like M2, Pettit or PFC, so that you can get the Hp out of the mods you have on your car, and run safely doing it.

Bad_Karma7 09-30-04 11:47 AM


Originally Posted by overkill
You are better off buying a tuned ecu like M2, Pettit or PFC, so that you can get the Hp out of the mods you have on your car, and run safely doing it.

Why is the right way always the most expensive way? I would just like to hear for once; this is the best way, and it's the cheapest way! :D

speeddemon7 09-30-04 12:57 PM

im running the version 1 installation. i may try version 2 and see if this fixes the problems.

Outkast 09-30-04 12:58 PM


Originally Posted by speeddemon7
ever since I installed the profec b spec 2 ive had horrible primary boost response.
Im thinking theres something not right with the profec installation.
I followed the instruction manual to a tee. I just cant see what the problem is.Ive tried and tried to find the issue with no luck.

Me too. I ripped it out and installed boost controllers. Remember guys, the primary feeds the prespool fpr the secondary so I lowered the prespool (less spike and more primary) and lowered the pressure to the duty (WG actuator - won't open until boost is reached- more primary) -Thanks E.B.M.
My primary response with Profec was gay.

Outkast 09-30-04 01:01 PM


Originally Posted by overkill
Yes you can use a Greddy profec b spec a to keep your boost at 10psi. The only thing a boost controller cannot do is limit boost UNDER stock level's or exceed the boost capabilities of the turbos.
Also, with the profec b, if the unit is installed and turned off f boost levels automatically are set to 7psi. That would make one think that it could hold boost at 10psi.

On a side note, it's somewhat pointless to mod your car if you are keeping stock boost levels. You are better off buying a tuned ecu like M2, Pettit or PFC, so that you can get the Hp out of the mods you have on your car, and run safely doing it.

The controller is also unable to improve the effiiency of your stock wastegate. Also, at stock boost levels with intake and exhaust only you can gain 60+ rwhp and a full second faster in the 1/4 and run a LOT cooler. Quicker boost response, better sound, gas mileage, all with stock ECU as long as boost issue is taken care of.

overkill 10-01-04 01:10 AM


Originally Posted by Outkast
The controller is also unable to improve the effiiency of your stock wastegate. Also, at stock boost levels with intake and exhaust only you can gain 60+ rwhp and a full second faster in the 1/4 and run a LOT cooler. Quicker boost response, better sound, gas mileage, all with stock ECU as long as boost issue is taken care of.

I dont think I ever said a boost controller can improve the efficiency of the wastegate. For that very reason, I ported my wastegate. I sure would like to see a dyno showing me +60 whp from just an intake, exhaust and a stock ecu. Please look at my sig. Minus the HKS Twin Power ignition, with those mods AND an upgraded ECU, I dyno'ed at 277rwhp, at 12-13 psi. With the HKS TP it will hopefully clear up my misfiring I had at high rpm, and I should be around 300rwhp. +60 whp with intake, exhaust and stock boost levels??? I dont think so. And when you mention running a lot cooler are you talking about intake temps, or exhaust temps? if you are talking about intake temps, A cold air intake is not going to yield cooler intake temps unless you swap out the crappy stock IC for an aftermarket one.

jpandes 10-01-04 01:15 AM

Nice. I still use a Home Depot Manual Boost controller to hold 15 PSI:D

overkill 10-01-04 01:15 AM


Originally Posted by Bad_Karma7
Why is the right way always the most expensive way? I would just like to hear for once; this is the best way, and it's the cheapest way! :D

I would say its cheap, when compared to doing it the wrong way, and spending $6000 installing a new motor because it blew.

SpeedracerRX7 10-01-04 12:53 PM

Can somebody post all of thier settings so that I can have a baseline for what to run. I am having some trouble getting the flutter out of the boost.

overkill 10-01-04 01:03 PM


Originally Posted by SpeedracerRX7
Can somebody post all of thier settings so that I can have a baseline for what to run. I am having some trouble getting the flutter out of the boost.

Hey I copied someones settings here on the forum, but do not remember who these settings belong to. I think I will use these as a starting point, for I will be running around 13-14- psi....

for 10 psi....

37-38% duty cycle
0-2% gain
9.5 Set/start boost

for 8 psi....
24-26% duty cycle

Obviously I cannot verify these settings, so use at your own risk.

speeddemon7 10-02-04 01:05 AM

hey outkast
what exactly did you replace the profec b with? im not sure whether its the profec itself or something else quite yet. but ever since I installed it ive had issues so who knows. For two days i had awesome boost response and then it went away.
Im getting tired of messing with the car. Just want good reliable and predictable boost response.
As for everyone else. Ive noticed drastic differences between everyones settings. Granted everyones probably running slightly diferent mods. But as a rule of thumb tune your controller to your car. Dont just use someone elses settings.
Heres an example
I was running a set of 23% for 10 psi with a gain of 9 and a set gain of 10
after installing the efiny y pipe no other changes, i had to change boost controller settings again in order to keep boost at 10 psi.
I was running a set of 23% for 10 psi with a gain of 8 and a set gain of 9
after installation
Now if for some reason your settings dont change but the performance of the car does.Youve obviously got a vacuum leak or some other problem.
Most importantly make sure your cars vacuum system is up to par. If it isnt and you fix the problems plan on readjusting the profec afterwards.Most likely turning every setting down a few notches. Since your systems efficiency will be improved.

Outkast 10-02-04 12:52 PM


Originally Posted by overkill
I dont think I ever said a boost controller can improve the efficiency of the wastegate. For that very reason, I ported my wastegate. I sure would like to see a dyno showing me +60 whp from just an intake, exhaust and a stock ecu. Please look at my sig. Minus the HKS Twin Power ignition, with those mods AND an upgraded ECU, I dyno'ed at 277rwhp, at 12-13 psi. With the HKS TP it will hopefully clear up my misfiring I had at high rpm, and I should be around 300rwhp. +60 whp with intake, exhaust and stock boost levels??? I dont think so. And when you mention running a lot cooler are you talking about intake temps, or exhaust temps? if you are talking about intake temps, A cold air intake is not going to yield cooler intake temps unless you swap out the crappy stock IC for an aftermarket one.

I was referring to underhood temps as well as exhaust temps. Due to lack of restriction, there is no more worry od exhaust overheat or pre-cat reflecting heat to turbos/engine/engine bay. I am aware of the function of the intercooler and its relation to intake temps. Also, I have seen full intake/exhaust FDs with stock ECU/motor/intercooler/turbos at no more than 11-12 psi put down 280 even 290 rwhp on a decent dyno. I don't know if anyone else can back me up on this but I personally know a guy Noel that had bad spark plugs, running rich and all kinds of problems and put down 260 on his first run and when his car warmed up 285 or so stock as can be besides inteke and exhaust. And he is not the only one. Your car makes good power but just because you used many mods to achieve it don't rule out the possibility that someone else with only the necessary mods can do it.

Outkast 10-02-04 12:55 PM


Originally Posted by speeddemon7
hey outkast
what exactly did you replace the profec b with? im not sure whether its the profec itself or something else quite yet. but ever since I installed it ive had issues so who knows. For two days i had awesome boost response and then it went away.
Im getting tired of messing with the car. Just want good reliable and predictable boost response.
As for everyone else. Ive noticed drastic differences between everyones settings. Granted everyones probably running slightly diferent mods. But as a rule of thumb tune your controller to your car. Dont just use someone elses settings.
Heres an example
I was running a set of 23% for 10 psi with a gain of 9 and a set gain of 10
after installing the efiny y pipe no other changes, i had to change boost controller settings again in order to keep boost at 10 psi.
I was running a set of 23% for 10 psi with a gain of 8 and a set gain of 9
after installation
Now if for some reason your settings dont change but the performance of the car does.Youve obviously got a vacuum leak or some other problem.
Most importantly make sure your cars vacuum system is up to par. If it isnt and you fix the problems plan on readjusting the profec afterwards.Most likely turning every setting down a few notches. Since your systems efficiency will be improved.

I put manual "Home Depot boost controllers" it is spiking way too high right now sometimes ABOVE 15 psi. I have hit fuel cut 20 times already. This sucks ass. Profec is gay for sequential and home dpot valves are ghetto and suicidal. Can somebody come in here and tell us how to control the boost?! I know Power FC can do it but with the stock ECU can I just install a big ass wastegate? Help

speeddemon7 10-02-04 04:40 PM

i guess i should have gone with the blitz sbc id in the first place.It came highly recommended from rotary xecret.
ohh well. I think my problem isnt boost controller related though.Something else must be wrong.Because when the car ran well it was pulling as soon as 1200 rpms and hit full boost by 3000.The car felt great and responsive. Ive already done the vacuum hose job and all of the solenoids are brand spanking new.Well maybe a year old at the most. Some of my check valves on the other hand are not new. I think maybe the vacuum chamber one is at fault.

Outkast 10-03-04 12:42 PM

I managed to get my boost down to 7 psi by plugging the wastegate actuator outlet. The primary feels like crap the secondary feels good. I am about 50% sure the car would run faster this way than stock. I know probably 99% of people here probably think that a modded car with 7 psi cannot run as good as a stock one but I will test it at Moroso and videotape. Stock was more responsive and I know the transition is "not supposed" to take place until 8 psi etc... Well if I run even a little better than stock than it was worth unresticting the exhaust for the reduced weight, heat, and improved sound. In my case that would be 14.4 or better since I am automatic.

Outkast 10-09-04 12:16 PM

G-tech Pro says I can run high 13s. Beat an Evo too the other night. Automatic stock FD intake, exhaust, 7 psi..... I can't beleive it because it feels so slow

Outkast 10-11-04 01:08 AM

Ran 13 and knocked


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