Flyinbiya

hey guys need help with this ,i put my pfc in last weekend ,i started watching the boost to see if my other gauge is reading wrong.well yesterday mornin i drove it to work and i saw .73 on the pfc boost gauge.then after work all icould get is a .58 and i think maybe i saw a 6 somewhere in there. i have done all the normal boost problem upgrades and it did help right at the xover and ic pipe coupler.i have checked all the acuator clips and rods ,the only one that was loose is the one one the very bottom.but it did have a clip it would just rotate around .any help here would be good cause i was gonna i try to see if i would be happy runnin higher boost with a few more mods and stay with twins.thanks

911GT2

I've heard that the PFC reads boost a little to low anyway, so it may not be accurate. Do you have a boost gauge? I'd trust that over the PFC

Also, try asking in the PFC forum, they could probably verify the above.

vudoodoodoo

You should get a seperate boost gauge.

Flyinbiya

yea i have a separate boost guage,its readin low too!so back tothe original problem! i need some help !!could a stopped up cat cause low boost ?

redrotorR1

Sounds like you have a boost leak. If your boost gauge only reads some low psi after transition, then I'd start looking at the pre-cat and cat for problems. Check the corrugated hose from the IC to the crossover pipe. You have to pull it off to examine it properly. That hose is prone to cracks that can leak boost.

Flyinbiya

yea i have replaced that with the greddy 3 piece piping for the ic .unless u r talkin bout the xover pipe ,cause that is stock ,but i did change the coupler between the xover and y-pipe.now the bracket on the xover pipe is cracked but it looks to be sealed in side the xover pipe ?

Flyinbiya

if the cat could cause me boost prob's ,will the pfc be ok if i put a resonated midpipe in with the pfc base map?

Flyinbiya

^

Mahjik

iTrader: (1)

Do you have a downpipe on the car or are you still on the stock pre-cat?

Yes, a clogged cat can cause boost problems however I would lean more towards your y-pipe if it has a crack in it. It would be a good time to switch over the Efini Y-Pipe.

Flyinbiya

i do have the m2 dp ,i thought about makin a midpipe,hey what about the pills in the lines?couldnt they be an issue?does anyone have a pic on where these pills are located ?

Mahjik

iTrader: (1)

If your car "was" boosting fine and all of a sudden it's not, that's usually not a boost pill problem.

Can you do a third gear boost test and post the boost pattern?

Flyinbiya

thats just it i have owned it since december and it has always been low .and yea i will post my pattern but i'm workin now. in the mornin its fine but afternoon about
8-6-8 .its crazy ,just my luck!

Mahjik

iTrader: (1)

It very well could be a clogged cat or it could be that crack you saw on your coupler. If you aren't planning on going single turbo any time soon, I would get the Efini Y-Pipe. If you are going single soon, you can check the main cat, however I would still fix that coupler crack before anything.

Flyinbiya

yea i think u missed what i said i have changed all couplers .the xover pipe bracket is cracked ,but i think its sealed inside the tube?what kinda mp u got ?

Mahjik

iTrader: (1)

A crack is a crack. I read what you said, but I would still get it fixed.

I'm not running a midpipe, I'm using the Bonez Hi-Flo cat. If you are going to get a midpipe, you better be ready to deal with boost creep. Not saying you will get boost creep, but a majority of people who using midpipes with good flowing catbacks experience it. Without the proper control, it's a quick way to blowing a seal.

Flyinbiya

where did u get the mp and did it make a difference in hp?

Mahjik

iTrader: (1)

It's the Bonez hi-flo cat:
http://www.rx7.com/cgi-local/3catalog.cgi?cat=4&part=2

I don't know exact numbers between the stock cat and the Bonez Hi-Flo. I replaced my entire exhaust in one shot, so I got a good performance increase.

If you are going for all out power, the hi-flo cat may not be what you want. You will definitely make more power in the top end with a midpipe, however, it does require more modifications as I stated above (not to mention making you smell like exhaust all the time).

fdeeznutz

i bypassed the pfc boost control and installed a manual boost controller perfect boost pattern. I also unplugged the plugs under the uim(can't remeber what they are called.)

karken29

OK Fly By.... here's a likely culprit to your weird boost problem...

In the mornings, when the car's was still cool I think you said it boosted fine and later in the day as thing heated up boost dropped off along with performance... Do I have that kinda right??

A common boost problem for 3rd gens is caused by a deteriorating solenoid that directly controls the Vacuum/Boost signal to the actuators for precontrol and waste gate. The solenoid I’m talking about is located in under the Upper Intake Manifold (passenger side of the engine) and held in place by a single 10mm bolt. If you look at the Siamese (2) solenoids that are right behind the coolant fill neck… bolted to the Upper Intake Manifold, front left side, Now bend down and look strait back behind them and you’ll sorta see the one I’m talking about. Anyway….

What happens when it goes bad is this.... a new Solenoid will ohm out between 30 to 40 regardless if its hot or cold. This is in spec according to Mazda....

AND a bad one will ohm out almost the same when cold... however, as t heats up from climbing engine temps... the bad one's resistance will change to something like 300 to 400, and the solenoid doesn’t function correctly. Since it controls the vacuum/boost signal to your actuators… Well I’m sure you get the picture.

Result??? Your Car doesn't boost completely to max performance. Why?? The solenoid, which controls the boost/vacuum signal to the actuators is dying.... so their control over the waste gate and pre-control function is way off.

Car run like ****!

When Dave @ KD Rotary does a silicone vacuum hose job on the “happy tray” for a customer…(some people call it the Rats-Nest) he routinely changes this part... According to him it always goes bad...

The part cost something like $60.00 + dollars and is a cheap fix. You can buy one through Malloy Mazda, Ask for Ray Crowe… He’s a good guy and knows 3rd gens…!!

If you need more Info PM me

Good Luck

Rich

karken29

In the mornings, when the car's still cool, I think you said, it boosted fine and later in the day as thing heated up boost dropped off along with performance... Do I have that kinda right??

A common boost problem for 3rd gens is caused by a deteriorating solenoid that directly controls the Vacuum/Boost signal to the actuators for precontrol and waste gate. The solenoid I'm talking about is located in under the Upper Intake Manifold (passenger side of the engine) and held in place by a single 10mm bolt. If you look at the Siamese (2) solenoids that are right behind the coolant fill neck, bolted to the Upper Intake Manifold, front left side, Now bend down and look strait back behind them and you'll sorta see the one I'm talking about. Anyway...

What happens when it goes bad is this.... a new Solenoid will ohm out between 30 to 40 regardless if its hot or cold. This is in spec according to Mazda....

AND a bad one will ohm out almost the same when cold... however, as t heats up from climbing engine temps... the bad one's resistance will change to something like 300 to 400, and the solenoid doesn’t function correctly. Since it controls the vacuum/boost signal to your actuators, Well I'm sure you get the picture.

Result??? Your Car doesn't boost completely to max performance. Why?? The solenoid, which controls the boost/vacuum signal to the actuators is dying.... so their control over the waste gate and pre-control function is way off.

Car run like ****!

When Dave @ KD Rotary does a silicone vacuum hose job on the "happy tray" for a customer. (some people call it the Rats-Nest) he routinely changes this part... According to him it always goes bad...

The part cost something like $60.00 + dollars and is a cheap fix. You can buy one through Malloy Mazda, Ask for Ray Crowe, He's a good guy and knows 3rd gens..!!

If you need more Info PM me<@-@>
o

Good Luck,

Rich

karken29

,.,.,

duboisr

THE above is referring to the turbo control solenoid. (held on with a stud and 10mm nut ).