For those who remember my thread a few weeks ago regarding the ebay downpipe i brought the car to Rotorsports racing to have a dp installed. I decided to go with the RX7 trix mild steel DP. I also replaced my stock vac hoses with silicone hoses. There are NO other mods on the car, stock everything besides teh hoses and dp but the double throttle butterfly has disabled and removed.

My car now boosts (and spikes) to 15psi creating a very volative environment which i am addressing however i do have a question. If i get the Profec B, will the Profec allow me to lower my boost so that i can get it back around 10-11psi? Can i use a manual boost controller until i get a Profec B? Is there any dangers to running a manual boost controller until i can get a Profec B? I would like as much information regarding this subject as possible. I've done a search but my questions relates specifically to my mods, or lackthereof. TIA for any insight anyone may provide.

Darril

 

Something is wrong. You will NOT spike to 15 psi with just a downpipe. I would look into the vacuum line running from the primary turbo housing to the wastegate as the first culprit.

Fix the problem, don't try to cover it up with a boost controller. And yes, a boost controller will allow you to keep boost at 10 psi, or even lower it to 7 psi if you want. A manual controller will be fine for temp use. Just install it into the wastegate line and leave the pre-control alone.

 

You should not be spiking or going to 15 with a DP. As mentioned check your vacuum line to your wastegate, if you have the type with pills, make sure they haven't turned when they were put in. You can check by blowing through or replace it with a straight piece of tubing and test your boost, it should be way down I think around 4psi. If boost drops check your pill in that line. If you have the kind without pills, make sure your new line isn't kinked or pinched, that would cause the same effect. Good Luck!

 

congradulations you found the quote button

 

Rynberg, i don't plan to "cover it up" with a boost controller, i just wasn't sure what was going on, which is why i posted this thread. I also wanted to make sure that a manual boost controller would be temporarily ok to use until i could get a Profec B. Thank you for the information as it turns out to be very valuable. I will inspect the car this coming weekend when i am free and see if i can figure out what is going on. The only other thing i can think of is that the boost guage is off (long shot here). Originally i had discounted the boost guage as the culprit because the car shows a perfect 16in of vacuum at idle and between 20-21 in of vacuum under deceleration, which i'm told is optimum.
However after speaking with Brian@Rotorsports today, he offered the suggestion that the boost guage may not necessarily be linear in it's readings. In other words, it may show the correct vacuum, but it may be off on positive manifold pressure. I will see if i can try a different boost guage to see if there is a difference. If anyone else has any other suggestions please let me know and i will make a checklist and go through the car. TIA!

Darril

 

bro i agree with ryanberg sounds like you have some vacuum line going to the wrong spot

 

Just a few thoughts here - were the solenoids and check valves tested while doing the hose job?
It takes some extra time (an hour) but is critical to making SURE the system works as designed.
Many tuners/shops/wannabees skip this step.

Could any of the vacuum lines have been kinked/pinched when re-installing everything? EASY to do. What brand hose was used? Almost all of the junk on the market can split when it is jammed on the larger nipples - even if it was carefully cut - during install, or soon thereafter.

Typically if they are bad/installed wrong it will cause low boost - but stranger things have happened in "The MatRiX".

Rynberg has the right first track to follow, and don't feel bad if he suggested that MANY guys go for the "easy fix". Listen to him. This is a VERY complex system and when it works correctly it is awesome, but it can be a mufugger to diagnose.

You have a problem that can cause massive hell ($$$) if you don't figure it out. Don't boost anymore until it's fixed. One "ping" and its all over...

 

My thoughts exactly.