maschinenpistole

iTrader: (1)

I have a pettit high flow cat that I am going to install. Some people have told me that it is okay to run it without a boost controller, and some others say I should. Concensus ?

Mods:
factory engine
factory turbos
downpipe
catback
cai
aftermarket ic
hks twin power

Thanks..

adam c

iTrader: (2)

Get a boost controller. You risk overboosting without one. Here's a link to a manual boost controller that is inexpensive and effective:

http://www.robrobinette.com/boost_controller.htm

Don't install the prespool controller.

maschinenpistole

iTrader: (1)

Thanks Adam..

mecman

iTrader: (11)

I agree. See my set up in my sig. I have seen boost spikes up to 14 psi. I am going with Damain's set up with Hallman RX pros to control the transition. Unlike most on the forum, I like the quick spool up on the sequential set up at low rpms.

Tom93R1

iTrader: (2)

If you are very technically and mechanically inclined (and careful) you can do the pre-spool. My boost pattern was all jacked up doing something like 9-6-14 before I did it. I was able to get it all smoothed out to a 10-7-10. This was when I had just down pipe and high flow running stock ECU up in the altitude of CO.
I would recommend the boost controller first and see what that gets you, then decide on the prespool after that.

adam c

iTrader: (2)

I am technically, and mechanically inclined, and careful. I was hoping to get a 12-10-12 boost pattern, to improve upon the 12-8-12 pattern I had with the stock prespool line. I spent 6 weeks trying to get the two controllers to work together properly. Adjusting one would throw off the other. Over and over and over again, I would make adjustments to try and get it right. It was quite the exersise in futility. I finally gave up, and put the stock line back in. What a relief.

When I was done, I concluded that the extra length of hose may have been the problem. The long hose may have delayed the pressure needed to get the quick reaction required.

alberto_mg

it wasn't all that hard for me. i bought a used Profec for $200 and boost is always perfect.

DaveW

Adam C,

You have often posted that you had trouble controlling the PC. Were you using needle valves (with the stock solenoid valves) or were you using Ball-spring type controller(s) (with the WG and PC lines to the stock solenoids blocked) when you had this difficulty?

adam c

iTrader: (2)

Dave,

My problem was with needle valves on the prespool. My needle valve on the wastegate works perfectly. Perhaps I was not clear that a needle valve on the prespool is difficult (or impossible ) to adjust.

DaveW

Thanks, Adam,

The reason I asked that is that I just completed doing a bunch of work (DP, boost gauge, Viton hose job, all water hoses, etc.) on my FD, and in the process, I installed a "Damian-style" dual ball-spring boost-control (both WG & PC) setup. I have yet to attempt tuning it, since there is still snow on the ground here, but I expect that it will work fine (per Damian's posts), and wanted to clarify what you had problems with.

Thanks, again.

adam c

iTrader: (2)

Dave,

When someone asks about a boost controller, many times I post this link:

http://www.robrobinette.com/boost_controller.htm

It is a link to a needle controller. It also has instructions for a needle prespool controller. Many people have had problems with the needle prespool valve, so I suggest not installing it when I post the link.

Please let me know how the ball and spring works on the prespool valve if you try it.

Thanks, Adam

PS. The next time I have my intake out, I am considering installing the stock wastegate line in place of the prespool line. It has a slightly larger pill. In a stock FD, it provided 10 psi. Maybe it will give me 10 psi at transition in the prespool location instead of the 8 psi I am getting now


.

Tom93R1

iTrader: (2)

I am using the needle valves and have about 4 feet of vaccuum line for each the prespool and boost. I dont know, maybe there is something else going on if you arent able to smooth out the transition but I was able to get pretty close to perfect from something that started out completely off at altitude.

Now that I have been running the PFC for some time I do think I should get rid of the controllers. The PFC can control boost quite nicely and eliminating one more piece of something under the hood that can go wrong is never a bad idea.

adam c

iTrader: (2)

Tom,

From what I have heard, the PFC boost controller isn't so good. You might want to PM Rynberg about that.

Adam

Tom93R1

iTrader: (2)

Hmm, last round of mods I did that screwed up the pattern I was able to get it all fixed again with just a few minutes of playing with the PFC. You have to set it by fiddling with the duty cycles, so more mods will screw it all up and you will need to fix it again. Being careful with that I have never had a problem.

What did Rynberg have happen from the PFC boost control?

adam c

iTrader: (2)

I don't think he had a problem. IIRC he told me that it wasn't a very good controller. You should really check with him for details. I don't have a PFC.

DaveW

OK, Adam, I'll post my MBC setup's tuning results (assuming the snow ever melts here).