high flow cat vs resonator & manual boost controller vs electronic...
 

I have an sr motorsports dp-bonez midpipe-greddy evo cat back...my set up is listed power fc, pettit cool charge iii stock location intercooler, hks intake, hks twin power, pettit motor with streetport...3mm apex seals...upgraded rotor housings, new stock twin turbos with wastegate ported...My question is I heard that even with the stock turbos wastegate being ported the chances of boost creep are still apparent so what would you guys recomend a highflow cat to add to the midpipe or just a resonator to add back pressure? Also do you think a manual boost controller would help to keep boost at a safe psi or do you recomend an electronic one? Ideas and input please thanks!!!:nod:

A lot of this has been covered, some searching is your friend.

All cars seem to be a little different when it comes to boost creep. Biggest thing a highflow cat does is get rid of exhaust stink. A resonated midpipe won't help much with creep, but will cut some of the noise down.

IMHO, manual boost controllers are ghetto on an FD. Get a good used electronic boost controller or get a better boost solenoid to use with the PFC.

Dale

High quality ball and spring MBCs (the bleed type ones are too variable) are perfectly appropriate for an FD. I have been using dual Hallmans with cabin controller (one for precontrol and one for wastegate) for years and I am not sure I could have debugged my boost problem without them. Not only do they allow rapid spool but they are perfectly predictable.

The problem with electronic boost controllers is that they tend to have a mind of their own (particularly the high end ones) and you are never quite sure what they are up to. (Witness countless discussions of tuning, say, the Blitz SBC-ID on many boards.) A single EBC is also going to effectively bypass the transition control system on a sequential FD.

Sorry but I forgot to mention Im non sequential too...:blush:

+1 2xMBC. simple and works.

screw mbc lol... seriously Im with Dale.

I have a profec spec II which is on the low side of ebc's and I just love it. Simple to adjust, use, and given that it displays boost in real time I completely did away with my boost gauge.

I used to have high flow cats on 2 of my fd's. Reluctantly I tried just a resonated midpipe and it made very little difference for stink or sound. I wish I would have switched to the midpipe a long time ago!

manual vs electronic boost controller debate has been done to death. Manual valves are like lawn mower carbs; they're simple but they're dumb. Electronic controllers can be pretty simple ranging all the way up to being very complicated. If you want something that is electronic but very simple to control (like a manual boost controller), look at the Greddy Profec S.

Here is a thread comparing all the major external electronic boost controllers: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/electronic-boost-controller-comparison-chart-952767/

From what I understand, a high flow cat adds backpressure while still allowing a free(er) flowing path for performance, and it's legal ;). A resonator helps baffle sound, only. However, I could be wrong.

I think that a high flow cat is ideal if you're concerned with boost creep/spike.

I have a ported wastegate and a high flow cat; I never experience any boost issues.

I've had 3 fd's all w/ the same mbc setup and straight piping all the way through to an apexi GTspec. Never worried about or had boost creep ever since. There are probably many other places you can put that money to use.

I sold my Hallmans to moconnor and bought a profec type-s. I liked the mbc's more with sequential. The dual mbc's gave me more prespool adjustablity than my profec Type-S.

For a non-sequential setup, you might as well go with an electric controller. It will probably hold boost better and help spool.

Your cat-back will have more to do with noise than your mid-pipe. If you get a hi flo cat, get one with an air-pump fitting.

Nope you are correct. If you ever pickup a resonated midpipe you will see that its just a straight through pipe and there is nothing in the way to impede the flow of the exhaust.

greddy type S boost controller.. easiest i bc i ever used.

as for the creep.. yes even if the wg is ported u still can get it.. i have the bnr stage 3 in seq with ported wg and still get creep some creep. but it doesnt go past 18psi for me which is what im tuned for

I am non sequential tuned to 15 psi with a resonated mp and rb catback. Ported wastegate, no creep. I think the racing beat dual being a bit more restrictive than some exhausts helps this.

I use the pfc to control boost. It works ok, but I think I can get better perf with an ebc.

got a resonator and rb catback, it does restrict but im not sure by how much.

A manual boost controler is asking for problems. All it takes is one overbooost or good spike and you will be paying for a rebuild. I have seen it happen too many times. Get a proper electronic boost controler. The power fc integrated control works decent with the twins. If you are getting spiking the apexi boost kit has a faster responding solenoid which helps. A simple electronic controler like the greddy profec spec s is acceptable as well. However, with full exhaust and twins you may not be able to keep the boost reasonable in cold climates. I'd stick with a cat.

The OP may already be aware, but since the discussion overlaps both topics.....a Boost Controller (Manual or Electric) will not control boost creep. It's only effective for spike.