areXseven

iTrader: (1)

Today I installed a MagnaFlow Dual 3" exhuast cat-back. It replaced the HKS Super Drager the FD had when I bought it 4.5 months ago.

With the HKS, the car never boosted above 12 psi, and the 12psi was only a spike at secondary turbo transition. When I got out of the Muff Shop I drove the car to work. I went WOT at about 80mph (car was in Drive). I noticed a big change in accelertation and I glanced at my boost gauge and it was at 15psi. I immedietly got off the throttle and brought the boost level down to 10 psi. By then I was going 127mph. I'm pretty lucky the engine didn't

Do I need to first buy a Boost Controller...or...just get an ECU upgrade. What other mods do you all recommend so I can safely take advantage of the additionl boost levels/HP.?? Thanks.

Mahjik

iTrader: (1)

You can try a boost controller, however I'll bet you are also going to need some more restriction in your exhaust or your wastegate ported.

There's that uncontrollable boost I was referring to a while back.

I would look for an ECU and/or boost controller first.

areXseven

iTrader: (1)

I recall your comment. Your were right. I guess the HKS was clogged, or the MagnaFlow just provides superior flow. Is there a place/shop that can "upgrade" the stock ECU.,...or is it best to replace it with an aftermarket ECU like from Pettit, etc,..?? Will I have to replace the injectors and/or get a FMIC?? Will I have to rob a bank???

adam c

iTrader: (2)

I agree except for the OR part

areXseven

iTrader: (1)

Why would I need a Boost Cont., if I install an ECU that is designed/tweeked to work with high boost engine and made to adjust and provide additional fuel management??. Please explain. Thanks.

ludeowner

I see a MP in your mods list, with that I would definately get an ECU upgrade and port your WG. Or maybe for the time being you can add a restrictor. I take it you dont have a MBC or EBC either?

areXseven

iTrader: (1)

What type of aftermarket ECU's are available for an Auto FD?? Or can I ship my stock ECU somewhere and have it "upgraded"??

DaiOni

replacing the MP with something more restrictive - cat/high flow cat would certainly be a fairly cheap short-term solution (potentially)

is it possible to run an auto FD with a PFC? - that would be my choice - along with a stand-alone boost controller

One of the problems with plug-in ecu replacements is that they lack the precise contol and monitoring that is instantly available with a boost controller.

Even the PFC, with hand controller, seems to be problematic

The number of people who prefer a stand-alone controller to the PFC add-on is an interesting point.

Any way you look at it, a solution is not cheap - but then, neither is a new engine

adam c

iTrader: (2)

You are boosting to 15psi. An ecu upgrade won't correct that. A boost controller will allow you to run safely, with an upgraded ecu, at a sensible boost level.

Mahjik

iTrader: (1)

The problem may occur that he has boost creep and still might creep to 15 PSI even with a boost controller.

areXseven,

Upgrading the ECU on the Automatics is tricky. If you replace the ECU with something like a PFC you'll lose the HOLD feature which most auto owners can't live without.

You can use a piggy-back ECU (one that doesn't replace the auto ECU but works with it) and get what you need. The PFS box is a piggy-back and I believe you can piggy-back the PFC. You could also check on the AEM, it might be able to replace the ECU and retain the HOLD feature, but I'm not sure.

Two things I would consider doing if I were you is:

1. Getting a boost controller. As I said, it may NOT stop the problem (if it's boost creep you are seeing) but it's a good first step.

2. Replace the midpipe with a hi-flo cat. Doing this will bring the boost under a more manageable state however you still may need a boost controller to lower things down a bit.

areXseven

iTrader: (1)

Magnaflow sells a Cat that can be welded onto any exhaust. Maybe I'll just buy that and have it place in the middle of the MP, in the same area/bay where the Main Cat used to be??

It really bites that so much has to be done and so many adjustments have to be addressed just to keep the engine from blowing, especially while tryin to create additional boost and H/P. In the long run, I guess it's worth it!. Thanks.

dubulup

stock fuel system can't really support 15 -17psi, so ECU to add fuel and boost controller to limit boost.
jmho

ptrhahn

iTrader: (9)

Wow, somebody must have stuffed a banana in your HKS... i wouldn't think there'd be anough flow difference with any aftermarket catback to make a boost control difference. Sounds like w/ the MP you SHOULD have had this problem, but somehow didn't.

areXseven

iTrader: (1)

How crazy can the boost get on an FD? Also after the ECU and Boost Cont. is installed, what HP do you think a healthy 1.3 lt. will produce at 15psi?? Should I consider an FMIC after the ECU and B/Cont??

areXseven

iTrader: (1)

Actually that HKS was so big (5" outlet), I think it had a Coconut stuck in it!!

Mahjik

iTrader: (1)

The stock map sensor will limit to a hair over 17 PSI.

With the stock turbos, stock fuel system, and non-ported engine, you'll probably be around 330-340rwhp if you have all the bolt-on mods running 15 PSI.

IMO, boosting over 12 PSI you should look into an aftermarket IC (whether FMIC or SMIC is up to you).

areXseven

iTrader: (1)

Mahjik: Thanks for the advise. I feel sorry for Santa!!

areXseven

iTrader: (1)

What is the maximum safe boost level/psi I should adjust the "profecB" (at WOT) ?

Mahjik

iTrader: (1)

With the stock ECU, I wouldn't risk running over 10 PSI. Even with that, depending on boost level, rpm and duration the boost is there you'll run into boost cut at some point.

areXseven

iTrader: (1)

Okay.....how about with a ProfecB AND upgraded ECU. Safest maximim boost level??

RX-7racer88

I say do an ECU swap probaly go with the pfc. Then if you want you can add a boost controler to it. The PFC has a boost controler bult in it also.

areXseven

iTrader: (1)

Where can I find an aftermarket ECU for my automatic and what type PFC do you recommend? Thanks.

Mahjik

iTrader: (1)

On the stock fuel system, I wouldn't risk anything past 14 PSI without using high octane gas. I know quite a few people who have run 13-14 PSI daily on the stock fuel system for years. 15 PSI would be the max I would ever push the stock injectors.

Keep in mind that even at 10 PSI, with all the air flow mods you have you are still making more power at the stock boost level than a stock FD. Someone made 266rwhp at the stock boost level:

https://www.rx7club.com/forum/showth...highlight=wade

A health stock FD will make around 220rwhp so that's quite a difference even at the stock 10 PSI.

GarageBoy

M2 can upgrade your ECU. If you get the P

GarageBoy

MS does ECU upgrades. If you get the PFC and the high boost kit, you don't need a boost controller (thePFC takes care of it)