rx7nam

please guys dont flame for this as i have used the search button. i wanna get a full exhaust system w/no cat(not sure what yet) and intake. i heard the car runs lean after this upgrade.
from searching i found a ported or upgraded wastegate is a must. im trying to stay away from an ecu. would a fpr(fuel pressure regulater) work instead of buying an ecu?? what mods do i need to get to avoid boost creep and all the other unhappy things??
wastegate and what else?

thanks to everyone in advance!

Narfle

iTrader: (16)

you need an ecu. If you dont have an ecu you cant make the power safely. If you cant make the power safely whats the point? Youll just break it. Try to stick to a more rational modifications path. Instant gratification isnt all its cracked up to be.

rx7nam

so im guessing wastegate and ecu like a power fc. anything else?

Narfle

iTrader: (16)

Its never a great idea to run a full exhaust on the stock twins. But, if youre brave enough you might survive with a power fc and wastegate porting.

Your best option is to buy a restrictor plate for your exhaust if you really must run a full exhaust.

ROTARYFDTT

iTrader: (4)

None of that is accurate. It should read, on stock twins without a ported wastegate. With this properly done, running a full exhaust is absolutely fine assuming you have the other supporting mods and PROPER TUNING. I ran 15psi non-seq. with every stock twins bolt-on for two summers and almost 10K miles without issue. This was full non-seq, ported wastegate, ported motor. Tuning was done by Banzai Racing.

From my readings on here, if you can run at stock boost levels on the stock ecu, you can run a full exhaust without blowing a motor. However, in my opinion I wouldn't do this because I haven't personally observed this. And there's no compensation for that "what if" situation where you run too much boost in the cold at night etc. etc.

If I were you I'd just consider a DP, CB, and a pre-programmed M2 stage 3 or if you can find one. Those are pre-tuned conservatively to 14.7psi (on nearly all you'll find, apparently early ones weren't this high) for a DP, CB, intake, larger IC. Even with the stock cat in place, the car will be pretty quick. I don't want to say for sure, but I'd bet you'd be fine with a high-flow cat and an M2 stage 3. Some guys awhile back said they were running full exhaust without issue but I'm not sure at what psi. I don't think thats a good idea, but it strengthens my view that a high-flow probably would be ok. Although I'd certainly have a boost gauge to monitor boost throughout all of this.

Here's a quick list:
M2 stage 3 or Pettit equivalent -350 from what I recall
DP - 100 for a good one used
CB - 400 for a good one used
intake, whatever dependent on IC choice, 150
IC - for stock location I'd go with the PFS unit which sell for around 650.
boost gauge - 50 to 150
mbc - 100 set to 12-10-12 or stock levels.

Thats a pretty cost affective path to go, and you'll get a lot of added performance safely and it'll be good for the car. Pettit and M2 also made different versions of for different mods. I'd assume that a Pettit ECU would probably be easier to come across. Although they seem to be few and far between these days in the for sale section though.

I however like the philosophy of don't buy things you'll end up replacing. So all and all I'd rock the stock ecu untill you can buy a PFC. You can probably get a safe map much easier than finding a pre-grogrammed ecu.

ROTARYFDTT

iTrader: (4)

Another quick thing, I'd suggest buying a unit from Pettit but its not really worth it imp because of current PFC prices. And while on the stock ecu, be smart.

Narfle

iTrader: (16)

While my information may have been somewhat inaccurate(as it was a blanket statement) your information is just irrelevant bullshit.

Your engine lasted 10,000 miles with that setupd(not quite an achievement). Your twins werent stock. You had a PFC. And you had it tuned. The reason you didnt experience boost creep is that the efficiency of the twins is so low at 15psi that you couldnt creep. You say 14.7PSI is a conservative tune on the M2stage3 and that the biggest piece of bullshit I have ever heard. 14.7PSI is the absolute limit of anything stock on the car, most importantly the fuel system. There is not enough overhead in the fuel system to allow for a conservative tune at 14.7PSI.

A full exhaust damages the turbos through overexertion and risks your engine with overboosting.
If you can eliminate boost creep then you can tune your car properly(assuming you have a tunable ecu which he doesnt). This may be done by porting the wastegate or adding a restriction to the exhaust(which you shouldnt have removed in the first place).

This guy has a stock ecu and stock twins(yours werent stock btw) and wants to run a full exhaust. I doubt he has a boost controller. I wonder if he has a boost gauge. Im trying to save him an engine and youre setting him up to spend and extra 3grand just to pop his engine early and blow another couple thousand. My post may be less than pinpoint accurate but yours is far more detremental. You should think about what youre inciting before you post a bunch of stupid BS.

ROTARYFDTT

iTrader: (4)

my motor didn't go 10K miles, I just switched set-ups (went single). As I stated, my twins were entirely stock, there was nothing done to the exducer or inducer wheels. The wastegate was ported, how's are they not stock? The amount of air they can push is exactly the same. And yes, do some research the M2 stage 3 ecu was conservatively tuned up to 14.7psi. I didn't anywhere say he could run that boost on stock fuel, nor did I really mention fuel other than suggesting to keep things at stock boost levels or 12-10-12.

sorry but again I think your giving bad information. I think I'm aiding more, you're just giving a broad idea of what he can do, at least I specified and gave him some concrete ideas. Rather than...ummm full exhaust is bad and you need a PFC. Well that doesn't help to a newer member too now does it? I don't think you can never have too much information.

and your right, my car's total bs I just talk out my ***. Sorry just saying what I've and many others have done. About the only thing I agree with you on, is the fact that the stock twins lose effeciency around 15psi.

also, a full exhaust won't damage the turbos through overexertion, this will only occur if your running high levels of boost. The same effect could happen without running a full exhaust.

ehos

How are you going to pass smog in California? Just curious how tough the smog laws are (can you pass with full exhaust/no cat?)

rx7nam

im planning to keep my stock exhaust system on the side.

thanks rotaryfdtt and barban for the info. to further help my question im lookin for the cheapest solution. im not planning on running any higher boost. im thinkin about porting my wastegate and getting the greedy e-manage ecu. i have friends that can help me tune, port and dyno at racetune.net . if any of you guys need tuning or work done around the bay area contact them and ask for frank hes one of the founders and specializes in rotary as well as other cars(say nam recommended). i tried callin him but only got a message.
i just talk to one of my other homeboys about my situation he said i would be fine with an fcd. is this true? hes a rotary fanactic himself but he always worked on fc3s.

rynberg

I strongly suggest you quit listening to what your "homeboys" tell you and spend some time to do some research on here. Read the FAQ thread, that's what it's for.

1. You don't mod these cars with the "cheapest solution", unless you want to see how "cheap" a blown motor is.
2. FCD is a bad idea with an FD.
3. The Greddy E-manage is a POOR choice for the FD.

You want cheap? Put a downpipe on the car and leave it alone. You want to spend a little more? Put a downpipe, cat-back, intake, manual boost controller, used Pettit/M2 ecu ($350-400), and run 12 psi. Done.

Don't remove the stock cat until you have all of the supporting mods.

rx7nam

i have been researching and came up with getting a wastegate and ecu. i said my friend only worked on fc thats why i asked you guys if this was true. he also said the best thing for me to do was send my ecu out.
when i said cheap or what not i just wanted to see what my options were. i shouldve been more specific with my budget. i was lookin to spend around 1000 to 1500. as i said b4 i planned on getting dp, full exhaust(no cat 3") system and intake but needed kno what else i needed to get b4 i put anything on my baby. from your recommendations would i still need to port the wastegate?

rynberg

YES, you will still need to port the wastegate or add restrictor plates, otherwise it will very likely boost creep on you. You will have to maintain 10 psi with the stock ecu, or 12-13 psi with a Pettit ecu to avoid blowing the motor.

I don't understand why you feel you just have to put a midpipe on. You can make plenty of power with the stock main cat still in there and you will be 100% less likely to blow the motor. BTW, do you realize you have to pull the turbos to port the wastegate (SEVERAL hours of labor)?

Way too many owners don't treat a midpipe like the serious mod it is. It should really only be done in concurrence with a fuel system and standalone ecu upgrade, for maximum safety.

Revin-Rx

So in your opinion, with the mods i have, do you think i'm putting the engine at risk because i don't have a ported wastegate???

Mods: Mildly ported engine, J-spec twins (run parallel), Intake, Down Pipe / Mid-pipe + small 3 inch resonator in mid-pipe / Catback (everything is 3 inch) , Blitz SMIC, Microtech LT8, Greddy boost controller (set @ 10 psi).

Revin-Rx

BTW i didn't mean to hijack the thread, but thought since this is highly relevant to my situation, maybe you could kill 2 birds with one stone.

Upgrayedd

iTrader: (1)

For 1000 to 1500 you should be able to do well for exhaust and an ECU. I would suggest a DP, CB, and an ECU... I spent $265 for a DP, $400 for a CB, and $870 for a PFC! All brand new... Plus, there are plenty of good ECU's out there for cheaper than the PFC which would allow you to run a MP and possibly port the wastegate as well, depending on whether you do the work yourself or not... But, I agree with Rynberg almost ALWAYS! He knows what he's talking about, and I would definitely stay away from the GReddy E-manage as everything I have read shows it does not do well on the FD...

dgeesaman

iTrader: (7)

Rynberg has said it clearly, but for your understanding here it is, boiled down differently:

First, 'full exhaust' doesn't mean midpipe, but many folks run a straight-thru downpipe and a performance muffler already. These are good, simple mods with few complications. It's the midpipe replacing the main cat that makes it a full exhaust and is the point where you need to be much more educated and observant about the car and it's boost levels.

Midpipes cause two things to happen:
1) Your boost will spike and/or increase in level
2) Your boost will not reach a constant max level - it will 'creep' higher and higher the longer you stay in full boost.

1) is something the stock computer's boost control system simply cannot keep up with. You need to install some sort of boost controller that is more robust - either a manual boost controller or an electronic boost controller. The stock duty-cycling solenoid + restrictor pill setup is simply out of it's useful range.

2) Boost creep pops motors, especially with an aftermarket ECU. (The stock ECU will *usually* cut fuel before going too lean, but ... one day it won't...). The solution is to port the stock wastegate so that it can vent enough exhaust. That's it, but it's not a 5 minute job since the turbos must be pulled and disassembled.

The whole tuning issue depends on the ECU and level of boost you want. Once you get a sufficient boost controller and your wastegate is ported to meet the demands, you have control. But you still need to set your boost to a level that doesn't exceed or push your fuel supply. Stock ECUs = 10psi. Remapped ECUs w/ stock fuel system = 12psi, and so on.

You have 3 options if you're about to install a midpipe.

1) Install the midpipe, and install an adequate boost controller, port the ECU, and upgrade the ECU and/or fuel system as required. Also figure out what you're going to do about emissions (smog tests?), noise levels, and odor.

2) Install the midpipe and install some extra restriction. This reduces the boost control issue and enough restriction will stop boost creep. It may even be enough to remain with the stock boost control system, though I don't recommend it. Restrictor plates or more restrictive components elsewhere (stock intake or stock muffler) are how to add restriction.

3) Don't install a midpipe. Stay with a stock cat or high-flow cat. The high flow cat may require better boost control, but usually it won't creep. High flow cat with a downpipe and muffler can produce nearly as much power as a full exhaust.

So think about it: 1) is a lot of work, which if you're simply after power is better obtained by other mods. Some people think because a midpipe is a little cheaper that it's a good idea - wrong. 2) is adding performance only to restrict it again since you don't have the required supporting mods. Tell me if that isn't silly. 3) is simple, easy, practical, and cheap, and won't pop your motor.

Dave

rx7nam

i appreciate all the info thanks again.

KeloidJonesJr.

iTrader: (8)

*edited*

james81

Sorry guys, I also need to get in on this, I'v got a Microtec system, a streetported motor and a full 3" exhaust, now planning to port wastegate, but deciding between an Apex Dual N1 system(from MP splits to two smaller pipes) and a single 3".
The Dual gives more backpressure but ultimately gives more total exhaust volume(cubic volume) for high revs, the single has nearly no backpressure.

So am I safer to go with the Dual? and possibly upgrade fuel system?

dgeesaman

iTrader: (7)

It doesn't matter which muffler. With your setup, you should be able to adjust your boost to the appropriate level, and then you're set. What boost controller are you running now?

The fuel system will need upgraded based on the boost level.

Dave

Sprockett

Give me a ******* break. Ryan posted information that he has first-hand knowledge of...not number crunching and keyboard wisdom. +1 to Ryan for making a good post with relevant information instead of the old "GET A PFC OMG!" post that is almost as common as "YOUR MOTOR'S TOAST". What Ryan suggested would work perfectly fine as long as the rest of the fuel system was working properly. Those pre-tuned ECUs can be had for pretty cheap, and are a safe way to run a full exhaust at stock boost levels.

dgeesaman

iTrader: (7)

Sprockett, did you notice that your quote was over a year old? ()

Actually a stock ECU is a safe way to run a full exhaust at stock boost levels.

The trick of course is to run at stock boost levels and never spike or creep above it.

Dave

Sprockett

HAHA no, sorry. I fail HAHA. Sorry, a bit bored at work.

james81

Thanks Dave, I'm still planning to get a good quality aftermarket one, what is a commonly used/ reccomended boost controller?