ThoRx7

is it okay to put a intake on the fd... cause my fd is my daily driver and i needed to get you opinion cause this one guy told me its not good because it could mess up my mass air flow censor.. is this true? its a hks intake for my twins... cause from him he says that tiny dust could get through the intakes to the mass air flow.. i dunno about it so what do u think?

Mahjik

iTrader: (1)

FD's don't use MAF's so there is no problem there. However, aftermarket intakes can increase the likely-hood of boost spikes. Unless you have the "need" for one just keep it stock.

4CN A1R

iTrader: (6)

^
you can solve this problem by getting a manual boost controller. but for now this sounds above you. you could get intakes but i would sugest not driving in cool weather, that way you avoid spikes.

dhays

iTrader: (1)

I pretty much don't have a clue as to what you wrote means. My FD has Greddy Airinx intake replacing the stock air box. It doesn't have (that I'm aware of) a manual boost controller. What potential problems should I be aware of? Again, I know very, very, very little.

Oun

iTrader: (3)

im guessing you dont have a boost gauge? on cold nights I would get boost spikes to 11 or 12 psi. damn texas weather

dhays

iTrader: (1)

I've got a boost gauge, but have only owned the car for less than a week. While I have driven it a LOT, most of that was while the engine was nice and warm (even though the air was very cold). I'm not sure I trust my boost gauge completely, but I think I may have seen it spike slightly past 10 a couple of times. Whenever I was asking for that much power, I normally had my eyes on things other than the boost gauge however.

Oun

iTrader: (3)

i say just go for it and install it. I used to daily mine for about a year with Apexi intakes. but now I have a vented hood and avoid driving during rain.

7dust

iTrader: (14)

How the heck is a boost controller going to help with cold weather spiking? A boost controller only bleeds off vacuum to your wastegate to help you raise boost above normal levels. If your wastegate can't handle the flow increase from an intake or exhaust - then its only going to compound the problem.

You need to port your wastegate or install an exhaust restrictor. Both are relatively "free" mods although time consuming.

OR

You can always keep your foot out of it - good luck on that one.

dgeesaman

iTrader: (7)

David:

Summary:
For a street driven car with just a couple of mods, I recommend keeping an eye on the boost gauge and installing the flow mods one at a time. Usually 2-3 flow mods will not change the boost settings and require neither wastegate porting nor a boost controller.

The details:
The stock boost control system uses a couple of solenoids and a preprogrammed control. As it senses boost pressure, it follows the ECU program that opens the wastegate and precontrol valves to keep that boost regulated. The air/fuel ratio is determined mostly from the boost pressure measured at the manifold. When running stock boost levels, with the restriction in the intake and exhaust similar to the stock components, this works pretty well. You get 10psi at pretty much all air pressures and temperatures, and your air/fuel ratios stay on the safe side of stoich.

There are 3 limitations that you need to be aware of.
1) Changes to the flow resistance of the intake or exhaust will change the maximum boost. I call these 'flow mods', which include: intake, efini y-pipe, intercooler, downpipe, high flow cat or midpipe, and cat-back. For example, you install an intake and downpipe, you may find that instead of max 10psi you're now getting 11psi. 11psi is sorta ok, but 12psi is not. The stock ECU limits you to about 12psi of boost. This is the so-called '10 psi rule' - AFR testing has shown that, if limited to 10psi, your AFRs will be safe for the stock ECU no matter what mods you have.

If it senses any more than that at the MAP sensor, it cuts fuel completely. The driver senses a big hesitation and the turbos slow down. Fuel cut works, most of the time. If you hit fuel cut due to a change in the car that increases boost, you need to fix it so that it doesn't hit fuel cut again. To solve this problem, you need a boost controller. Aftermarket boost controllers allow you to reset the boost to the appropriate level (10 or 11psi for a stock ECU).

2) The stock boost system is not 'fast'. If you install flow mods the reduced resistance can cause the prespool system to spool excessively, leading to a spike in boost at 4500rpm when the prespooled secondary turbo joins the system. The stock solenoids and computer just aren't fast enough at opening the wastegate, and these spikes are really dangerous because they sometimes also happen too fast for fuel cut to kick in. These sudden spikes are prime time for detonation and engine damage. Fortunately, those adjustable boost controllers are also much quicker, and usually stop spikes from happening.

3) The stock wastegate, when controlled by an adj. boost controller, can run really well until you get plenty of flow mods. But with enough flow mods the stock wastegate can reach a choked flow situation, where the wastegate reaches its limit and then boost levels start to rise beyond the boost controller setting. No matter what setting is used on the boost controller, the boost just steadily rises under heavy load. This is called boost creep. The solution is to enlarge the wastegate opening (located inside the turbo housing - not a simple job). By porting the wastegate larger, boost creep goes away. Most FD owners don't see boost creep until they install an aftermarket intake, downpipe, intercooler, cat-back, and finally a midpipe. The midpipe is a big change in flow, and as such I recommend always porting the wastegate prior to installing a midpipe.

Dave

4CN A1R

iTrader: (6)

your thinking of boost creep. spike and creep are different.

you can get your boost controller to limit you all the way to 7psi if you like

4CN A1R

iTrader: (6)

it has nothing to do with your intakes. the only problem you may have is boost spike. this happens at wot usually when your in cool weather. your boost may spike at 11-12psi. if you have a boost gauge, you can monitor it. you dont want to be pushing that kinda boost on the stock ecu.

you could also just read wat Dave typed above^^

bajaman

Listen to what everyone on here has written, and quit listening to your friend, because he doesn't have a clue about these cars. And for God's sake don't let him TOUCH or adjust anything!!!

dhays

iTrader: (1)

Thanks Dave. That was a great explanation. It really helps as I'm just beginning to learn about the systems. My FD, (as far as I know) has several mods that would effect "flow". On the exhaust side there is a Bonez downpipe, Bonez high-flow cat converter, and Racing Beat dual tip cat-back. On the input side there is just the Greddy Airinx intake system. One of the things that I've been wondering about is weather the stock ECU can handle the potential changes there. I've got a rotary mechanic that I'm going to have check out the car and this is one of my questions for him.

dgeesaman

iTrader: (7)

I would expect that setup to be producing more than 10psi.

Make it a priority to use a boost gauge (even a temporary one) to see what your boost is maxing at. I'll bet if it's a stock ecu/boost control, you'll need to install a boost controller to dial it down.

Dave

dgeesaman

iTrader: (7)

Some cars will not tolerate aftermarket intakes and the MAF will throw codes. This car isn't one of them.

I wrote about the real issues in another post. *That's* what you need to pay attention to.

Dave

jmluke1

thanks dave, that was a real learning exp. u helped me understand a little better. now how hard is it to find someone to port the wastegate ? or is it even possible to try myself ? i just cant stand having a stock car. ive got alot of aftermarket parts just waiting!!

Sgtblue

iTrader: (16)

I assume that if you intend to port your wastegate, you intend to install a midpipe. Before you commit to that, you might want to search and read on it a bit.
If you have emissions, you won't pass with a midpipe. There is also noise considerations and most frequently, a foul smell. There are alternative "hi-flow" cats. Admittedly they don't perform as well as a midpipe, but better than the stock cat....and they solve those issues. One last thought, since the wastegate is internal on these cars, just accessing it is alot of trouble.

gracer7-rx7

iTrader: (16)

Dgeesman got it right.

The one thing I don't like about open intakes on a mostly stock, daily driven car is all the noise from the air pump and BOV and cRV. Kind of annoying.

adam_c had a nice mod to the stock airbox that helps increase air flow. Works very well and quite cheap. As always though, keep an eye on the boost gauge after flow mods. The stock systems (intake and exhaust) are quite good at helping to restrict boost. Once you start increasing air flow, you risk running more boost than you have fuel to support. Usually more noticeable in cold weather when the air is denser.

jmluke1

ive got a new full exhaust from the turbo back,no cats,im in fla and we dont have emissions, and fmic. car is still completely stock,im trying to learn more about it before i do anything.so i havent installed anything yet, because i would like it to be as dependable as my vette,if at all possible.

jmluke1

can a pop off valve be added to control boost spike ? or would it just keep fluttering as the boost levels creep ?

Sgtblue

iTrader: (16)

Open exhaust and FMIC? This means you also have some sort of aftermarket intake. I don't mean to argue, but your idea of "completely stock", and mine, are much different.
Blow-off valves are actuated by vacuum (or lack of it under load) not by any pre-set max boost pressure.

Mahjik

iTrader: (1)

Yes. A pop-off valve can aid as a last chance safety system. They aren't too common these days though but they probably could have a saved a few motors on this forum.

Mahjik

iTrader: (1)

A pop-off valve is similar to a blow-off valve, but is used differently. It is actuated by a pre-set pressure.

Sgtblue

iTrader: (16)

Sorry, and thanks. I mis-read.

FutileLover

iTrader: (1)

thanks for the explanation dave... looks like i should get a boost guage

ive got a bone stock R2, except its got a hks downpipe and muffler (still has maincat)

i experienced a massive hesitation at 5.5k RPM one morning when getting on the highway, it was cold out (30-40*F)

i didnt know what it was but "fuel cut" makes sense