Hey guys.

Is it true that if you do a full exhaust from turbo back(eliminating the catalitic converter) and a full air-intake re-build, eg: stainless piping, aftermarket BOF with pod filters all blocked off from the engine and its heat. The car will leen out and not run as rich as it dose now and may dettonate. I know the boost will spike and im going to get a cap on it or a controler to keep it 10psi. I have an exhaust from behinde the cat. so its just a muffler. It came from Jap like this. It runs realy well. Makes pops now and then some times doubble ones when you push the clutch in fast or when you change gears....but thats besides the point.

I hope someone has some helpful info for me. Thanks guys.

My car is a 98 model Type RB-S.

Cheers.

 

Does anyone know?

 

you don't NEED a new ECU for those mods. boost controller is not going to limit boost, your ECU and wastegate will do that for you. yes, you may get some spikes with the exhaust flowing so much more now, but i doubt you're going to run lean unless you plan to artificially raise the boost levels significantly - which you could do with a boostl controller.

that's my understanding ... if i'm wrong, hopefully, i will be respectfully corrected.

 

I've been under that the impression that an ECU is generally pretty important if you're running full 3" exhaust + full intake.

 

Yea thats what i thought 2, but aparently the map sensor adjusts on its own but you still get spike from the free flowing of the Air intake and exhaust system which can be eliminated with a boost cap, or so some one once told me. I dont want to increase my boost. The factory 10psi is plenty enough for now. I just want to help the engine breath better and keep it cooler. Also hopeing for a little better throttle response and fule econemy.

 

exactly ...

yes, i would recommend using some of the money you would have used for a new EMS and upgrade the cooling system, then keep the rest if you don't plan on modding the car any further.

 

with a full exhaust and intake on an FD and turbo FC, you will need something to control boost - i.e. a boost a controller. the wastegate does what the boost control solenoids tell it to do. the boost controller controls the solenoids and allows you to set a max boost preventing against spike and usually boost creep too. MAP sensor does not control boost. never heard of a boost cap. sounds like BS.

On the stock FD ECU you can pretty safely run up to 10 psi anything over that and you're asking for trouble. Search for a recent thread that rynberg posted on in the 3rd gen section.

 

So when do you have to get an aftermarket ecu ? I would like to keep everything runing smoothly but just better. More air flow, free flowed exhaust, better cooling and still 10psi and no more.

 

Everything in that post is wrong.

 

okay ... I humbly retract. but i am ready to learn, so anything you have to offer will be gladly received.

however, i still can't see how the stock ECU wouldn't be able to handle the spikes of just intake and exhaust mods. wouldn't the factory have made it capable to account for all sorts of variables that may create boost spikes, other possible lean condtions or anything that could lead to detonation (some cheap fool using 86 octane gasoline, severely cold days, high altitudes, etc.)? are the stock Gen III ECU's just that shitty?

on everything else, i'll keep teaching myself until i get it all right, but again, anything you can offer will be received gladly.

 

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Right...so as I asked will the car be fine with full 3" exhaust from turbos back with no cat....cos here we dont have to have them....just put a resenated pipe in its place. Also the air system. Get a boost controler and set it to 10psi so that it dosent creep or spike.

 

There are very few people on the Forum who you ought to pay attention to with an issue this critical & I am not one of them.

For what it's worth, it will boost more at transition, spike, and lean out. How much, God knows. More boost needs more fuel, generally a lot more.

If you actually can limit your boost to 10 then the stock ecu should have no trouble keeping up but I don't think the stock ecu and wastegate can prevent you from spikes with a full exhaust.

The map sensor is a sensor, it controls nothing. It just reports to the ecu what your boost is.

You need to get advice from serious tuner because most of us here will get you into trouble. A hell of a lot of twin turbo cars lost motors and my bet is the midpipe was a factor in most.

 

Well the guy who survices my car is the fastest RX7 in NZ. He has a 8.6sec bat with a 20b in it with 700+hp. I asked him about it and he recons that it wont need an ecu for those mods cos my car is runing realy rich anyway. All I need is to stop the boost dead at 10psi and the car will be sweet with those mods. Well thats what he recons anyway.

 

So you're going to buy a boostcontroller ?
I've got the same problem and i don't want to blow my engine !
Let me know what you're going to do about it.

thx