I am about to rebuild my engine (new front & rear housings, only engine performance mods are HKS Downpipe) and I am considering doing a street port. I have done quite a bit of reasearch but would appreciate confirmation on the following:

- I can run the setup on the stock ECU
- No lumpy idle symptoms
- No noticeable loss of low end torque
- No boost creep/spike
- No problem with twin turbo setup
- Does it increase or decrease engine life ?

The cost of the porting is small (much less than in the US) and my mechanic believes I should definetely do it.

What do you guys think

I thank you all in advance

 

Personally I would not a street port with the stock ECU because the stock ECU has no way of "knowing" about the extra airflow. You will run leaner than if you just left it alone I think. Will it blow up? Probably not... but I'd be worried.

With only a downpipe, a street port won't really be that great anyhow.

Brian

 

If you already have a downpipe, just like Wargasm said, I would be worried about the rotary running leaner, which if you don't detonate your engine, will shorten engine life unless you modify your ECU to send more fuel in.

Tom

 

You will need to upgrade your ECU when you port your engine.

 

if you do not get an upgraded ecu one of the things you most likely get is some type of idle problems (exesively rich),reason being with the porting vacuum @idle is less then normal, therefore the computer thinks the car is accelerating and will try to compensate and add more fuel ,it will not harm the engine (running without a proper ecu ,i`ve done it) but its kind of a pain

 

When you talk about upgrading the ECU, does this mean I will be ok with a reprogrammed "stock" ECU

 

Unfortunately, probably not. None of the re-chipped ECU's (like Pettit or M2) have a compensation for a ported motor. You would need something tunable like a Power FC or Haltech or AEM EMS.

So the cost of doing the street port may not be that much, but the cost of having everything else to make the port effective is pretty high.

 

Not true. The Pettit ECU's are designed to work with ported engines and do work with them fine. Check this thread:

https://www.rx7club.com/showthread.p...hreadid=229715

and look down for RTS3GEN.

 

here is where it gets a bit shady i guess both yes and no ,i`ve tried the pettit upgrade its great but i did have to re-adjust my fpr in order to aid idle,and sometimes it would still get a bit too rich on idle ,but nonetheless great ecu for people who are not able to get to a tuner or just for people who dont want to go through the hassle of programming and tunning,personally i like haltech or microtech,i hear the power fc fram apexi is good,never tried it though

 

I've been around many cars that are ported and using the Pettit ECU. They've never had idle problems (or are you saying it was just running rich?).

What wideband were you using in determining how rich the car was running with the Pettit ECU?

 

none ,but the car was rich enough fo it to die ,and without adjust my fuel pressure at idle it would keep doing so ,i`ve even spoken many times with cam about this ,he told me that sometimes different engines react differently,i guess its possible

 

I guess that could depend on the type of porting. However RTS3GEN has a Race Ported engine from Pettit and he has zero problems running their ECU with it (especially tuning 11 second passes with stock twins seq).

 

i know i had a friend also with the pettit ecu (streetported) no problem, hey thats funny my friend also ran 11s with the twins ,,so there ya go , like i said not a bad ecu , i believe it also gets rid of that nasty fuel cut , doesnt it ??

 

The unlimited version does remove the 14.7 PSI fuel cut that the limited version has. I'm not sure if the unlimited completely removes fuel cut or just moves it up to the limit of the stock map sensor. That would be a better question for Cam.

I'm running the limited version as I have no need for anything over 14.7 PSI.

 

i bet ...the need for speed right

 

As long as you stay at very low boost levels you will have no problem with the stock ecu. I am using my stock ecu to break in a new race ported motor and it has been ok. But then again in 2000mile i can count on one hand how many times my boost gauge came out of vaccume. just be careful and get a tunable unit.

 

I am having my engine street ported right now, and I was told the ECU upgrade would keep the idle smooth, but not nessisary for reliability...

 

But what about the other points other than the ECU, low end torque loss for instance, is this noticeable...I do not want to worsen my 0-62 times

 

Porting does cause a lumpy idle. How lumpy depends on the size of the port.

Once you open up the exhaust a little (get the turbos spooling quicker), you'll never notice anything.

These cars all seem to act differently to different things. I don't think the porting will "cause" any boost creep or spiking. However, added in with some other mods, it's possible to make them worse if you are to see them later. I wouldn't worry about this until it happens IMO.

Nope, you can run the stock sequential twin turbos with a ported engine without any problems.

Nope. A ported engine requires the same care as a non-ported engine. Stay away from running lean and overheating then you'll be fine.

 

You learn something new every day. Thanks for puttin me in my place again Mahjik.

 

Thanks guys this is great
I think I will go with light street port
I will let you guys know what happened
Thanks again

 

Following discussions with my mechanic, he suggested I keep the stock ECU as is but use a fuel controller, notably the HKS Super AFR (for its fuel correcting CPU).

Question...what do you think of this...and if this is OK, is the Apexi S-AFC better by any chance.

Thanks