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-   -   Quick Question (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/quick-question-605290/)

thiasRx7 Dec 13, 2006 07:15 PM

Quick Question
 
Hey guys. I am running almost stock with exceptions of DP, MP, Apexi N1, Intake and have removed all emissions. I blew the old motor and am now ready to get it rebuilt. My question is will I be able to run a street ported engine with the stock ECU. Or will I need to just stick with a stock motor til I can afford to get a PFC and all the other goodies I want to get. I plan on doing many upgrades in the future which is why I want to put the street port in now while I'm getting a rebuild, but if it will only lead to problems which cause me to have to pay out my ass before I am ready, I don't want to do it.

Please help and thanks ahead of time,

Matthew

VegasFD Dec 13, 2006 07:19 PM

You'll be fine with a streetport running the stock map, as long as you can control boost at 10 psi. But get rid of the midpipe, and put the main cat back on. That's probably why you blew your motor in the first place!

DDagman Dec 13, 2006 08:11 PM

I have a street port, DP, HF cat, and Apexi GT spec and intake. I have a stock ECU and no boost conroller but i do not creep, it doesnt go TOO cold here. If you live ina place where it gets very very cold, you want to get a PFC before running even a HF cat, but once you do, you will have lots of fun with the street port. It is a huge difference from the stock one.

rynberg Dec 13, 2006 08:29 PM

full exhaust with intake is not "almost stock", lol, and is why you blew your first engine

Get a proper ecu, port the wastegate, upgrade the fuel system and GET THE CAR TUNED BY SOMEONE WHO KNOWS WHAT THEY'RE DOING. Otherwise, do as VegasFD says and put a stock main cat back on.

thiasRx7 Dec 13, 2006 08:30 PM

Hey thanks for the quick response. I'll be sure to put the main cat back on. I know for a fact thats the reason I blew it in the first place because after I put it on I could never quite get the boost set right. Street port here I come!!!!! Thanks for the help.

Matthew

vtakk eg Dec 13, 2006 08:47 PM

i have a stock car besides my PFS catback , so are you all saying if i put a DP,MP,and , intake that my motor will blow, with just thouse mods? please elaborate

<==newb sorry

IRPerformance Dec 13, 2006 09:08 PM


Originally Posted by DDagman
I have a street port, DP, HF cat, and Apexi GT spec and intake. I have a stock ECU and no boost conroller but i do not creep, it doesnt go TOO cold here. If you live ina place where it gets very very cold, you want to get a PFC before running even a HF cat, but once you do, you will have lots of fun with the street port. It is a huge difference from the stock one.

I would keep your boost in check. You may be on borrowed time. I would never do more than 2 mods that affect air flow through the engine without changing the ecu on these cars. Also, I recently tore down an engine that lost a coolant seal. I found detonation damage right before the apex in the center of each face of the rear rotor. No broken apex seals, but the rotor is trashed and it would only be a mater of time until the seal let go. My customer was running an intake, downpipe, and catback on a stock ecu. The computer just can't handle it.

NeedFD Dec 13, 2006 11:22 PM

honestly i wouldn't be driving your car with those mods and no pfc.. if you must, then keep off boost or driving hard..

Mahjik Dec 14, 2006 08:15 AM


Originally Posted by vtakk eg
i have a stock car besides my PFS catback , so are you all saying if i put a DP,MP,and , intake that my motor will blow, with just thouse mods? please elaborate

The FD uses a MAP system. So, it does not detect the amount of air coming in and make adjustments. Whatever it was programmed to do, is what it does. So, as you start making changes to the airflow (intake, exhaust), the ECU programming doesn't change.

Now, it has been proven that the stock ECU can take most bolt-on mods without needing a change *IF* you can keep the boost at the stock 10 PSI. The problem with running an open exhaust is that you can then run into problems controlling the boost (even with a boost controller) and thus blow the engine like the original poster of this thread did with his/her car.

You might think "Why would I put all these mods on the car only to keep the car at the same boost level?". Now, manifold pressure (boost PSI) is one thing, however airflow (CFM) is another. You can and will be flowing more air at the same boost level with the modifications, thus resulting in more power without increasing the boost.

vtakk eg Dec 14, 2006 08:03 PM

I have done about a days worth of research to no avail...
my question is: Can I safely fun Intake, DP,&CB?
(on stock ecu)
thanks
chase

Mahjik Dec 14, 2006 09:07 PM


Originally Posted by vtakk eg
I have done about a days worth of research to no avail...
my question is: Can I safely fun Intake, DP,&CB?
(on stock ecu)
thanks
chase

Answered above:


Originally Posted by Mahjik
Now, it has been proven that the stock ECU can take most bolt-on mods without needing a change *IF* you can keep the boost at the stock 10 PSI.


thiasRx7 Dec 15, 2006 02:12 AM

I blew my motor being stupid cause I liked the loudness of the car with a fully open exhaust. With the MP and the stock MAP, I could never get the boost fully under control. I even put the main cat back on for a short time which maintained the stock 10-8-10 boost pattern, but like I said being stupid I liked the car better with the MP and couldn't keep my foot out of the gas pedel and blew the motor. So my words of advice are if you are going to keep the stock MAP dont use a MP unless you are one of the lucky ones who can actually get your boost under control with it.

VegasFD Dec 15, 2006 03:53 AM

I don't think you understand. The timing and fuel "maps" of these cars are completly different than the "MAP" system mahjik was referring to. For instance, the the stock ECU reads boost off of the MAP sensor, which stands for 'manifold absolute pressure'. It's different than the maps we refer to when tuning an after market computer.

T2 Tsunami Dec 15, 2006 04:06 AM

maybe this will help...I'm a previous S5 T2 owner and I learned the hard way with this 7...open air, exhaust, FCD=76k blown engine....Atkins street port, upgraded all...from injectors, fuel pump, turbo...and anything that was accessible=almost perfection. If you supply the right ingredients...the rotary engine can take most out and be a daily driver.


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