standard ecu?

[welshrx-7]

i was talking to a guy in a local garage and he was telling me that the standard ecu\'s can blow your engine and said a change for a after market one would be a good idea. is this true he said it was something to do with the standard one giving the wrong mixture? my car is standard except a decat full through

[Squallai]

um....if your car is a standard, then the startard ecu will do the job.
unless you have moded your car, then i think the standard ecu is good enough..

[Ricco_04]

Yeah he\'s pretty much right.  If you have decatted (which you have) then you run the risk of running lean and detting the motor

[Fendamonky]

The stock ECU is good for stock boost levels. Once your boost raises beyond 12psi (which is very easy to do) than the ECU will no longer supply enough fuel and you run an extremely high chance of blowing your engine. If you have a good boost controller, and can limit your boost to below 11psi, than you should be ok with fully decatted exhaust. The boost level (with stock twins) is the most critical thing when it comes to safe fueling with the stock ECU.
 
I would have to agree that an aftermarket ECU would be your best option though. You would be surprised how much power you can gain with just a decent tune (I picked up 40whp off my initial tune, alone, at Re:worx).

[DC-TYPER]

i was talking to a guy in a local garage and he was telling me that the standard ecu\'s can blow your engine and said a change for a after market one would be a good idea. is this true he said it was something to do with the standard one giving the wrong mixture? my car is standard except a decat full through

 
tell him to stay away from your car   lol, but yeh, if you have a straight through you should change the ecu, although some people run fine without...there is a risk!

[michaelb]

i was talking to a guy in a local garage and he was telling me that the standard ecu\'s can blow your engine and said a change for a after market one would be a good idea. is this true he said it was something to do with the standard one giving the wrong mixture? my car is standard except a decat full through

Mate, I don’t want to scare you but you will blow you engine with a full de cut and no programmable mapped ECU (standard ECU cannot be re-programmed) to allow for more fuel needed…for the sake of £300 (second hand Apexi ) don’t end up with a £4000 bill for a re-build, get the unit on this site...

I would not drive the car with a full de cat and no map to accommodate the above mod..99% of members on here will share my views…

Regards,
Michaelb

[Fendamonky]

Mate, I don’t want to scare you but you will blow you engine with a full de cut and no programmable mapped ECU (standard ECU cannot be re-programmed) to allow for more fuel needed…

I have to say that I am going to be one of the 1% insofar as that I feel it\'s more a matter of boost level than type of piping. If he had a good boost controller (say greddy Profec B, II) and added restriction to his exhaust (through restrictor plates) to the point where he could consistantly run 10psi (not counting the, very real, chance of boost creep) than he would be ok with the stock ECU. Though very effective boost control is the critical to safely run a fully decat exhaust. In no way, what so ever, do I condone running a straight through exhaust with the stock ECU (it\'s like playing with matches in a gunpowder factory), just pointing out that it is possible if planned and executed correctly.
 
Typically three things are needed to safely run a free flow MP:
- Programmable ECU (with correct mapping done)
- Upgraded fuel system (stock system maxes out at 13psi)
- Reliable boost control
 
I tried to upload/paste this chart of where the stock ECU hits fuel cut, but photobucket is being stupid. So here is a link to rx7club.com discussing this overboost (the chart is about half way down the page) http://www.rx7club.com/showthread.php?t=752571

[michaelb]

I have to say that I am going to be one of the 1% insofar as that I feel it\'s more a matter of boost level than type of piping. If he had a good boost controller (say greddy Profec B, II) and added restriction to his exhaust (through restrictor plates) to the point where he could consistantly run 10psi (not counting the, very real, chance of boost creep) than he would be ok with the stock ECU. Though very effective boost control is the critical to safely run a fully decat exhaust. In no way, what so ever, do I condone running a straight through exhaust with the stock ECU (it\'s like playing with matches in a gunpowder factory), just pointing out that it is possible if planned and executed correctly.
 
Typically three things are needed to safely run a free flow MP:
- Programmable ECU (with correct mapping done)
- Upgraded fuel system (stock system maxes out at 13psi)
- Reliable boost control
 
I tried to upload/paste this chart of where the stock ECU hits fuel cut, but photobucket is being stupid. So here is a link to rx7club.com discussing this overboost (the chart is about half way down the page) http://www.rx7club.com/showthread.php?t=752571

Hello mate

You are probably right re installation of the boost controller but TBH in all the years of RX7 ownership and also being part of the club, with out being funny,  I yet to come across anyone on here favouring a boost controller over an Apexi pfc…

I would not recommend increasing BOOST to 1 bar and over on stock twins as the turbos would get spat out. I have (stock twins, full de cat, HKS super dragger, HKS suction racing kit, engine ported and proper map) close to 350bhp, 0.9 boost at 90% injector duty (3rd gear max revs), still on stock injectors.  It is not necessary to change the injectors if you are running what I have set up, but I guess it wouldn’t hurt re safety margin…

Regards,
Michaelb

[Fendamonky]

Oh, I totally agree that it would be idiotic to choose a boost controller over an ECU (which type depends purely on who is going to be doing all your mapping, and what they are most comfortable/proficient with). I was not necessarily looking to prove you wrong or start an arguement (I agree with you 100% on needing an upgraded ECU before doing any flow modifications). I was just trying to say that, if you can/will keep the boost at stock levels (assuming minimal engine modification, not talking a medium single @ 10psi =P) than the stock ECU should be able to handle it perfectly fine.

Pushing the stock twins to 1 bar should still be fine for performance (they will wear out much quicker than at something like .8 however), though anything over 1 bar is when you will really begin to see the stockers loosing their breath because they are extending well beyond their efficiency range.

I\'m just playing devils advocate with regards to the boost control issue. Though I\'m not sure why you felt the need to mention your mods (I\'d be happy to compare mods and results in another thread, or PM\'s, if you\'d like... you may be surprised ;-) hehe) though a safety margin up top is DEFINITELY a good idea since you never know when you might spike.. I\'d hate to lose my engine because of it..

So yeah, personally I agree that a programmable ECU is the best option, just wanted to point out that it\'s not the only option.

Cheers,

Levi

[michaelb]

Same here mate, would not dream of starting an agro on here, I agree with 100% of what you mention

Re my mods â€" they are far from impressive but I wanted to mention that with a lightly modded RX7 like mine still using stock twins it is not really the ‘done thing’ to go over 1 bar of boost as the turbos will not last long and also the injectors will max out â€" classic example was Warthog â€" he has a BHP record I think in the UK on stock twins but he will be the first on to admin that they will not last much at that boost level

Regards,
Michaelb

[Fendamonky]

Hehe, yeah. I\'m a big fan of the whole "better safe than sorry" ideology when it comes to the rotary.

Just to clarify (I\'m a yank, our terms tend to be different) when you say BHP to you mean Base (flywheel) Horse Power, or Brake (wheel) Horse Power? In the states BHP means flywheel hp, and is rarely mentioned after reliability mods =P

Warthog, he had 389 at the wheels, did he not? (that\'s ****ing MENTAL for *stock* twins!! lol)

[michaelb]

Hehe, yeah. I\'m a big fan of the whole "better safe than sorry" ideology when it comes to the rotary.

Just to clarify (I\'m a yank, our terms tend to be different) when you say BHP to you mean Base (flywheel) Horse Power, or Brake (wheel) Horse Power? In the states BHP means flywheel hp, and is rarely mentioned after reliability mods =P

Warthog, he had 389 at the wheels, did he not? (that\'s ****ing MENTAL for *stock* twins!! lol)

No worries mate, my girlfriend is American (from Miami) so I speak your language LOL

Personally, I was talking about my flywheel horse power…yeb, the ‘almighty’ Warthog had 389 BHP at the wheels

Regards,
Michaelb

[welshrx-7]

thanks for the help got a standard one back on till i get the cash for the bits i need cant wait to get it sorted sounds mad wilt a standard one on it.

[clive]

The standard ECU has many protection parameters built into it and will not let you blow the engine up with physical changes like an exhaust system and induction parts.

If the engine runs too lean from too little fuel or too much boost quite simply the ECU will cut the engine out via a boost or fuel cut.

I have found that Jap import has a bit more tolerance than a U/K car as it would seem that the Jap car puts in more fuel via a different program

First time I had this happen with a third Gen years ago after an exhaust change that was just a bit too much, I got to 5,000 revs and the engine just cut out, you can imagine I thought I had detonated the engine but all was well.

It\'s also worth knowing that this safe standard ECU can be used if you need to start a very modified engine that has a big turbo, big injectors and big ports etc etc when you are worried about the map in your aftermarket ECU.

I have driven very very modded FD\'s many miles to Rolling roads to get the car mapped with the stock ECU painfully having the engine cut out at 2800 revs but safe in the knowledge that the engine is safe.

In short providing you don\'t use any electronic "trickery" to fool the stock ECU you will be fine.

Hope this helps

[DC-TYPER]

The standard ECU has many protection parameters built into it and will not let you blow the engine up with physical changes like an exhaust system and induction parts.
 
If the engine runs too lean from too little fuel or too much boost quite simply the ECU will cut the engine out via a boost or fuel cut.
 
I have found that Jap import has a bit more tolerance than a U/K car as it would seem that the Jap car puts in more fuel via a different program
 
First time I had this happen with a third Gen years ago after an exhaust change that was just a bit too much, I got to 5,000 revs and the engine just cut out, you can imagine I thought I had detonated the engine but all was well.
 
It\'s also worth knowing that this safe standard ECU can be used if you need to start a very modified engine that has a big turbo, big injectors and big ports etc etc when you are worried about the map in your aftermarket ECU.
 
I have driven very very modded FD\'s many miles to Rolling roads to get the car mapped with the stock ECU painfully having the engine cut out at 2800 revs but safe in the knowledge that the engine is safe.
 
In short providing you don\'t use any electronic "trickery" to fool the stock ECU you will be fine.
 
Hope this helps

 
ta da!  the angel has spoken