Can anyone help me?

Leads i have so far :

japtrix, a company in florida is rumored to do this,.. there website is still under construction however, i am going to call them monday.

corksport, there custom ecu may be able to do this but it's $$

Some cars didnt have it from the factory? This is one area i need help on,.. if someone out there has excedded 8,000 rpm under acceleration (NOT a missed shift) please let me know your year/model/ecu number.

someone out there has to have done this,...

 

first confirm your reasoning for needing to do this.
Second, you're going to need an ingition controller to even handle reliable spark above 7k.
third, the ignition controller may solve the problem itself depending on what circuit kills has the rev cut.

 

AFAIK there isn't a rev limiter. Other than the fuel cut. But that is....big surprise....because youdon't make power up there.

 

Justification: motor is an aux bridge port and built for 9k max. It's getting close to dyno baseline time and i'd like to have a complete baseline for when i add the piggybacked megasquirt and other mods( this is very far down the road) Also im tired of the car cutting out right when its pulling its hardest...

I havnt seen any proof the stock ignition wont handle 9k, its only 1k over s5 factory redline.

I have heard that the factory s4 ecu is actually to slow to process anythign above 8k but i dont know how much i believe this.

The rev limit is fuel cut so an ignition box wont help

 

yes i do,.. and the fuel cut is a rev limiter.

 

without a mod list how are WE supposed to know that?

I don't know how or why you are running on a stock ecu on a bridgy. Haltech or microtech is what you NEED.

 

It's an aux bridge with fully functonal sleeves,.. drives like stock. stock ecu does fine except for the rev limit. The whole point is i want to baseline with the stock ecu up too the same rpm so that when i do go with another computer system ( improbably going to go megasquirt with the stock ecu controlling timming,.. get that running baseline again and see how much ditching the stock ecu amd AFM got me then work on a custom manifold and baseline that.)

I'm well aware that the stock ecu is the current weakpoint in the system but i would like to dyno it as is, and have that extra 1k or power until such a time (even with the stock ecu the car is still fun *** hell and it would be that much funner with 1 more k of rpm) as i can get the other mods together and actually have time to tune it.

so,.. does anyone have any experience ,.. or even rumors of where this can be done?

 

I don't think the stock coils can handle 9k rpmin the first place. I wouldn't dyno any higher than fuel cut.

 

One thing you could do is swap to an S5 EFI setup and you can go up to ~8500 without fuel cut butting in.

 

thats a huge amount of work,.. and im pretty sure they dont hit a limiter until 9k,.. theres a video of a vert being abused floating around the web...

 

my friend's s4 na ecu didnt have a rev limiter but mine duz. we tried looking for his old ecu though and couldnt find it so i cant really help u out. however these ecu's do seem to exist.

 

i'm fairly sure there is no limiter on the ECU, if there is the easy way to go around it is put an RTek chip in.

but really i wouldn't push harder than you already are or you will pop the cork!

 

You really need stand-alone EMS to fit your needs.
The stock ECU cannot handle the fuel delivery requirements for a BP, so why you trying to test the limits?
You'd be lucky to not end up with a dead motor.


-Ted

 

Part of the reason the S5s can run faster is that their ECU runs twice as fast (main chip clock speed). The S4 ECUs, from what I have heard, cannot reliably fire the coils much above 7400 RPM. They fire, but not consistently. This isn't an issue on a stock engine, which is badly choked off by intake & exhaust by that RPM anyway.

As for a fast way to disable the rev limit, I can't think of one. Even if you did, you would still run into the problem with the ECU being unable to fire reliably at higher RPMs.

I'd just dyno up to the stock limit right now. You can compare the dyno graphs up to that point, and when you can reliably fire things off above 8000, you'll have that power available as well.

-=Russ=-

 

CDI will take care of that easily.


-Ted

 

If I remember what I read from the site that dismantled and analyzed the S4 ECU, the hardware used to trigger the ignition was physically limited to 7400 RPM or such based on the processing speed. It would fire above that, but not consistently - skipping cycles or such.

I'll see if I can find the link to it.

-=Russ=-

 

I'm with you on that one.

 

i have seen some places advertise upgraded ECU main processors, i wonder how feasible that idea is..

 

Mazdaspeed7 has had various bridged setups on his car as I've read over at nopistons. He runs with a megasquirt for fuel and stock ecu for spark and goes to 9k just fine.

 

i was about to say the same thing as drago, that vert seemed to rev to 9 k fairly easily and just stayed there, but theres not a bad thing to upgrading

 

I believe the key word here is "VARIOUS"

 

I guess you have not seen any FC dyno graphs... spark break up commonly starts around 6-6.5K.

 

hey i have an s4 and i dont have a rev limiter if you want ill trade you my ecu for yours casue i actually want a rev limiter lol

 

EVERY s4 I have seen had a limiter function between 7500 and 8200 on the stock tach (which, btw, can be off as much as 700rpm on the top end).

BUt yes, even if you did bypass the limiter setup, how do you know that the ecu is even set up to even FUNCTION above it? Did it ever occur to you that this was the entire REASON for the limiter, because there is no further programming beyond that point? As a designer, why would you map an ecu, install a limiter at a point, and then map farther? IF there is an existing higher map, it probably is not very accurate or tuned, and pushing a setup such as yours this way is asking for trouble.

Just baseline right now with what you've got, worry about the rest with accompanying mods.

 

ok,... i guess its a lost cause,.. just called japtrix and there answer was "probably not".

I could have sworn someone at teamfc3s was running one of there ecu's on an s4 and hitting 9k,.. o whell.

so next question,.. with a cdi box and megasquirt for fuel,.. will the stock ecu be able to spark to 9k?