There's a thread about running higher rev limits than stock... but I'm considering doign the opposite..

I want to lower my rev limit to 7300 or maybe 7200. My current mod list in my sig is all I'll have until the car is out of warranty in 2012.

My main concern here is safety, and not wanting to over rev the engine... is there any reason that LOWERING the rev limit would make the car unsafe? I would assume that as long as I'm not constantly bouncing off it every time I shift, that it's perfectly fine.

Thanks in advance.

 

Are you asking if it is unsafe to bounce off your rev-limiter? Because not reving so high could only prolong the life of your motor.

 

well if the Factory sent it @ 7600 why would you think it's unsafe or that it would shorten the life of the engine and then give you a 100,000 mile engine warranty

 

Running your car like that is more unsafe then taking a properly tuned car to redline I can garauntee you that. Don't be silly, your rev limiter from the factory is 7600, do you really think they'd let you blow it up from the factory?

If you really wanted the car to be reliable and safe you should have left it stock, and if you go to the dealership with those mods installed for some warranty work, they're going to laugh at you and tell you your warranty is voided.

Just a heads up.

btw your car is probably 12.5AFR at 3500rpm right now and in the 9s at redline, so not only is it lean as hell when you hit boost, it's fat enough up top to foul plugs like a champ!

 

he means: You don't have a warranty anymore because you modified the car.

 

my car is back to stock in less that a hour I am a mechanic

 

Do you have the cables to reflash the computer as well? Mitsu can tell if the computer has been reflashed. And I don't think he was talking to you, but speaking to the OP anyway.

 

good for you, bad for everyone else. This is the root of why Mitsu gives people such a hard time on warranty claims, even when they deserve the warranty work!

 

it's not my factory ecu I have a spare and yes I tune cars as well but don't get me wrong I wouldn't take it in for crap only somthing really serious I also have a service writer

 

lol the factory rev limit is not there for people to bounce off of it.
They put it there for those who miss shift or go into a wrong gear etc... many reasons, NOT performance related what so ever.
The engine having an unsquare bore and stroke shouldn't really be pressed past 7300. You won't make any more power, just increase heat and tensile load on the rods.
Now for a purpose built engine with a rediculously large turbo, there isn't any choice but to rev higher. On a more modest setup with say a 50trim, 7300rpm will be your best bet for a max rev limit. Again past that your really not making any power, just unneeded and unwanted stress

 

Like I said I would not take it in for crap It would have to be serious if I blow a head gasket I would fix it if I melt or crack a pistion I would fix it if I broke a transfer case it would be back to the dealer for me wouldn't you

 

what about when you shift to the next gear? If you set your rev limit lower, you'll be hitting the next gear too low in the powerband for peak acceleration through the gears.

 

Please clarify what you mean here.
What does lowering the rev limiter in the ecu have to do with a lower rpm when shifting gears?
But you may not be speaking about the ecu, then I understand what you mean.
At that point it will depend on what turbo you are set up with. What cam profile etc.
If you are shifting at 7000rpm on a stock turbo, then your next upshift will bring you to around 5000 rpm. That is actually high when in relation to peak torque.
On a 50trim style turbine wheel, 5000 rpm is Optimal.

Maybe I misunderstood your question

 

it's not just hp/tq., it's gear ratio also. The longer you can stay in a lower gear (to a point), the quicker you're going to accelerate. Shifting close to redline on a stock turbo'd car, or even my 50 trim is optimal. I copied a calculator from another thread that figured this all out for you, and displays it graphically. I forget who the original poster of the calculator was, and I can't seem to find the thread I copied it from. But it's a great tool.

 

You are correct its not just about HP and torque, Its about Torque and volumetric efficiency. The gearing plays a small role as we have been dealt our hand already with the stock evo gear box. (This of course does not mean that gear ratio does not play a role, its just that most of the time people will have more torque building upgrades on their evo rather than internal transmission changes)
With that being said and our gear ratio is a controlled variable, Engine Torque will accelerate the vehicle. Staying in a numerically lower gear seams to "use up" that torque quicker. On average a stock turbo'd evo will loose steam fast as you move up in rpms. Its evident. As you increase rpm and hold throttle position constant, the car gets slower! Of course past the point of peak and good torque multiplication.

Anyway, do we agree that 7300 rpm is a good rpm to keep as a redline?