thepnub

Subject = Question.

Ive searched and used the search. Theres not much information on Scion tC performance other then CIA's and Headers. Please help if you know anything about Increasing Redline on the Scion tC.

Thank you much in advance,

Kyle

Nychold

You need a head capable of higher RPMs (the ZPI stage II, I believe, goes up to 7500), and a stand alone ECU or you have to remove the rev limiter on the stock ECU.

thepnub

Removing the Rev Limiter would over torque my head at higher then 6k RPM right?

Im going to do some research on Removing the Rev Limiter. Kind of blanked on that.

If its an easy shot then you can do it and not worry about not being able to go back to Original for Warrenty.

thepnub

Quick Research.

Pulled from a info site.

Simply removing the rev limiter, without making any other modifications to a car, will do next to nothing. In some cases, being able to rev the engine higher will yield slightly better performance, often at the cost of more engine wear.

You should only worry about raising the rev limiter once you've done substantial work to the engine. My personal advice would be to have at least the full exhaust upgraded (including the exhaust manifold and downpipe), a sport camshaft and some way to get more fuel to the engine.

Sorry about me answering my own question. I drew a blank on rev limiter.

But it did spark one more question.

When adding 8.5Boost Turbo on a stock motor with a E Manage system. Will it automatically up the Rev Limiter to utilize the higher end spin?

Keeshwah

Found this posted on another site and I found it very informative and it makes a lot of sense to me.

Toysport on FE Heads

draxcaliber

why would you do that? the power start dropping after 6000 rpms anyway increasing revs after that would be slower than downshifting, a waste of gas, and bad for your engine.

you would have to have a strong built engine like a zpi block that can go up to like 7500 rpms i believe, and tuned to make power at those levels.

kanundrum

He just want 11k rpm das all

thepnub

Thanks for the info. I think the main thing I want to do is make it a bit faster. Im not looking to smoke a engine swap JDM Civic. Im just looking for a bit more then what came from the factory.

Thanks for your input. Helped a bunch.

tcengel

Blah blah blah to everyone else. You can use a E-manage Ultimate to raise the limiter. I recommend 6800 rpms top though.

Nick06tC

^ exactly.

People are right in saying without a properly flowing head, it is a HUGE help. but the question was, how to raise the rev limiter.
ALL, you need is the Greddy Emanage Ultimate, and you can set it as high as you want.

Is it safe, well thats a whole new question, that he didnt ask.

Nychold

Uhh, yeah he did. The term "redline" actually implies the maximum safe RPM. Otherwise you go into the red (unsafe) RPM. Simply removing the rev limiter just increases the red zone, but does nothing to increase the redline.

http://en.wikipedia.org/wiki/Redline

Yes, I'm aware that Wikipedia isn't the most reliable source on the web, but in this case, they're right.

Nick06tC

I guess I assumed what most people refer as the limit of where your ecu cute fuel and no longer allows you to rev.

What you are explaining is the factor redlimit, which is set at the maximum safe RPM.

I can go into an emange and set the limit at 20,000 RPMS if i want to, will it be safe, nope. But that will be the redline.

thepnub

Did some more research and found. (Research from other Scion Members via PM and misc websites posted here or in PM)

Factory Engine Rev Limiters are set below maximum safe redline. Therefor increasing engine life and keeping warranty cheaper for the manufacturer.


I think what I was trying to ask was seeing if I could remove the rev limiter and increase my Max Safe RPM's.

Stock Factory Rev Limiter is set below safe redline to maximize engine life. There for increasing your max red line to 6500 or 7500 on our Toyota Engines is perfectly fine.

Voids Warrenty of course. And wears the engine more then with the factory rev limiter. But it is safe if you limit your actions on this.

Example. Boosted engines can safely run 8psi on a stock motor. That being without horrible wear and tear on your engine (daily driver). But it is safe to boost 8.5 to 9 with sacrificing some more wear and tear.

It is true though that increasing your Rev Limiter to 8k+ means no power after 6.5-7.5k RPM's. But that extra .5 -1.5 does make a differance. Specially if your looking for .1 - .3 off your time.

3min3m2

also, in a turbo and or supercharged car, they still flow more air at higer RPMs, and can increae the RPMs, with a good intake and eshaust system to support them

sure an intake manifold and head would help, but (this is applying my old old old old old tech) v-8s can run bigger carbs(more fuel) and charger of sorts(more air) and with a good ignition, bam hit 5-6k(describing older engines, not newer, lighter fuel injected engines revving to 6k factory

but the point is, a stock engine can handle it, and a boosted engine should be able to handle it, as your RPM range generally shifts to the right with increase air-flow mods