I was just wondering how much can u increase the rev limit on the tC w/ stock internals?

I know the car is 6200 rpm redline...but possible to do 7000 safely?

Anybody even increase the rev limiter?

Dunno how much of a "safe" increase is possible because of the tC's stroke length...

Thanks for your thoughts.

 

Moved to PH...

Would this be a Cam-Con thing?

 

ZPI has to finish off their 1320 runs.

it's possible with emanage ultimate.

safe? time will tell.

 

hmm...OK

ZPI, if possible, please drop any comments about current status, etc.
thanks.

 

I know one of the big limiting factors on super-high revving is the VVTi. Because its actually attached to the cams it makes it challenging.

I'm looking forward to ZPI's StageII Head. Valves, springs and retainers should give the tC a *safe* 7000rpm top....a much needed one. I always feel like I'm against the limiter...kinda like driving an SpecV.

 

lol.... i know what you mean with the spec v. My roommate has one and that car is worse than ours

 

why would you want to? doesn't the hp peak at about 5700?

 

when i go turbo, i'd feel a lot better if i had a higher rev limit to go w/ it.

 

which the long stroke on our cars, we're going to be running out of power by that rpm, it would be a waste, our engine just wasnt designed to rev that high.

 

Mean piston speed is the problem, the 2AZ hits 20 meters per second at exactly 6250 rpm. Mean piston speed over 20 meters per second means shorter service life.

Yes, I know very well the Integra Type R's mean piston speed goes up to 24 meters/second, but I also know they designed the rest of the engine to do that. Conservative engineering practice (Toyco's founding principle) says redline at 20 meters/second (6250 rpm) will last at least 200,000 miles.

This is true of all engines from the smallest model airplanes to the largest container ships. Mean piston speed determines the true rpm limit, not valve springs. If your valves float before you hit 20 meters/second, your engine has not been well designed. Toyco's legendary 2JZ-GTE and 3S-GTE engines are not limited by their valvetrain in stock form, they are limited by mean piston speed.

Still, you can rev the 2AZ to 7500 rpm and not exceed 24 m/sec mean piston speed. Why is it a waste of time right now? Because the head won't move enough air to keep the torque up above the current hp peak. If you put in bigger valves and do the commensurate port work, put in bigger cams and the appropriate springs/retainers, and dramatically increase the size of the rest of the intake and exhaust, then you won't see the torque drop off at higher rpm and you'll make more power up top.

Of course when you do this, you sacrifice port velocity at lower rpm, so your power at lower rpm will suffer. Ever wonder how it is that an F1 engine never revs below 10,000 rpm? Big ports moving lots of air at very high rpm, making torque where they can to get the power to win. Those are the same type of compromises you will make with the 2AZ if you want more power at high rpm.

 

We have reved the tC to 11k with out incident. We rev to 7500 on our shop car daily.

We would suggest that a 7k RPM rev limiter would be safe and ideal for daily driving. We make peak power at Redline on all stage 1 dynos. So to say that the car is not making any power past the 6250 mark is incorrect. Unless you have dynoed the car and tested this theory.

With a stock head or are head package I would suggest 7k is a safe range. 6800 for sure. We go to 7500 on a abused engine with 10k of the hardest miles known to any Scion and she is still going strong.

The ultimate is a great device there are still some bugs that needs to be worked out when using it on the tC. We have been in close contact with Greddy on this and will hopefully have the settings down by the time you all would want one.

Thanks

-Kenny

 

You'd be wise to check for cracks on the wristpin bosses of the pistons in that engine rev'd to 11 grand. OEM pistons are pretty good, but not that good.

 

yeah this was an accidental rev but the car is still going strong we are hoping to breack it soon so that we can pull it apart and get some better stuff made.

 

hahaha 11k you beat my record damn you

 

LOL

that's a hell of a record to break

put a bike engine in there and you can beat it back and not break

 

how do you know it was 11k? what exactly happend?

 

ZPI reved to 11k i have only hit 8725 or some crap like that its stored on my rsm it was in a miss shift from redline on 3rd in to 2nd i pulled down and towards me like a dumb as and the rev limiter saved my car lol

Hasn't happened since but the tC seems to be all good as of right now but i do take care of her maintenance wise all though i do put the hurt on her when we take trips to the drag strip or when i'm cruzing the highway

 

BTW, this is one hell of a good testament to the integrity of the valve train design. You surely can't get away with this on a late model GTS Celica.

 

agreed.

but can you do this?
http://videos.streetfire.net/Player....3A4402BB81&p=2

 

I remember watching that video last year haha... That's a tough lil engine. Gotta love old-school honda motors...