Got 2 questions.

1.If you install a bigger turbo can you rev your rpm higher than stock? I think I saw someone mentioning that you can rev it up to 9k with supporting mods but im not sure.

2.On a stock car how high can you safely rev the rpm? Redline is at 7k but I think I reved it up to 8k before but im not sure if thats ok or not.

 

The turbo alone does not let you "rev" higher. What does though is the tuning you use. Some EM will raise the rev limiter or remove it completley ... When you upgrade your turbo you need engine management ..

 

Yes, raising the rev limit in the ecu/engine management will allow higher revving. Valvetrain components are also a limiting factor as well as stroke. A higher stroke limits piston speed and at high rpm valves can float causing misfire (among other things), terminating power output. Valvetrain lightness and spring tension are also important in a high revving engine.

 

so not necessarily you need a built motor to achieve higher reving engine?

 

Yes the engine needs to be able to sustain high revolutions without risking damage or durability. Many high revving race engines have a short life anyways. Many are rebuilt after being run for very few hours.

 

you could go upto 9000rpm on stock engine with bigger turbo. However, you need to use a Standalong EM to control/ adjust and tune it before you do all that.

 

I would never take a stock motor to 9k, ESPECIALLY with a huge snail.

 

need to upgrade the valvetrain before u go past 7800. or the motor will blow.

 

Yep.

The head needs to be completely worked over. You'll need better valve springs, lighter (and stiffer) valves, more agressive camshafts (to take advantage of the faster combustion cycle), and a few more mods.....I would also see a high-flow fuel pump, a lightweight flywheel, and bigger injectors as being some of those supporting mods.

Most people change their turbo around the same time they have these other things done, so don't get confused and think that just beacuse they change their turbo, that they are able to rev higher.

 

^^
basically you need cams to allow you to breath at that high rpm. that is one of the biggest limiting factors to the evo is the smog friendly cams they come with stock.

 

nuts. All you need a headstud, then you could take it up to 9000 rpm.

i've seen it done before, but maybe that's some sorta fantastic dream that i had. sigh...

I also didn't say this is for a long term plan. your motors just not going to last that long with that sorta abuse.

 

i take my honda's b18cR up to 9k daily for the past 2 years, no problems yet... adding a headstud will not allow the motor to make any power that high. that is the point of revving that high is to actually make power up there. and to do so it needs to "breath"

 

Oh no doubt it's been done. But like you say, it's not the path to long term motor longevity. You can probably zing it to 9K rpm quite a few times at the drag strip before you spin a bearing or float a valve into a piston. I wouldn't want to run it at 9K rpm for 30-45 seconds straight, lap after lap in a 20 minute run group on a road course. Your motor would be toast. Probably almost as quickly as some of these 2.3 stroker conversions running 8,500-9,000 rpm. Prolly works great on the drag strip but I wouldn't want to run them like that for extended periods.

 

why not? all you really need to worry about is valvetrain. the honda i mentioned earlier is for road course driving only at hpde's, those are 20 min. sessions and i'm never below 6k rpm at times up to 9k rpm. its all in the valve train to keep the valves/rockers following the cams and not "floating". if you want to mention piston speed, the b18c is even an undersquare motor and still has no problems. i dont see why a 4g63 could not do it with the correct valve train?

 

You COULD, but the whole thing is, you don't have to with a turbo 2.0L. There's a lot of torque available with maximizing the stock turbo and without going crazy with the breathing mods, an 8k redline is possible and I've been beating up my car all year at the track and haven't floated a valve yet.

Give me time, though. :-)