I was talking to this guy who had his evo for a while and he said that you should shift at 8k rpms when racing on a stock motor (with mostly stock everything else). Is it possible? and where should you really shift when racing? Also my other friend said that aem short ram intakes are horrible for power because the intake pipe absorbes heat (makes sense) but why are they so expensive.. I have one but have not yet installed it and was wondering on what you guys think. Thanks for the advice in advance.

 

Its not even possible! aem is a decent intake...

 

You can rev to 8k on the stock internals, but shifting at 8k would be pretty stupid unless you have an upgraded turbo that can make power up there (our stock turbo can't). With stock cams on the stock turbo, you'd want to shift around 7000-7200 when drag racing. With cams, depending on the duration, you can do 7300-7500. You were just repeating stuff that you didn't fully understand, so I think "your friend" was correct in what he was saying as far as the stock motor being able to rev to 8k, but there would be no reason to shift that high.

AEM intake is fine, but not without a tune. Also, the hard pipe portion of the intake is not recommended on the Evo due to it messing up the MAF readings. The filter portion is fine, but you still need to be tuned for it.

 

I respectfully disagree. I have seen 8200 on my Stock 04 a couple of times on the 2-3 shift. Seems to be the time when I check the road ahead and really no time to make the shift at 7500 like I intended. Having said that, I don't think it's good for the engine and I doubt the benefit of the few extra revs in the last gear are worth the potential damage.

 

Uh, that is not possible on a stock Evo, because the rev limiter is at 7600. Plus, it takes a while to get from 7500 to 8200. What device told you that you peaked at 8200rpm? In order for you to do that, you'd have to have no rev limiter. Not to mention that 7500 is way too late to shift a stock 04 anyway...

 

i've read in AEM instructions that their coating on the pipe reflects heat, not absorb it.

 

Yep, it has magical heat reflection properties. The deal with any open element air filter is that your engine bay air is HOT. That's why the stock intake box is great because it takes air from outside the car and there's enough insulation to keep your intake temperatures down.

 

I agreee, unless you have removed the rev limiter, there is no way you will be able to take it past 7600. Unless you are talking about a missed shift down.

 

Hey thanks for all the info guys. I will be putting on the aem intake soon with other parts then definately get a tune. And i also read that the rev limiter on stock 03/04 evo is 7600 so i figured the 8000 rpm shift would be either impossible or hurt the engine.

 

Well, with a flash, you can raise it as high as you want (and with other devices), so that's not an issue. We can safely go to 8000rpm on the stock internals, but it's usually not necessary.

 

I guess my car doesn't know that it's not supposed to go that high. Unless the stock Tach is trash, I've seen it very clearly registering 8200 during the shift from 2nd to 3rd on at least two occasions. As far as I know it would have kept reving or blown if I hadn't made the shift. Bought it new from the dealer and the only mod I have is a Bushur instake.

 

Yes, the stock tach is inaccurate, and yes, the momentum of acceleration can cause the rpms to go higher than the rev limiter after clutch-in, but there's no way you actually continued to accelerate to 8200rpm unless something is seriously wrong with your car. I'd have it checked out, because that's bad news...

 

I can see the momentum thing. In 2nd gear it accelerates really hard and quick, honestly, the torque has dropped off badly on my stock Evo by that time that a shift at a lower RPM is certainly prudent.

 

it totally depends on your car's power curve. just compare the power at 8k and the next entry rpm point of your next gear. If 8k makes more power than the next entry point( around 6k rpm I guess), you should shift at 8k. If not ,you have to shift early. there is a sweet spot for each gear.

Edit: I forgot to mention that you have to calcuate with the gear ratio. so 2nd gear power is stronger than 3rd gear. cacluation should look something like
if ( (Horse Power at 8k) x (2nd gear ratio) > (Horse Power at 6k) x (3rd gear ratio))
{ shift at 8k;}
else
{ shift lower;}