powerloss high RPM

K

killergoof

Member
Hi everyone,
Im new to the forums, just test drove a mazdaspeed 3 on the weekend, 2009, red, and i LOVED IT. I live 4 hours away from any mazda dealer, so when i was in the city i had to. And now im on the verge of a big purchase the wife just needs to come down with me to sign the papers (course i need time off work so i can get the car). But i noticed something. The car was quick, very quick ( I dont think the sales person was too happy with me as im pretty sure that that test pilot car wasnt broken in just yet for that) but i gave her WOT. But once the car reaches around 5500 RPM there is a major power loss. Now is there a boost cut off, or something of the sort to insure people like me dont ruin the car? or is there something thats holding the car back. I have looked and looked ( and i bet the answer is right in my face) but i havnt seem to been able to find a topic on this. If anyone can direct me to the topic of even explain why this power loss is happening that would be great thanks everyone. Happy modding.
 
Alright, so gotta shift at 5500 rpm, is there anyway to overide this? Get more outta the rpm range or is it just better to leave it at that?
 
bigger, better flowing turbo and mani, *maf as well as a tune.

also the car wasnt broken in. once broken in, should fall off around 5800-5900rpms(hits a seriously wall after 5900 after break in)

so shift should be around 5800-6k. ideally, 5900.

when i go back to the track, im going to shift around 5800-5900 vs 5900-6200(which i did last time.) i felt a loss of power b/c of staying in gear too long and know i could have improved upon my time which other guys have agreed based on my slip

should manage 13.5 @104-105
 
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killergoof said:
Hi everyone,
Im new to the forums, just test drove a mazdaspeed 3 on the weekend, 2009, red, and i LOVED IT. I live 4 hours away from any mazda dealer, so when i was in the city i had to. And now im on the verge of a big purchase the wife just needs to come down with me to sign the papers (course i need time off work so i can get the car). But i noticed something. The car was quick, very quick ( I dont think the sales person was too happy with me as im pretty sure that that test pilot car wasnt broken in just yet for that) but i gave her WOT. But once the car reaches around 5500 RPM there is a major power loss. Now is there a boost cut off, or something of the sort to insure people like me dont ruin the car? or is there something thats holding the car back. I have looked and looked ( and i bet the answer is right in my face) but i havnt seem to been able to find a topic on this. If anyone can direct me to the topic of even explain why this power loss is happening that would be great thanks everyone. Happy modding.
Click to expand...

What you noticed is primarily the result of a relatively small turbo.
The upside is lots of torque in the lower RPM range.
 
Give me the tire roasting please!

After racing several times, I think that 5900 is a little too late to shift at, I think the sweet spot is 5700, at least with the mods I have.
 
There is aftermarket engine management such as Cobb (www.cobbtuning.com) that will hold the throttle plate open all the way amongst other goodies. Expect about 30 on the HP & TQ as far as gains go.
 
Even with TP and breathing mods, you will still have a power dropoff in the upper rpm's. Heck, even the replacement turbo guys still see a dropoff. The car is just not designed for high rpm breath ability.

You need upgrades to the throttle, turbo, exhaust, camshafts, BIG MAF...its a big list to get extra power past 6k.

Heck even the highest dyno'd Mazdaspeed3 still sees a power dip after 6k. Of course its a hella lot less then stock :).

333fi88.jpg


Basically it's better to drive the car in it's "designed" power band, instead of trying to rev it like it's got a 7k redline. Honestly the redline in this car should be 6k.
 
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On that particular graph, the car was slipping on the dyno at some point, that's why the torque intersection is a bit off.

Supposedly they're going to redyno and post a new graph later, but not till they're more along the lines of 425+ whp.
 
Personally, a simple mod like a CAI helped smooth things out for me. Still has a power drop, but not near as bad as it used to be.
 
alright thanks alot guys, really excited about this car, will have one in the drive way hopfully in a couple weeks ( Want a white one and the guy at the dealer said that could take awhile :p )
 
The benefit of the K04 turbo our cars have and the coordinated intake and exhaust sizes is that the car is a torque monster with usable torque as low as 2300-2500 rpm, and it has little boost lag.

This means it comes on boost quickly and produces fabulous low and midrange power. The six speed tranny helps us keep it in the power band which is about 4000 rpm to 5500 rpm.

The small turbo cannot continue to compress air without adding a lot of heat to the air once it gets to 5500 rpm. Heat reduces the number of oxygen molecules in the same volume unit of air, so you do not gain any more power by continuing to run the engine up to redline, and power drops pretty dramatically.

This is really not a bad thing from a drivability standpoint. There really is no fix for the 5500 rpm power max beyond going to a bigger, but more sluggish turbo.

However, this engine responds very well to a good cold air intake or short ram intake in place of the restrictive stock air box and filter. It also responds well to aftermarket replacement of the highly restricive downpipe and the two catalytic converters ahead of the excellent from the factory very high flowing stock cat back exhaust.

These cars produce good power with these very minimal mods. Even with just an intake alone, guys are running high 12's low 13's in the quarter on DOT drag radials and all stock otherwise. The problem is not power -- it is traction.

To unleash the engine's capabilities during wide open throttle runs in the lower gears, simply push the DSC button on the lower dash above your left knee to disengage the part of the engine "nanny" that wants to prevent wheelspin. There are still other "safety" features that we can't disengage like a torque restriction on the lower two gears, and a power restriction in those gears when the wheels are not pointed straight ahead. I don't see those restrictions as that much of a problem because you can't get the power down to the front wheels in those gears now, even with the restriction, without the tires going up in smoke.

As to the rpm issue, there is good news in the way the rpm limiter works. When you hit the limiter, it just holds the rpm there. It does not cut power.

This means you can power shift or flat shift at 5500 without ever lifting the go pedal from the floor, if so inclined on the drag strip, and you can't hurt the engine and you will not have a cut out of power.

You can see my mods, which are pretty modest. With a good launch I'm running 13.4 quarters at 106-107 on stock tires shifting at 5500 (with potential to do better), which is no big deal among this group, but will put a serious whipping on many unsuspecting opponents.

Welcome to our little corner of the world. Explore, read the various "sticky" threads and play with the "search" function. I hope you find your white MS3 and enjoy the fun you will have with it.
 
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I dont normally take the RPM past 5K for any circumstances, but now that I have the AEM CAI in there, I might try it again to see if I can tell any difference. But in the 24 hours and 20 miles I have on it, I can say that I do notice a difference in throttle response, and in the already potent midrange. Will have to wait a day or two to try it out until the pain in my back from my exertions getting the thing on there have been overcome by time and Vitorin.
 
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