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We discussed about this many times. The K04 should max out at 366 cfm witch should mean, with quick calculations, around 4900rpm for the Speed6. Now we know that it's higher then that, but still, it can't push enough air.

What I want to see is someone adapting a variable geometry turbo that will provide the 15.6psi from 2500rpm to 6500rpm.
 

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run 2 different sized turbos in sequence. the small one will provide low end boost and the large one high. i think ive seen it done somewhere, i just forget where.

edit:
supra sequential twin turbo.
 

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run 2 different sized turbos in sequence. the small one will provide low end boost and the large one high. i think ive seen it done somewhere, i just forget where.

edit:
supra sequential twin turbo.
[/b]
Yeah, but that kind of effect can be achieved with variable turbine geometry these days.
 

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run 2 different sized turbos in sequence. the small one will provide low end boost and the large one high. i think ive seen it done somewhere, i just forget where.

edit:
supra sequential twin turbo.
[/b]
I believe Mazda used just such a setup on the RX-7 turbo...
 

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My opinion (which I'm sure no one is interested in)...

When i got my car I went to a local turbo car... he is the KING of turboes (his name is Dennis Lugo, owns Lugo Performance here in Orlando) and let me tell you, anything I have ever wanted to know about turboes he has answered without hesitation... he also turboed his lawnmower...

Well anyways I have known this guy for at least 10 years, and I can tell ya he knows his stuff....



Now to the point, he got in my car... took it around the block, romped on it... really worked the car....

With no previous knowledge of the car

He told me "car feels like its got a small Borg-Warner or Garret"...

I agreed and promptly asked.... did you feel the boost fall off horribly???

And I quote here "Yeah, it was very dramatic, car was pulling like crazy then felt like it took a nose dive... that car has a serious wastegate issue, the turbo is capable of making the pressure but it feels like its not holding the boost its making..."



I saw this thread today and came back to that conversation, and I'm all for product development for the speed6.... so people lets get rolling...
 

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Ah, that must make it true then. Glad that issue is solved.

We discussed about this many times. The K04 should max out at 366 cfm witch should mean, with quick calculations, around 4900rpm for the Speed6. Now we know that it's higher then that, but still, it can't push enough air.[/b]
Careful, I think posting facts is against forum policy.
 

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Once I was on a test drive in this cool car. After a few minutes I said...is this a 6? And stretch looked over and said...yes dumbass.

We know that the WGA may have a problem just from the boost spiking. However that's not going to suddenly move the torque peak up 1000 rpm.

By the time the massive drop in power occurs, the car's already lost a massive amount of torque.
 

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this is the product that they make for the srt-4. I don't know enough about how they work, but my cousin seems to be interested in giving it a whirl...

http://www.agpturbo.com/product.php?produc...&cat=276&page=1
[/b]
Cause the SRT 4 turbo is a 16g capable of more than 50% more flow than the k04.

You can weld shut the WG actuator if you wanted to you are just gonna cook your turbo and create a heat gun on an already small turbo.
 

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Right, but the turbo can't maintain sufficient boost at redline. It can't move enough air. The wastegate shouldn't be open at all.

Are you suggesting the wastegate opens at redline because Mazda decided the turbo too big and mighty?

This mod could be good for smoothing out the torque curve and/or adding boost (deliberate overboost) below 5000rpm, that's it. It's not going to affect redline torque at all. My extensive experience with slandering others on forums and my one-day internet turbo education says so.
[/b]

stretch, i originally suggested the WGA was crap because the SAME symptoms were being realized by srt-4 owners.... at the time i made the suggestion i didn't know the capabilities of the K04 turbo. i ASSUMED Mazda hook the car up with a turbo that had potential, not a "meets the needs and thats it" turbo.

As you probably know, the other automakers (DSM, DCX, even Subaru) running factory turbo's had provided the tuner with a great platform to work on... Now.... knowing that the K04 flows as much air as a McDonald's straw... I recind my previous statement about the WGA being the cause of the problem... I still think it will be a worthwhile mod nonetheless...

what's the stats on the K04 anyways (.AR, housing size, cfm's...)

The K04 should max out at 366 cfm[/b]
is that correct... holy shit.. I thought the worst stock turbo ever belonged to the 95-99 Eclipses and Talons with the T25.... :huh:
 

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A better torque curve will depend on who is driving the car. Many MPS 6 owners love the low end torque. Some wish they had more grunt past 5500. You can't have peak power at redline and also have lots of low end power.

Right now peak torque is around 3-4k (depending on whether or not you've got an intake, and will probably shift again if you run a turboback). Shifting the peak to 5500 or 6000 will require quite a bit more work then just an intake and exhaust. [though it should be noted, the gains from intake/exhaust are pretty big on FI car's, and you will shift the peaks, just not by 1500-2000 rpm.]
[/b]

Allright, then I see what you mean. Some thinks a better torque curve means plenty of torque down low, and some want plenty of torque high in the rev range. However, this was nothing new to me. What was confusing me was the statement of 0 gains in whp, but still a gain in torque. I thought that a gain in torque in a specifik rev range automaticly gives more power(whp) in the same rev range, since there is a connection between torque and power.
 

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Once I was on a test drive in this cool car. After a few minutes I said...is this a 6? And stretch looked over and said...yes dumbass.

We know that the WGA may have a problem just from the boost spiking. However that's not going to suddenly move the torque peak up 1000 rpm.

By the time the massive drop in power occurs, the car's already lost a massive amount of torque.
[/b]
Crossbow... no need to be a wise ass...

And what you are NOT looking at is the HP curve...

This motor WITHOUT A DOUBT in NA form would make most of its power at 6K or above...

Look at the HP curve from the CP-E dyno... I mean I can almost see the car dropping boost right around 6K...

I do realize that the turbo is running out of breath up top... but for a car to cause a SUDDEN loss of boost like that looks right to a wastegate issue...
 

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Wiggum,

Was just having a bit of fun, sorry!

I'm ignoring the hp curve because its not as relevant in this discussion. If you want more high end, you need more high end torque. The torque peak and drop off is extremely low (because mazda wanted the car to fly off the line), and moving that torque peak up is not going to be solved by fiddling with boost past 6,000.

Even if you added 30-40 ft/lbs after 6k, it still wouldn't be worth reving much past 6. Heck its really not worth reving much past 5.7 or so with the gearing.

After talking to sigma at length last night, I'd have to say I agree with him. The car isn't designed to rev much past 5500. It would be much better for those involved to concentrate on trying to enhance the power where it already is, instead of trying to remap and tune the car.

Horsepower= (Torque X RPM) / 5252

You aren't going to make much horsepower if you don't have any torque.

http://www.elec-toolbox.com/Formulas/Motor/mtrform.htm
 

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My biggest problem with that is that we will NEVER see the cars potential if we focus on 5500 and below... because turbo aside the motor makes its power up top...
 

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Wiggum,

Maximum power is made at high rpm's. But you can't have maximum power at upper rpm's AND tons of power at low rpm's. We don't have infinity profile cam's yet =/.

What you have to do is look at the angle of the graphs. The more torque the has at a specific rpm, the greater the angle of increase. When you are running out of torque, the line flatlines and begins to drop.



I overly simplified the cp-e dyno to help illustrate this.



Look at the angle of the hp graph (black line) vs the torque graph. Notice how it begins flattening out? Also notice how it drops when the torque falls 90 ft/lbs.
 

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My biggest problem with that is that we will NEVER see the cars potential if we focus on 5500 and below... because turbo aside the motor makes its power up top...
[/b]
Correct, which is why a wastegate actuator isn't going to be helpful. You need a bigger turbo. :p
 

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True... but for my use i don't think a turbo that takes till 4K to spool is going to make much sense....
 

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It depends on your goals wiggum. You basically start off by setting a goal like...

I'd like at least 300 whp @ 6000 rpm.

Then you go about building a setup to obtain that goal. The higher the final output you want, the more tuning, tweaking, and part replacing you'll have to do to reach it.

If you just want a small amount of more power, like 10-25%, thats usually obtainable with simple bolt on's and a good tune. This however won't drastically change the torque curve, so it'll just be 10-25% more power at your current torque/power peaks.

If you wanted to increase torque/power substaintally at 6500 rpm, (say to 250 whp), that would require a substaintal amount of modification.

It's far easier to add to the car's exisiting torque/power curves then trying to move them.
 

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My goal is in my sig... and RPM wise I would like to see it around 4K... maybe a lil earlier...

Quick Edit: I'm talking engine torque, not to the wheels... so assuming 18% drivetrain loss i'm looking at 339 FT LBS. to the wheels...

Don't know for sure until next week when I get it dynoed but I should see around 280 FT LBS i hope... CP-E got 264 on their "conservative" dyno sheet...
 
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