Ok, so I finally got my stock IX turbo installed this week and dyno'd tonight. The details are that it's the same dyno (Dyno Dynamics) at 6800' where we take the standard correction factor and cut it in half. It's usually as high as 1.31-1.32, so we use 1.15-1.16, but there was good air tonight (cool and dry), so it was only 1.28, therefore, we used 1.14. This helps to normalize the different readings from the previous day to now. It was around 80 degrees last time and 60 degrees this time, so a .02 difference in CF seems good enough.

Besides putting on the IX turbo, other changes include switching from a MEGAN TBE to a Buschur TBE. I also means that I went from a Forge VIII WGA to a stock IX WGA. Even with the turnbuckle and nut turned all the way down, there was still very little preload, so I wasn't ever able to get higher than a 21psi reading on the dyno's MAP sensor. I ended up sticking with an MBC setting where the boost peaked just below 21 and tapered to 17.5psi by 7000rpm. Previously, the MAP log was showing a peak of 26.5psi tapering to about 17-18psi by 7000rpm.

On the previous run, we were having trouble dialing in the load and the rpm signal (brand new dyno), so I ended up not getting a torque reading and had to use MPH instead of RPM. On the new dyno, we got a nice torque reading and are able to show RPM on the x-axis. Sometime in the next few days, I'll have them take the old HP reading and overlay the new HP reading on the MPH axis so that they are compatible. For now, we just have to look at them separately.

05 w/stock turbo, Megan TBE, cams, alky, bolt-ons, 6800', 1.16 CF


05 w/IX turbo, Buschur TBE, cams, alky, bolt-ons, 6800', 1.14 CF

 

LOL at first I thought that line was your torque but I quickly realized how wrong that was with the PSI label

Looks like the 9's turbo definitely has quite a bit more wind to it
Curious to know the PSI plot on the 9's turbo.

 

looks like there was a great improvement with the 9 turbo.
when you physically have both turbos next to each other does the 9's compressor look noticable larger?

 

Yeah, I put PSI on that other graph, because there is no torque to show.

I do have a graph showing psi on this run with the IX, but I don't think it's accurate, because I see no way in hell that I made 348wtq vs 324whp with only 20-ish psi. Plus, I kept cranking my MBC and would only get .5-1.0 psi with 15-20 clicks. With the boost set another 20 clicks higher than this run, I actually hit 371wtq, so I know the boost was going up more than half a psi. On the 371wtq run, I only made 316whp, so I turned it back down.

What I found was that no matter how high my peak boost was, the boost profile would always be identical after 5000rpm or so. That's exactly how my VIII turbo behaved up here at this altitude. 24, 26, and 28psi would make different peak torque, but after 5000rpm, the power curves were identical, so I had to choose if it made sense to push the turbo hard for a little extra torque for only 500-1000rpm. This time, I chose to turn it back down to a reasonable level that still made good power without knock.

 

Yes you can definelty tell the differance between the two.

 

Yes, very much so. When I first got the IX, I couldn't tell, because the VIII was tucked down inside and hard to see, but when the VIII came off, it looked like a different turbo due to the compressor housing being so much smaller. The IX was NOTICABLY larger, and that aspect is why I think I made more power at basically the same boost levels.

 

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this leads me to believe that the extra power made by the evo 9's are due more to the larger turbo than to mivec. seem likes your making about the same power and evo 9's with similar mods

 

Uh-oh looks like Warr might get outta 12's !! With that high of torque man wouldn't that be a optimum turbo (not best) for your road racing courses?

 

Only ran a 12.30 with 109.5mph traps on the previous power level, so I don't think the extra 24-25whp will quite get me there. However, I do also have a separate kill tune for race gas + alky, and I now have a 4th gear that can finish the run instead of shifting to 5th, so maybe I'll have just enough to hit that elusive 11.99 here at altitude. Not counting on it, but I do believe I will at least beat my 12.30...

This setup is good for road racing, but it's still not enough power to keep up with a real powerful Evo, even one that spools a little later.

 

The thin air of that altitude must be really killing you up there! Your car is nice and fat in the midrange, but really pukes-n-dies up top.

Regardless, I agree with whoever said it will go elevens now. You just need to race somewhere that isn't eleventy billion feet above sea level.

 

Yep, that's all correct.

 

Very interesting. Thanks for taking the time and effort in putting this all together.

I too believe that the larger compressor housing is the most significant factor in the IX's ability to make power. MIVEC comes in a close second.

 

In terms of peak power gains, I personally think the revised coolant passages in the head help more than the MIVEC, because that allows IXs to run 24-26psi on pump gas while VIIIs have to run 21-23psi usually.

 

I think a IX would spool up a little quicker and maybe not taper off, this is where the mivec comes into play

Warr is making good power but I dont think he's making similiar power to a IX w/ the same mods...on a low reading mustang dyno a local IX dynoed 331awhp & 305 awtq at 23 psi. No alky, straight pump. His mods at the time were 2.75 dp, 3" tp, 3" cb, ebc, hks intake, fuel pump, ams fmic, ams licp, ams uicp, ported & coated hotside and mani, ss O2 housing

 

Never even thought to take that into account. Does your theory rely on the passages being larger? closer to the cylinder walls? more of them? I assume that because of the revision the temperature inside the cylinder walls is reduced thus aiding in a cooler temp right before combustion?... am i off?