Hello,

Today I went back on the dyno a tested the X bit more. I found something out that is very interesting and most people NEED to know when you modify the Evo X.

I will start out with my process. I wanted to see how much power we would try and squeeze out of it so I put a bit of VP MS109 which is unleaded gas. There was a half tank of 91 in the car already so really probably put us up to maybe a 97-98. Hard to say an exact octane rating but that is just my approximation at this point.

I turned up the boost and noticed something funny. When the boost was around 25psi at 5500rpm the IDC was around 115%. Now at first I didn't think too much about it as a lot of time IDC calculations are off but I noticed at that RPM the car starts to lean out. So I did one more pull and added fuel and verified that in fact the car is leaning out.

Now I know there is talk on here of these cars having 650cc injectors or something of that nature. This may be the case but this car is in dire need of fuel at or around 5500rpm. I would be curious to see a test of the X pump vs. the 8/9 as I dont think this pump can handle a whole lot.

We are going to try and get a new pump in it today and see what we yield from there.

As always raw data soon to follow.



Thanks,

Mitch Mckee

 

Here is some of the data I was talking about.

You can see that the IDC directly correlates with the lean AFR.




So I would say that a word to the wise is to address your fuel system when you start to modify your Evo X. I am not sure how the fuel pump install will be and if it will be a band aid or a total fix but I will be sure to document my progress regardless.

Mitch Mckee

 

Interesting read, definately something to keep an eye on. What all mods are done to the car? Do you think the leaning out is do to the boost level on the car that yall have set or in general? Did it lean out with the same mods at stock boost levels? Thanks ~Trent

 

The car has:

TBE
Intake
EBC
IC Pipe

No it was not leaning out like this on the stock boost level. With the increase to almost 26psi is where I am seeing this. On race gas I would not say this is damaging but on pump it would be for sure.

Mitch M

 

Can the injector duty cycle mapping not just be increased at higher rpm to compensate for this or is it maxed out at that point? The reason that I ask is because one company a while back flow tested the injectors and pump and found that in addition to the 650 cc injectors that the pump flowed SUBSTANTIALLY more than an EVO 9 pump, but not as much as a walbro 255.

 

I increased the fuel in that part of that map in those load points substantially and it made no difference.

I can only increase the fuel as much as the injector allows. I will double check air leaks and make sure I am not pulling in air from somewhere else but from everything I have seen, the car is leaning out from IDC being too high.

I am curious to see if anyone else comes across this or if it is isloated to this car but I doubt it.

Mitch Mckee

 

Very interesting, keep up updated

 

Am i missing something? How is it possible to have over 100% duty cycle, wouldn't that just be full on?

The graph makes sense though, the cpu tries to give it full duty cycle in order to correct the A/F ratio, but not enough fuel is reaching there so the IDC stays full on at higher rpm.

 

 

^That's the test that I was referring to earlier. Thanks for finding it, guerillah. Let us know what the issue could possibly be mitch, cause the fuel system shouldn't be running out of steam at these power levels. I hope it's just an air leak somewhere... fingers crossed. Or, perhaps it's something to do with the fact that the injectors are a high impedance design? Could that have any effec on how they respond to IDC tuning?

 

I hope this is an anomaly. I was hoping to achieve 400 whp (dynojet) without having to upgrade the fuel system. When AMS posted the flow rates of EVO X injectors and pump, I was really excited. Now, I’m getting a little disappointed…. I haven't seen anyone achieve 400 whp with bolt-ons and a tune. Now this???

 

I double checked everything. I cannot find a reason why it would be doing this other than the fuel system is maxed out.

I would like to see some other findings. I dont think this is just this car being funny although it may be.

I will run it some more and see what I find.

Mitch M

 

Road Race ran into the same problem with my car.

I am looking for the dyno plots.

IDC was maxed out at about the same RPMS, but on 91.


Mods:

3" Catback
3" Testpipe
Full 3" Intake
Full 3" Lower Intercooler Pipe (coldside)
2.5" Upper Intercooler Pipe (hotside)
Griffen Custom 3" FMIC
EBC set to 22.5 psi

The air is FLOWING, the fuel on the stock injectors/pump can't keep up, and the motor wants MORE.

it looks like 330-340 is going to be the MAX on STOCK fuel setup

-Chris

 

That is what I am seeing as well. The motor is moving a lot of air and fuel just cant keep up.

I would be curious to see your logs I bet they match mine.

Mitch

 

Doesn't make sense compared to others. AGP has made over 400awhp, AMS has made near 380awhp, big valley made 400awhp, turbo trix 380awhp. THe only thing I see in common with all of those is they did not use ecutek, either AEM FIC or nothing at all.