interesting.....that is about how mine looks except at 5500 i got to 85% and 6k go to 100%. So is there any sort of wastegate modification or HP wastegate actuator used? or just the porting work?

 

Question: Would stock cams make it easier to hold boost pressure to redline? Would you expect to be able to hold this boost with aftermarket cams?

 

Yes stock cams, fmic, throttle body, wastegate actuator, etc.

The car is setup within certain rules for Nasa Time Trials so it's not modded much.

 

From what I have seen, I would imagine yes, it might be a tad different with cams. I'm hoping to do so more testing on another car with cams etc.

Yea I was surprised as well that I had to actually bring down the duty cycle up top to keep it around 24psi. At one point it was holding 25.6 psi up top I believe but I would need to double check the dyno logs.

Stock actuator

 

Nice work! Makes life easier on the turbo too.

 

Stock cams will definitely make it easier to hold boost

 

That's what I thought.

 

I believe razorlab will be testing a IX turbo ported in the same fashion but with revolver cams within the next couple months. I think those should for sure test that theory.

 

I cant wait to get my car back from being tuned on the GM 3 port and ported IX turbo on my VIII.

 

Damn, and I thought I was doing good, but I was only holding to low 23's by those rpm's.. I was get a pretty substantial drop almost all the time at 6400 rpm..

After you verify with another turbo, post up some pictures!!

 

That will be interesting. I have seen at least one car add an aftermarket intake manifold and have horsepower increase while boost pressure decreased by .5 to 1 psi IIRC.

 

yeah psi being pretty much a back pressure rating is a liitle misleading to some people since psi doesn't=hp, but the fact that a stock turbo could support and hold that kind of boost like it did does show there's significant improvements made... I'm no tuner though so maybe Bryan could explain it better. I just grind things.

 

Impressive nonetheless, but it's mostly due to the stock cams. Anything that enables the engine to flow more mass air at the same boost pressure, like cams, will soon reach the limit of the stock turbo and the boost pressure will fall off.

The stock turbo can only flow so many lb/min. The boost doesn't tell the whole story.

Nice work, though, Bryan.

 

Yup I agree. However, it's still holding more boost, for much longer, than I have ever seen on other stock cam Evo 8's with the same type of mods. It has the potential to hold more boost as well since the WGDC was pretty low. And yes, of course boost is not everything.

Here is a complete mod list for the car used for this:

2005 Evo RS
PTE 780cc injectors
Walbro fuel pump
Buschur UICP
LICP
Stock motor
Stock cams
Stock FMIC
Stock throttle body
Stock wastegate actuator
Stock ECU
Intake with open filter
JDM/Evo 9 BOV (crushed)
Ported Evo 8 turbo with 10.5 hotside
TBE exhaust
Tubular 02 housing
GM 3 port boost solenoid
ECU controlled boost (still load target)
110 octane

This car has been through a bunch of different parts combo over the last year or so as it has been fitted within different Nasa Time Trial classes. It started out with a 50trim, with GSC S1 cams, nisei FMIC and it made 412whp/349wtq on our mustang with a track tune. Same 110 octane.

Then it "downgraded" to a Evo 9 turbo (unported) with a Forge actuator, still with GSC S1 cams, nisei fmic and it made 364whp/326wtq on a track tune, still on 110 octane.

Now it sits with the above mod list, stock cams, stock fmic, stock 8 turbo ported, so basically it's really close to a "stock parts car" with normal small upgrades with supporting fuel, and yesterday it made 327whp/315wtq on a track tune, still on 110 octane.

So taking away the GSC S1 cams, FMIC, and Evo 9 turbo, it dropped "only" 37 peak hp and 11 peak torque.

Obviously, from the tuning stand point I was able to run more timing with the current mod trim, because of course it's flowing less air. However, I was also able to run more timing than I usually can with the same config, and I really contribute that to the turbo porting. We are talking almost 10* more timing up top in the current trim.

When I get some time, I will try to do overlays of the 364whp and the current 327whp curves and see exactly the differences.

Keep in mind all these tunes are circuit track tunes, so please keep that in mind when you look at the numbers. I had the car on the dyno for about 4 straight hours yesterday messing with stuff and I barely ever cooled the car down. I was also tuning the car in 4th gear as well revving it out to 8200 rpm run after run. That is 133mph in 4th at 8200. We have good fans on the dyno but obviously not good enough to simulate the air flow you would have on the car at 133mph on the track. Think of the heat this car was generating... at one point I think I did five 4th gear pulls in a row with no cool down to make sure it was solid. 100% knock free every pull. This was with the "final" tune of the day, being 26psi peak and around 23psi at 7900 rpm. 11.9-12.0 AFR

Then at the end we did 6-7 1/4 mile pulls on the dyno because we where having fun. No cool downs, I just kept beating on the car and it was pretty much knock free all day long. The last 1/4 mile pull had a quick blip of 2 knock counts in 4th gear and that was it.

 

What's the timing curve looking like? Have you ever tuned on 93 or 91? If so, how much less timing were you able to run?