i'm at the end of my rope, maybe someone here has an idea i haven't thought of.

i have one of my HKS turbos on my IX (i have two ... long story...). before i swap it out to see if there's something wrong (i don't like doing extra work if i don't have to), i thought i'd check here to see if i'm missing something. at 25psi it only made about 300whp per VD, and at 27psi, it's around 325whp.
first off, how can i be at 27psi, on 91oct, with NO knock? my boost gauge reads from the IM, by the way.

here is everything i can think of that may be pertinent info:

8.5:1 JE pistons, stock bore, ceramic coated. rings gapped to 22/24, IIRC.
Greddy 265 Easy Cam
polished exh ports (no porting)
port-matched exh. mani to turbo gasket ( did not touch head side)
port-matched head/IM (no polishing)
Mil-Spec TB seals
engine is a fresh build with all new seals and gaskets.
comp test = 135/135/135/135
leakdown = 5-7.5% on all cylinders
EGR blocked off with stainless steel plug in the head, disabled via EcuFlash. all EGR equipment is still attached and hooked up.
boost leak tested up to 22psi before the tester popped off. no leaks, takes forever to bleed down.
IAC cleaned and swapped out for an extra
MAF cleaned, but maybe not enough?
new o2 sensor (car sat 6mos so figured it may have been bad).
new Wideband
GrimmSpeed 3-port boost controller
no exhaust leaks.


the car also idles rough and lean at startup after it's up to operating temp (17:1-20:1) and has stalled on me while letting off the gas/putting in clutch to pull into a parking lot. it's only done that once.
idles better with A/C on (assuming due to idle being higher)

 

Lower compression is helping you run more boost.
What parts of the setup is new that the car isn't tuned for?

 

it was tuned on the stock longblock, a different turbo, etc. with a MAP 2.5 it made right around 350whp or so.

the pistons/rods/porting are all new. cams are the same. i'm told the 7460R (non kai) should do about 350whp on 91. i can't really find info to confirm as all the links i find have links to dyno sheets that are not longer any good.

could the .3 diff in compression explain the lack of power allow for that much extra boost? stock compression for a IX is 8.8:1, i believe?

also, i believe both my HKS turbos are ported, if that matters.

do i just ask my tuner to up the boost until i see knock? i was GREATLY advised not to run this turbo over 27psi, so have decided to keep it to 25psi for track days.. which sucks because it makes less power than a stock IX turbo.

 

I would go for a full retune. If your not seeing knock, I would start with lower boost and up timing a little at a time. You never said what your W/B reads during a pull. With more boost you may be hitting a different load cell then what you were tuned for the first time and it may not be the right timing/fueling setting for your new setup as you never hit it before.

.3 wont make much difference in comp ratio. But it may help with more timing.

 

a/f is pretty good. my tuner has made one adjustment so far, but he's also commented on how the turbo should be making much more power.

 

My car did 350whp on VD with a 9 turbo, S2 cams, and an intercooler on 91 octane. Hell, my car made 300hp/300tq vd with just a 9 turbo, exhaust and intake/ I'm not familiar with the HKS turbo, but I would hope it can out do that. Something definitely seems off. How much timing is he running?


If the cams are new, That would be why the idle is off. What injectors and fuel pump are you running?

 

Not sure of timing. I let Jay handle all that.
Cams are the same as last build.
1050s, 255. 40% duty cycle.

 

Jay can change the target Idle with ease.

Did you degree the cams when installed or just drop them in and align up the notches via the notches. Was the head machined or just bolted back on?

What about a exhaust leak? It can throw off W/B numbers.

The Turbo will let you know when you are out of its range. For each LB of boost, you will see X amount of gains, when that gain gets low like 5hp per LB you know you have reached the peak or past the peak of the turbo and time to turn it down a bit. That is not a rule, its just what I have seen from time to time.

To me the TQ curve looks weird. And it does not look like it is running out of steam the way the HP keeps going up.

 

Because there may not be enough ignition advance to test the detonation threshold. Ignition advance is where the power is made. There comes a point whereby increasing boost is offset by the amount of ignition retard required to accommodate it. Past that point, one is losing ground.

Also, 25 or 27 psi is occurring in the midrange only, and doesn't play into your peak power figure. You're seeing ~21 psi at peak power.

 

Is it an HKS 7460? The only link I could find said that turbo is 51lb a min so smaller then a green but bigger then the stock 16g.
http://www.lancerregister.com/showthread.php?t=371280

I'm not familiar with the HKS turbo but if you and your tuner think power is down I would dig a little deeper. BTW I'm only trying to be helpful with my following suggestions.

Your compression and leakdown numbers seem good. What was the PTW with drop in pistons on the stock bore? What is the recommended PTW with your particular JE pistons? Ring seal issue at high boost?

Have you measured crankcase pressure under boost?

How do the spark plugs look?

If cam timing and everything else checks out then I would put it on a dynojet . Schedule an appointment with your tuner and run the car. Bring some race gas as well. They can mount an external wideband for a secondary afr reading and your tuner can make changes that you can see easier.
A lower smoothing number will give you a better idea on how good/bad the engine is running at every RPM point. You can also listen for audible knock while standing near the engine compartment if your exhaust isn't too loud. The factory knock sensor is very good but the further you get from stock ( PTW, aftermarket pistons/cams etc..) the more likely it is to need different sensitivity.
At the point that you have a new engine that isn't performing 100% on the street I think a few hundred bucks spent on a dyno is worth it to really investigate .

 

yeah, but i could swear i used to get knock at peak torque. it's been a while, so i may be mistaken. but good point about the lower boost at higher RPM.

i'm not good at tuning, so i'm not sure if the timing is good/bad/etc. like i said, i leave that up to Jay. i stay out of stuff i don't understand LOL

i'm not sure of PTW measurements as i didn't put that part of the engine together. i checked with JE and Buschur and was assured they were, in fact "drop in", meaning they were the proper size and no machine work had to be done, etc. that's the extent of my involvement with the piston installation.

ring seal issue at high boost? maybe. i THINK i've noticed some blue smoke when brake boosting and pushing it hard.

i've never measured crank case pressure. i don't have a way to right now. it does not blow smoke under normal driving/boost, that i've noticed. nobody said anything at the last autox. no blowing out the dipstick, etc.

spark plugs look perfect. no discoloration, no detonation, not black, no lean conditions.

i've checked the timing more times than i can count. it's spot on, every time i check it. the only thing that can't be confirmed is if, for some reason, the MIVEC system wasn't functioning right. i verified the pulley was installed into the MIVEC gear correctly. i also rotated the cam gear back and forth to verify oil was being sucked/drained out.

a dynojet is fine but we're using the EXACT same VD settings/program/etc that we've used for years. going to another dyno would be comparing apples to oranges, but i understand your reasoning. Jay has been asking me to get the car to him, but it's not easy for me to get the car 4hrs away AND get back there to pick it up.
my WB sensor is brand new.

i used "smoothing 2", but i guess i could drop it down.

no audible knock, though the valvetrain seem a bit noisy. i assumed that was due to the upgraded valve springs.

i'm very certain if the car just needed more timing, Jay would have taken care of it. he is familiar with these setups.

 

also: i have not noticed any oil in my IC pipes, turbo, etc. everything has been clean as a whistle.

also, i updated the OP with info: i have a Grimmspeed 3-port boost controller.

 

** edit reposted info.

 

Well, that ended abruptly.

Care to explain?

 

From what I remember, Aby was running 27 psi back in the day on 91. He did plenty of playing around, and found that (especially on octane limited fuels) that the Evo motor loves boost and hates ignition advance. So, keep ignition advance low and crank the boost. Easy power on limited octane

27 psi has been done before on 91. People tend to run more boost nowadays on 91. Like 23-25. Back in the day (2006-2007), you'd see 21 or so. Maybe 22.