After doing some work on the car to resolve an issue with leaking exhaust valves (see https://www.evolutionm.net/forums/ev...ggestions.html) and adding a few other parts along the way I took the car back in to get retuned, but left with less than spectacular results and a new issue with the car dramatically losing power at around 7300rpm.

A quick rundown of what all was recently done to the car: http://mitsustyle.com/forums/showpos...&postcount=195

List of important stuff:
Evo 9 turbo
Megan O2 housing
Buschur 3" turbo back exhaust
RMR intake w/ Perrin filter
Nisei intercooler piping
Evo 9 BOV
MAP Rev2 intake manifold
MAP ported exhaust manifold
MAP Stage 3 head w/ GSC beehive springs
GSC S2 cams
At the time of tuning it had an eBay intercooler, but now has an ETS 3.5"

Boost leak test is good, compression test is 170-175 across the board.
Timing marks all line up.
Timing belt was done at 66k, 101k on it at the time of tuning, stock cam gears.
Even after the new intercooler the power loss still exists and is noticeable on the road.

Dyno graphs before the head swap:


HP vs AFR: http://img242.imageshack.us/img242/7246/afr.jpg
HP vs boost: http://img196.imageshack.us/img196/1521/boostw.jpg

Dyno graphs after the head swap and other parts:


HP vs AFR: http://img532.imageshack.us/img532/6112/hpafr.jpg
HP vs boost: http://img153.imageshack.us/img153/8072/hpboost.jpg

I took the valve cover off and everything looks good, nothing loose or out of place, no odd noises like a collapsed lifter or anything. At this point I'm stumped and am looking for opinions on what to do. I was in contact with Greg at GSC but after sending him my dyno graphs I never heard back from him. DB Performance tunes a great number of Mitsubishis, and this isn't Shane's first rodeo. He said that any more timing or less fuel it would knock, so I'm inclined to believe that the tune is spot on. It has been beat on it a fair amount since then and the high RPM issue still exists, though it has kept up with two different cars that dyno'd at 330whp on the same dyno.

The only other piece of info I have to add is that when the power drops at high RPM there is a slight vibration associated with it, but the car feels like it pulls out of that power loss when it reaches 8000-8400 and the vibration subsides. It's nothing violent at all, but is plenty noticeable.

Scheides has helped a ton with this car, he knows it as well as I do. I'll let him chime in with anything that may be worth adding.

EDIT: Forgot to add that we swapped out my coil packs and wires for those off a car with something like 16k miles on it, same issue.

 

Matt, I haven't ever seen these dyno graphs.. they might have been caught in a spam filter of ours...

Id suggest checking the balance shaft to make sure its not 360 out as its a gear reduced pendulum. The one that rides behind the oil pump. if you notice on the side of the block you will see a 14mm bolt that is the balance shaft lock/checking shaft. when the engine is at top dead center you should be able to put a strew driver or smaller Allen (6" long) into that hole if the screw driver only goes 1-2" in than you need to rotate that gear 360degrees. If it is indead out you will have some higher RPM vibrations that could be pulling some timing making it harder to rev.

 

The car was not pulling timing at any point as I remember looking at the log myself, it was simply losing power and had the odd vibration. I will check out the balance shaft as well as inspect the crank pulley.

If I can't get my hands on one of the log files I'll see about getting it logged and post it up.

 

Bump can anyone figure this out?

 

I would recheck the timing. Redo a the compression test, do a leak down test, and a boost leak test. also check out your shaft play on your turbo.

 

Here are two logs that Shane at DB Performance sent me:
https://spreadsheets.google.com/ccc?...XVmhpQlE&hl=en
https://spreadsheets.google.com/ccc?...yM2QxY2c&hl=en

Between autocrossing and everything else that goes on in the warm months my calendar is packed... Who knows when I'll get a chance to look at the timing gear.