I have created a thread in Evo Engine / Turbo / Drivetrain forum detailing what I'm experiencing but since I fully believe that it is not mechanical in nature I'm asking for some tips on what it can be in this forum. My situation is posted here:

https://www.evolutionm.net/forums/sh...6&goto=newpost

In 1st and 2nd gear I don't see my target 21psi of boost until 4000 or so rpm. This is about 800 rpm later than what I saw before this problem started. If I floor it in fourth at 2000 rpm I'll get my 21 psi by 3250 rpm due to the time allotted for the turbo to spool.

I'm self Flashed with JDM MAP sensor, aggressive MIVEC timing map, mirrored & advanced all three timing maps, installed GST motorsports 26 psi boost pill and adjusted WG duty cycle to hold 21 psi with boost error correction set at zero. I was running the mileage mod as well but since over 90% of my driving is city driving it wasn't doing anything except causing slight stumbling in the light load and RPM areas. I am running stock everything else except for the boost pill and reflashed ECU.

After I dialed in the WG duty cycle to maintain the boost curve at 21 psi it spooled great (before the problem started) with the advanced MIVEC map and additional timing with only occasional 1 and rarely 2 counts of knock. Intake air temps have been within 5-10 degrees so I don't see that as a cuase of reduced spool. I pulled the turbo tonight and inspected the turbine, wastegate actuator, and flapper valve and they all check out fine. There are no boost leaks either since I pressure tested the system. There were no exhaust leaks either and the wastegate sealed properly. This tells me that pressue ahead of the turbine wheel should be the same as before this problem set in. I also tested the stock IX diverter valve and it held without any boost leaks. Turbo compressor wheel is fine as well and the turbo has no shaft play. Does anybody have any ideas? There isn't anything I can link to what caused the start of this but I do know when it started. Going to lunch a few weeks back it was boosting great and halfway there I lost all my early spool. I wasn't datalogging at the time but did afterward with the problem still there and only 1-2 counts of knock running on the hi octane maps. I'm out of ideas and turn to the community for ideas.

 

replied to your pm.

 

Don't worry. you are fine.

This is the nature of all turbo engines. Turbo engine can't produce equal power at lower gears (this is somewhat true for N/A engines also).
Spool up and power will be always a lot better in higher gears.

boost = product of load

1 and 2nd gears will never produce the equal load of the 3rd or 4th gears. . Hence, lower torque and power in lower gears (slower spool up and less boost).

You will experience the same thing when you reduce any drag or mass of your car.

 

I agree ... it doesn't seem too out of the ordinary ... I hit full boost around:

3rd - 3400 RPM
4th - 3200 RPM
5th - 3050 RPM
6th - 2900 RPM

Basically, the engine spins up so fast in lower gears the turbo just can't keep up as well ...

 

maybe catalic converter starting to "block" ??

 

a/f ratios to rich, restrictive cat maybe like he said

 

I get what everone is saying but I have definitely lost power and early spool I had previously. This wasn't coupled with any changes in hardware or a change in a flashed rom.

Razorlab, YGPM

Thanks and I'll be checking the factory cat next. Any other ideas, please keep them coming.
Rich

 

Here is a 2nd gear log and you can see that it doesn' hit 20+ psi until 4000 rpm even with the wastegate line pulled.

TPS RPM TimingAdv JDMMAP LoadCalc KnockSum
12.9 2843 30 -11.9979 -7.866248618 0
12.9 2343 28 -12.5783 -8.016953991 0
12.9 2312 28 -12.5783 -8.016953991 0
12.9 2281 28 -12.7718 -8.016953991 0
12.9 2250 28 -12.7718 -8.016953991 0
12.9 2250 28 -12.5783 -8.167659363 0
12.9 2218 27 -12.7718 -8.016953991 0
12.9 2218 27 -12.7718 -8.167659363 0
12.9 2187 27 -12.5783 -8.016953991 0
12.9 2187 27 -12.7718 -8.016953991 0
12.9 2156 27 -12.5783 -8.016953991 0
16.4 2125 26 -12.5783 -8.016953991 0
20.0 2125 26 -11.9979 -8.016953991 0
20.0 2093 26 -11.6110 -8.016953991 0
22.3 2093 27 -10.4501 22.76304601 0
25.4 2156 32 -8.70896 38.15304601 0
33.7 2218 33 -5.22650 69.56792878 0
37.2 2093 26 -3.09833 80.45007849 0
48.2 2187 19 -2.71139 79.51282924 0
60.0 2218 25 -2.13098 84.47375138 0
64.7 2218 24 -2.13098 89.30234064 0
68.6 2312 22 -1.74404 89.45304601 0
74.5 2312 23 -1.55057 94.13092989 0
93.7 2375 23 -1.16363 94.43234064 0
100 2437 23 -0.77669 98.79053955 0
100 2468 22 -0.38975 103.8807721 0
100 2562 21 -0.00281 104.0303092 0
100 2593 21 0.38413 108.1327662 0
100 2687 20 0.77107 112.4670984 0
100 2750 19 1.35148 119.6058179 0
100 2812 19 1.93189 126.8543079 2
100 2875 17 2.51230 131.6360576 2
100 2968 16 3.47965 142.2321352 2
100 3031 14 4.25353 151.2892386 2
100 3125 11 5.02741 160.4793785 2
100 3218 9 6.76864 173.6696618 2
100 3312 8 8.50987 186.2963373 2
100 3406 6 9.67069 196.9025906 2
100 3531 4 11.99233 216.2417224 1
100 3625 2 13.92703 229.1730018 1
100 3750 -1 17.79643 258.8435305 1
100 3843 -1 19.53766 280.5380252 1
100 4031 -1 22.43971 296.3230606 1
99.6 4093 -1 24.18094 308.5874655 1
51.3 4218 -1 17.40949 295.6485967 1

 

that favors the "cat" thing...
that's the 1st thing you should check imo

 

I'll check the cat next.

Thanks

 

I have worked on a few evo's with slow spool, including mine, and it turned out the wastegate actuator was not tensioned. maybe it went lose after a while, i dunno. basically, that unside down cup (where the WGA diaphram is) has to be about 1/8" away from the base. if it is touching it, its lose.