Hello, i have m50b25 (2800 cc) 84mm x 84 mm non vanos
-cr 8:1 wiseco pistons eagle rods
-aem intank 300 lph fuel pump
-gt35 turbo exhaust ar .68 intake ar .70
-525 cc injector
-kdata megasquirt
-stock head and cam
-mls cmetic head gasket with arp head stud
-boost is 1.25 1.3 bar
now the trouble:
i dynoed 530-540 hp first 3 4 dyno with afr 11.5 and egt ok no more than 900 920 c° max
now after 3 4 launch on dyno, without mod ecu i get 420 430 hp, no boost leak
Has anyone had similar experience?
Log of parameter is ok, afr is still 11.5-11.6 but get 100 hp less
I had stock valve on exhaust, can i have trouble with exhaust valve? i need nimonic?
i am lost
"without mod ecu"
What does this mean? Also, are you able to log timing?
As are we... you didn't provide one single thing that could let us understand what is going on to help you.
You're basically asking us to guess.
Post the data log from your dyno runs from start to finish, identifying the ones run with the power loss, and post your dyno sheets along with any other data (AFR, BOOST, etc).
That would be a start.
If it's .68AR on same dyno, same temp day, same gear, same fuel, etc. it's possible the IC heat soaked and your timing was reduced. High intake temps cause me to lose 80hp on summer days too.
I found little leak in exhaust flange between manifold and turbo but boost is still ok
- - - Updated - - -
.ar68 is bad?
Not bad for response. It'll run out of steam faster. Just know you'll lose some power up top. Especially on hot days and back to back pulls
I think is something related to valve train
Does anyone know if are there common problem relatin to boosted m50 with more than 500 hp?
Valve..spring...hydraulic lifter cam are all stock
Found leaks on exhaust manifold but turbo pressure is still 1.2.
Exhaust manifold leak can lead so much performance?
Bookmarks