Cam Timing or Turbo Efficiency
08-29-2015, 10:08 AM
#1
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Cam Timing or Turbo Efficiency
So finally we got our F24C 10:1 engine running with Full-Race Forward Racing T4 Twin Scroll on GTX3576R @ 1.06
before the clutched started slipping, we are seeing a pattern on the dyno which doesn't seem too normal.
Since it is a 2.4 Stroker, we are aiming at only the 74-7600rpm redline.
the max tq on a single boost level would only hold from 4000-6000rpm then hit a big drop till redline.
Peak HP happens at around 6200rpm due to the drop.
I personally think the cam timing is slightly off since the cylinder was machined when we changed the piston.
would this be the contributing factor?
I am on the BC Stage 2 cam that I had for my 2.4 ITB setup. I already have the TODA Cam Gear Installed. Any recommendation on cam timing after I get the cams degree?
before the clutched started slipping, we are seeing a pattern on the dyno which doesn't seem too normal.
Since it is a 2.4 Stroker, we are aiming at only the 74-7600rpm redline.
the max tq on a single boost level would only hold from 4000-6000rpm then hit a big drop till redline.
Peak HP happens at around 6200rpm due to the drop.
I personally think the cam timing is slightly off since the cylinder was machined when we changed the piston.
would this be the contributing factor?
I am on the BC Stage 2 cam that I had for my 2.4 ITB setup. I already have the TODA Cam Gear Installed. Any recommendation on cam timing after I get the cams degree?
08-30-2015, 01:38 AM
#3
I would try running stock cams
On my old 2.4 f24 stroker i also ran a garrett gtx3576r .63ar with a 10.5 compression 2.4 motor with stock cams and stock cam gears. The redline was set to 8,000rpm but the power keeped on climbing made 512whp 356tq on 14psi on straight 91 octane and 618whp 442tq on e85 and 18psi.
On my old 2.4 f24 stroker i also ran a garrett gtx3576r .63ar with a 10.5 compression 2.4 motor with stock cams and stock cam gears. The redline was set to 8,000rpm but the power keeped on climbing made 512whp 356tq on 14psi on straight 91 octane and 618whp 442tq on e85 and 18psi.
08-30-2015, 12:32 PM
#6
The BC stage 2 cam is probably optimized for a naturally aspirated build and for top-end power. Therefore, I'm guessing too much overlap for a turbo setup with a relatively small turbo. I would try going back to the stock cam.
08-31-2015, 01:00 PM
#7
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So finally we got our F24C 10:1 engine running with Full-Race Forward Racing T4 Twin Scroll on GTX3576R @ 1.06
before the clutched started slipping, we are seeing a pattern on the dyno which doesn't seem too normal.
Since it is a 2.4 Stroker, we are aiming at only the 74-7600rpm redline.
the max tq on a single boost level would only hold from 4000-6000rpm then hit a big drop till redline.
Peak HP happens at around 6200rpm due to the drop.
I personally think the cam timing is slightly off since the cylinder was machined when we changed the piston.
would this be the contributing factor?
I am on the BC Stage 2 cam that I had for my 2.4 ITB setup. I already have the TODA Cam Gear Installed. Any recommendation on cam timing after I get the cams degree?
before the clutched started slipping, we are seeing a pattern on the dyno which doesn't seem too normal.
Since it is a 2.4 Stroker, we are aiming at only the 74-7600rpm redline.
the max tq on a single boost level would only hold from 4000-6000rpm then hit a big drop till redline.
Peak HP happens at around 6200rpm due to the drop.
I personally think the cam timing is slightly off since the cylinder was machined when we changed the piston.
would this be the contributing factor?
I am on the BC Stage 2 cam that I had for my 2.4 ITB setup. I already have the TODA Cam Gear Installed. Any recommendation on cam timing after I get the cams degree?
I'm running 9.4:1 2.0l with a gt3076hta, at 26psi boost running a 0.82ar housing it ran out of puff at 7k. Emap was 52psi. We tried the 1.02ar housing and it made more power but ran out of puff at 7.5k, emap was 39psi(ideally we want to see 28-30psi). The problem is the huge amount of overlap on the na cams. I'm not sure what the centrelines of the Brian crower cams are but I wouldn't mind betting they run more overlap so will make this problem worse. Might be something for you to bare in mind.
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08-31-2015, 03:28 PM
#9
Hitting "full boost" doesn't mean anything if it doesn't carry to redline. Have you verified you're carrying your target all the way to the limiter?
09-01-2015, 09:09 AM
#10
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Originally Posted by tidus888' timestamp='1440956491' post='23731325
Boost is holding well. Full boost @ around 4000rpm. That's why I wanna know if anyone else experienced "tq" drop after 6000rpm.
Boost level is constant after 4000rpm to 7400rpm (our target redline)
we were holding a nice 17.5psi from 4000rpm to redline (tq from 4000-6000rpm was 380-385 ft.lb)