Jun 272's Vs. HKS 280's 55-60whp!
#61
EvoM Guru
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Originally Posted by Migsubishi
I guess all that high duration is good for the motors being spun upwards of 75-8000rpm, in which top end power through duration is greatly increased?
Long duration cams also make for some more interesting possibilities when playing with cam timing.
#64
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AMS, as soon as you test jun 264's vs hks 272's on factory turbo with factory ecu, i will buy the set that impressed me the most from you. Alson my friend sabastion with the silver evo put some jun 264's in his car that i belive that you did the install and with race gas he put down close to 400 whp ,he had a standalone that you guys tuned but still i want to see the stock ecu. Please help just an average guy like me figure out what im going to do. ooo by the way i have 50000miles on my motor is there anything else i should do to prep for cams?
Thanks
Jason
Thanks
Jason
#65
Originally Posted by Ted B
I know the lift for the Revolver, HKS and JUN. I'm only missing the lobe centerlines for the JUN, which will help to clarify the picture somewhat.
If turbodan has the spec sheets, I can recognize the lobe centerline data when I see it. The 110/115 Int/Exh specs sound believable. That would mean that when installed straight up, the JUN cams are timed like the HKS set at 0/+2.5. The wider LSA would actually create a better idle, but the duration at 1mm for the JUN cams is so long that it will still give a very lumpy idle (as we've heard).
If turbodan has the spec sheets, I can recognize the lobe centerline data when I see it. The 110/115 Int/Exh specs sound believable. That would mean that when installed straight up, the JUN cams are timed like the HKS set at 0/+2.5. The wider LSA would actually create a better idle, but the duration at 1mm for the JUN cams is so long that it will still give a very lumpy idle (as we've heard).
#67
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Thanks for the image. That confirms what we've determined for the JUN 272s:
JUN 272:
Duration: 235 deg @ 1mm Int / Exh
Lift: 10.8mm Int / Exh
Lobe Centerlines: 110 Int / 115 Exh
The JUNs have a wider LSA than the HKS by 2.5 degrees. This tends to smooth the idle and make the midrange a little less peaky, but don't let that fool you. With 235deg duration at 1mm, it's going to have a very lumpy idle and will require a large turbo and stout internals & valvetrain to get the most from it.
JUN 272:
Duration: 235 deg @ 1mm Int / Exh
Lift: 10.8mm Int / Exh
Lobe Centerlines: 110 Int / 115 Exh
The JUNs have a wider LSA than the HKS by 2.5 degrees. This tends to smooth the idle and make the midrange a little less peaky, but don't let that fool you. With 235deg duration at 1mm, it's going to have a very lumpy idle and will require a large turbo and stout internals & valvetrain to get the most from it.
#69
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Originally Posted by LuxuryBroker
do you need an upgraded valve train to run the JUNS
#71
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Originally Posted by EVO8LTW
If they have 10.8 mm lift, then they are comparable in lift to the HKS cams, so I wouldn't think you would need springs/retainers, except maybe to stay reliable above 7500 rpm? I had always understood JUN cams to require springs though
Getting JUN cams? Get the springs.
#72
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Originally Posted by Ted B
The reason why is not necessarily lift, but because the JUN cams have much more aggressive ramps than do the HKS cams. For example, the JUN 272s pack 235 deg of duration at 1mm into 272 deg of gross duration. Compare that with only 214 deg duration at 1mm for the HKS 272s. This means the JUN cams will open, lift, and shut the valves much more abruptly. The stock valvesprings will have a difficult time controlling the valvetrain at high rpm with these ramp rates.
Getting JUN cams? Get the springs.
Getting JUN cams? Get the springs.
(Off topic) are you still considering the revolver vs hks 280 test????
#75
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Hey AMS:
Your power gains with the JUN cams compared to HKS 280s was on a large turbo Evo.
Do you have any dyno numbers with the JUN 272 cams on a stock turbo Evo versus the HKS 280s?
or
Do these cams really need a larger turbo to see effective gains?
Thank you very much.
Your power gains with the JUN cams compared to HKS 280s was on a large turbo Evo.
Do you have any dyno numbers with the JUN 272 cams on a stock turbo Evo versus the HKS 280s?
or
Do these cams really need a larger turbo to see effective gains?
Thank you very much.