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PostPosted: Mon Apr 18, 2016 8:15 am
by Litle brother
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Re: Mod-S cam VS 3.8 RSR cam in a 3.2 short stroke

PostPosted: Thu Apr 28, 2016 1:12 pm
by scarceller
The first ModS cam closes the intake valve at 52deg ABDC
While the second closes the intake at 65deg ABDC

If you do not up compression when using the more aggressive 2nd cam you won't like the results. The 2nd cam at 65deg ABDC will not have enough dynamic compression to achieve peak torque.
I also suspect it will not work well on a static compression of 10.3:1 but the first cam with 52deg ABDC should do OK at 10.3:1
The 65deg ABDC cam needs more compression to achieve a decent level of dynamic compression.

When you select a cam it's very important to select the correct static compression for that given cam.

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PostPosted: Thu Apr 28, 2016 9:51 pm
by Litle brother
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Re: Mod-S cam VS 3.8 RSR cam in a 3.2 short stroke

PostPosted: Fri Apr 29, 2016 5:31 am
by scarceller
At 10.3:1 that first cam is the better choice. Please do post back results.
Best of luck.

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PostPosted: Wed Nov 08, 2017 12:57 am
by Litle brother
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Re: Mod-S cam VS 3.8 RSR cam in a 3.2 short stroke

PostPosted: Wed Nov 08, 2017 7:54 am
by Steve
Porsche driveline losses are 12%.

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PostPosted: Wed Nov 08, 2017 4:25 pm
by Litle brother
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Re: Mod-S cam VS 3.8 RSR cam in a 3.2 short stroke

PostPosted: Thu Nov 09, 2017 3:04 pm
by Steve
The 12% is what I measured after running several engines on our engine dyno, followed by running the same engine in the car on a Dynojet chassis dyno. Those are THE best ones to use for power measurement since the operator cannot do anything to skew or affect the results.