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Discussion Starter #1
Anyone, Has Magnuson solved the lift to shift issue? Anyone get there feet wet with Edelbrock SC yet? I am looking to buy a twin screw and the Edelbrock price looks nicer than Mag just not sure why
 

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I was unaware that edelbrock is coming out with a SC for the 3.6 wrangler. they have a good SC setup for other applications hopefully it will work well here also.
 

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Discussion Starter #3
yea, i just spoke with them. They claim to have no issue with shifting in automatics. They just told me they start shipping the end of this month. I hate being a ginni pig
 

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Over on the JeepLab forum, I heard that the latest tune from Magnuson solved the driveability issues, and is now "nearly flawless".
 

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Endelbrock SC

A couple of things I have read about the Endelbrock SC, the stock oil filter can be used and they offer a 100K drive-train warranty. I'll have to save up my pennies :)
 

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Discussion Starter #6
im searching for best pricing on the Edelbrock now. I think that is the way i will be going
 

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Edelbrock has a dyno chart on their website but it's only for 4,000 RPM and higher. And it doesn't look much better than stock below that based on the curve.

I'd like to see the real results from idle to red line before I'd take an Edelbrock over a Magnuson. The Magnuson has quite an improvement in off idle torque and that's what I would want in my Jeep. I don't care about what it does near red line since I rarely run the engine that high.
 

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Both of these FI systems will have minimal effect on torque and hp below the point where the boost builds high enough to close the bypass valve. Wherever that point is, typically somewhere around 3K+ RPM and below, the supercharger is basically free spinning to reduce parasitic loss and produces no extra power below that point allowing the engine to function normally in day to day normal driving. Above that is where the extra power is produced
 

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The bypass valve closes in response to manifold vacuum, not engine speed.

Both Magnuson and Edelbrock use the same core supercharger unit (Eaton TVS 1320), which is a roots/twin-screw hybrid, and can make boost at low rpms... if you push down on the skinny pedal enough to close the bypass valve.


 

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I guess I should more specifically say that bypass valve does not require boost to cause it to close. The supercharger is capable of producing boost throughout the rpm range, but the bypass valve being open prevents it from producing boost. Manifold vacuum approaching atmospheric pressure (pushing the pedal down) is what closes the bypass valve to allow boost to be produced.
 

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Intake runners and intake restrictions have a large bearing on the power curve as well. I think tuning will be the separation between the power and drivability of the two.
 

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oops... I posted an old version of that boost curve chart. Here's the updated version, using the latest tune from Prodigy:

 

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Where did you get that from? that looks nothing like our curve.
I found this dyno chart of a RIPP supercharged Wrangler that includes boost in the chart:




I can't remember where I found it, and can't find the original source again now, but it was very clearly presented as a dyno chart of a RIPP supercharged wrangler.

The boost curve nearly perfectly matches a quadratic curve.

Since your website states that the optional high altitude pulley produces 9-11psi, I assume this chart is from a kit with that pulley (10 psi peak in the chart). Your standard kit is marketed as 8 psi, so I represented the standard kit's boost curve as a quadratic curve that peaks at 8 psi at redline.

If this does not accurately represent your kit's boost curve, I'd love to see what it really looks like.

BTW - here's Magnuson's chart that I pulled their boost curve data from:

 

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I found this dyno chart of a RIPP supercharged Wrangler that includes boost in the chart:




I can't remember where I found it, and can't find the original source again now, but it was very clearly presented as a dyno chart of a RIPP supercharged wrangler.

The boost curve nearly perfectly matches a quadratic curve.

Since your website states that the optional high altitude pulley produces 9-11psi, I assume this chart is from a kit with that pulley (10 psi peak in the chart). Your standard kit is marketed as 8 psi, so I represented the standard kit's boost curve as a quadratic curve that peaks at 8 psi at redline.

If this does not accurately represent your kit's boost curve, I'd love to see what it really looks like.

BTW - here's Magnuson's chart that I pulled their boost curve data from:

Looking to see if we can get a clear chart up for you.
Typically, our systems(3.6L) are making @5 PSI at 3000RPM. About 3psi at 2000 RPM.

RIPP
 

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Discussion Starter #16
Ripp let me pay my respect your system is awesome. It appears to me you guys have truly pioneered the way for all others. I am simply rolling with my gut here when i say for MY jeep I am leaning towards a twin screw. From my experience and seat of the pants knowledge, the twin screw doesn't have the lag that a turbo or centrifugal charger has.
 

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Ripp let me pay my respect your system is awesome. It appears to me you guys have truly pioneered the way for all others. I am simply rolling with my gut here when i say for MY jeep I am leaning towards a twin screw. From my experience and seat of the pants knowledge, the twin screw doesn't have the lag that a turbo or centrifugal charger has.
That is totally understandable and respectable. In no way are we trying to hijack this thread. Just questioning the info that was posted about our product.
Best wishes with whatever system you choose and see you on the trails!:thumb:

RIPP
 

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I'll own up to being the one that derailed the thread. I should have just posted the original Magnuson dyno chart with boost curve to make my point that the Magnuson makes significant boost at low RPMs (to counter the claim that it doesn't produce gains until around 3000 rpms). I was lazy and just posted the comparison chart because I had it pulled up in another browser window at the time.


Back on topic... Edelbrock really needs to put more effort into producing a good dyno chart:



What's up with the baseline ending around 5700 rpm when the engine revs to 6500? Why is the baseline peak power at only 5600 rpm when it is pretty well known that the stock engine has its peak power right at/near redline (6500). Why does this chart start at 4000 rpm? Let's see the low rpms!

I know that the answers to these questions are likely related to:

1) The stock electronic speed limiter shutting down the baseline dyno early. Solution: install the "modify stock tune" option from the Diablosport tuner and raise the speed limit before doing your baseline!

2) Automatic transmission will just downshift if you try to do a dyno run from low rpms. Solution: use a manual transmission Jeep to create your dyno charts marketing material!

I doubt that the Edelbrock truly has minimal gains around/below 4000 rpm as indicated by this chart. That's likely just a side-effect of starting the dyno run at 4000 rpm and pressing the throttle smoothly/slowly enough to avoid a downshift.

I would expect the overall character of the torque/power curves to be pretty similar between Edelbrock and Magnuson. It's going to come down to a difference in tuning and bypass valve hardware.
 

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I'll own up to being the one that derailed the thread. I should have just posted the original Magnuson dyno chart with boost curve to make my point that the Magnuson makes significant boost at low RPMs (to counter the claim that it doesn't produce gains until around 3000 rpms). I was lazy and just posted the comparison chart because I had it pulled up in another browser window at the time.
Yes I made that claim that the SC produces minimal gains under 3K RPM (....the edelbrock chart you just posted starts at 4K....lol but that is just their crappy chart) The previous vehicle I had when going FI there were minimal power gains to be had under 3K so I mistakenly assumed that was typical of all SC, but that was a very different beast with 2 more cylinders and not applicable to this situation. I apparently I ruffled your feathers with that remark that was not my intention. I look forward to more information about these superchargers as I would love to put one on my wrangler.
 

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The previous vehicle I had when going FI there were minimal power gains to be had under 3K so I mistakenly assumed that was typical of all SC
No feathers ruffled here.

That's a common mistake to assume that all superchargers have similar boost curves, or effect on the torque curve throughout the RPM range. There's centrifugal, roots, twin screw, and variations of roots/twin screw (likely more that I don't know about), proprietary patented designs from specific manufacturers, etc., all with different boost curve and efficiency characteristics.

Magnuson and Edelbrock both use the same Eaton supercharger unit that is considered to be a roots/screw hybrid, so the charts I posted for the Magnuson boost curve should be pretty close to what the Edelbrock will do.

Keep in mind that the boost curve isn't everything. Efficiency is important too, and efficiency is not constant throughout the rpm range. For example, at some given engine speed product "A" could make more boost than product "B", but also be less efficient at creating that boost, which would cause intake air temps to be higher (hot air is less dense, less combustion energy available, may require more conservative tuning to avoid knocking), and also cause more parasitic loss to drive the supercharger, resulting in product "B" actually producing more net power to the wheels at a lower boost level.

In the end, the most valid objective performance comparison we can hope for is a dyno chart from the same type of dyno comparing net wheel torque/power curves of the different kits.
 
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