JMFab o2 Dump
heres a pic JM sent me through email:
The larger Turbine tube on the design is where they saw the huge increase in power gains. they do neck down to 2.5 inches because EVERY single downpipe necks down to 2.5 inches at the O2 Housing flange. It is a fact, so they had to go down to 2.5 inches unless they built their own downpipe to sell with their O2 Dump. That would not have been cost effective for the end user/buyer, for everyone that bought the product to also Have to purchase a new downpipe.
The JMFab design has a straight turbine tube, take a look at it, the differences with EPM design is that EPM turbine tube has a unique 3 inch CLRadius which to the eye is a super smooth bend. Unlike JMFab's staright turbine tube, in that the exhuast gases Slam into the back wall of their turbine tube.
The JMFab design has a straight turbine tube, take a look at it, the differences with EPM design is that EPM turbine tube has a unique 3 inch CLRadius which to the eye is a super smooth bend. Unlike JMFab's staright turbine tube, in that the exhuast gases Slam into the back wall of their turbine tube.
The JM Fab piece uses a 2.5" tube straight through. While not as big of a diameter it has one continuous diameter and no abrupt transitions. This makes more sense to me and is how I would build them.
There is nothing unique about 3" on 3" CLR tube. We've been using them for years on our exhaust pieces.
If the 3" tube is welded straight to the flange with a 2.5" diameter outlet there is no necking down. It would be an abrupt transition and flow very poorly. Can someone verify this?
The JM Fab piece uses a 2.5" tube straight through. While not as big of a diameter it has one continuous diameter and no abrupt transitions. This makes more sense to me and is how I would build them.
There is nothing unique about 3" on 3" CLR tube. We've been using them for years on our exhaust pieces.
The JM Fab piece uses a 2.5" tube straight through. While not as big of a diameter it has one continuous diameter and no abrupt transitions. This makes more sense to me and is how I would build them.
There is nothing unique about 3" on 3" CLR tube. We've been using them for years on our exhaust pieces.
cb
There is a transition from the 3" pipe to the flange on the EPM part, but there is a lip on the inside of the flange as Chad stated. The transition doesn't reduce the size all the way down to 2.5" as it is on a bias. I believe 2 different full 2.5" designs were tested and both made less power than the final 3" design that was decided upon.
I agree that a lip on the inside of the lower flange is not ideal, however testing showed that it did not influence the performance of the part. It's simply one of the compromises made due to clearance and 3rd party DP compatibility.
I hope this helps clear up some questions.
I agree that a lip on the inside of the lower flange is not ideal, however testing showed that it did not influence the performance of the part. It's simply one of the compromises made due to clearance and 3rd party DP compatibility.
I hope this helps clear up some questions.
Last edited by TouringBubble; Dec 5, 2008 at 08:10 AM.
cb
one other thing,
with competitors parts we have seen a leak between the two sides of the turbo, the WG port side and the turbine outlet...
or they supply a crappy gasket that doesnt seal or some spray... at idle they leak through the dump tube, basically an exhaust leak..
these dont...
food for thought.
cb
with competitors parts we have seen a leak between the two sides of the turbo, the WG port side and the turbine outlet...
or they supply a crappy gasket that doesnt seal or some spray... at idle they leak through the dump tube, basically an exhaust leak..
these dont...
food for thought.
cb
lol think you said you loved them enough?
like i said i'll do a comparison soon when i get my hands on them.
looks like we got some jmfab fanboys.
and some to EPM.
no need for fights when both had not been tested to confirm what makes more power.
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JM FAB doesnt get the credit they deserve and seem to get overlooked at times....i know i would have went with this design instead of a competitors if i had known at the time......o and there stock turbo ex mani is badass
if you a preference by all means, make ur choice... but, we do quite a few evos
and tend to know what fits and what doesnt...cb