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Who on here has an exhaust dump installed?

I am looking into using a McCord MPP2 Electric exhaust dump...BUT. My downpipe, as well as cat-back is only 2.75". Which I would like to keep it that way for noise reasons. Now the problem, McCord only makes 2 1/4" 2 3/8" 2 1/2" and 3" dumps.

Now, what I am thinking of doing is buying this 3" manual exhaust dump:



And then getting reducers welded on each end to make it fit on my 2.75" downpipe. I could fork out the $300-$400 to get a 3" downpipe made for my car but I do not think that will be worth the minimal gains between having a 2.75" with open dump and 3" with open dump. With the dump closed I am perfectly fine with the 2.75" exhaust as it is really quiet.

Is there anything wrong with using reducers to make the 3" dump work with my setup??

Here is what the McCord electric dump looks like: (attaches to opening of a manual exhaust dump)



Thanks.

 
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Eh? I am not sure what you mean. Elaborate.

 
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Oh , now i get what you mean. Considering the MPP2 dump only costs $110 I would rather just use that instead of using an old throttle body,welding a flange to the throttle body, and wiring up an electric motor and switch. Especially since the materials, motor and wires have been tested to withstand 1600F temps.

But I do have a couple throttle body's lying around, I may actually try that out so I can sell it.

Anyways back to my original post....

 
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Well, US dollars.

$27 for the manual one, and $110 for the electric add on.

 
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Those look pretty sweet. I dont know anything about them , but I do know a bit on the manuals .
They are usually really freakin hot when you want too open em up.
The gaskets blow out .
Also , how low is your car??,
And where are you going too mount these things under the car , like accessibilty problems??.
Are you going too have too jack it up too open the manuals.
Just a few thoughts..77.

 
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No need to go under the car. All I will be using from the manual dump is the piping itself. Instead of using the block off plate the bolts on/off I will be using the MPP2 electric dump which will be controlled by a switch from inside the car.

Ground clearance, currently my car is really en low, to low. But I am changing suspension setup this year so it will sit a bit higher. The dump will be welded onto the downpipe right before the cat.

Since nobody has really freaked out yet, I guess it will be alrite to use my "ghetto" 2.75" to 3" setup...

 
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I get it now . I thought you were comparing/deciding between the two set ups . Like I said the electric ones look sweet. I dont think the difference of a 1/4 inch dia. is going too make much difference. Its only going too be like 8 - 10 inches long section ??..77.

 
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its not ghetto at all your just working with what you got....and i think it should work out ok ......yea those electric ones kick ***.......i helped a guy at the track one day with manual HOLY ING PAIN hotter then hell no room to work blah

 
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If turbocivic wouldn't be so lazy, he could chime in an dtell u all the wonderful problems he's had with his electric dump...

What a diaster... he's had to replace the motor4-5 times already beacuse something always melts.

 
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Honestly I wouldn't bother with any of these dump tubes at all. Do you really want to go through all this crap for minimal gains anyways? Not to mention having an obnoxiously loud exhaust? With muffler technology that it is today the HP gains by going open really isn't worth it IMO. Save your $110 and go with a bigger DP instead.

Lots of cars going 9's, 8's, and even 7's with mufflers these days.

I prefer being a silent assasin.

But to answer your question about using a reducer to go from 2.75 to 3 inch is completely fine, you need not have to worry about any cost in performance if that's what you're thinking. There are exhausts out there that are reduced from 4 inch to three inch (i.e. 4in DP to 3in midpipes/mufflers).

 
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Yea I know what you mean. But the MPP2 dumps are a new design with different motors. They also open considerably faster than the old design McCord had.

4" DP with a 3-4" cat back will make my exhaust to loud for daily driving (to my ears anyways). I don't like the attention you get with cops from a loud exhaust. This way I can control when the car is loud or not.

Minimal gains? Average gains are 20ish whp. Although a buddy of mine gained over 50whp just from running open dump on the dyno.

Anyways I really don't think switching from 2.75" to 3" down to 2.75" again will effect much so that is what I will do.