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Discussion Starter #81
Its funny about this mod. I thought it was pretty silly until we did it on Josh's car. Now with Jeffs R32.4, and the times I have driven that with the "surge monster" GT-RS turbos on it, it doesn't surge. I haven't done a lot of cruising in it, but I would hear surge in the first 30 seconds of driving other GT-RS cars with no split outlet pipe.
 

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Sean, is that car a 2.8 stroker? Cause if it's a 2.6 or 2.7 overbore, and GT-RS ain't shufflin' on it, I might go put those in!
 

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Not that I doubt of it being better than stock but it would be interesting to measure the difference in airflow through them ie. puting them on a airflow test bench.
 

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they would flow the same but the front turbo air would not go in two directions, it'd just go out the exit as it should.

Front turbo air meeting the rear turbo flow at 90 degrees, what was Nissan thinking?

I hope this reduces the workload on the rear turbo.
 

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eeemm... dont think so, if you achieve a better flow pattern, air velocity increases thus increasing overall airflow. So if one of them doesnt (90º design) have a "good"flow pattern (turbulence) then air velocity decreases... etc etc. you know.
Just put em on a bench! hehe
 

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they would flow the same but the front turbo air would not go in two directions, it'd just go out the exit as it should.

Front turbo air meeting the rear turbo flow at 90 degrees, what was Nissan thinking?

I hope this reduces the workload on the rear turbo.
What you flow in must flow out - so if you were pushing some of the front flow rearwards then rear flow would be reduced. It makes no sense to say it would flow the same but be better!
 

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Discussion Starter #88
eeemm... dont think so, if you achieve a better flow pattern, air velocity increases thus increasing overall airflow. So if one of them doesnt (90º design) have a "good"flow pattern (turbulence) then air velocity decreases... etc etc. you know.
Just put em on a bench! hehe
I don't drive or race a flow bench.

However on a car, it was worth about 10 whp. Not only that the surge was noticeably better.
 

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10whp, no kidding, and all I was looking for was some better pickup :)

I've got -5s which did surge when the map was off, but I sorted it out. On my car, -5s surge when the season changes and you haven't changed the map to compensate. I've now got my three maps for winter, spring/fall, and summer.

Maybe the best way to think of it is a way to reduce parasitic power loss, although it's technically not parasitic as it is an inefficiency, making a part (rear turbo) work harder than it has to - or diminish the work it does perform.

Rear turbos tend to die first. Partly the heat from its location, partly fighting the front turbo. Would be interesting to see if this mod extends the life of a rear turbo - but that'd be a long term test, and too many other factors to say for sure. But it seems like it would.
 

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another reason...

Another reason this may help the rear turbine relates to the same thing as the lift/vacuum generated over a flat surface when you apply air over it.... Dynamics of Flight 101-lol, IE- take a piece of paper hold it by it's edge, so your arm is elbow down, hand up, fingers pinching the edge of the paper, with flat side of course laying against your arm and facing up... then blow across the TOP, NOT under the page... the paper lifts. The front turbo has only moved it's compressed air a few inches so its air speed will be slightly greater than the rear. The upgraded divertor plate sends it forward, the air flows across the plate and meets the slightly slower air from the rear turbo and gives it a little pull/vacuum to draw rear turbine air forward, drawing it into the flow of the front turbine... Unlike the Nissan set up that creates a wall of air and pressure that the rear turbo has to fight FIRST before it can be actual pressure applied at the intake valve. The Japs were only trying to make a 300 horsepower car... they didn't expect us round eyes to start playing with their GOD... ;-)
H.
 

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Would there be any worthwhile difference between the modified pipe compared to the Nismo and the Apexi setups? They merge alot smoother then the stocker.
 

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You do this to keep a stock look under your hood. AND go about it the less expensive way too! If you have a friend that welds alum' and got urself couple hours it might cost ya 5 pound, 8 dollars and a 6 pack of good brew.... HKS/Nismo will cost ya some weeks waiting, and a WHOLE bunch of dollars.. but it's your choice. I already polished my turbo outlet pipe, and like the look of it with the HKS hard pipe kit and polished intake..
 

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is it just me, or does the car "feel" slower with this mod, simply because the power delivery is smoother and they're less of a "hit"? I've been wondering if I were running slower (over 8 seconds to 100mph from a stop, felt like), but I had no timing gear, and when I'd let off the throttle I was hauling ASS.
 

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Discussion Starter #94
is it just me, or does the car "feel" slower with this mod, simply because the power delivery is smoother and .
Don't smoke weed, and then go on test drives.

From my test on it, the power was about exactly the same until the upper rpms. I would say you really couldn't feel it much.
 

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Would there be any worthwhile difference between the modified pipe compared to the Nismo and the Apexi setups? They merge alot smoother then the stocker.
Hi buddy,
where did you find these setups? All I find is intake to the turbo but not from the turbo to the intercooler.
cheers,
joe
 

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Hi buddy,
where did you find these setups? All I find is intake to the turbo but not from the turbo to the intercooler.
cheers,
joe
Or buy one of these for £70, (+£30 deposit until you return your pipe). ;)
 

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They both - Nismo and HKS look like very expensive pieces of aluminum pipe. I suggest you modify the stock twin turbo pipe, and take the rest of the money, and donate it to single mum's down at the local gentleman's establishments.
:)

Yes they are very expensive, look vastly overpriced IMHO. But forgetting the price for a moment (which I admit is hard), looking at the designs you would expect these to be better than the modified TT pipe as there is a smoother path for air flow. My question is, how much better are they (and I assume there's not much in terms of performance to choose between the Nismo and HKS).

Cheers,
Kingsley.
 
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