Unequal Length charge pipes?

NYSpeed Automotive
1

Cliffs: Any major drawbacks to merging hot charge pipes of unequal lengths?

Scenario: Parallel TT on a V8, small frame oil bearing turbos, 1.8ish Pr, BOV on the cold pipe, and individual DPs / exhaust.

They do make TT FMICs with twin inlet single outlet such as: http://store.max-redline.com/servlet/-strse-141/Twin-Turbo-Intercooler-27"x13"x3.5",/Detail
However it’d be pretty damn hard to route the cold pipe.

The other option is to use an already available “standard” FMIC with single I/O per side. To do this I’d run the psngr hot charge pipe forward and across the engine and merge it with the drvr pipe with an almost parallel joint. From here into the FMIC.
It’d be (2) 2" pipes into (1) 3" pipe, so there is no loss in surface area - actually a 10% increase.

Herein lies the rub: The psngr hot pipe will be ~2.5’ -or- 0.06 CU FT (engine drawing 400 CFM full tilt) longer then the drvr pipe. This will create an imbalance in volume / mass on spool-up as well as throttle closure. My question is will this imbalance actually be enough of an issue to be concerned about?
Cause the passenger cyl bank to choke up relative to the driver cyl bank?
Uneven turbo shaft & bearing wear I’m not too concerned about…

2

short answer: no.

3

semi long answer. It’s not this simple , because you’re dealing with compressible flows, but this will give you a feel.

At 400 CFM, that’s 200CFM/turbo.

At that flow rate, the time required to displace .06CU Ft^s is .018 seconds.

4

However, have you thought about running the charge piping like this:

http://img.photobucket.com/albums/v516/ctnewman2/TT_PLUMB.gif
TT_PLUMB.gif600×600

5

that looks like an upside down uterus. just saying.

6

PB is blocked.

Thats about what I came upwith as well, but I’m still not fully operational yet this morning so I wanna make sure Im not missing something. The only thing I could really come up with to be afraid of is a cunt hair of extra back pressure on the passenger head by slowing up the comp wheel on transition.

It’s going to be ~22#/m / turbo on the hot side (~180*) @ full tilt.

7

So I assume you’re Y’ing them even length? That would be a bit of a packaging concern as it would lead to a tight 90* (effectively a 180* for drvr turbo) almost right off the Y.

8

dif hosting:

http://onyxsyndicate.com/newman/MISC/TT_PLUMB.gif
TT_PLUMB.gif600×600

9

I realize that you can’t mirror a turbo like I did, but having a 180 degree silicone elbow won’t really hurt flow, and they’re compact.

10

eeehhhhh. Interesting for sure. At first glance it seems overly complicated relative to the gain of even length. It also presents another (minor) concern of having the restriction (IC) more upstream for one turbo then the other… bringing us back to effectively square one. :lol:

I’d rather keep the powerstroke intercooler as well since its a pretty nice / efficient unit. You’re sketch also presents a routing problem as there isn’t alot of room in the nose of the car – the upper pipe set would be running into the header / light panel.

for reference:

http://www.toohighpsi.com/Ericmustang/Images/ericmust30.jpg

11

http://www.pegasusautoracing.com/productdetails.asp?RecID=2079

http://www.pegasusautoracing.com/Images/M/E135-51.JPG

12

I really think you will be fine. The skyline has differing length charge pipes, to a lesser extent, and almost all factory turbo cars have unequal length exhuast manifolds, so I think you’re getting a little hung up on it all.

13

haha - trust me I’m not that worried - almost all of the components are throw-away common / cheap, just asking if I was missing something. Tks tho.

14

I know all about overthinking things…