the Dune Buggy Archives
DBA Forum - Not logged in
Previous Next Up Topic Engines / Subbug - Subaru Power / Vacuum Plumbing Sizes? (9937 hits)
By @Jeff GS Date 2009-12-01 00:19
Starting to get into the nitty-gritty of the engine plumbing process.  I need to order up some vacuum tubing for the various ports on the engine and turbo and wondering what others have used?

As of this point is look like I have at least (4) different sizes I need to contend with:
Fuel Pres. Reg. and 2 ports on the intake measure in at 0.153" OD.
Turbo wastegate and pressure port connections are 0.186 & 0.190" OD.
Samco BOV is 0.235" OD and large port on the intake is 0.260" OD
Last is the MS MAP sensor @ 0.125" and guessing the connection on an Autometer boost gauge is also 1/8".

I want to run a quality silicone vacuum tubing for these functions, but these appear to come in mostly metric sizes (along with all the hype of why one brand is better than another, hose thickness, curing process....).  Doesn't seem like the metric sizes available cover very well the sizes I measured?
3mm is close enough to 1/8, that seems OK.
4mm (0.157") seems a hair big for the FPR to intake connection, but too small for the larger turbo fittings?
5mm (0.197") again too big for the turbo fittings?
6mm (0.236") might work OK for the BOV to intake?

Any advise here?  Looking for a nice snug fit that won't leak or blow-off under boost!  Where did you buy your hoses?

By @Jeff GS Date 2009-12-02 00:48
Well, shooting from the hip here...
I took the plunge and ordered some 3.5 and 5mm hoses.  They "might" work for just about everything??  Guess I'll find out when they get here.
I had some old 3/16" tygon tubing I test fit on some of the larger fittings.  It would work on the turbo and BOV/intake fittings, so hoping the 5mm hose will work as well here.
The 3.5 seemed to be the best compromise for the smaller fitting sizes.  I'll still have to get something else for the MS fitting, but we'll see how these work first.

Also found out my exhaust header is finished getting coated!  Yooo-hooo!!  I'll be picking it up on Thursday and can't wait to see it - finally completed!

By Terry F Date 2009-12-02 05:37
I've used these guys, no troubles what so ever...

By @Jeff GS Date 2009-12-02 12:26
Yep - dropped about $80 with them yesterday.  Good (silicone hose) selection and good quality.  Boostcontroller has really long leg elbows available, these can come in handy when you don't want to piece multiple sections together with connectors, clamps, etc.
I also use Treadstone for some items too - namely my aluminum intake tubing (really nice quality stuff) and some silicone elbows and straight pieces.

By Terry F Date 2009-12-02 21:44
Just took a look at the Treadstone site, looks like a great source. Thanks. -Terry
By @Jeff GS Date 2009-12-04 21:49
Got the hoses today.  5mm works very nice for the large intake BOV fittings.  3.5mm is perfect for the turbo and W/G, but I think a little too large for the others.  Hose is nice and stretchy, so need to go a bit undersize to get a good tight fit.  I'll have to order some more hose for the smaller fittings, but probably a toss-up between 2.5mm or 3mm.
I've got 1/4" fittings on the coolant catch to overflow tank and vent, the 3.5 works nicely for that so sure some will end up on there as well.

Just when I'm excited to start re-assembling the freshly coated header, turbo and more plumbing on the engine they're calling for snow!  :-(

By Jay H (X-20) (ManxVair CC) Date 2009-12-13 17:14
Winter fact #1: it's difficult if not impossible to build good boost on snow covered roads. :-)
Don't ask me how I know.

By @Jeff GS Date 2009-12-14 21:16
Got any "Proof" of that statement?  Some nice action photos would do it....  :-)
By Alden A 305 Date 2009-12-14 22:35
Yeah.... What Jeff said.......Prove it!!!!   :-)

Did you seriously get the buggy out in the snow?  I dont believe it... I need some proof...
Mattoon Illinois
By Jay H (X-20) (ManxVair CC) Date 2009-12-23 02:31
I had it out last year... All I could do was doughnuts. Seriously..... I was doing doughnuts in the back yard while two of my buddies were doing doughnuts on their quads. The rear tires gave plenty of floatation and in 4th gear they spit out quite the rooster tail. I wish I had it on video. Very little boost even in 4th gear! :-)

Previous Next Up Topic Engines / Subbug - Subaru Power / Vacuum Plumbing Sizes? (9937 hits)

Powered by mwForum 2.10.2 © 1999-2007 Markus Wichitill