The Project Pad

The quick answer is that the more big piping you have, the better it is for the flow... so at least at first glance I'd be temped to say that you should make your 3" transition as soon as possible.

2.5" piping will not really ever start to run out of flow... it will have pressure drops related to flow rate which become impractical at a certain point.

If you give me an approximate flow rate (I usually just go with 1000 CFM), length of pipe, and diameter of pipe, I can calculate the pressure drop for you. Basically the higher the pressure drop, the more differential pressure the turbo sees, and the result is potentially working the turbo at a less efficient part of the compressor map to get your desired boost at the motor.

The only thing I'm not understanding is your 80mm tb (75mm is 3 inch) and why you'd be tapering down to it? You'd really be tapering up. Anyway, just make the transition as smooth as possible and practical.

loxxrider wrote:The quick answer is that the more big piping you have, the better it is for the flow... so at least at first glance I'd be temped to say that you should make your 3" transition as soon as possible.

2.5" piping will not really ever start to run out of flow... it will have pressure drops related to flow rate which become impractical at a certain point.

If you give me an approximate flow rate (I usually just go with 1000 CFM), length of pipe, and diameter of pipe, I can calculate the pressure drop for you. Basically the higher the pressure drop, the more differential pressure the turbo sees, and the result is potentially working the turbo at a less efficient part of the compressor map to get your desired boost at the motor.

The only thing I'm not understanding is your 80mm tb (75mm is 3 inch) and why you'd be tapering down to it? You'd really be tapering up. Anyway, just make the transition as smooth as possible and practical.

pre ic is a 45 deg out of turbo and 45 into ic, ~18 overall length

post ic is about 2 feet with a ~8-9" centerline radius 90 about 8" before tb and a 45 out of ic

yeh i meant to say go back up to 80mm, i was looking at the system backwrads or something ha

so im trying to decide where to go 2.5" >3" in the pre-ic tract

yah lets jsut for 1000cfm to keep it kinda simple

yah lets jsut for 1000cfm to keep it kinda simple

136 in^3 / 2 rev * 7500 rev/min * 1 ft^3/1728 in^3 = 295 ACFM (actual ft^3/min at whatever boost pressure and temperature you are running, assuming 100% VE)

I vote for leaving the exhaust just how it is. It sounds insane! Good work BTW.

40v4kq wrote:I vote for leaving the exhaust just how it is. It sounds insane! Good work BTW.

There will be a 4" dump in this car's future

YES!!! Wheres the "like" button?

With my new (Euro urS4) steering wheel, I had no horn. It eventually started going off randomly about every quarter turn on the wheel to the point where it really wasn't driveable anymore (embarrassing), so I decided to do something about it. I ordered this big washer from McMaster-Carr a few days ago and used it to make a sort of slip ring.

The brass thing in this picture



and this one on the wheel



have to make contact through a slip ring in order for the horn to work. This is the ring I ordered. It came with a 43 mm ID which I had to bore out to 45 mm.



After it was bored out correctly, I also had to make a relief in it so it would sit flush with the column cover.



The horn works like a charm now! All I have to do is glue the metal ring to the column cover and I'll have a nice, permanent solution to the horn issue with the new wheel.

I also got around to installing my V8Q door sills. Don't mind the messy interior. The car is still in major project mode!



I get my intercooler piping in the mail tomorrow, so I am getting my insurance reinstated and getting the title ready to register the car on Monday Then all I need is exhaust!

That was EXACTLY my idea to fix my horn. You beat me too it, lol. Horn is very low on my list. Make two by chance????

Strange that yours would randomly pop off the horn though. I've never had that happen.

Yeah, I dunno why it was doing that. I can give you the part number to the washer. Then you just need a drill and a way to hog the I.D. out. I really don't want to sit there with a dremel for another hour making the extra two millimeters in diameter myself lol.

Haha, I was partially joking anyway. Part number would be cool though. If not, I'll just have my father machine one when he's machining the weld on rings for my strut housings. What is the thickness, I.D. and O.D.?

Check out my project thread guys - I hacked up my stock clock spring to get my Nardi wheel and adapter to work

Reminds me of this practical joke I read about:
A bunch of car guys wired up their buddy's horn to the brake switch. Every time he braked, the horn would go until he lets go of the brake pedal.
THAT's embarrassing.

Lol. That's funny. I'd be using the handbrake until I had time to pull the horn relay.

Looks good Chris! Get that beast back on the road already!!!

Nick, the washer is here: (43 mm I.D.)

http://www.mcmaster.com/#standard-flat-washers/=hsp4dy

Honestly, it is probably better to just have it machined if you can do it easily. You need 45 mm ID and close to 80 OD. The thickness really isn't important as long as you can cut that relief out and still have a surface for that pin to contact. I thought mine was going to be too thick, but it worked out fine.

Good idea Casey, I would have done that, but I threw mine away long ago.

Rough IC piping mock-up. Yes, the hood closes and yes, the new wastegate is going to fit below the pipe.

There are some tight turns in this setup and some very goofy turns near the throttle body... I think in the future I'm going to get a different tb (sorry Hank) and rotate the 4" section coming out of the plenum up such that the upper charge pipe doesn't have to make that stupid drop down to the throttle body. It is all because of my retarded tb choice too lol.

Of course, most of the tight turns seen here will also be able to be eliminated once we break out the welder and start cutting stuff up and all silicone couplers will be replaced by welds or Vibrant Vanjen connectors.

That really looks awesome!

Nice that is a hot air intake no? My only problem with the 3b style mani, you're superheating that pipe above a header

It does look wicked

JonathanL wrote:Nice that is a hot air intake no? My only problem with the 3b style mani, you're superheating that pipe above a header

It does look wicked

The OEM heat shield does a great job at keeping that pipe very cool. Mine is always cool to the touch unless the car is sitting still.

Yep, heat shielding is the key!

Ordered all my stainless bends and straight, new vband, flex pipe, nice reducer, etc.

Fab is going to happen next Monday

:woowoo:

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