I dont. I basically made them as long as I could. For what the project is, it probabaly wont really matter much how long they are. My wife will never know the difference.
Dan
I you want, you can use simple Helmholtz Theory to calculate it. As an engineer it’s not perfect but it’s better than nothing.
Right. Im not too concerned about it though.
Runners are all cut to length and ready to flare. Also bent up a mount for the oil cooler.
More on those later.
Dan
I would shorten them a little for packaging reasons. you are awfully close to the rad and it will make getting at things difficult later on.
well all know that longer runners make more torque, but once boost is in the picture, it throws alot of that N/A based theory right out the window. plus the VW 16v setups of that era are revvers. it would be a shame to hamper what they are already good at by making the runners longer and trying too boost torque down low, and killing some of that top end scream in the process.
then again the stock runners on those motors were mega long so i could be full of crap. 
Brian
They are a little shorter than in the pic. In the pic I was just sorta holding the plenum on the runners (which were not yet cut to lenght or flared, and prob went almost all the way thru the plenum).
Anyway, they turned out 4.5" long, which is prob 1/3 the lenght of the stock runners, at least half. And yes, the 16v is def a reving screamer, so I dont think these runners are going to be hurting that at all. If I was leaving them 12" long, or making them longer you could def scold me, haha. I think these will be just fine.
I should prob have about an inch of clearance between the plenum and the radiator. Mabyee we’ll find out tonight!.
Dan
Made the oil cooler mount today. I still need to make a tiny scoop for the bottom of it, and some metal mesh to protect it from road debris. But the basic shape and placement is done. I will add real hardware to bolt it to the car once the lower core support work is done. (the little single phillips screw wont stay).
I may also add a small strut at the bottom to keep it from swinging around.
And it doesnt hang low, its acutally about 1/4" higher than the front lip spoiler.
Dan
3191
yeah the pic makes them look like 12" long
Brian
Ok, well incuding the section of the lower intake that I am welding the new runners to, they are max 6" long. I sorta forgot about that yesterday.
And yes the angle of the pics and the fuel rail in the way etc makes it look much longer.
Dan
Great fabrication. I really like your builds.
Keep up the good work :tup:
I finished up the Megasquirt assembly today at work. So that is all ready to go.
Also some goodies showed up yesterday and today: BOV, silicone couplers, clamps, charge pipe and exhaust tubing, and a couple of vband assemblies.
I also machined the fuel rail for the hold down straps and machined up the straps quick too. I just need to trim the one end to lenght and TIG them to the intake.
I managed to mess up one of hte runners trying to flare it so Ill have to get some more tubing next week and redo the one. Hopefully I will be at least starting to tack the intake together by tues/wed.
Dan
Finished welding the AN bungs on the fuel rail.
I machined the threaded part of the RMR cup off and bored it down so the bung would sit almost flush before welding as I needed the clearance to the head.
I also finished welding up the exhaust mani. I still need to clean it up inside where the flange box meets the tubes.
I welded a Vband ring to the turbine housing outlet… F a flange.
Also, made a mounting plate for the WG actuator. I needed to move it back some so it could clear the shock tower (also hides it nicely under the compressor). Its sort of held together with random bolts right now (and missing a couple) I just need a couple standoffs and the correct hardware. I then cut, rebent, and rewelded the acutator rod, which seems to work nicely with the hand vac.
Mani and turbo mounted (notice the nice wg clearance now). Also you can now see how the charge piping is going to route.
Next up is finishing the intake manifold. The 2.5" live center that I bought to use as a flaring die for the runners is due in today or tomorrow. Once I have them flared I can more or less weld the whole thing together.
More to come.
Dan
lookin sharp!
Holy shit, Dan. You’re getting good with that TIG. :tup:
^ Im getting pretty decent with it. Still have a long way to go…
i need to learn how to weld
Looks great Dan!
awesome as always man!
another spectacular display of your fantastic craftsmanship, keep up the good work!
Impressive, I am very interested in how you are going to flare the manifold runners, please take pics of how you do it
in! I cant believe I have never seen this thread.