Thanks for the compliment, and yes, I could have done that, and I am sure I could have done a lot of different things too, but that intake does not meet my criteria; in fact it does not even come close.

Yes, Martin. Although I didn't write much about it, that is the reason I made the inside bottom opening of the bell mouths a little larger than the inside diameter of the 2 inch 16 ga tubes, so I could do just that--flare the upper end of the tubes to give a sort of "easement" into the tanget. I Learned about easement curves in my early railroad days and have given the concept a lot of thought in respect to how I design some things.

I cut the inlet ends of 7 of the tubes off at the length that I finally decided on. The very front one, and maybe the second one back, are going to require a bit of the 90 degree bend to be removed so as to raise the inlet end up a bit off the floor of the plenum. The tops will still be in the correct sloping plane, but the bell mouths will not exactly line up with the rest, which wont effect anything that I can tell, except the length, but only by about 5/16 of an inch, although I have not yet cut the very front tube, so I can add as much length as I might need to even it out. The front tube, the "A" tube as I have it marked, is the one I cut originally and that I cut off right at the top of the bend. I still have the raw tube bend for this one and will cit it with more of the straight tangent tube on the upper end, out to where the bell mouth will need to fall.

I think this intake is going to meet my first criteria which is to FIT under the 928 hood when it gets lowered. That aspect of this effort was pretty much based on some careful design and planning. The next part of the FIT criteria will be to fit the other stuff around and under it that I will need to to make it work.

The next criteria is FINISH. (I don't intend the caps to represent shouting, but rather just boldness.) It looks like finish is going to be much more organic in nature, although there is some design necessary for the plenum, but even that is turning out fairly organic. I have changed the sides from being at a 45 degree angle to being 60 degrees, mainly because of the need to clear the fuel rails at about where the sides will need to "turn north."

I still plan to use the S4 TB and that is going to fit under the intake in its usual position, but I am not too sure about the MAF. I am going to use the original one, but I may have to articulate it a bit and maybe move it back some to fit under my plenum, but I don't think that is going to matter since I am sure that I am also going to need to design and fab a completely new air filter box. If so I think I can design it around wherever I move the MAF, at least if not too far.

Then I'm going to have to design and fab the method of getting the air from in front of the engine to the air filter box. That will have to be in the same location as the original, but also low enough to clear the hood. It may also be a little different at the front ends on top of the radiator, but I think not too much since the radiator is likely to be custom and not as tall as the original.

Jerry, nice work as always with the intake, however I am writing to you about your back. I've had three spinal operations and they are not for the faint of heart. I hope they have mentioned the risks because they are very real.

As I have no idea what issues are troubling you, I will just be general in advice. Get a second opinion, make sure it's the same as the first opinion. If it's not get another opinion. You can't undo the doctors errors. Hence the required caution. When I started seeing surgeons there was several worrying aspects. They said I may make you worse. They said I can't fix everything wrong with your back so we have to pick the worst issues to address.

Because of the area my wife works in, she hears about the ones that go wrong. Sometimes quite young ones, she was recently dealing with a fellow who went in for a disc replacement in the neck and she knew the doctor who did the op and he was well regarded. Anyway that fellow woke up a quadriplegic, now lives in a nursing home and is in his forties. We have friends who gave us some fire wood. I said I don't want to lift it. "Why not" I explained the ops and he said they had just been to a fund raiser for a friend who was made a tetraplegic by an op that went wrong.

Make sure you are certain you are going down the right path with the right people is my message and to anybody else who is reading this and may be thinking of taking this step. Others might not be in that position now but remember what is written here before they commit to an operation. If you are overweight, lose the weight, get fit by non weight bearing activities like swimming. My back and neck improved further after the surgery as I was then able to spend time getting back to work hardening through steady paced exercise. It took well over a year to do that. In fact I say I probably took two years.

Good luck if you must go down that road, I hope you make a speedy and steady recovery and don't over do it if it works out, spinal surgery is just patch up surgery.

Thanks Blue for your concern and suggestions. I have spondylolisthesis of L5 which is where the central part of the vertebra is broken away from the dorsum part in back and then moves out of position toward the front. I was either born with it or I have had it since I was about 10 when I crashed my bicycle. It was not diagnosed until several years ago when I was in Law School and I was told then that I would eventually have to have my back fused. Now I do. The forward displacement of L5 is about 50 percent from a side view and the nerves are pinched. The surgeon is going to pull L5 back mostly into position and then fuse it with L4 and S1. I have great confidence in him. He is also a race boat pilot, and I will not be surprised to learn that his boat is powered by two 928 stroker motors.

Jerry,

That's a severe condition you are putting up with, I'm surprised you can still get around. I'm no doctor but from what you say you are getting the appropriate treatment. I'm a bit surprised your surgery is delayed, normally once the decision is made it is quite quick for serious cases like yours. Mine, not that it matters was backwards 'retro'
. You'll feel much better after its done. All the best Greg

Thanks again, Greg. The delays are kind of a long but not very interesting story. When I am on my feet for about 10 to 15 minutes doing something like standing in the courtroom, shopping at Sam's club or such or just standing talking to someone, my right foot starts to malfunction and I get pain in my back. However, I find that I can work on my feet for a few hours at a time in my shop without issue. I think that is because I am always slightly stooped over in the shop and that seems to be just enough to alleviate some of the pressure on the nerves.

Jerry you're lucky you can still function to some extent, you may find you will need a drug called Lyrica after the surgery, it is for neuropathic pain and this type of pain occurs when the nerves are compressed for long periods like yours have been. It works great and has minimal side effects as long as you keep the dose low. If you don't keep the dose low you can have weight gain and fluid retention. My dosage got too high and I just couldn't eat enough. That's how you get the weight gain. I managed to increase my fitness and halve the dosage and as such, I now don't have the side effects.

Thanks again, Greg. I'm glad you finally came out well; and thanks for being concerned that I will do the same.

Now, back to the intake.

I cut the final tube off, the one for the very front, but I think I cut it off too short. I'll going to order a couple more bends and do the front two tubes over. I think I have it right, now. I also received the steel ball and it works pretty well to flare the ends except the ones that need flaring right at of within the bend area, which I think has been work hardened enough to make the tubing very resistant to flaring this way.

Jerry--

Have you looked at the tubing expanders that the muffler guys use? Fits inside, tighten a bolt on the end to force expanding fingers out to stratch the tubing. It's what they use when a slip-over fit is needed, plus it "rounds" slightly distorted or collapsed tubing. Better auto parts stores have them, or you can probably talk a local exhaust place into letting you use one.

Thanks Dr Bob for that suggestion, but that is not the kind of flare that I am wanting on the ends of these tube bends. Take a close look at the end of the tube in this picture and you can see what I mean.

the "auto store" ones are cheap s**t that don't really work.
better off going to an exhaust shop with a hydraulic flaring machine and handing the guy $20 or so for his time.

maybe worth making a die and pressing the tubes into shape?

Go back and read the last couple of pages of this thread and then think this through a bit, then tell us just how you think that might be accomplished.

I was thinking that you were trying to expand the end to solve a loose fit in the flange adapters. Using the tubing expander would give you a straighter run to the joint at the head, plus clean up some of the tube collapse at the transition from the curve to the straight run, such collapse inevitable even with DOM bends.