Drax240z

Weld has been wire brushed since it's been done... the best way to tell a quality SS weld in my experience is by weld colour. But it's gone!

LOL, those are awesome!

Yeah it's not like we are talking about Thrust SSC here. I'd be curious to know what kind of effects the engineers of an F1 team would expect due to frictional heating of their airfoils however. I would imagine that their local air velocities can be quite high compared with their actual speeds.

Ah John, a good point in that this shouldn't necessarily be considered on a molecular level, as the interaction with the environment is not complete when just considering the path of 1 molecule, the interaction of that molecule with the surrounding ones has great effect as well. Naca report 383 is very interesting in regards to optimal angles of attack but I'm not seeing it's relevance to the discussion... Unless somehow I've missed something in the first 8 pages. Hrm... still thinking a bit on this one. Considering the wing & fluid as a system does seem to indicate that there is energy being transferred from the wing to the fluid. (in the form of a higher velocity) However, I would say the counterpoint is that the fluid is transferring energy to the wing as well in the form of heat. (due to friction) I suspect the actual magnitude of energy transferred is much greater in the wing->fluid transfer though. Anyway, a properly designed diffuser will add downforce to the rear of a car. (isn't that the topic?)

I'm not sure I buy that... you are saying that 2 objects of similar mass & inertia (air molecules) are travelling different paths, with the same initial energy and starting in exactly the same position. Because KE=1/2*M*V^2 you are saying that the one that takes the longer path MUST be at a higher velocity (and therefore lower pressure due to the ideal gas law) in order to arrive at the end of the wing chord at the SAME time as the other particle. Yes this all makes sense to me. However, I don't see what is making the definition that both particles MUST arrive at the end of the chord at the same time, why wouldn't the one travelling the longer path experience a greater loss of energy due to friction, and arrive later than the one that had the shorter path?

I've never seen an L-series run as well on Champion, Bosch, Autolite, Motorcraft, etc. plugs as it will on NGK's. Yes there is a NOTICABLE difference in changing to copper electrode NGKS over any of the above. The plugs won't solve the problem you are having, but they will solve others that will creep up. BPR6ES, BPR6EY-11 or non-resistor type plugs of the same heat range and size are very good in NA L-series engines. I've seen this problem on ZX's, and it has been fuel pump, ignition module, or simple contact corrosion in those cases. It's a tough one to nail down over the web, I think you are going to have to get in there and test a bunch of things to see for yourself.

Geeze Terry, don't tell me you are going to rip it all apart again and start fiberglassing!

Well the problem is that flow seperation occurs regardless of velocity, and pretty much a fixed angle for air. (~10-12*) One large benefit of a gradual curve on a diffuser is that you have no sharp angles and you give the air a chance to 'turn' without seperation. If you have a gradual enough curve then you can essentially turn a very large angle without flow seperation. (ie: the front of a 747) What I suspect with the Ferrari in question is that they did some serious wind tunnel testing and found out that they could follow the body lines much more nicely, and still create significant downforce, even with localized turbulant airflow. I am sure it is very functional on that car, but I would bet that there were some compromises made in terms of looks in this case.

Hey Anthony, love the car. Did you manage to do the flares and keep the rear doors so they will open?

Uh... sick!!!!

Actually Terry you bring up a good point, I have read some of the counter-Bernoulli theories as well, and they make some good points as you discuss. Basically the arguement is that by forcing the air in a direction, and equal and opposite force is exerted on the 'wing', be it a barn door or whatever... Hence the ability to fly. I think the biggest stumbling block for me with Bernoulli is this: Take a wing for example, you have air seperating at the leading edge of the wing, and following different paths to meet at the end of the wing. Due to the wing being curved the air over (or under) the wing much be faster than on the other side. This velocity differential creates a pressure differential which in turn creates lift. What I wonder is... why must the air travelling on both sides of the wing travel the span of the wing in the same amount of time? Anyway my comment in the above post wasn't intended to start this discussion.

Well the other side... I can't recall how many times I've had someone elses shoddy work in here that I need to fix. The customer goes to the cheap source to try to save a few bucks, and ends up getting a garbage job done. Then ends up paying more in repairs in the end, trying to get someone to make chicken soup out of their chicken $hit. If the first guy does good work, then go for it. I'd just look at an example of his work first and make sure you are getting the quality of work that you want.

Hmm, honestly I would start with a 75 or 76 parts car and go from there. I think it will be more cost effective in the end. Those years also have the cleanest manifolds, baffled fuel tanks that will fit in a 240z and the simplest EFI. What you will need: - Wiring harness - EFI Fuel pump - Intake manifold, complete with injectors, fuel rail, pressure regulator, throttle body, etc. - AFM - ECU I think that about covers it. (but I am sure I've forgotten about something) In order to achieve your power goals you probably would want to use the turbo AFM, turbo injectors, 240sx TB. I'd also recommend a 75-76 tank, or some modifications to your 240z tank (either a sump, or baffles) to make sure you don't starve for fuel on corners.

Hi Anthony, I'm glad you asked this question. Something I've seen far too much of, and while using regular bolts is an acceptable solution, it isn't necessarily the 'proper' solution! The nicest way I've seen of using rod ends is in a situation where you use a full shouldered bolt sized correctly for the rod end, and both sides of the bracket have holes reamed to the size of the bolt as well. The shoulder should be the same length as the thickness of the brackets+rod end, and should not be able to be tightened down more than that. Sorry for the poor picture, but here is an example: You can see in the picture that the bolt isn't any longer than necessary. Also the shouldered section ends flush with the mounting bracket. The nice part of this is that NONE of the loads are placed on the threaded section, decreasing the chance of failure for a given size. (ie: you can use a smaller shoulder bolt and have the same strength as a larger threaded bolt) Ah, a better picture: Using standard threaded bolts with through holes will lead to slop, and it will likely wear the holes larger over time and increase the slop even more. By all means try other methods first, this is sortof the 'money is no object' approach... the things we engineers want to do, and accountants don't let us do.

Well with all that said... A breast in hand is worth two in the bra.

The draw (at least for me) with the higher rod/stroke ratio wasn't rev potential, so much as detonation resistance. Meh, it was always a "food for thought" idea to me, I may try it sometime.

Z31 (turbo) O2 sensors, at least canadian versions, don't use the standard M18x1.5mm thread pitch, they are much smaller. 240sx's use the same size however. Try getting one through Nissan.

If you mean the "journal pin" for the last pics I posted, then I can't remember how they were held in. Yes the helical gears were free to slide axially on the journal pin though. The case does NOT have any kind of holes for the worm gear to ride in however.

I don't have all the numbers in front of me but I'd try to make some strides towards raising the rod/stroke ratio to 1.7-1.8:1 if possible. (standard 3.1L stroker/LD28 crank being 1.60:1) It sounds like 510six has answered most of your questions though!

It is very common to need shims in this application. Some of the energy suspensions bushings work tight, some don't. Shimming will fix it!

Well lightening the center section, as well as drilling 3 holes through the entire section in order to mount it in a custom aluminum housing. Pretty rough going with that material, as it is surface hardened.

I was looking thought some old data I had and came across these, I thought I'd throw them into this discussion for completeness.

Well can't remember E30 325i exhaust, but I know the E30 323i euro model had 2, 3 cylinder manifolds off the engine, and twice pipes all the way back. The only place they met was a dual in, dual out resonator in the tranny tunnel. Great sound.