78280z

I've heard that a heating torch and a steel spatula (for scraping) work pretty well. Make sure ventilation is adequate of course...

Unfortunately, it looks as if the roof was dented/uneven at some point in your Z's life and one of its previous owners used bondo to repair that dent. The bondo gives the thickness to the chunk that's missing. I would recommend sanding the entire thing down to the metal, fix the rust, get the panel as straight as possible, and then repaint.

I think the one you're buying looks better than the purple one.

I am also wondering if the HP's are any good for the occasional autox and/or track day.

I completely agree with jeffer949. I have considered a number of ways to attack my build, and that makes the most sense to me, too.

I think he means building one from scratch (think locost project) and incorporating the hardtop and rear bodywork into his design.

Been in school for about a month. Courses for this semester: Dynamical Systems, Advanced Engineering Math, Experimental Methods in ME, Mechanical Vibrations and Control, Thermodynamics, Virtual Tools in Engineering Design, Shop, and Welding.

Black Dragon Automotive http://www.blackdragonauto.com/

I know what you mean. I was just saying that I think it would be a good idea even for the group buy. I mean, looking at it from a business standpoint, I don't think the majority of customers want to buy a product that they then have to immediately modify for it to work properly.

I agree...I think it would probably be best to have those changes made before sending to SSAC. That way, they could copy those changes and the group buyers would not have to worry about further modifications. (Since most of us are going to be using a T04E, T04B, or some other type of T4 turbo, we might as well have SSAC take care of the machining to address any fitment issues.)

I agree with everyone's comments regarding SSAC using the design. We will be bringing them a lot of business just from this group buy alone. They will undoubtedly sell a ton to other Z enthusiasts as word gets out. I think we should professionally point out to them that, since we will be bringing them so much business, they should give us a good deal. Their original estimate was $200 per header and I would certainly like if they stuck to that.

Sounds good. Keep us posted!

Those definitely look great. Inspiration for me to buy them when I get my 280 done...

Okay well honestly, I haven't made much progress in the design. I've mostly been doing research and trying to figure out how to accomplish this. The flange was not difficult at all to draft in 3D, but as far as the runners' paths go, they are extremely difficult (at least for me) to draft in 3D. Plus, just drafting is not enough; we would have to describe each runner's 3D path in terms of bend radii and such so that SSAC could build it. It would be extremely difficult to ensure accuracy in describing a 3D path. So, at this point, I'm thinking we have a few options. First, I could contunue designing the header, but instead of 3D drafting, I would build an actual mockup that we could send to SSAC. This would take me a while to complete, and it sounds as if some of you here are on tight schedules. So this might not be the best option for everyone here. Second option would be to buy the header that VinhZXT has offered to us and have SSAC replicate it with certain modifications available to us (turbo flange, wastegate, etc.). This could probably be done in short order and would be better for those who are looking to buy in the very near future. I guess it really is up to the masses since, in order to have a successful group buy, we need to have a lot of people involved. So, everyone chime in and let it be known what you think should be done.

Drafted up the pieces that will mate the port shape to the tubing and an approximate placement of the turbo flange... Since I have limited 3d cad experience, it will take me much longer than expected to complete the runners. But, hang in there, it will get done eventually.

Okay, so I have been making almost no progress due to continued long hours at work and some software issues. But I did draft up the flange with 1/8" wall thickness of the runners around the port shapes. That got me wondering how it will be possible to make the welds between the flange and the runners in certain places (red circled areas): I guess it should work somehow (I took a look at pics of MONZTER's header in posts #55 and #56 http://forums.hybridz.org/showthread.php?t=116979&page=3) although I don't really know much about fabrication practices. So, coming from an engineering background, I just want to make sure that the part I'm designing can actually be built. Any input is greatly appreciated.

Take a look at this thread http://forums.hybridz.org/showthread.php?t=135580 and post #11. Cygnusx1 brings up an interesting idea. Could urethane body parts be made for a Z?

I have read that the rocker panels and quarter panels provide much of the structural support of the Z's unibody. Since I will be replacing both rocker panels and rear quarters on my Z, I am wondering how to go about ensuring that the unibody does not come out of alignment while I am replacing the panels. Any suggestions? Thanks in advance for any advice!

Sorry for lack of updates...busy weekend and long hours at work lately, so progress has been a bit slow. Plus, this will be the most difficult part of the design process, so it will probably take me a few weeks. But, I will do my best to get it done ASAP. I'll post updates as it comes along!

JSM, thank you very much for the measurements. Those will definitely come in handy! Tony D, thanks for the suggestions. I will do some more research and see what I can find that will help me in the design process.

Good to know. I will consider putting in a brace later on in the design process. However, we are still at a standstill as far as design goes until we get some measurements. If anyone has a stock manifold, please spend some quality time with your favorite measuring tape and post up your results.

Okay so it sounds like we know where we want the flange: somewhere aft of center, but forward of the stock manifold. So, if someone could take some measurements and post them here, I will be able to start drafting! Thanks!

No problem, it's coming together well! Okay so we know the desired runner length. Now to accommodate the widest variety of applications, we should probably keep the turbo flange close to its position on the stock manifold, correct? To ensure that this is all drawn up correctly and clearance issues are avoided, I need some measurements. First, I need to know the approximate position of the turbo flange relative to the manifold flange. Maybe pick a point on the manifold flange and then give me X,Y, and Z measurements to the four corners of the turbo flange? Whatever you think will give me the best idea of the location of the stock turbo flange. Second, I will need to know the limits of the overall size of the complete header. Perhaps give me the X,Y,and Z dimensions of a 3D rectangle that the header must fit inside. Once I have that information, I can start looking at ways to route the runners.

Alright, Second Order of Business complete. So now we move on to the Third Order of Business: The Equal Length / Pulse Tuning Dilemma. Here's some info from Nigel's post to refresh our memories: So, we need to decide on the grouping in the collector and the desired length of each runner. As for the grouping in the collector, the L28's firing order is 1-5-3-6-2-4. So, the grouping should be 1-6, 5-2, and 3-4. As for the runner length, the reference that Nigel used suggests short lengths are best. However, I've read that runner length is dependent on where you want your torque delivery in the RPM range, with short runners favoring high RPMs and longer runners favoring lower RPMs. But, this train of thought may only apply to N/A applications. So, which is the correct theory and based on that, what is the desired linear length of each runner?

Okay so I guess then our First Order of Business is complete. Moving on to our Second Order of Business: Runner Sizing. It has been suggested that we use 1 5/8" tubing with a 1/8" wall. Does this mean that 1 5/8" is the outer diameter? If so, this sounds good to me.