78280z

Heres what I have so far (based on the file from the downloads section): Both are 1/2" thick. The one-piece may not be ideal because of thermal expansion issues, but there are arguments that the effects may be negligible (see thread http://forums.hybridz.org/showthread.php?t=118387). Which design do you guys prefer?

Does anyone know the actual diameter for the bolt holes in the flange? (I am going to use SketchUp to help design some stuff, so I need that information in order to properly scale my drawing.) Thanks!

OTM, I see what you mean, however, that bolt hole may not have to be used. If we make a solid one piece flange(http://forums.hybridz.org/attachment.php?attachmentid=6672&d=1208626726), or even a three piece flange (made by Trust: http://forums.hybridz.org/attachment.php?attachmentid=6739&d=1208934766), those bolt holes are not used. As for the overlapping of the tube inside the port shape as OTM and Slow Old Car mentioned, here is the thread about shaping the tubing to match port shape: http://forums.hybridz.org/showthread.php?t=123881. One of the most important things to mention about that issue is that the two center ports have a different shape than the others. I'm sure that the manufacturer has methods they could use to shape the tubing to match port shape.

Again, I don't want to be bossy or offend anyone since I'm a relatively new member (you guys have been around for much longer and know more than I do about cars). But, I think it will be much easier to get this done if we really stick to the plan and take care of things step by step. Let's leave the discussions of equal length runners, turbo flanges, and wastegate flanges for later. First Order of Business: Manifold Flange As stated above, there is a CAD file of a manifold flange in the downloads section of this forum. So, we have the exact dimensions we need as far as the shape of the ports and placement of bolts. After doing some research and looking at recomendations of forum members (JIM73240z, ColdFusion, 240hoke), we also have a flange thickness of 1/2". Is this agreeable to everyone?

Yes, it will be an enormous undertaking, but I'm sure the many experienced and skilled members of this forum will be willing to help out and lend their knowledge if we ask them. I have some CAD experience, and I'm sure many others do too, so I'm sure we could throw it down if need be. We should check into how they would want our design prepared (CAD, SolidWorks, etc.) But anyway, before we even think of starting to design, we should really nail down exactly what we want. Obviously, we should go for a tubular design for best flow (and since that's what most everyone is after). Here's some advice from Nigel (page 3) on that: Based on this information and other posts in this thread, I'd like to take this opportunity to help organize the design process. I think we should take things step by step and not try to throw everything together at once. (Disclaimer: I do not intend to give the impression that I know everything about the design process nor do I intend to be bossy, I just thought it would be nice to have a clear cut plan. Let me know if you think I should have added anything else.) So, here's my plan: First order of business is to size the thickness of the manifold flange (that mates the header to the cylinder head) and the location and size of the holes for the exit ports of the cylinder head (should match locations of and cross sectional areas of the exit ports of the cylinder head). Second order of business is to size the runners (inner diameter and wall thickness). Again, we need the measurement for cross sectional area of the exit port of the cylinder head. Third order of business is to decide about the pulse tuned and equal length dilemma so that we may decide exatly the path of each runner and how they will come together in the collector. Careful consideration will need to be taken here to ensure that everyone will not have turbo clearance issues. This phase will involve much cooperation among members to ensure proper measurements and to start the ball rolling on drafting the design in CAD. Fourth order of business is to decide what type of turbo flange to use. Fifth order of business is to decide what type of external wastegate flange to use. So, there's my five step plan to turbo header success. Again, if you feel I have left anything out, don't hesitate to let me know. If you guys all like the plan, then lets go ahead and start with our First Order of Business.

Hmm...then I'd say we should design one and give them dimensions.

Agreed. Like I said in my previous post (page 6): I would not want to pay $200 for the addition of an external wastegate and slightly better than stock flow characteristics when stock headers can be found for $50. We have the opportunity to design a turbo header, have it produced for us, and be able to buy it for around $200. Given the opportunity, why not design the best performing header we can (that also best accommodates everyone's interests)? At the very least, if we don't want to design one from scratch, we should find someone who has a custom tubular header (like the ones shown in pics earlier in this thread) and have that one replicated.

Well, as far as I can tell, the original purpose of this group buy was to obtain a turbo header that flows better than the stock header and has an external wastegate flange. Now we are faced with the decision of designing just that, or replicating the stock manifold in stainless and adding an external wastegate flange. If we replicate the stock header in stainless, it may flow slightly better due to the differences in roughness in materials (basic fluid mechanics losses stuff), but it will still be almost identical with the exception of the addition of the external wastegate. As far as I'm concerned, I would not want to pay $200 for the addition of an external wastegate and close to stock flow characteristics when stock headers can be found for $50. We have the opportunity to design a turbo header, have it produced for us, and be able to buy it for around $200. We might as well give it our all and design the best performing header we can (that also best accommodates everyone's interests). Just my two cents...

That's what I was thinking (hoping) initally. But, either way, it's got to be cut out and patched. The rust battle continues...

Grand-Am GT Classic at Lime Rock Park in CT. Will probably post some pics later. Other than that, hanging out with the gf and family.

Thanks for the confirmation, I figured I was screwed. Well I guess I should start looking into options to replace that section. I will probably go with a patch as Challenger suggested since it will be a street car. So 1/8" is overkill? What would you suggest? 12ga or 14ga maybe?

I'm not quite sure, so could someone help me out a bit? Just to familiarize you, this is a picture of the area behind the (left) driver's side front wheel. I am wondering whether the rusted area in these pictures is the frame rail? (but hoping that it is just the inner fender well) Thanks for your help!

The above links will get you some good patch panels, but if you are looking for complete replacement panels, look on the classifieds here and on other Z forums as well as craigslist for your area. Good luck with your projects!

Has anyone played with the idea of using a (two) TD04 turbo(s)? Lag would be very minimal and each turbo can supply 15-18psi reliably. I am thinking about going this route on my 78' 280's stock L28 (with supporting mods such as megasquirt and injectors).

Agreed. I have also been waiting to see some pictures of the 513's mounted on a Z. For a street driven car, these should be some good wheels. We should take note of brake and suspension setups to see what will fit.

Today I will begin tearing off some body panels in my attempt at saving an S30 Z. Is there a method to finding where the spot welds are for the rear quarters and the rockers? Thanks in advance for any replies!

I'm interested in the header and my wallet is interested in the price.

RedEvilrps13, I have also heard some stories about some people experiencing the breaking and cracking. Others have had no problems at all. I guess it is really up to the owner whether or not Rotas are "track quality." Anyway, my guess is that anyone who has the money to build a dedicated track car has planned out their wheel/tire/suspension setup meticulously and will not spare a dime for one of the most important performance features of their car. For street use, Rota's should be just fine.

Some Rotas may be "knockoffs," but I wouldn't necessarily say that their quality is subpar. Many members on this forum are buying Rota RB's (which are panasport/watanabe "knockoffs") and I know many Subaru owners use Rotas for autocross and track events. Just a thought...

Thanks for the reply. Are there any diagrams anywhere that show the locations of the body panels' spot welds? I've been looking all over my factory service manual and other manuals and I can't find one. Is there an easy way to find the spot welds if there is no such diagram?

I am starting my bodywork soon, I have accumulated everything I need. I have a '78 that I am going to save by replacing both rear quarters (complete replacements with doglegs and everything) and both rockers (complete replacements). I know it would be cheaper and less work to buy a clean shell, but I want the learning experience. I guess I'm jumping in headfirst since I don't have all that great of an idea of what I'm doing since I have never done bodywork before. So, I have a few questions. 1) I understand how patch panels are done. (Bad section is cut out, patch is carefully cut to match hole and create a butt joint, and tack welds are used along the entire seam.) I am confused though since I have complete replacement panels, should I be looking to take the old panels off by drilling out stock spot-welds and then put the replacements on by spot welding? 2) There are a few tiny holes in the floor and inner fender. Should 22 gauge sheet work for patching those? Thanks in advance for any information and for your patience in dealing with my questions. I know I'm in over my head, but I want to learn. Thanks again, and I look forward to any input!

zmaster you kind of stole my thread:nono:...just kidding:biggrin:. It's okay, I share your confusion about door glass compatibility. But, as far as I understand it, there were three different (incompatible) door glass styles: one for the 240z, one for the early 260z, and one for the late 260z and 280z. (See post#6 here: http://forums.hybridz.org/showthread.php?t=95244) I've also heard that another issue some Z's run into is that at some point, a door was replaced with a door from a Z with a different glass style. So even though your Z might be a 280 for example, your door could be from a 240, so you would then need 240 door glass. (Ugh, so confusing.) So, the only way to be sure you get the right replacement glass is to measure everything up beforehand. Thank you very much for your offer, it is very generous. I will check to see whether my doors are from a 280 or from a 240 and I will get back to you.

Just wondering what the average price for door glass (one side) is. Thanks in advance for any replies!

Note: The above prices were quoted on 2/7/08 I contacted Tabco again today (2/28/08) to place my order and they tell me their prices have gone up. Now they want $44.95 for the Front Fender Lower Rear Section and $69.95 for the Rocker Panel. Are they trying to make some extra cash on my order or what?!

I contacted Tabco recently to ask about parts availability and prices. Good thing I checked. Apparantly they have not updated their website in a few years...their current prices are as follows... Parts & Prices Front Fender Lower Rear Section 16721 L-R $36.95 each Rocker Panel O.E. Type 16740 L-R $54.75 each Dogleg 16750 L-R $33.75 each Rear Quarter Lower Rear Section 16752 L-R $45.75 each Shipping is not free anymore. They quoted me approx. $20 to upstate NY. So anyway, has anyone done business with Tabco lately? It seems wierd that they haven't bothered with their website in so long. I'm just wondering if they're still legit?