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Drax240z

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Everything posted by Drax240z

  1. Well I'm not an expert but I'd say its pretty normal.. a crack propigates under load and then catastrophic failure occurs. Its pretty common for a crack to occur and then take time to propigate until failure. I'm sure some of the aircraft engineers on the board can fill us in on crack propigation and failure due to fatigue.
  2. Yes they run those big alternators for their offroad lighting. 325amps is a lot of lights! The biggest problem I've found with low output alternators is that they don't supply much current at idle speeds. This means when you stop at a street light for example, your headlights may dim. (anyone who has a Z has seen this!) You could spin the alternator faster with a smaller pulley, or go to one that makes more current overall. I believe the relationship between the horsepower to drive the alternator and its output is pretty linear. Regardless of your alternator output, the draw from your car will be the same. ie: if you need 40amps to run your car, you'll need 40 amps to run your car whether you are using a 45amp alternator, or a 130amp alternator. In each case, your car will get the 40amps, so a 130amp alternator will gain you nothing, except that it may produce more current at idle, which may be just where you actually need that boost...
  3. Not necessarily Mat. You can design for an infinite fatigue life. If the design is strong enough, the induced strain from deflection is not enough to start a crack and propigate it. Even after millions of cycles this can still be the case. Obviously, imperfections in material and stresses and strains higher than those the bracket is designed for can greatly shorten this fatigue life from infinite, to a very finite and approachable number of cycles. A jt1 pointed out this relationship is not linear, a 20% increase in strain can cause a 90% reduction in fatigue life. Back to the origional point, the 3/8" won't necessarily be the first to break due to fatigue, it depends what the new loads are and where these loads put the fatigue life. If someone has access to CARLOS spectrum data somewhere through work, then we can see exactly what number of cycles we should be designing around.
  4. Congrats. Hey Pete, any chance you are going to photodocument or do a photo shoot with your car sometime soon? I'd love to see some more pictures.
  5. I've uploaded some pictures of my car if anyone is interested. They are in my personal gallary. A few before and after shots, even though it isn't technically "after" yet because I am not done...
  6. Try 1 first. If you start cutting holes in your shrouding you'll just kill the airflow at idle. With some experimentation with spring rates you could try some hinged doors on the shroud so that they stayed closed at idle, but opened up as speeds increased.
  7. Wow, that engine bay sure is small compared to the S30's! I too think this is the car nissan SHOULD have made out of the 350z. (I guess that would be 260z... Hmm, I see a marketing problem here) Great swap, keep us updated!
  8. What engine, engine management, modifications from stock, etc? Check for clogged air filter, fuel filter... obstructions in the intake, etc. See if you have a nice strong spark. Check your timing...
  9. Well... there are a few people here with more sponsorship experience than me I am sure, but I'll give you a few pointers that I've learned. - Getting sponsors is the toughest part, your best bet when coldcalling is bring the actual car with you to their business. Make is shiny, and make sure you can start it up for them if they ask. Everytime we'd pull in with one of our cars, we'd basically stop the whole business from operating for 10-15 minutes while everyone checked out the cars. If you can get the staff interested, then you are off to a good start. - Once you have sponsors, treat them like gold. Let them know often (we did a monthly news letter) exactly what is happening with the car, and where they can see it next! Also when you show the car, make sure you have some type of sponsor board up as well as their name on the car. - Approach things very professionally. We had the most sucess when showing up in team polo shirts, with our car, race trailer, formal sponsorship brochures, business cards, etc. The more professional you look, the happier the business will be to be associated with you. - Try to find sponsorship for parts/labour that you might need, rather than asking for cash. Cash is tough to come by, but if a company can donate a bit of time or one of their products its much cheaper for them, and you are still getting ahead. - Make sure you thank you sponsors with a quality framed picture of the car with their name prominantly displayed. These always end up on the walls of their business, and will give you some "free" advertising to their customers. These customers can turn into future sponsors! You have to spend money to keep money coming in... If you want to see some of the brochures and stuff we've made, shoot me an email. Oh, we made a few videos for sponsors too, they are a big hit as well. Anyway, good luck.
  10. Well of course I do! Its on the same page that tells you how many gigaleagues are in a terrafathom... duh. Hmm, ceramic and stainless looks and sounds awesome, but I was thinking just a simple steel shield. From the sounds of things I can leave it for a couple of weeks and concentrate on other things a bit. (like tuning!)
  11. Hey, thats my next swap! I'd really love an IS300 + SupraTT engine/6speed for a daily driver. Pretty nice cruiser/driver/long trip car if you ask me! As for why I don't just get a Z with a turbo in it... I'll have that too!
  12. Other options for diffs are probably the same as the early Z. 88 300zx SE has the clutch LSD, and later turbo cars have the viscous. I'd check out the viscous swap first as they are more plentiful in the junk yards, and a better setup if you can get them in easily. (the clutch ones happen to install in the early Z much easier, so they are used a lot in the S30's) Check out the drivetrain forum for more info...
  13. Perchloroethylene (PCE) what they use for drycleaning now! Often used in brake cleaner. If its really course dirt, just start with some foamy engine clean, and a hose, and then go to the PCE what davy suggests.
  14. I had the same problem a couple of weeks ago. I'm pretty sure this will solve your issues. - Remove the fuel rail from the car with the injectors all attached to the rail. - Take a small, pointy object (I used a small finishing nail) and poke the pintle of each injector until you feel it move. (It will only move 0.020" or so) You should feel that it is a bit sticky when you poke it. - Reattach everything and give it a shot. I found that all 6 of my inectors were glued shut slightly with varnish, and they had been sitting for 3 years or so. I'd run some injector cleaner in your tank and try to clean them out that way, though in truth they should probably be removed and professionally cleaned.
  15. I'm curious to know what people are running for heat shielding around their turbo in their early Z. Has anyone run for any length of time without any head shielding between the brake system and the exhaust/turbo? Has there been problems as a result? What about the steering coupler and TC rod bushings? Any problem with the rubber and the heat together? Just trying to figure out whether I have to do this right away or if I can take some time and make it pretty.
  16. Some really nice looking setups here... I'm almost ashamed to show mine in such company!
  17. Personally I don't think there is much difference in quality as far as SKF and NTN go. Both are awesome companies to deal with too in my experience... offering our FSAE team free bearings for the whole car, every year. With that type of service, I can't recomment either enough!
  18. Ah, so basically you have a 4-2-1 header on each side of your engine. Which will lead you to a nice broad torque curve without sacrificing top end depending on your pipe size of course. An interesting note: depending which cylinders your collect in the first collector set, you'll have a much quieter engine as you get some cancellation as far as noise goes. However, this isn't helpful for max power. (though the losses are small at low gas velocities) At least thats how it goes on a 4 cylinder. I'd imagine though the timing will be different on one bank of a V8, the priciples still apply.
  19. Looking good! How do tri-y headers work anyway? Is it 4 into 2 into 1? Its a bit hard to see in the picture. Does the name "tri-y" come from the 3, 2 into 1 collectors necessary?
  20. Well so much for staying out of this. But Bob pretty much echo'd my views on the whole situation. My concern is genuine, and if I haven't put that across in a very tactful manner I apologize. (however, I think if you re-read my posts you'll see they aren't trying to slam people) My goal was to educate, question, and prove or disprove that there was enough knowledge/research to carry on with a design like this. I think we all need to take a step back and look at the big picture for a second. We're all wanting the same thing in the end, big, beautiful, safe brakes that suck your eyeballs out of your head. By questioning said design and forcing someone to back it up, are we going to end up farther from that goal? No. We're going to all come away with more knowledge, so I can't put my finger on why this is a bad thing to anyone. To reiterate: I'm not out to get anyone, and from Bob's last post it's pretty clear that he isn't either. Its hard to play the adversary sometimes without ruffling some feathers, but please guys lets keep it civil and constructive, and end up with our eyeballs stuck to the windshield.
  21. Your bracket will deflect. Yield strength isn't simply the strength until deflection, look it up. - At what temperature is your 36ksi yield strength? What happens at 40C? At -40C? - Are you sure you have 36ksi yield mild steel? - What if its a 3800lbs Z, fully loaded, big guy, etc? - What if the car is pulling over 1G in braking? - What if you hit a pothole while you are at max braking? - What is the safe fatigue life of this braket? - Are you sure your 36ksi mild steel is 36ksi throughout? - Are there any stress concentrations on the part? - Is the area you are doing analysis on the most stressed part of the bracket? I'm not saying your bracket isn't strong enough. I'm saying you can't prove it. Yes, at least you've gone this far and done some basic stress calculations, and with fairly conservative estimates on the loads, you have a static factor of safety of 10 at the point that you are calculating. Obviously I have been schooled by you, and I know nothing of what I speak. Hmm, I guess I wasted 5 years of my life on an engineering degree, when I could have just read this post. Anyway, I'm out of this discussion, do what you wish with your parts and good luck with them. I hope for your customers you don't have any problems and none of this is ever an issue.
  22. Do you know who you are talking to there? Is it an 18 year old kid on a summer job, or a professional engineer with years of experience? I'm not saying their assessment is incorrect, only saying that finding someone else to agree with you doesn't make it right. Well I've heard of "Grade A" beef... but never "grade A" steel. But what do I know? Listen Juan, I don't want you to think that I am trying to shut you down, or detract from your business (or anyone else doing a similar thing) I am just strongly suggesting that in order to ensure you are doing things safely, you should have your designs verified by someone that knows how to verify it, in a way that would stand up in court. Its not like you are designing a wood shed here, you are working with brakes, and a mistake most likely means someone is seriously injured. Furthermore, a mistake may not come out in the form of a catastrophic failure for a few years, after fatigue. By then, you might have 100 cars with your system equipped, and each and every one might be in jeopardy if the safe life is too short. What do you do then? I'm by no means saying stop what you are doing, I am simply saying that you should know what you are getting in to if your parts are not strong enough to give a fatigue life long enough to cover the length of time the part is used.
  23. You know, I was wondering when this was going to happen with the little companies out there making Z parts. Don't get me wrong, I love that people are making aftermarket parts for the Z cars. However, as far as I know none of these companies employs any engineer that can back up their designs at all. Everything is designed on heresay and gut feelings, and while for the most part people have a pretty good idea of what works and what doesn't, consider what happens the first time something fails and someone dies as a result. Consider trying to back up your design in court as a "gut feeling" regardless of your past experience. I can promise you that it won't get you far. For gods sake, if you aren't educated as an engineer, either find someone that is and pay them to clear your parts, or have some physical testing to back up your design. Put them on your own car, document the hell out of the conditions you put them in and the results, and THEN sell them to the public. Same story for brakes, control arms, wheel spacers, whatever. Cutting corners will cost you your livelyhood, or someone else their life. There is a reason why engineers go to school to become engineers. It isn't simply a formality. Juan's 1/4" bracket may or may not be sufficient. But until you consider all cases, know the loads, temperatures, material, vibration, shock loading, etc. I wouldn't set my self up for a big fall by mass producing it.
  24. If the car is a lemon........... do you get lemonaide?
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