heavy85
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Posts posted by heavy85
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I like this one. Full racing suit with gloves and all but no helmet and limited other safety gear (like a harness).
http://www.youtube.com/watch?v=juA5x4RNiWY&feature=related
Cameron
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What I meant was how do you expect to cool the car after its turned off with mechanical pump not moving. You mentioned using a Helper electric pump.
Unless the mechanical pump is replaced with the electric I don"t see how running an extra electric could help when the car is off
These pumps have very poor efficiency. It's not like there is a seal or something so the water would just flow through the mechanical pump. Maybe not as well as with the pump spinning but at least quite a bit would get through. Take a look at an impeller water pump (or turbo) and you will see this pretty easily.
Cameron
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But with that in mind...I don't see how you can come to the conclusion that reducing the pressure difference doesn't reduce the power required. I mean...plug in a smaller number for "Change in Pressure" on the right side of the equation, and you get a smaller number for "Power" on the left side of the equation.
As far as the electric pumps burning up with too light of a load...would I be correct to assume that these types of pumps are designed to work against a load? Can we be sure that this applies to an L6 water pump as well?
Remember the thing I kept saying? Flow is a function of pressure in a NON-LINEAR fashion. In the example I gave it was a square function but in reality its probably somewhere between depending on the pump design. Keeping on the square function if you cut the flow in half the flow will go up by 4 times for a given speed. Power = 1/2Pressure*4Flow = 2*The original power. So by lowering the pressure you are disproportionately increasing the flow and therefore increasing the power. The electric pump is then running at a HIGHER load (power).
The point is you can reduce the pressure to save power but ONLY if you resize the pump to operate in that lower pressure range. Using the same pump could hurt you.
Cameron
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I assume the point here is to reduce parasitic loss by reducing the pump pressure? If so impeller pumps are not fixed displacement and vary nonlinear with output pressure. This means for a given speed the flow varies as a function of pressure ... and in a non-linear fashion (this is important so remember this). Power is flow*pressure. Now remember that non-linear aspect I keep saying? For example if you cut the pressure in half you dont get double flow (constant power) you may get three or four times the flow. So the resulting power will be 1/2pressure*4flow = double the power you started off with. So reducing pressure is not necessarily the answer to saving power with these type of pumps. You really need to properly size the pump to meet the system demands. OK so real world example. Electrical motor driven fuel transfer pumps for relatively large engines (think commercial marine stuff). They have to calculate the pump discharge line losses and to make sure the pressure is HIGH enough to not burn up the electric motor. Kind of not intuitive but that's how it works.
Cameron
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Looked pretty bitchin to me. Nobody around, rail looked safe, kid did a big ass wheelie. What's not to like here?
On a semi-related note, here's an even younger kid having fun at a much smaller wheel. 6 year old tearing it up in a souped up 24V Power wheels Jeep. Not nearly as exciting, but it's amazing how a 6 year old can countersteer and all that, where I had friends who were 20 and didn't know how to react in similar situations in real cars...
At least he was wearing a 'seatbelt' .... makes me want to wire two batteries into the kids power wheels. Hmmmm
Cameron
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You want to know what really sucks ... at least for me ... my driveshaft shipped today & will probably be here tomorrow or Friday at the latest. That's all I need to take the LS powered 240Z on it's maiden voyage this weekend. Well except the fact we are SUPPOSE TO GET 4-8" OF WHITE STUFF LATE THURSDAY! Yes I meant to YELL!! Erg.
Cameron
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The cable between the positive terminal on the battery and the master cut off switch should be as short as possible.
Also the same "problem" that suggest applies to even the negitive cable, it can make a curcuit in teh very same way as a shorted positive cable, whihc can actually be looked at as "shorting" as well, though all it will be doing in the case of a negitive ground vehcile is completling the circuit and making the master cut off switch pointless.
Depending on where the battery is at you cannot make the positive terminal short (no pun intended) and still have access from the outside or near the window (SCCA type rules). Also, the 'problem' would require a double failure on the ground where only a single failure on the positive side would cause major issues. Hence why I say it's more robust. For example if there was an accident and the positive battery cable before the switch got damaged and shorted to ground. This has nothing to do with the quality of installation but has bad side effects if on the positive side. If the same thing happened except the ground shorted to frame then (one failure) then the switch still does not work but you are also not shorting the battery so there is really no issue unless the positive cable simultaneously shorts (two failures). True you cannot 'cut-off' power but at least you can use the ignition switch to turn everything off. Understand the alternator concerns but still overall see the ground and more reliable again taking into account possible failure modes and their effects.
Cameron
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Our power went out for a few hours this fine evening. 10 degrees (F), ice, heavy sustained winds.
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Tony D, you are missing a lot of the basics of how an automotive electrical system works.
You can completly remove the battery from a running vehicle disconnecting the negitive first if you like, and it will continue to run on, I have done this several times, out of need to move cars around with an improperly sized battery or none at all and boosted it from another vehcile, I do not however recommend doing this as it can ruin electrical components, due to there being no filter to remove the AC ripple that is present in the charge lead from an automotive alternator.
Many sanctioned racing bodies specify the master kill switch must be on the positive side, NHRA, IHRA being a couple, although I haven't looked myself, but I believe NDRA, NMRA are also like this.
It's MUCH easier to have a car shut off, by switching the positive side of the elctrical system, since it's much easier to cut the charge lead from the alternator than it is to interrupt the ground path of the alternator. It can be done as simply as running the charge lead from the alternator to the battery side of the master kill switch. Better option is to use a 4 pole master disconnect to also shut off the charge lead and have no positive potential on that charge lead back to the alternator.
If you were to run the ground from the engine block to the battery through the switch, you still have the potential that a gorund path may be present, through sensors, the tranny, to the drive shaft, to the Diff, etc.
In a negitive ground car it's much easier and more finite to switch the positive, there's just far too much potential for the ground path to not be interupted.
I think your missing the point. Sure you may need to kill the alternator somehow but otherwise the ground is the more robust way to isolate the battery. If you look at all the failure modes where you might need to kill the battery the negative side will take care of many more than the positive side would. All it takes is a short from positive to ground ahead of the switch to make the switch worthless. Those of us who have experienced this on the Z with it's close proximity to the hood will attest to this being a fairly common.
Cameron
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You said that you used "SBC to LS adapter plates". Which rubber (or poly) mounts did you use: stock LS1 fbody style or SBC units? What did your passenger side end up looking like - the same SBC adapter plates used?
If possible, I would love to see more pics of the headers and how they fit - I think my K is almost identical to yours, but I can't imagine headers fitting - there's barely enough room for the 2 1/4" pipe off the manifold on the pass side to run betw frame rail and starter as it is.
OK so I was halfway though typing a reply when the power went out. Ice followed by sustained high winds which are still howling in the background. Any ... I used Energy Poly SBC mounts. They seem easier since they have ears that go around the frame mount as oppose to the fbody that require the mounting ears to be on the frame if you know what I mean. I bought generic adapter plates that bolt on with the factory LS four mounting bolts but use one of the front mounts to also attach the SBC mount. The plates have two tapped holes for the other two SBC mounting bolts. The look like a square with a triangle attached to the front. Anyway I used them pretty much as is on the drivers side. If you are using the JTR headers you will quickly figure out the passenger side the the tricky one and the mounts have to be far forward of the stock location. For this side I slid the adapter plate forward so it only used the two front factory LS mounting bolts then welded on ears to the plate to pickup two additional mounting holes near the front of the block similar to the John's mounts. This also require drilling and tapping a couple extra holes in the plates. Here's a front shot:
If you look up several posts you can see the headers come with a nifty 2.5" adapter that is mitered at a fairly sharp angle. These were key in getting the 2.5" exhaust through there. This is also pretty good pic that shows the exhaust and mount.
Looking good Camron, Fast progress!That reminds me, I need to get to work as well! by the way, have you gotten the engine running yet?
Ha Ha - fast progress ... only a year behind schedule. My target was May '07. Looks more like March '08. It's running and only a driveshaft away from being drivable which if all goes well should get it back by end of this week
.Cameron
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So probably the last installment to this thread. Added a rear strut & harness bar. That rollbar tubing is heavy stuff! It's also a lot easier to weld than the thin sheet metal on the rest of the car. This is all I'm doing to the rear at least for a while until I have a rollbar installed ... some year from now. Obviously I'm anxious to see how all the works out on the track but I'm sure I'll have future posts on that.
Cameron
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Dude - you've got way too many projects. Need to step back and figure out what you're trying to get out of them. If I read between the lines you dont really need the money so why are you building two cars just to sell? Unless you're trying to start a business or something take some meds and focus. There will always be a next project. Hell if you do them all now then what do you have to look forward to? I think most who make fast progress have rich parent on summer break from college OR are more how shall I say ... have more years under the belt and their wives want them out of the house anyway so have plenty of time and $$. These are not worth losing your spouse over. My garage time is pretty much limited to after kids (four of them) go to bed plus a few hours on the weekend. But I still do make progress. In fact I expect to get my driveshaft back by then end of the week and hope to be driving the LS1 Z for the first time this weekend. Having a family does not mean that hobbies have to go away but there needs to be a balance. Figure out what's important to you.
Cameron
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Per the 2008 SCCA Solo rulebook for Modified class:
"2. Master Switch - All cars shall be equipped with a master
switch easily accessible from outside the car. Spec Racer
Fords shall be wired per RFSRII. The master switch shall be
installed directly in either battery cable and shall cut all
electrical circuits but not an on-board fire system, if so equipped."
So it appears that ground side is acceptable - that's where I put it anyway
.Cameron
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Only thing I see is the O2 sensor is at the bottom. I've read (emphasize READ no first hand experience) they last longer if mounting pointing up otherwise they collect moisture and can be prone to related problems. Where did that Cat headshield come from?
Cameron
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Pull the head off before you load it. Two guys can lift a shortblock without too much drama. My dad and I pulled and engine out of my first Z when I was 14 this way (MANY years ago). Hell I load/unloaded the bare block myself into the back of my Focus dd to take to the machine shop.
Cameron
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I had the same experience when I ordered mine a couple years ago. I used them anyway and just used zipties to clamp them on. Doesn't work real well but better than nothing.
Cameron
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As far as the anti-sway bar goes, I don't use a rear sway bar. If I did, I would rather attach upward to the strut housing rather than down to the control arm.
I thought this too because you can get better motion ratio / longer end links / more range of motion / more consistent through travel / etc .... HOWEVER wouldn't attaching to the strut also add more sideload to the strut ... the thing trying to be avoided here?
Cameron
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Logically (at least to me
) the 5+ point without the sub belt is worse than stock three point because as you are pushed into the shoulder harness it's only means to resist you is to pull up on the latch which happens to be in the center of your lap thus pulling up the lap belt allowing you to slip under. Like that run-on.... I can notice this because I only use four of the five when I autocross and when I try to cinch down the shoulder straps it forces the lap to ride up. With the factory three point if anything as you are pushed into the shoulder strap it would tighten the lap belt because that is where the reaction force goes since it's all one continuous belt. Could be all wet but it makes since to me.Cameron
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You'll figure it out
When jacking the car one bridge is used for the jack the other one is used for the stands. Not totally necessary but ultra conveint (sp).
ignore the junk see the bridges, one under the Xmember the other for the stands.
Am I seeing that right - is your car in the living room on carpet?
Cameron
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The more I think about it and see the examples here the more I think I might just break down and make a new set of control arms.
Jon - repeat after me:
My name is Jon
I'm a fabaholic
My car will someday see the track again ... maybe
(repeat)
Step away from the welder and get that thing on the track already!
Cameron
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I found a 280z window for my Z for like $12 at the junkyard to replace mine that had some chips in it. Scratch free perfect window! Someone had already taken the regulator too so it came out really easy!
Just look around the junkyards until you find a good one.
Haha ... maybe in "Z Dreamland" but they simply dont exist around here (central Illinois). Everything around here is only late model stuff only and not even pick and pull.
Cameron
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Not to divert too far but those were fun times ... back in the day ... late '90's for me. Back then if memory serves UTA (assuming from your avatar) was using some exotic Jap spec engine. 250 cc vs everyone else running 600 cc which given the ~17k RPM (from memory) could still choke the restrictor. Sounded cool as hell and shifted constantly but the judges didn't take kindly to the $$$. Also remember an aircraft type skin for bodywork but maybe that was another team. Back then mountain bike shocks with push/pull rods were just started to emerge. I was over in the Georgia Tech camp.
Cameron
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Jon - here's something else to think about and an experiment that I think would help validate your thought. Disconnect the top of the strut from the car. Now push the top of the strut forward and backwards with a reasonable amount of force. How much does the top of the strut move? If it's more than very very little then your control arms are not doing anything to help with rotational loads into the strut. Reason is that the strut/housing would have to deflect that amount before the control arm would even start to take load. If the top of the strut moves very very little then the LCA may take some load. One could argue that a stiff control arm would put more load into the strut. In reality the unibody will move around relative to the LCA. By making the LCA stiffer or not using a toe-link type of set-up you are taking away that degree of freedom (flexible LCA/soft bushings from the stock set-up) and as the chassis flexes and gets out of perfect alignment then it could bind up the strut - similar to what is said above. Not saying in the real world that's going to happen nor do I think there is anything wrong with your design I'm just giving some things to think about and a little experiment in your free time.
Cameron
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... but IMO trying to resist the rotational torque via the LCA is like trying to open a door near the hinge ... not real effective nor a loadcase I think the LCA was designed for.
All IMHO
Cameron
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On the home stretch!!! Need some more help though!
in Gen III & IV Chevy V8Z Tech Board
Posted
If you want to save some $$$ then you can take the fuel fittings off a junkyard GM whatever and reused them by carefully (the fittings are plastic) removing the factory hard plastic line and using some fuel injection hose. Or just swap to an entire fbody tank like I did so the regulator, pump, etc is all already there. Again would save some $$$ but eliminates the spare tire well if you care.
Cameron