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Shock pots are definitely in the 'extra for experts' category when it comes to datalogging. At the level we are all at there are HEAPS of other better return for the money things to work on. Don't let me put you off if you just want to do it for fun though as I'd love to have shock pots on my car too. I have a good mate who used to do data analysis in the IRL (now V8 Supercars) and when I asked him what the 5 most important sensors on the car are his reply was 100% those that quantify driver input. Like Rookie says even professional drivers can be pretty shit and you can learn a lot from some basic data. His top 5 were: Throttle position Steering position Brake pressure Speed Gear Roman I think you should buy one of these http://www.autosportlabs.com/racecapturepro-2/ Imagine all the awesome MS paint graphs you could make then? I'd enjoy this shit out of reading your project thread updates that's for sure. It was interesting to see that not a single person in SS2000 uses any data analysis. There may be some drivers logging data but I saw only 1 laptop out at the track the other weekend and I'm pretty sure they were only looking at engine stuff.

Something that's been rattling around in my head for a while now is what is a good way to accurately measure suspension points on a car. I would really like to model the suspension of my AE86 and do some analysis of it in a program like Susprog3D (http://www.susprog.com/). Ideally I'd like the points accurate to within 1mm. The easiest way I have seen is putting your car on a hoist and leveling it over a big sheet of board and just using a plumb bob to project the points downwards. Anyone got any good ideas for how to do this easily and cheaply?

I use VRMesh a bit. Good for taking a point cloud and turning it into a stl. Not good for turning surfaces back into features though. I'm pretty sure Novamech uses this package http://www.innovmetric.com/en/products/polyworks-modeler

How about getting one of the Walbros (just because they're cheap/plentiful) that do E85? That seems like something worth future proofing for.

I'm going to suggest just scaling the fuel tables linearly based on the new-old injector sizes. Assume dead times will remain the same. It should be fine for initial running. Having said that I have a LC1 that you can buy/borrow if you want?

Lots of guys run the standard cast manifold with good success. If you want to save a couple of bucks then it's easy to do later. The downpipe made a big difference up top when I fitted one to my Silvia though.

Unless the battery is completely poked then that shouldn't be the source of your woes. Still, it's easy to check I guess. Take the alternator out and have it tested would be my suggestion.

Ok sure, but if all you need to do is scale the output then adjusting the reference voltage will work fine.

Oh and it will be linear. I've never seen a TPS that isn't (now someone will prove me wrong haha).

Another couple of thoughts. Does the ECU have a TPS calibration mode? Most do. Maybe the ISC valve is working sweet but it's fully opened when running and still not enough air is flowing. What happens if you crack the throttle stop a small amount to allow some more 'base' idle flow. I can imagine this could have been messed up through the process of swapping throttle bodies? Bit of a long shot and maybe you've already checked...

The voltage modifier that Silicon Chip did a few years ago is pretty much the only 'off the shelf' product I can think of: http://archive.siliconchip.com.au/cms/A_111774/article.html I think it would take care of your two problems fairly simply. As already mentioned by H4ND you should be able to swap two of the three wires on the TPS to reverse it's action. If it's also giving you the wrong range I can think of a couple of dirty hacks that could help to scale the output. Basically your TPS is acting as a variable voltage divider between GND and some reference voltage (probably 5V, 8V or 12V). So you have GND on one terminal, the reference voltage on another, and the variable voltage output on the third. If you want to double (for example) the output then all you need to do is double the reference voltage. You need to be careful that the maximum voltage that the ECU sees is less than the reference voltage otherwise you're likely to see smoke or possibly start relying on the protection circuitry in the ECU which is not great. Building a small high accuracy reference voltage supply is 100x easier than any other option I can think of (including the voltage modifier above).

It might be worth asking Sheepers. I think he had some done recently.

The entire Motorsport Manual is available online: http://www.motorsport.org.nz/resources/motorsport-manual Schedule A is the one that relates to how the car is built. The rest of it probably won't be of huge concern until you're ready to go racing.

Lucky for you this is one of the more clear parts of Schedule A. Have a look here under section 4.12 article 1. (h). " Where fuel lines pass through the cockpit metal tubing or hose with an outer steel braiding shall be used and any joins in the fuel line shall be made with industry quality threaded connectors. " So you're fine to do this with either metal 'bundy' tubing or braided line only. Any connections have to be with AN fittings, not brass barbs and hose clamps. It sounds like this won't be a problem for you but any tanks, pumps, filters, etc must be isolated with a fireproof firewall if they're inside the cabin.

This totally needs more explanation/pics/burnout videos. Well done Amy!

1st sentence = Ned's not really wrong at all. His description is just more technical than the level you're thinking about it at. 2nd sentence = Wrong. You have this upside down. When the points open the primary side collapses and this induces a voltage in the secondary. Along with the voltage being induced in the secondary you also have back EMF which creates a large (negative) voltage on the primary side (across the points). The condensor sucks up some of this back EMF energy and therefore reduces the arcing that eventually burns out your points and creates noise on your stereo. 3rd sentence = Also wrong. The current doesn't really matter. It's the high voltage in the reverse direction that creates the arcing that burns out points. I just want to make sure we have the tech straight. I know it's not really relevant to this thread but some of the stuff up there ^^^ is pretty misleading.

Just to clear up some confusion here. Dave's not entirely correct. Not all condensors have the same capacitance (as KK suggests). Now I'm not sure how you know what value you want for a specific application but there're definitely not all the same.

No problems. I know bugger all on the subject and wouldn't mind educating myself is all.

Spence, how long ago did you read the article in racecar eng about slide throttles? I tried having a look for it but didn't have any luck.

I like KK's idea because at the end of the day it looks like welding is going to be the only option. Damn pen pushers! If you weld to the corners there's a huge amount of heat sinking. Plus you could always weld it as a series of tacks or stitches, like you would on a piece of sheet steel to reduce warping. Cool it down after each stitch or something?

That looks awesome dude. What's your plan to finish these parts? Tumble them and then anodise? Cheeky question. Would your mate be willing to do CNC machine work for others at prices that aren't as expensive as retail rates?

I totally understand re. trust issues. I'm exactly the same. But some fights just aren't worth fighting in my eyes and rebuilding diff heads is one of those things. It's not through lack of wanting to learn how to do it either. I'd just hate to miss a race meeting because I forgot to put a washer in because I'm not doing it for a living every day. Good to see you've found the problem.

Step 1. Weld up open diff head for drag day. Step 2. Send the LSD to Steelie Gears like I suggested 2 months ago! Is it the same noise regardless of what direction you turn?

If you open it up and take some high res shots of both sides of the circuit board I can make some educated guesses for you. Assuming Ed can't come through with the info...

I imagine the cost to make them diffusion-proof would outweigh the benefits?