another DIY FCD and other DIY links of interest

[kidwired]

Hey you brainiacs,
I found this DIY FCD, just wonder what you think?
http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

[Tleg93]

It seems ok to me. I think noise suppression is a good idea. I'm not too big on having a potentiometer in the circuit because they tend to drift with temperature. It just seems like a potential headache.... Anybody get that?

[kidwired]

I just found something else VRG3 may be intersted in, I recall a post about a throttle controlled FCD?

anyway found this article on DIY BOV and it has info about a gadget that monitors the throttle position sensor

http://autospeed.drive.com.au/cms/A_2181/article.html

[kidwired]

wow this guy has some great writeups on Turbo DIY stuff. I'm too tired to keep reading so you guys have at it.

http://www.xmission.com/~dempsey/perform/

[vrg3]

I found this DIY FCD, just wonder what you think?

That design is a lot like my initial design. My revised design is a little better, I think, because the offset voltage has a slightly smaller effect. Mine also has a lower output impedance, though that shouldn't really matter in real life.

Scott's probably right that a low-pass filter on the input is a good thing. It couldn't hurt to stick one on the input of my FCD.

If you do decide to build this one, don't use an LM358 as they suggest. It's only rated for 0 to 70 degrees Celsius. The LM224 is basically two LM358s in one package but with a wider temperature range.

It just seems like a potential headache

You can actually eliminate the pot if you just pick some appropriate resistors though.

anyway found this article on DIY BOV and it has info about a gadget that monitors the throttle position sensor

That gadget is similar to what I described in the thread about a TPS-controlled MBC but with a timer attached, but based on the rate of change rather than the position.

wow this guy has some great writeups on Turbo DIY stuff.

Yeah, the mini-Mopar crowd was one of the first to start doing easy cheap mods on factory turbo cars. Very cool.

[Tleg93]

Are you selling the FCD's Vikash? Maybe I'll just use the LM324 but I'm just curious what you're asking, if you are. PM me.

[vrg3]

I have built and sold some before, but don't have any right now...

Don't use the LM324; it's got the same temperature limitations as the LM358. The LM224 is what you want.

[Tleg93]

Hmm, why not use the lm124 then? It's temp range is from -65 to +150.

[Tleg93]

Ahhh, I see why. It's only available in an soic package. It's mil temp spec though.

[Tleg93]

Three posts in a row, woo hoo.

I just ordered six of the dip package lm224's and a couple of the lm124 surface mounts. I have some surface mount pcb's I'm going to try and make a small package style device.