I'm a project oriented guy and with my brother's recent transition into the darkside I have also been able to experience the "change". I'm a N/A guy so a turbo car is different but fun in different ways. I built the map limiter as an early christmas present and I added my own touch because I felt it was needed.

I noticed that when I drive my brothers car (the turbo car) not only does it throw a code but it's difficult to start from a stop with the code and the stage 4 clutch. I also noticed that I never can pay attention to the boost gauge, especially when it reach's 10lbs and pulls HARD. The LED's you can see from the corner of your eye so its much easier to monitor. I also have a thing for lights hehe. Take a look at the pictures below, I slaved over that damn point to point board forever but it was fun and difficult all at the same time.

As seen below its a simple circuit but I also added the LED display to display boost pressure. Each LED represents aproximately 1lb of boost. On long high gear pulls, when the vacume gauge catches up the gauge and the LED's are no more than 0.5LBS apart. I really like the led's too because they show you when its spooling (yellow) when its in normal (average) boosting range (green) and when its excessive (for a stock motor) red. BTW it was designed before my brother uped boost to 10lbs heh. I have a video but for fear of running out of bandwith im not going to post it. However if you REALLY need to see it just PM me.

Check it...







And save the best for last, my slaveing over the board for literally hours to wire every pin correctly without burning other wires or creating shorts what a pain.


Testing ....





I could be picky and calibrate it further (using 4 potentiometers) but its close enough and I'm tired. Hope you guys like it.

 

thats some serious proto-board soldering there. nice ground rail.

 

Looks very nice, i wish i knew more about electronics.

Rob

 

Schweet. Easier to pick out colors from the corner of your eye, than to pick out which number your needle is on. Take a look at the shift lights the pr0s use...greenyellowred.

 

That is a great idea. Can you make me one? Here is some Ebeer

 

... willing to share schematics?...

 

Yeah, you'll have to wait until I get back to school however.

Will post later. peace.

 

Hey guys, do you think I should try and put together a kit for this with a pre-routed professional PCB? Let me know and I can start laying it out. With the PCB (printed circuit board) just about any one who can solder could put it together and all you need is a multimeter and a 13+V power source to test it.

 

Sounds like an LM3914N to me hehe

 

yup its pretty straight forward, just a few reference voltages and your there. The hardest part is fitting it into that box so if you want a big one - it should be easy


[Modified by stizzit, 9:41 PM 10/8/2002]

 

 

Hmm...Purdue University,

sounds like an Electrical Engineering student.

 

uh huh!

 

I want one pretty please.

 

Stizzit is the shiznit. When can we expect our first HT group buy?

 

I would love to see these in H-T'ers cars and Im not out to become rich (until I graduate hehe) however there are a lot of other versions of this device (minus boost indicators). If there is interest I will put together a pricelist to build 10 units (decent discount from electronic suppliers in qty of 10) and will only mark up for the time i will spend layout the circuit boards and then assembling and testing the units. You guys tell me what YOU want.

B20C5: Thanks!

BTW: I cannot take full credit for the MAP limiting part of the circuitry, I took filetofit's concept and modified it (and simplified) accordingly, so props to him for such a clever circuit.


[Modified by stizzit, 12:55 AM 10/9/2002]


[Modified by stizzit, 12:56 AM 10/9/2002]

 

[qoute]Sounds like an LM3914N to me hehe[/quote]

ahh....the LM3914N.....thats what I make a/f gauges out with!

 

id like to see some schematics

 

legendboy: yeah its a good chip mostly, a bit expensive and very picky as to the supply voltages a currents.

Aeka: You've probably already seen it, a simple LM3914 and op amps as in filetofits circuit with a few pot's and your done.

 

... i thought it was a LM6134AIN... not LM3914... or did you switch chips with your modifiations... can you please clarify?... thanks...

 

... also, can any of you EE guys (filetofit, stizzit) out there develop a custom circuit that allows more than 2 adjustment point... like 3 or 4... i would like to run something similar to this (w/550s)... -35% at idle, -45% across the board, and -35% at wot... lemme know... thanks...

 

What about Zip's SMC?

I believe filetofit has the circuit at the bottom of his webpage to run 440's as for the adjustments I dunno if he included them - havne't looked at that much. I could make a circuit to use thottle position to determine map cut like you're talking about if you wanted. You say -35%, -45%, -35% but I assume these are AFC readings which are generic? Do you know what map voltages you want?


[Modified by stizzit, 9:01 AM 10/9/2002]

 

i could be wrong... but i thought the smc ran off of rpm and not throttle position...

 

so all you want is throttle position, not rpm?
the circuit just got more complicated tho
I'd have to think of an simple way to do it but off the top of my head
you'll need 2 comparators to determine WOT from idle from mid


[Modified by stizzit, 9:29 AM 10/9/2002]

 

... i think that rpm dependant is the most desireable (like the vafc)... however, i think that it would be very complicated and difficult (i am no ee guy so i dont know for sure)... but i would be interested in a circuit like filetofit's except instead of having only 2 adjustment point, having 3 or 4... to me it seems like it would be another op amp or two and more potentiometers... but like i said before... i am no ee guy...


[Modified by 1.8T_EG, 10:10 AM 10/9/2002]