Dave Robsons Challenger R/T

Jeff · Post by **Jeff** » Wed Oct 08, 08 3:10 pm

Hey hey! Veroboard...... Have not used that since my Amateur radio days.

Dave-R · Post by **Dave-R** » Wed Oct 08, 08 3:19 pm

There is probably a better product to use these days for all I know but that is what I used to use in the late 70s to mid 80s which was the last time I made anything like this.

Jeff · Post by **Jeff** » Wed Oct 08, 08 3:25 pm

It does the job Dave! I am sure once you seal it all up, it will last forever.

Dave-R · Post by **Dave-R** » Wed Oct 08, 08 3:44 pm

Better not seal it up in anything just yet as I might need to make another one to run alongside it depending on what I hook up to it. This thing will only run 1.5 amps without getting too hot.

I still want to figure out a way to fit two throttle position sensors on the six pack. One on the centre carb and one on one of the outboard carbs. That way I will be able to see exactly when the outer carbs are open and how far.

MetalChuckKey · Post by **MetalChuckKey** » Wed Oct 08, 08 6:59 pm

Dave wrote:There is probably a better product to use these days for all I know but that is what I used to use in the late 70s to mid 80s which was the last time I made anything like this.

Nah, the original and best, here's my 5v regulator I built a few months ago

Dave-R · Post by **Dave-R** » Wed Oct 08, 08 8:55 pm

Mine is better looking than yours.

Dave-R · Post by **Dave-R** » Wed Oct 08, 08 9:00 pm

Still can't get this vacuum sensor to work though.

I seem to have 5v on the output of the sensor which if it was working would mean 1 Bar negative pressure.

I hope I have the wires into the sensor right.

Green +5v.
Grey common.
Black signal voltage.

I have tried connecting the wires up differently to see if it will work at all but still nothing.

Driving me up the wall this is. I wish I knew more about modern car electronics.

Dave-R · Post by **Dave-R** » Thu Oct 09, 08 11:08 am

I tried every possible combination of wiring the MAP sensor up last night (6 different ways) with no luck. Can't get it to work. So my only conclusion is it is knackered.

Dave999 · Post by **Dave999** » Thu Oct 09, 08 11:21 am

whats the code number of your MAP senser?

should be able to find a product sheet

is it a

Freescale MPX4250AP ?? i.e motorola

http://alpha.octopart.com/Freescale_Sem ... 4250AP.pdf

dave

Dave-R · Post by **Dave-R** » Thu Oct 09, 08 11:28 am

I will check tonight. Thanks Dave. That sheet you linked to actually helps a lot because now I understand what it is and how it is supposed to work. Thanks.

andyrob · Post by **andyrob** » Thu Oct 09, 08 11:47 am

whens this car goona be ready ???:lol:

less effort went into building the space shuttle

Ian Z · Post by **Ian Z** » Thu Oct 09, 08 12:05 pm

less effort went into building the space shuttle

and look what happened to that.

Dave999 · Post by **Dave999** » Thu Oct 09, 08 12:12 pm

well you can get them from farnell if yours is broken

15 quid i think

there was a global shortage so i had to get one from the US but that was about a year ago. I had to promise i wouldn't use it for terrorism (fax a signed declaration and everything) before they'd let me have it...said i didn't care about the pressure wave caused by my exploding jacket i just wanted it to measure the prototypes i was testing out in my back bedroom

loads of extra pins just for mounting....they are not supposed to be connected to stuff

only 3 of em do anything useful..

if you find a nice bulkhead connector for taking your MAP signal from the manifold through to your box of electroniccy bits let me know

i've just got a a hole drilled through the side of me box.....and id rather have a nice brass 2-3 mm OD bulkhead fitting with barbed connector on each side so i can keep my MAP sensor in a metal box in the car and just run a pipe to the connecion on the carb.

been trying Model stores.....a petrol or methanol Tank kit for model car boat plane usually comes with such a fitting but you end up paying for the full tank set and 40 odd quid for a 2 quid brass bit seems a bit steep.

you can buy plastic by the 1000 or 10,000 but i don't need that many

Dave

Dave-R · Post by **Dave-R** » Thu Oct 09, 08 12:20 pm

I admit the car has become a "low priority" since that mad dash to try and get it ready for the Nats.

But to be honest. Just taking my time and doing the odd little bit here and there is actually very nice. I don't feel under any pressure and it is not holding back my recovery from illness.
I actually feel very well at the moment. Probably the best I have felt since Jan 07. It's a nice feeling. I don't feel so old.

I would have been finishing that exhaust pipe this week but I ran out of welding wire last Sunday and can't get any until this Saturday. Saturdays are good days for a bit of welding anyway. I don't know why. They just are.

Working MAP sensor of not I will finish breaking in the cam (or breaking the cam) and get the timing and idle mixture right at least before this month is out. I am not going to go anywhere with it this year. Too skint now anyway. But it WILL be on the road early next year. I am 100% sure of that.

Dave-R · Post by **Dave-R** » Thu Oct 09, 08 12:35 pm

Dave999 wrote:if you find a nice bulkhead connector for taking your MAP signal from the manifold through to your box of electroniccy bits let me know

I was thinking of mounting it where the ballast resistor is because I don't need a ballast resistor any more and it will require just a short(ish) length of hose to run to the carb base. The 5v regulator I will mount either under the dash somewhere or behind my electrical board where the battery used to be. I have not decided yet. I only have to worry about losses in the cable from the sensor to the LM-1 meter.

I think I might pinch the TPS sensor off the Neon at the weekend and see if I can figure out how to mount a couple to my carbs.

At the end of the day, even if I get non of these sensors working, I will still be able to record air/fuel and rpm. The aim is to adjust the center carb for good mileage. With the outboards tuned for max power. I have tried to do that anyway. But probably not as well as this system will allow me to.