Aaron's Custom ST16x Econometer

Thanx :thumbsup:


For those that don't know, here's some interesting info on a Vacuum Gauge some call the wonder tool, I'm quoting so don't shoot the messenger :-

There is one tool that can tell so many things about an engine it’s simply amazing. Yes, it’s a vacuum gauge. And it must be the best kept secret to tuning in the world. We’ve walked around performance cars and visited the pits at professional drag races for years, seldom have we seen a vacuum gauge in use.
A few cars have them like most BMWs at one time, but they were disguised as a fuel economy gauge. Besides, the vacuum gauge shouldn’t be in the dashboard it should be in the engine bay. Every car and boat we’ve raced on an ongoing basis has had a vacuum gauge permanently installed on the engine. Not to be viewed while driving but to be viewed while dealing with the engine.

The engine is in fact an airpump. The better it pumps air, the better it runs. A vacuum gauge measures the difference in pressure between inside the intake manifold and the surrounding air, and therefore measure the effectiveness of this airpump. That means that the vacuum gauge can be used extensively both for diagnosing/troubleshooting and for tuning. A vacuum gauge will be mentioned many times in the tuning section on these pages.

So, if you don’t have a vacuum gauge, get one! You can do like us, have a beautiful AutoMeter vacuum gauge complete with mounting cup permanently fixed to your engine, or you can buy a cheap vacuum gauge as a testing tool and use on all your engines. Absolute accuracy is not critical, it’s more the relative movement that is important. And remember to plug it to manifold vacuum, not the ported vacuum port on the carburetor.

Diagnosing/trouble shooting....... Fortunately a lot of different faults can be found with a vacuum gauge, because the behavior of the needle is different to most situations. Here are the 7 most common scenarios (engine idling and warm):

1. Steady needle, at 15-22: Engine in good condition. (An engine with long duration camshaft will have a lower vacuum and a less steady needle, maybe 10-15 with 1-2 “jerks”. That’s still an engine in good condition).
2. Steady needle, lower than normal: Ignition timing too late or vacuum leakage.
3. Steady needle like in 1. but occasionally fluctuates at idle: Ignition miss or sticking valve.
4. Steady needle like in 1. but drops regularly: Valves need adjustment or burnt valve.
5. Floating needle, maybe in the area 10-20: Carb out of adjustment or vacuum leakage.
6. Shaking needle, becomes worse as rpm increases: Ignition miss, blown head gasket.
7. Shaking needle, becomes steady as rpm increases: Worn valve guides If we’re driving and suddenly the engine behaves differently, then we first check the vacuum gauge, then we know where to start.

 

Yes on the CEL diags

Not that I'm aware, the Euro cars have an econometer light which needs investigating - no idea how it works?

16M/sec - Impressive, reminds me of the 80's with Z80. Z88's, 286 and 486 cpu's. Evidently a humble Z80 was capable of controlling and flying a jumbo jet!

 

i want this, with readings like stig said, iat, water temp, boost, oil temp/ oir press, fuelpressure?, injector duty cycle ? and integrated in the dashboard - there is the place
if u could squize a a logging capability that would be awsome, btw. nice work yust carry on, finaly somebody that makes something for 4 gen ...

 

It was common in other Toyota models too, and works quite simple. It's hooked somewhere around the TB, and only measures difference in vacuum if I get it right. So it only gives you an idea of how hard are you pushing the throttle pedal.

 

:lachtot

 

True, but if you go easy on the pedal it will stay green as you still have enough vacuüm but if you put it down immediately it turns orange immediately so it is a bit sensitive and not just on/off.

 

Yup, I guess if you accelerate gently the difference stays the same and it will stay green. And yes again it's not digital, if you increase throttle slowly you can see the green fading out and the orange light fading in.

 

Man this would be awesome, and it would save me having to find space on my bonnet for 20 odd gauges - then I could ditch the flat peak cap and get one to wear facing forward.


Seriously you could market something like this and put autometer out of business

 

Ok, I'm gonna brain dump on you now.

My car:
1989 GTS with a 1999 Calidina motor (genIV 3sgte). Everything about the motor is stock (coil over plug, etc).

Gauges:
I have installed aftermarket boost, oil pressure and water temp gauges. They're all Prosport electronic series.


I'd like to have something to monitor the following.
-oil pressure
-coolant temp
-oil temp
-transmission temp
-wideband air/fuel
-boost/vac

Now I have most of that covered except for the transmission and oil temps and the wideband o2. Would it just be a matter of splicing it inline with the various gauges I have?

 

Either way, we are all going to want to get our hands on this. Nice job aaron.

 

Man this is excellent
That display even looks like the one on my modded xbox -

 

Yup, once again, awsome job Aaron, I look forward to purchasing one of these.

 

I did. It's the Xecuter 3 mod with a 16 bios selector, IR, USB etc.
I used to do xboxes as a hobby but sadly there's no demand anymore and the 360 was no fun (RROD:aargh) at all so I dropped doing it.
http://www.emodchips.com.au/x3lcd.html

I think it would be nice mounted on a panel with buttons to go under the radio, unless someone has a better location