Okay, the big question!

So, are you using Throttle Position Sensor or a Manifold Absolute Pressure sensor?

Cheers,
James

you can use either but having both connected is definitely an advantage for Turbo'd Engines

i havent got a clue

hello james when i looked into this for my mega jolt i was told that map is fine until you start to use high lift cams with big overlaps
if thats what you want to use then tps is better the only thing i couldnt find out was at what point does this start so i have stuck with tps just to be safe ps i will be running a 285 cam
hope this helps dave

[Edited on 2/12/05 by dblissett]

So where do I put these devices on my 45's????

James,

The Megasquirt in standard mode (Speed Density) uses MAP as the main variable but can use TPS for determining acceleration enrichment and for flood clear functions, although you can use the rate of change of MAP for accel enrichment (MAPdot).

I put both as I'm using hybrid Alpha-n mode in the Megasquirt on the Duratec with individual throttle bodies.
This is where it uses TPS as the main input but also compensates for engine load with MAP.

I changed over to this mode of control after finding that MAP did not give good control at high (90kpa+) values.
Several others I spoke with on the Megasquirt forum seemed to have similar experiences.

Are you interested in which for fuel, spark or both? I assumed both.

Cheers,

Colin

[Edited on 2/12/05 by CairB]

I used Map with my megajolt set up when first installed as i was using a 32dft carb and think that subject to getting a steady vacuum signal it is a better measure of engine load, I also think it is possible to do so on multi carb set ups as long as a damper is used.
I am upgrading to Megasquirt at the moment and intend to use both Map and Tps inputs for the reasons mentioned above.
Paul.

Im using TPs becuase it seems easier to install. However i may change if it doesnt work right.

The latest MS code for MS II uses both and you can "weight" the input from 100% TPS through 50/50 to 100% map.
This gives you the best of both worlds.

[Edited on 2-12-05 by BKLOCO]

I'm using a DTA ECU and Jenvey throttle bodies on a Zetec and I've been advised that it is best to use a TPS on non turbo engines.

Mick

isn't true!

TPS only gives you an "wanted" power indicator and doesn't tell you nothing about the biggest power factor AIR.

The map sensor tells you how much air there is sucked in the engine...

I would use MAP and TPS for Accel enrichment...

for turbo engines you need map because else you cant guess the amount of air sucked in by the engine....(the over pressure)

the problem with TPS and RPM is that it is the more old fascionated way...

I think MAP is more difficult to tune but once done its the best solution...

TPS is more easy...but doesn't deliver the best torque figures.


Tks

most competition engines use TPS as a primary input.

Technically the "best" solution is to use both, but on a naturally aspirated engine TPS on it's own is the best solution in the absence of using both. It reacts much faster and very importantly, it remains linear across all throttle openings, which vacuum most certainly does not.


I use a TPS only based system on my grasser engine, and I don't think its exactly lacking in performance, 204hp from a bog std 2.0 XE vauxhall engine is not too shabby!