Complete Megajolt Ignition For A Pinto - Advice Please

[Guest donaldthomps]

Hi, thinking of getting a complete Megajolt setup from these guys.

 

http://www.ebay.co.uk/itm/320635841566?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Has anyone used these setups before, will they make the engine run better?

 

I have a 2L Pinto with a Fast Road CAM and Weber 45's going on.

 

I guess the TPS version is best?

 

Thanks

 

Donald

[richardm6994]

Yes, yes and yes.

 

The eBay seller is triggerwheels....(google to get to their website) which is the best place to go for mega jolt.

 

I ran tps and its easy to set up but I've been told map is slightly better.

 

Power was really smooth with mega jolt and i would suggest it to anyone (I'm going to be running it on my v8 as well!!)

 

 

[Shaft]

I had it on my pinto also Donald. Ran MAP and can highly recommend it mate.

[Guest donaldthomps]

I had it on my pinto also Donald. Ran MAP and can highly recommend it mate.

 

Hi, is there any additional setup or parts required for the MAP version?

[Shaft]

Depends on your inlet / carb choice mate.

I had bike carbs and therefore 4 individual inlets. I knocked up a plenum to feed the MJ so it had a even feed otherwise it would pulse due to the firing order.

We can have a better chat at Newark Donald.

[Guest alfaGTA]

Mine is also running MAP off a fitting on the original pinto inlet manifold, if you are ordering a new megajolt specify which sort you want-map or tps. There are plenty of ignition maps around that'll get you up and running 90% then a rolling road session to get it safe for your engine, worthwhile upgrade for drivability but not much more bhp

[Snapperpaul]

In my opinion and it is only an opinion

MAP is an actual measure of load

TPS is an approximation as it only measures throttle angle

That said both work well

I have MAP fitted but also have a TPS version i intend to fit both in the future and test

[Dave R]

i aways understood, tps unless you run turbo/supercharger ?

 

was told map would work normally aspirated, but you lost some of the available map table ?

[Guest woolly]

I built mine from a kit very pleased with it as said very smooth proved reliable over 2 year's so far except dodgy second hand crank sensor.

Highly recommended.

Webber tps not cheap from experience if map then will have to be well damped with the Webber

[Guest donaldthomps]

So for the MAP version, can the vacuum be feed from the manifold on weber 45's?

 

And excuse my ignorance - the one feed from the manifold is enough / correct?

[Guest donaldthomps]

Depends on your inlet / carb choice mate.

I had bike carbs and therefore 4 individual inlets. I knocked up a plenum to feed the MJ so it had a even feed otherwise it would pulse due to the firing order.

We can have a better chat at Newark Donald.

Hi, I have weber 45's - and thought the vacuum feed from the manifold?

[Shaft]

My take on the TPS versus MAP debate...

 

TPS only lets the ecu know how much the throttle is open at any given moment.

How is the ECU to determine from this single piece of information the load the engine is under? Half throttle in 2nd gear crawling in traffic is completely different to half throttle in 5th gear going uphill on the motorway as far as the load the engine is under is concerned.

 

MAP on the other hand isn't interested in how much the throttle is open and responds entirely to the engine load.

 

Downside of TPS is the possible cost if having to retrofit.

 

Downside of MAP is having to ensure it reads a consistent and balanced Hg value from all cylinders.

[Shaft]

 

Hi, I have weber 45's - and thought the vacuum feed from the manifold?

 

Will have a chat at Newark mate.

[Snapperpaul]

You don't loose any of the map

The base setup covers turbo but if NA you just change the Kpa settings

You can change every setting in every box whether MAP or TPS and change the resolution for revs I.e you want more adjustment up to 3000rpm then less after that

Easy

Most engines run to max advance by 3800rpm then go flat you can modify the map to max revs and also run much more advance on light throttle/ over run

Basically it will copy your 2D distributor and the vacuum advance then do that for every rev/load combination

I even run much less advance on cranking to help starting on a high compression engine then as soon as it kicks the advance springs to 16+ degrees, holds for 50 to 1200rpm then rises quickly to max advance.

There is also a function to record live data as you drive, it identified for me a VR sensor wiring fault but all the data shows is acceleration in milliseconds between map points

Whilst I sort of understand as in if you change settings and it gets quicker carry on, if it gets slower go back, doing this on the road, which you can as you can run with a laptop connected and change settings on the fly

But I think you would spend less on petrol and time if you rolling roaded

[richardm6994]

 

 

TPS only lets the ecu know how much the throttle is open at any given moment.

How is the ECU to determine from this single piece of information the load the engine is under? Half throttle in 2nd gear crawling in traffic is completely different to half throttle in 5th gear going uphill on the motorway as far as the load the engine is under is concerned.

 

 

TPS and MAP both have 2 pieces of info at any one time to determine the ignition timing, which is why they are both 3d ignition systems. In the case of TPS it compares the percentage of throttle opening against crank speed.....i.e. 2500rpm at 100% (5th gear crawling) will be a different ignition timing to 6000rpm at 100% (5th gear flying).

 

MAP also works out how much throttle you have open at different crank speeds, but it does it by measuring out how much vacuum there is in the inlet manifold (the less vacuum the more the throttle is open).

 

Both systems give very similar results as basically you are measuring the how much throttle opening you are giving through the rev range....

 

no vacuum at 2500rpm is the same as 100% throttle open at 2500rpm (both the 5th gear crawling scenario)

 

MAP comes into its own mainly when turbo or superchargeing as manifold pressures / vacuum no longer give an accurate indication of throttle opening..

 

That's how I understand it anyway....