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Megajolt owners...
MikeRJ - 25/11/05 at 11:58 PM

Is anyone using a megajolt to provide sparks on a 20XE? With a TPS instead of MAP sensor?

If by some fluke someone is actualy using this arrangment, is there any chance of a copy of the ignition map? This is for a friends Mk2 Escort rally car which he's preparing on a very "locost" budget.

paulf - 26/11/05 at 09:22 PM

Have a look on the megajolt web site there are some maps on the first page including a base map for vauxhall 16 2.0
Paul

MikeRJ - 26/11/05 at 11:04 PM

Unfortunately only for a 20XE using a map sensor, it's going to be significantly different with a TPS.

paulf - 27/11/05 at 09:49 PM

I think you wil find that the 2.0vx map is for a TPS .The load bins go from 20 to 235, a Map sensor is 20 to 100kpa.This map was modded from the 1800 vx MAP version.
As I see it the map and TPS figures are roughly interchangable, ie if you keep the same advance figures and divide the load sites by the difference between closed and full throttle positions 20 to 235 or 20 to 100 you will have a rough starting point to allow the engine to run well enough to get it rolling roaded.
Paul

quote:
Originally posted by MikeRJ
Unfortunately only for a 20XE using a map sensor, it's going to be significantly different with a TPS.

MikeRJ - 27/11/05 at 10:37 PM

quote:
Originally posted by paulf
I think you wil find that the 2.0vx map is for a TPS .


Well, that's great if it is.

quote:

The load bins go from 20 to 235, a Map sensor is 20 to 100kpa.This map was modded from the 1800 vx MAP version.
As I see it the map and TPS figures are roughly interchangable, ie if you keep the same advance figures and divide the load sites by the difference between closed and full throttle positions 20 to 235 or 20 to 100 you will have a rough starting point to allow the engine to run well enough to get it rolling roaded.


Unfortunately from my megasquirt experiences I don't think TPS and MAP will be anywhere near simmilar. The MAP reading is pretty much directly proportional to engine load, where a TPS is very, very non-linear. Everything happens in the first bit of the throttle opening and then the difference tails of rapidly as the throttle is opened further.

Hopefully it will get it to a rolling road though, not that anywhere around here would be interested or capable of mapping a DIY controller.

paulf - 28/11/05 at 07:54 PM

I understand what you mean about the TPS being non linear and think MAP is a better measure of engine load ,but doesnt seem to be popular as it is not as easy to implement.
When I fitted the megajolt to my car I set a 2d base map and adjusted that for best performance and then added the extra 3d map bins by trial and error , i never had it on a rolling road but it still ran very much better than the original Dizzy set up.Im sure that most rolling road operatives could map the system if you took a laptop along with you , it cant be any harder than the commercialy available set ups.
Paul.

chriscook - 6/12/05 at 03:54 PM

This is the setup i'm using but haven't tried it with the MegaJolt plugged in yet - just in limp home mode. So if you do come up with a map for tps.....

Sorry i can't actually be any help.

Chris