MSQ'ing a Lotus 920 (Esprit GT3)

[cammmy]

Hi All

I'm completely new to this and would like to replace the standard ECU in my Lotus with a MSQ.

What I would like to do initially is drop in the MSQ (Probably an MSIII/Extra as this car has staged injectors) with an adapter pigtail and apply the factory map values to the MSQ in order to get the car going as it was. I'd then like to change the injectors and turbo and have the car dyno mapped to suit.

The questions I have are:

Is this a sensible way of going about things?
Has anyone on here ever put an MSQ in one of these?
Does anyone have the standard mappings, or know how I could get them? I have seen the tables for an S4S (2.2L + bigger turbo). The problem is the people who generally have these sell chips; so aren't likely to want to just give me the standard maps (and the chips cost more than an MSQ).

Any advice appreciated.

Cam

[Matt Cramer]

Often, trying to copy a factory map can be more trouble than it's worth, unless you know both MegaSquirt and the stock ECU mapping software very well. The manual has a pretty good walk-through for installing a MegaSquirt on something where no base map is available.

[cammmy]

Thanks Matt, I was hoping that would be a good way to speed up the process and more importantly, reduce the number of chances for me to mess things up.

I actually have your book as well so will be going through that and the manual again many times in the near future.

If anyone does have a turbo Esprit map as a starting point, that would be very helpful.

I guess one advantage of mapping from scratch would be the ability to ditch the secondary injectors? Or would it be worth utilising since everything is already there? I'll need all the help I can get for the emissions test so best to keep smaller primaries?

Thanks
Cam

[Matt Cramer]

MS3's secondary injector control code is 23 years ahead of how GM ECUs controlled the secondary injectors. GM just switched them on with a relay and cut the duty cycle in half; the relay's time delay made for extremely rough transitions. MS3 can simply ramp in the secondary injectors gradually so you can't tell by feel when they cut in.

[cammmy]

Brilliant, thanks.

[cammmy]

Hi All

This has been a pretty slow process, partly because I'm learning as I go along and also because of problems I've had with parts not fitting; nearly there though! The last bit of wiring is for the VSS which has gone from a 2-wire sensor to a 3-wire, then it's time to plug in the ECU and start testing.

My question is. for a base MAP, could I use some of the MR2 Turbo settings (particularly the spark table) from the below page and dial them back a bit, just to get it running under it's own steam and onto a dyno?

http://www.megasquirtpnp.com/mspnp2_maps.php

My car is a 2L Turbo that probably makes slightly more power than a stock MR2 Turbo.