Birdman's Back To Front XE Build

[gazwad]

Glad to see you're getting back on this, would be good to see you out in it next year - join us for a trackday or two maybe? Throttle bodies will sound awesome!

[Birdman]

Glad to see you're getting back on this, would be good to see you out in it next year - join us for a trackday or two maybe? Throttle bodies will sound awesome!

Thanks Gary. We will see if it works out.. Engine issues to be addressed first / rebuild, then upgrades. Would be good to get a power run done at dyno on old induction and then again after on ITB's. I'm thinking about Shrick 276 Cams maybe.

Just spent first day cutting and grinding on the frame build for the Saab mini. Went quite well.. I will update that build thread soon.

[Birdman]

So the 2nd hand Megasquirt turned up in the post for £100. All seems v good condition inside the casing. It is a Megasquirt 2 version 3.0.. So not the latest, but not the v early ones with obsolete processor. Will have a fair bit of functionality. Next up, get a cable and download Tuner studio to see what project map is currently loaded, I also need to identify a few fly-lead wires on the main Bosch connector that goes between the ECU and the standard XE loom.. 4 are connected to a relay, so that may be either be for coil or fuel pump , the other 2 I don't know. Probably understand a bit more when can see the map. See if it was configured for a MAF, like std car or another sensor. Anyway, happy for now... 20210925_085823.jpg 20210925_085833.jpg 20210925_085807.jpg

[Birdman]

Downloaded Tunerstudio and Mega Log Viewer yesterday. Wow, there is a lot to learn. Good job this is a longer term project. Set about trying to work out the wiring and pinouts on the short loom from Megasquirt to Bosch Motronic 55 pin connector. Worked out what many wires do, but very difficult without serious magnifying glass to see what pin numbers have been soldered. I think I will have to break out the test meter and ring through to the front pins, because impossible to see what is really going on , on the backside of the 55 pin multiplug. My eyes are shot. I have read in the Megasquirt manual, that there is an ITB mode that takes MAP for some of the rpm range and I think Speed Density for the lower RPM range. This was created because ITB's can give crazy vacuum fluctuations at lower throttle openings. So I think I will be using that, TPS and Engine speed for main sensors, with CTS etc for correction.

[Birdman]

OK, spent the other night with test meter ringing through the 55 pin connector and have worked out what the 16 or so wires on the short harness to Megasquirt are for. So it all seems wired correctly with Sensors: TPS, CAS and CTS wired to the connector and two fly leads that would connect to O2 Sensor and MAT. Then there is the inbuilt MAP sensor actually in the Megasquirt. So that should facilitate everything fuelling wise. I don't think I will know how ignition was being controlled until I start up the ECU through tuner studio though.. Bought serial to usb coms lead for that, but now seems have to power it up as well.. Not sure if I should get a JimStim to facilitate that and to test the ECU is handling signals from Sensors.

[Birdman]

Very little happened this year so far on the White Mini. Certainly too hot in the garage this summer. Picked up a this item though for a few £. It is a stainless head shim with multi layer steel gasket each side. Reusable and gives 1.9mm gap. Enough to turbo an XE to medium power, without a change of pistons. At the price of £9.99, I had to have it. Have always thought about stealth turbo install, with barrel charge cooler, better radiator set up and turbo hidden behind the back of the sump. I think I could have room and use a spare little GT25 from Saab that I have. Have map sensor on the Megasquirt, so its an option for one day.. I reckon I would need a n external scavenge oil pump to provide a return.. 20220804_114651.jpg Just thoughts and dreams for now..

[Birdman]

Got a C20XE Inlet manifold for £19. Chopping time.. 20221217_115758.jpg 20221217_133724.jpg 20221217_133734.jpg 20221217_115850.jpg

[Birdman]

The GSXR 750 throttle bodies are currently spaced for a Zetec, so I need some longer 6mm studding. I think middle bodies need to move out 3-4 mm outwards and the the end bodies about 8mm. Got spacers sorted. Not an urgent project, but I wanted to get the cutting done and throw the rest of the manifold away.

[Mini Vlatko]

It looks to me that you're doing exactly same thing as I did
If you need any measures (spacers for example) or pics just let me know...it's no bother

[Birdman]

Work in progress, but got some m6 studding and some alloy spacers of various sizes. Bit of a struggle removing the original m6 studding. Part way converting the GSXR750 ITBS from Zetec spacing to now XE spacing. Next up, brackets to hold XE fuel rail and some bungs for the original bike ITB injector holes... 20230403_175341.jpg 20230403_175347.jpg 20230403_175418.jpg 20230403_175421.jpg 20230403_175448.jpg

[Birdman]

Got a jimstim from the USA, so I can test my Megasquirt 2 ecu, just need a couple of leads and I should be able to simulate all the sensors and hook it up to Tunerstudio. Check it works firstly, then save the XE ITB map that I was told is on it.. Thinking I may actually use the ECU on my other project with the SAAB engine. Might also buy the upgrade daughter board to make it Megasquirt 3. All ideas at present.. 20230513_181158.jpg