Sooo, who knows what about Megasquirt?

I've done 2 Triumph 6 pot conversions.

The first on my Vitesse in 2006, based on homemade plenum manifold.

www.shadetreegarage.co.uk/Megasquirt1.htm (ancient, crappy and out of date website)
www.triumphowners.com/registry.cgi?section=triumph&vehicleID=574&i=0
Still running largely unchanged since the addition of the ignition part. It just works. I leave it alone.

Goes and has been extensively tested in daily use and by caning it all over Europe several times, including extensive Alpine & Pyrenean action. Engine is standard MkII internally and makes about 120bhp now. Capable of 40+mpg if I can control my heavy hoof (rare!). Typically mid 30s average. Low 20s beating it round the Alps (but huge fun!) about 14 mpg on the Nurburgring (utterly terrifying).

Second is my 2.5PI, done last year. That's based on modded PI inlet & plenum with single TB. Less fully developed as I've only just overcome (I hope) fairly major engine issues (rusted bores, cam lobes missing). Only done 350 ish miles since engine rebuild but working much better now!

Also assisted a friend converting his US spec TR6 which also uses PI inlets and plenum. This is also recent and needs further mapping work but it's gained a good few horses!

PI TBs are a tight fit under a Vitesse bonnet especially with a fuel rail on top. That's why I made my own manifold. PI TBs have 46mm butterflies as standard - which are a bit big, making balancing critical and low-end mapping tricky. Might be some benefit in retaining individual throttles if your cam has alot of overlap.

I use MS2 on version 3 hardware and Ford EDIS 6. This does batch fire and can control 1 coil (or Ford EDIS) on standard hardware. It is possible to add two more coil drivers pretty easily to do wasted spark ignition without the EDIS. MS3 can do sequential (cam sensor also needed) which might help tidy up a ragged bottom end if you have a wild cam, but not much else.

Do take take advantage of the mappable 3D ignition possibilities. makes at least as much difference as the injection itself.

Do buy yourself a wideband O2 sensor - autotune is bloody magic!

It really freaks people out watching you tune a 60s car with a laptop......

Nick

people often use a zetec coil pack and external edis4 box with mega ,

Vitesse




PI


Nick

Based on the Vitesse install:
TB is Rover 216 Vitesse (you'll never find another one of those!) with the AAV cut off (it didn't work), but anything of similar size will be fine. It's 54mm IIRC and that's plenty big - 70mph cruise uses about 6% throttle. TPS was attached already. Lot of people use Rover K series 1800 TBs - the aluminium ones rather than plastic. AAV is a Bosch bimetallic jobby from Golf1 GTi - no ECU involvement.

Injectors from Peugeot 205/309GTi 405SRi. Flow about 214cc/min. Bit big for this engine in fact so using a 2.5 Bar regulator to reduce flow a little. That comes from Vauxhall family 2 8v series of engines (Cavalier/Astra/Calibra 1.8 or 2.0) and conveniently comes with hose tails.

Again, choice is huge - anything with flow in that ballpark will be ok. BMW 320 would probably be good and come in convenient sets of 6.

Fuel rail is a cut and shut of two Peugeot ones as the pair spacing matches Triumph. Ugly but effective.

Fuel pump also Peugeot 405 (same as Astra, Cavalier, Jag) mounted under boot floor and fed from the tank drain via a strainer. I put a short tube section in the banjo so it's not sucking right off the tank bottom. Original line does return duty. Works well - no starvation/surge even when tank almost dry (basic tank shape is a big help)

Trigger wheel from 1.8CVH Sierra, crank sensor from Fiesta. EDIS6 from V6 auto Mondeo and coil-pack also. You can use an Omega coilpack if you prefer - makes plug leads alot less hassle!

Manifold is 1 1/4" exhaust tube, which has 30mm ID matching the port size and some 1.6 mm plate. Suggest you don't bend the runners as much as I did. Misses the clutch m/c by miles but space is REAL tight at the front as a result.

The original aim was absolutely as simple and cheap as possible. Cost under £300 for the injection only, triggered from the points (!) including ECU.
Added the ignition a year later (£100 ish) then the wideband LC1 (£120ish). Upgrade to MS2 version 3.0 wasn't strictly needed..... I wanted barometric correction for the big mountains though. Old ECU is my spare.

Cheers

Nick

Nice idea..... but they might be a bit big. Anything over 40mm is a bit big IMO. PI TBs are 46mm - and are too big - even for 2.5s

Bike TBs from something 600cc ish might work though the spacings are troublesome and you need two sets.....

Nick

Nick, that is superb info up there. Most helpfull thanks.

I think in the interests of under bonnet space/plumbing I'll be building a manifold/plenum and using a single large TB on the end, rather than ITBs. Maybe not 'quite' as efficient, but it will be a lot easier to fit in around the new exhaust manifold I'm making. It may actually be better as the manifold runners could be upswept slightly to get away from the exhaust, whereas ITBs would be rather close and therefore inlet temperatures would rise.

As Nick said, big cam + plenum = low speed shunting.

Get some big snorty ITB's on it man!! :-)

true, but its the conventional wisdom of people like Daves Walker and Vizard - people that know their onions, which is why I listen.

A 275 cam and up is likely to cause reverse pulses, so Speedys' head banger cam is pretty much garunteed to have a low power band like a badgers bottom.

So get on and build it then..... I'm watching with interest

Nick