Zetec injection question

[Bonzo]

Early days for me & my 1.8 Zetec install but I have a bit of a dilemma over the injection method.

I'll start from the beginning.

After almost 2 years of worrying about engine choice I finally opted for the 1.8 Escort Silver top Zetec engine.

I will be using the Megasquirt ECU to run the engine.

I ended up with 2 sets of throttle bodies. CBR900 R1 & CBR900 R2. ( Long story )

After a bit of reading & a nice chat with Martin Jeffery ( Engine tuner )
It would appear that injection, directly into the head is a little more effective than injection into the thottle boddy.

As the Zetec has a separate injector rail, both options are available when I make the inlet manifold.


If any members have chosen the Zetec + throttle body combination, I would love to have your input.

[adrianreeve]

Ronnie

It's reasonably easy to do both. After a fair bit of research, I decided to use the injectors in the throttle bodies, as the performance difference is marginal on an otherwise standard engine. It seems to have more effect on torque tahn power, and having the injectors in the manifold tends to bring the power band slightly down the rev range. For high states of tune, this will make more of a difference, but as I say, for reasonably standard engines, it doesn't make a lot of difference. It's far easier to make yourself a manifold if you keep the injectors in the throttle bodies, as then you're basically looking at a flange and four tubes. However, if you decide to go with injectors in the manifold, an ST170 manifold has injector mounts, and also 4 useful stubs to mount your bike bodies onto. Been coverd many times on various websites,a nd I'm sure you've already Googled these!. Just beware, if you're not using the manifold on an ST170 engine, the manifold doesn't line up as exactly as some would suggest, and to get the best out of it, you'll need an adapter plate to address aroughly 10mm step between manifold and head.

Hope that helps!

Cheers

Adrian

[Bonzo]

Cheers Adrian

Martin Jeffery did say it was rather dependent on how far I am looking to go with the engine. ( Power wise that is. )

To be honest if I manage 140 BHP without too much expense I would be quite happy.

The 1.8 Escort is listed at 115 BHP as standard. Perhaps if I fit a pair of 2 litre cams & a good tune with with the megasqiurt then I should be near the mark.

I have been unable to find any data on the flow rates of the Honda injectors.

Have you any data on them Adrian ?

The Fireblade R1 bodies are from a 929cc engine ( Black injectors )

The Fireblade R2 bodies are from a 954cc engine ( Green injectors )

[adrianreeve]

I'll have a look for you Ronnie.

I've got a 2l Silvertop, and I'm hoping for 165-170 bhp with bike bodies and a decent exhaust (plus of course the megasquirt map). Think you may be pleasantly surprised with your expectations!

Cheers

Adrian

[Bonzo]

Thanks again Adrian

I did find a small amount of info on the MS forum, mainly guestimated flow rates based on BHP produced by the original engine.

My searching was interupted buy a new search.

Trying to find the operating range of the IAC stepper motors that I have found.

When I built the Megasquirt I opted for the stepper motor idle control as opposed to the original ford type idle control unit.

I did find a couple of stepper motors in self contained units that are ideal for the job. Rover K series unit & a Renault unit.
All I have to do now is find the tec data on them.

[spud69]

Took mine to bogg brothers yesterday and achieved 160hp at the wheels for a 2.0l blacktop, zx6r carbs + megajolt. All for £400, very pleased...

[Bonzo]

160BHP at the wheels is good going, only costing £400 too

The engine tuner that done the mapping on my eldest lads scooby is quite familiar with the Megasquirt system so loose plans have been made to give the car a final mapping once it is complete.

With a little luck I will able to get things somewhere near the mark

Bike carbs & Megajolt are my plan B if things go pear shaped with the MS & Injection.

[adrianreeve]

Ronnie

Where are you going to plumb in your IAC Valve? I was wondering about going without, as the CB900 bodies have what is in effect a choke cable that I could use instead, but it does seem abit at odds with the control you get with a mapped system to then have a 'choke'.

Hmm, not sure!

Cheers

Adrian

[thwang]

hi spud
bogg brothers are they daves sons if so has dave retired now?
thwang

[Bonzo]

Hi Adrian.

Yes the CBR throttle bodies do indeed have a wax-stat auto choke.

I have no idea how it would function in conjunction with the MS ECU though.

I have stripped the chokes from one set of bodies & think it will be easy to adapt them for the air intake pipes from the IAC unit.

I suppose they could also be blanked off & the extra intake pipes placed into the inlet manifold stubs.

I'll try & get a couple of pictures up of the IAC units I have found.

It would be a good idea to try to post a sketch or two to show how I intend to set up the IAC system.