New to injection, help needed.
Turbo Mini Forums

I'd like to go over to injection on a 1310cc engine that im building using megasquirt.

I wanted to know what would be the best throttle body to use, i take it i can use an SU manifold (i have a hif44 manifold if that could be used?)

I did email jenvey but they told me to use a weber style TB but i didnt want to mod the bulkhead.

Thanks

Hi,

If you want to keep your HIF44 manifold then you'll be thinking of a wet manifold system. There are lots of pro's and con's to this, use the search facility and do a bit of reading. Having said that I've got a very similar wet manfold setup on mine and I'm happy with it. It's got a single SF45 Jenvey throttle body to replace the SU and I have it mounted on a turbo inlet manfold via an adaptor (which Jenvey can also supply now). I have 2 injectors on mine but you can get the SF45 with 0,1 or 2 injector positions. Check out the SF45/2 on Jenvey's website, it means the lower injector is a bit difficult to access in situ but it's an easy way of getting 2 injectors on 1 body.

Regards

Neil

Thanks for the response neil.

Maybe a stupid question, but what would be the advantage of using 2 injectors on it, instead of just the one?

Regards
Mike

Edited by Miglia on 10th Sep, 2007.

Hi,
You can use a smaller injector for idle and low revs to get good control of the fuelling, then stage the second bigger injector for when you put loads of boost in
Cheers,
Gavin :)

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Thanks for the reply. Im planning on running it on a NA engine, so would i gain any advantage from using 2 injectors, or would i be better off using one?

Also, is it alot more difficult to get it to work with the 2 injectors?

Thanks

I use the same set up as Neil but NA also. There are a few threads below this one that detail the approach and you can see some pics at my site

www.nooneonline.co.uk

You use 2 injectors due to the siamese inlet ports on the A series. You install 2 identical injectors and then fire each one every 180 degrees. The SPI fires a single larger injector twice every 360. You can stage the injectors as suggested but it is easier to run two smaller ones. I have 2 x 310cc on the SF2 throttle body and fire them every 180 degrees. Using this method you dont need to be aware of the engine phase, other than crank angle. I use the emerald K3 ECU but most of the other ECUs are suitable too. Firing every 180 is how most 4 cyl engines work when using TB's so its easy to configure. You can get into sequential injection but on an A series its not that easy (understatement) hence the trouble getting Megasquirt to work using MPI.

Good luck, PM me if you want more info

Edited by dn89mini on 11th Sep, 2007.

Check out the (slow) progress at.......
http://www.turbominis.co.uk/dn89mini