fuel injector selection

For discussing injector selection,manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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toon1
MegaSquirt Newbie
Posts: 26
Joined: Tue Oct 17, 2006 9:39 am
Location: CA

fuel injector selection

Post by toon1 »

by the calcs. in the MM, my motor (1679cc, 85HP TIV) has a 12.5lb/hr fuel requirement.

I have 14lb/hr injectors that at 50psi will get me the correct req. fuel.

While working with the stim it showed that with all the settings @ a simulated WOT the inj. where at 93%.

I also have some 21lb/hr inj. that on the stim show good DC and idle PW(about 2.6-2.8) but these are seemingly big for my eng. req.

I'm leaning to the 21lb injs.

What do you guy's think
MS1 V3.0 MS&S Extra
Porsche 914 1.7
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FiatFreak
MegaSquirt Newbie
Posts: 24
Joined: Thu Sep 09, 2004 2:40 am

Post by FiatFreak »

I'd start with the 14 lb injectors. There are problems with idle quality if you get too big. I'm fighting the battle now with injectors that are just a little too big.

Start with the small ones, tune it, and if you are running out of headroom at WOT, then you can play with the bigger injectors. Sure you'll have to do some retuning, but if this is your first time tuning with MS then having injectors that won't give you problems at idle is a BIG plus. Tuning the second time around with bigger injectors will go a LOT faster. You'll have to make changes to req fuel, but I bet the VE map will only change slightly.

Just my .02.

-Patrick-
'81 Fiat Spider - Turbo charged, MSII, EDIS4
'04 SRT4 - Daily driver
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