MicroSquirt.com read only forum (Jan.15,2018)

Does this datalog look like it's within the norm? I'm new to this and I'm trying to tune but it seems like my map readings are jumping around a bit and I'd just like to know if that's normal or something I should look into.
Thanks for the help.

No love?

phongshader,

It looks okay to me. MAP is rarely perfectly smooth. You can add a restriction and a plenum (usually a fuel filter) to smooth it, if you like. This is describe in the manual. I wouldn't bother if this was mine though, and my vehicle's signal is more 'bouncey' than yours.

Lance.

Thanks Lance.

phongshader wrote:No love?

MSII 2.33, V2.2, Megatune 2.25, LC-1
Olds 215 v8 in a '59 Alfa Romeo Spider 2000

So, what type of 215 intake manifold/throttle body set up did you use, and/or how did you mount your injectors?

Just wondering.

If it's somewhat similar to the way I'm setting up mine, might I possibly get some sort of idea for setting up my fuel tables, by using yours?

As a starting point only, just to get it running.

I'm using an Offenhauser 360 intake, an Autonomics throttle body http://www.auto-nomics.com/cgi-bin/show ... 0850-002-D, and 42lb injectors. I just posted my msq here http://msefi.com/viewtopic.php?p=138261#138261

phongshader wrote:I'm using an Offenhauser 360 intake, an Autonomics throttle body http://www.auto-nomics.com/cgi-bin/show ... 0850-002-D, and 42lb injectors. I just posted my msq here http://msefi.com/viewtopic.php?p=138261#138261

Let me get this right, you are using 8 injectors, and the flow rate is 42 LB each?

On a 215 cid engine?

Those sound a bit big for that engine, don't they?

8 X 42lb injectors comes out to 571 HP!

Even with only 4 injectors, that comes out to 286 HP.

MegaSquirt info wrote: However, do not install injectors with a much larger flow capacity than you need. Very large injectors will create idle pulse width issues that will make tuning very difficult.

Even if you got 250 HP out a 215 cid engine, that comes out to 18.4 lb hr injectors.

Am I missing something?

My second posting did not take!

I now can see the throttle body you are using as the site was not available to me at first.

It is only 4 injectors, but that's still a lot for a 215 cid engine, isn't it?

@ 5500 rpm's on that size engine, they use a 390 cfm carb, and a 750 cfm throttle body is almost double that.

And the injector computer on this site says that your engine should be able to put out a maximum of 286 hp, (and 250 hp is a bit of a stretch for a 215 cid, 2 valve per cylinder, cam in block engine).

I would assume it would supply more fuel at an idle than I would expect that engine would use idling causing a rather big issue with vary poor idle quality.

I also not that the computer here suggestes throttle bodies and injectors much bigger than I'm finding installed out here in the real world of EFI production automobiles.

Or are the suggestions here about injector/throttle body sizing seriously conservative and manufacturers are choking things up for emissions sake?

If so, I might need to re-think things.

I was conserned that the little 19 lb injectors I pulled from an older stock Ford 302 EFI V8 were going to be too big to get me started even though my fuel requirements are going to require more volume than gasoline.

(I know the injectors I selected are not set up for E85 use, but I'm just going to use them to get thinge started and will drain and flush the fuel system after each test run.)