750s on a B16g???

[DSMafia]

Ok guys I just bought a set of 750s for cheap, hence why i got them....now my question is how hard is it going to be to tune these damn things for idle??? Im running a big 16g on a 1g engine swap... now i have an fpr and the safc... so im thinking i should be able to tune it for idle between the two of them.... is anyone out there running injectors this big on a 16g with a decent idle?????

-JOhn

 

[FastRthenU]

they are BIG TIME over kill for a big 16g. As far as tuning goes, im really not sure. How about you sell them to me for my 60 trim But i think you are going to have some problems with them. They are just way to big for you aplication

 

[nine5raptor]

450/750 = .6 so you are adding in 60% more fuel for a given duration of time w/ the injector open. I think the afc can only tune down 50%, correct? If so, you will need to lower your base fp.
safc--60%-50%=10%
lower base fuel pressure 10% = 43.5-4.4 = 39.1

of, course these are only estimates, ever car is different, and you don't absolutely need 0% fuel trims, but this should give you a start.
you already have the injectors and plan on using them, so try your hand and see what works.

 

[tanner261]

Yes they are overkill, but the car will still run. You will have to lower your fuel pressure and lean out the AFC. I ran 720's with a 16G and they give you a lot of timing throughout the RPM range. Some say it is too much and I would have to agree with them. I blew a HG without any knock and 30 degrees of advance with a base of 5 degrees. Yep, too much timing is not good for a Felpro HG. If you have a 1G you can set base timing to zero degrees, but I wouldn't recommend it. So basically I'd recommend not using the 750's and going with a smaller injector.

 

[DSMafia]

hmm i didnt even realize I would have to worry about gaskets.....being as that I'm taking a 3hr trip here soon, is there anything to do to kind of prevent gasket problems.......

 

[DrZiplok]

Give your right foot a rest?

 

[GSX4LIFE]

Originally posted by tanner261
Yes they are overkill, but the car will still run. You will have to lower your fuel pressure and lean out the AFC. I ran 720's with a 16G and they give you a lot of timing throughout the RPM range. Some say it is too much and I would have to agree with them. I blew a HG without any knock and 30 degrees of advance with a base of 5 degrees. Yep, too much timing is not good for a Felpro HG. If you have a 1G you can set base timing to zero degrees, but I wouldn't recommend it. So basically I'd recommend not using the 750's and going with a smaller injector.

Im sorry, but as I have always understood it, timing does no damage on its own. Too high advanced timing "can" cause knock, whick will eat a HG quickly. I dont understand how you blew a HG with no knock. I actually had this exact conversation wiht HighPsi91. Im not doubting you. Im sure you blew the HG. But are you sure you had no knock? Doesnt seem right to me.

 

[DSMafia]

update on the injectors guys...They run great! I set my fpr back to 35psi(1g engine remember) and adjusted accordingly with the safc....
idle actually isnt that bad, but i still run a little rich through most of the power band...

 

[tanner261]

Originally posted by GSX4LIFE


Im sorry, but as I have always understood it, timing does no damage on its own. Too high advanced timing "can" cause knock, whick will eat a HG quickly. I dont understand how you blew a HG with no knock. I actually had this exact conversation wiht HighPsi91. Im not doubting you. Im sure you blew the HG. But are you sure you had no knock? Doesnt seem right to me.

If combustion is timed wrong, you are going to see extremely high cyldinder pressures the moment before TDC. I cannot say that my car wasn't detonating because I wasn't logging it at the time. But I can say that I can see timing in real time from the TMO Stage III EPROM and the car was tuned correctly beforehand. I did not see the factory boost gauge display a significant drop in timing when the gasket blew. Another guy on DSMTalk experianced a blown HG as well with too much timing. I'm just saying that you should be cautious with huge injectors.