I wanna change my 680cc GSL-SE injectors because I think its leaking even though I Cleaned and balanced... I was thinking a 660cc greddy injector, because it'll make it lean just by a bit.... and 720cc is just too big??? I think I'll get better mpg off of the 660cc...

 

anybody know??? what's going on ROTARY EXPERTS???

 

Just say something... will it work or not... to use a 660cc on a GSL-SE....???

 

from my exerience 84's came with 680's and 85's have 720 injectors from the factory, not sure if they changed the ECU to make up for the difference.

 

REALLY!!! I'VE got an 85... didn't even know this....

 

I'd buy your leaky SE injectors for the right price if you get new ones.

From all I've read all SE's are the same injector. I think just differences in measurement systems/ listed specs have caused the 680 VS 720 cc confusion.

Shouldn't have a problem dropping in the 720's, closed loop cruise mode the ECU will compensate, and ~6% difference in fuel won't make much difference when you're not in closed loop.

R

 

I've had 3 sets of SE injectors cleaned thru RC Engineering.
with the 2 84's coming in around the 680 mark and the 85 in the 720 area. Could be a fluke, but I think others have had similar results when cleaning the injectors and getting the flow results back.

 

alright... how about the 660cc... you think that'll be fine???

 

I think 660's would be fine...But if you could just as easily get 720's personally I'd get 720's.

I had 8 SE injectors cleaned and flowed, 4 from each year and they all ended up the same. ??? Difference between 680 and 720 is so small, I don't feel it's a big deal either way.

R

 

The thing is that I've put the 460cc 2nd gen 86-88 in my GSL-SE before... it would not run below 3k and the thing was lean... my point is that the 680cc I think is too big and that's one reason why mpg is bad on my car... if I can take away about a good number of cc and still keep it running then I'll fine... another questions... what's the convertion on cc to per pounds... like 30lbs. fuel injector or such... compared to a 550cc, 460cc, 680cc,

 

I wouldn't put in smaller injectors than stock to get better fuel economy.

CC/min = LBS/HR x 9.71 . So 680cc/min is about a 70lb/hr injector.

 

Thanks faster7... that's a lot of pounds per hour... Why would you not recommend going smaller just a bit???

 

Yep, they're big uns!

Smaller will be leaner across the board. Probably be fine on a mildly modified NA car, but why bother? If the closed loop O2 feedback system is working on the open road, it shoud get the same fuel economy either way.

660cc is so close to 680 I doubt you'd see a difference at all. Which I guess is good and bad.