RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   New Member RX-7 Technical (https://www.rx7club.com/new-member-rx-7-technical-256/)
-   -   Differences between gls-se and FC fuel injection (https://www.rx7club.com/new-member-rx-7-technical-256/differences-between-gls-se-fc-fuel-injection-1080632/)

sa22rally 03-22-15 04:13 PM

Differences between gls-se and FC fuel injection
 
Hey there can anyone tell me how much difference is between the two systems becaus the rules og my rallyclass only allows me to use original injection but with different computers in my FB and since GLS-Se injection is virtually impossible to find here in Denmark maybe even Europe i was hoping there wasnt much difference?.
As a second question how well do a original injection work with aftermarket computers And do i even need one for a large street port og maybe a semi p-port ore can i use the original equipment.?

Best regards Rasmus Andersen

misterstyx69 03-22-15 04:28 PM

hmm.
I'm not a 1st gen guy,But is the GSL-SE injectors not 680cc?
the Sec Gen runs 460s in N/A.
So that in my reasoning would tell me that the FC computer would be giving different fuel amounts compared to the FB (GSL-SE) computer.

If I'm wrong I am wrong,But I had to toss that out there as a thought.

sa22rally 03-23-15 06:56 AM

Allright i guess my question is how Much different the major parts like intake manifold and the sensors ect are

diabolical1 03-25-15 03:14 PM

the SE injection (in my humble opinion) is quite primitive in comparison to the Gen II system - and that's saying something because i believe the Gen II is primitive. :)

the SE

1. uses 2 injectors only. most are 680 cc. i've seen it tossed around here and there that some of the last '85s got 720s, but i have also seen it disputed, so i really don't know. they are low impedance though.

2. no computer control of the ignition. it uses the same electronic distributor system as the 12A cars since 1981.

3. upper intake manifold are different, as is the throttle body - notably smaller than the Gen II. it's been quite some time since i messed with this stuff, so i really can't remember if the lower manifolds are different compared to the Gen II. what i can say for sure is the Gen intake (as a whole) will bolt to the SE engine without issue.

4. for sensors, you may want to download an '84-'85 shop manual and check it out for yourself. i have an SE engine and most of the original parts for it, but i never owned an SE. if it comes to it and you can't get info, i can go dig up my old intake system and tell you what it had. just let me know.

Gen II

1. uses 4 injectors - 460s. '86-'early '88 were low impedance. from what i have read, there were some later '88s with high impedance injectors, but due to the clip configuration, they are NOT compatible with the '89-'92 high impedance injectors.

2. use the crank angle sensor - and the ECU does full ignition control. there are 2 signals.

3. as i said, the complete intake will bolt up to the SE engine (though from what i've read, the S5 system may or may not require some grinding for clearance). of course, if the computer and harness are being transferred, then you get to use all injectors. if not, then your secondaries will be reduced to plugs that prevent a vacuum leak - and of course, you'd have to swap in the SE primaries or you won't have enough fuel.

4. TPS, AFM, O2, coolant temp, BAC

that's pretty much all i've got from the top of my head. hope it helps.

sa22rally 03-26-15 04:30 AM


Originally Posted by diabolical1 (Post 11890568)
the SE injection (in my humble opinion) is quite primitive in comparison to the Gen II system - and that's saying something because i believe the Gen II is primitive. :) the SE 1. uses 2 injectors only. most are 680 cc. i've seen it tossed around here and there that some of the last '85s got 720s, but i have also seen it disputed, so i really don't know. they are low impedance though. 2. no computer control of the ignition. it uses the same electronic distributor system as the 12A cars since 1981. 3. upper intake manifold are different, as is the throttle body - notably smaller than the Gen II. it's been quite some time since i messed with this stuff, so i really can't remember if the lower manifolds are different compared to the Gen II. what i can say for sure is the Gen intake (as a whole) will bolt to the SE engine without issue. 4. for sensors, you may want to download an '84-'85 shop manual and check it out for yourself. i have an SE engine and most of the original parts for it, but i never owned an SE. if it comes to it and you can't get info, i can go dig up my old intake system and tell you what it had. just let me know. Gen II 1. uses 4 injectors - 460s. '86-'early '88 were low impedance. from what i have read, there were some later '88s with high impedance injectors, but due to the clip configuration, they are NOT compatible with the '89-'92 high impedance injectors. 2. use the crank angle sensor - and the ECU does full ignition control. there are 2 signals. 3. as i said, the complete intake will bolt up to the SE engine (though from what i've read, the S5 system may or may not require some grinding for clearance). of course, if the computer and harness are being transferred, then you get to use all injectors. if not, then your secondaries will be reduced to plugs that prevent a vacuum leak - and of course, you'd have to swap in the SE primaries or you won't have enough fuel. 4. TPS, AFM, O2, coolant temp, BAC that's pretty much all i've got from the top of my head. hope it helps.


Thank you that helped alot unfortunatly that means i am only alloved to use the gls-se manifold. And that is no where to be found in Denmark. And from what you are saying it Sound like it might not be enough for a semi PP ore a large street port eigher.

Aaron Cake 03-28-15 10:55 AM

Absolutely not adequate for a semi-PP. Workable for a street port.

The short and simple answer for "what is different between FC EFI/manifold and FB EFI manifold" is "EVERYTHING".

diabolical1 03-29-15 02:38 PM

yeah. what Aaron said ... if you're limited to using the stock SE stuff, then you'll be limited to a streetport AT MOST.

what are you allowed to do with exhaust? because if you can't open up the exhaust, then it probably wouldn't even make sense porting it.

sa22rally 03-30-15 04:04 AM


Originally Posted by diabolical1 (Post 11892677)
yeah. what Aaron said ... if you're limited to using the stock SE stuff, then you'll be limited to a streetport AT MOST. what are you allowed to do with exhaust? because if you can't open up the exhaust, then it probably wouldn't even make sense porting it.

The class is called Classic rallycars and there are no limitations on exhaust and no limitations on ignition and the computer for the ignition and efi but i have to use the Stock intake withl throttle body etc.

diabolical1 03-30-15 11:47 AM

well, it sounds like you have some wiggle room then. if you upgrade the ignition to Gen II parts and get good management, then you could make some decent increases with porting. i wouldn't expect BIG numbers (and i don't know what your competition is or what numbers they make) - my guess (and that's all it is) is you could probably get around 170 (flywheel) depending on how worn the sealing surfaces are.

the intake will be a hindrance for sure. the throttle body is sort of a joke. if i recall, you're also dealing with the heaviest rotors - i want to say they are close to 12 pounds. heavy flywheel, 3 mm apexes, etc., etc. - really nothing in there helping you out.

i guess all of what i said is just jibber-jabber without knowing what it is you want from the engine, the car, etc.

sa22rally 03-31-15 05:25 AM


Originally Posted by diabolical1 (Post 11893155)
well, it sounds like you have some wiggle room then. if you upgrade the ignition to Gen II parts and get good management, then you could make some decent increases with porting. i wouldn't expect BIG numbers (and i don't know what your competition is or what numbers they make) - my guess (and that's all it is) is you could probably get around 170 (flywheel) depending on how worn the sealing surfaces are. the intake will be a hindrance for sure. the throttle body is sort of a joke. if i recall, you're also dealing with the heaviest rotors - i want to say they are close to 12 pounds. heavy flywheel, 3 mm apexes, etc., etc. - really nothing in there helping you out. i guess all of what i said is just jibber-jabber without knowing what it is you want from the engine, the car, etc.

Thank you fortunatly om alså alloved to use carburator so i Will be sticking to
My 48 Ida on my 13b 4-port

yakumo2897 04-04-15 08:35 PM

Interesting thread, that I am glad you created. I had no idea there were different. Kinda figured they were the same. The more you know I guess. :nod:


All times are GMT -5. The time now is 05:07 PM.


© 2024 MH Sub I, LLC dba Internet Brands