GSL-SE Air/Fuel needs w/ streetport? (ideas discussion)
#1
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GSL-SE Air/Fuel needs w/ streetport? (ideas discussion)
I've been wondering this for awhile...
It's always been said that the "flapper door" is the limiting factor for the GSL-SE intake tract, so how well does this worth with a streetported motor?
Reaosning, I've scrapped going turbo for awhile, but the relative cost of rebuiding and porting my motor wouldn't be outta range at all. *DEPENDING* on what else needs to be done at teh same time..
Can teh stock GSL-SE ECU handle a SP motor? Injectors? AFM upgrade? S-AFC? Standalone? etc etc etc...
Anyone with any experiance out there please chime in. I know most of the 12a guys just run a bigger carb, or jetting and viola'! they're done...
What about us stupidly complex FI guys?
Thoughts, comments, ideas, discussion? Lemme hear all of your thoughts and ideas.
Thanks!
It's always been said that the "flapper door" is the limiting factor for the GSL-SE intake tract, so how well does this worth with a streetported motor?
Reaosning, I've scrapped going turbo for awhile, but the relative cost of rebuiding and porting my motor wouldn't be outta range at all. *DEPENDING* on what else needs to be done at teh same time..
Can teh stock GSL-SE ECU handle a SP motor? Injectors? AFM upgrade? S-AFC? Standalone? etc etc etc...
Anyone with any experiance out there please chime in. I know most of the 12a guys just run a bigger carb, or jetting and viola'! they're done...
What about us stupidly complex FI guys?
Thoughts, comments, ideas, discussion? Lemme hear all of your thoughts and ideas.
Thanks!
#2
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that's in addition to:
https://www.rx7club.com/forum/showth...hreadid=123442
https://www.rx7club.com/forum/showth...hreadid=123442
#3
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actually the limit on mine has been the fuel system. mine only gets to about 6500-6800rpms before it falls on its face cause it runs out of gas.
mike
mike
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i think that if the injectors were mounted further away (closer to the tb) it would help
mike
mike
#5
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Mike
When I removed the long primary exhaust and installed a short primary with 3" muffler, I lost low end but the car wanted to keep pulling up high. I wouldn't recommend changing to the short system thoug regardless.
rx7gslse: My GSL-SE is streetported. With a 2nd gen intake manifold transplanted onto it, a long primary exhaust system, and the stock ecu/afm etc. the car hits 14's in the quarter. Like Mikes car though it is on its face after 7000 rpm. If I could retune it there would be much more power.
When I removed the long primary exhaust and installed a short primary with 3" muffler, I lost low end but the car wanted to keep pulling up high. I wouldn't recommend changing to the short system thoug regardless.
rx7gslse: My GSL-SE is streetported. With a 2nd gen intake manifold transplanted onto it, a long primary exhaust system, and the stock ecu/afm etc. the car hits 14's in the quarter. Like Mikes car though it is on its face after 7000 rpm. If I could retune it there would be much more power.
#6
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rotarygod,
is it on it's face due to fuel needs, or air restriction? I'm already rulling the RB full dual longprimary exhaust system and a cone intake, so the easy extra stuff is done.
2nd gen intake? S4 I assume?
is it on it's face due to fuel needs, or air restriction? I'm already rulling the RB full dual longprimary exhaust system and a cone intake, so the easy extra stuff is done.
2nd gen intake? S4 I assume?
#7
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S5 intake actually, highly modified at that. Judging from past rotary exhaust experience I will have to say that it is running out of fuel up high although the small afm isn't helping much either. My 2nd gen always pulled so much harder on the top end but the afm is 25% larger. It also has more fuel injector up top. On the GSL-SE it is prety much a combo of the two. Lack of fuel and air. Don't bother with something like an S-AFC to correct the fuel mixture. This is a two fold problem. A standalone ecu can correct both as well as improving power everywhere. It is cheaper than a streetport and will do more anyways.
Here's what I found to make the most difference in mods. The long primary exhaust by far and away is the biggest single gain period. The next 2 big gains for speed are an aluminum flywheel and converting the distributer over to direct fire. Each of these gains was about equivalent to doing the streetport. Yes you gain power from a streetport on the 6 port engines but most of your gains are from everything else. Do the port job last. Even after a computer. You may be pleasantly surprised.
Here's what I found to make the most difference in mods. The long primary exhaust by far and away is the biggest single gain period. The next 2 big gains for speed are an aluminum flywheel and converting the distributer over to direct fire. Each of these gains was about equivalent to doing the streetport. Yes you gain power from a streetport on the 6 port engines but most of your gains are from everything else. Do the port job last. Even after a computer. You may be pleasantly surprised.
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#8
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hmm good to know...
Exhaust is done, car is apart waiting the arrival of the AL flywheel already...
So you're saying a standalone on a stockport will gain as much or more than a port job on a stock FI system (microtech LT-8 of course) Obviously the gains of the two combined woudl be much more significant...
Hmm... maybe I'll get in on that groub buy afterall..
http://www.team140.net/modules.php?n...article&sid=17
Exhaust is done, car is apart waiting the arrival of the AL flywheel already...
So you're saying a standalone on a stockport will gain as much or more than a port job on a stock FI system (microtech LT-8 of course) Obviously the gains of the two combined woudl be much more significant...
Hmm... maybe I'll get in on that groub buy afterall..
http://www.team140.net/modules.php?n...article&sid=17
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i'm gonna do an f10 so i can add 2 more injectors and prolly an s5 manifold. the f10 is cheap too
mike
mike
#10
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yeah, well I'm still gonna go turbo someday, so I might as well buy something that I can still use, right?
about what level are the stock -SE 680cc injectors good to? I've heard roughly 200+, but I dunno...
How much gain do you think the S4 (less work) or S5 manifold would give? (other than teh fact you gain the two injectors)
about what level are the stock -SE 680cc injectors good to? I've heard roughly 200+, but I dunno...
How much gain do you think the S4 (less work) or S5 manifold would give? (other than teh fact you gain the two injectors)
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well they went from 135hp to 146 and then to 160. the s4 and s5 exhausts are bascially the same
mike
mike
#12
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yeah, but on an S5 they also went to lighter rotors/e-shaft and rasied the compression...
that has to help too, can't give it all to the manifold...
that has to help too, can't give it all to the manifold...
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true, but we have nothing else to compare
mike
mike
#14
The injectors were smaller on the S4 and S5, SE injectors are sought after in the second gen domain as they are rated higher. The reason for the higher power output is due to 4 instead for 2 injectors and a highly tweaked intake... You could see a decent (read approx 20hp for what I have heard) just by switching over to the S4 intake and TB, now add the S4 AFM and add more to that figure.
I'm trying to get my hands on an S5 intake and TB due to the VDI port... more power based on N/A caracteristics of the rotary.
Just my $.02
Kyle
I'm trying to get my hands on an S5 intake and TB due to the VDI port... more power based on N/A caracteristics of the rotary.
Just my $.02
Kyle
#15
Oh yeah and when you go turbo either go it all the way or mod your 6 port and make use of the extra injectors on the intake of the S4 or S5. How do you do that you ask... Megasquirt...
#16
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On a GSL-SE if you never intend to rev up over about 7000 rpm then there really is no point in using an S5 manifold over the S4. If you get it working properly you'll have the VDI actuate at around 5500 rpm or so. Above this point is where it starts to shine. That manifold will give you useful power to about 9000 or so. With only a 1500 rpm range of gain it is at best 2-3 hp more by 7000 which is where you need to shift. Whats the point? Its more of a hassle to get working. If you get a standalone and can rev it up higher then you will see a benefit. On either style manifold you will need to port match the lower manifold to the engine since the GSL-SE intermediate housing ports are smaller than the 2nd gen manifolds port openings. Enlarge the engine port runner openings or fill in with epoxy some in the manifold. I filled some in. If you plan to add a turbo just stick with the S4. Less hassle and unless you are using a large aftermarket turbo, you won't have power up high enough anyways. The stock gear ratios are designed around the cars rpm range anyways so try to stay fairly close to the stock limit maybe going only a little higher.