Maxing injectors Bolt on LS1
Maxing injectors Bolt on LS1 I for some reason am having problems with high injector duty cycle on my car and I know I shouldn't be.
All I have is a stock 2000 LS1 in my RX7 with:
JBA Shorties
4L60E w/ TCI 4000 Stall
Gutted stock cats
Custom 2.5 to 3" Y w/ 3" Catback
Custom CAI tube
Ported Stock TB
LS6 Intake
ASP Pulley
2001 Fuel Injectors (28.8 #)
2001 PCM
Walbro 255 LPH Fuel Pump Rewired with heavy gauge wire directly to pump
Stock Corvette Regulator at 58 psi constant, fuel pressure doesn't drop
-6 Line return and feed
Stock Cam, Stock unported heads
I get about 95% DC at WOT at 6000 rpm with the new injectors (before had 26# stock injectors). Before I was seeing 99% DC at WOT. The pulsewidths are 19.5 or so IIRC. I was hoping the new injectors would drop the DC to at least 8x % DC. I don't see any KR at WOT and the O2's stay fine. I wanted to eventually run a 75-100 hp dry shot or add a pretty big cam but don't feel comfortable with the duty cycles so high.
I only dynoed 302 RWHP recently on a dynojet dyno (unlocked through IRS).
I don't understand how the DC can be so high.. the air fuel ratio wasn't that rich.. low 12's on the dyno. My friend even leaned out the PE enrichment to pull the WOT air fuel down because it was running too rich on a stock tune.
I have heard of 400rwhp through stock injectors and I'm not even close.. in a M6 the car might dyno 340 or so but that still isn't close. I know I can get bigger injectors and it looks like I will but I just don't see why I need to without the power required for them.
All I have is a stock 2000 LS1 in my RX7 with:
JBA Shorties
4L60E w/ TCI 4000 Stall
Gutted stock cats
Custom 2.5 to 3" Y w/ 3" Catback
Custom CAI tube
Ported Stock TB
LS6 Intake
ASP Pulley
2001 Fuel Injectors (28.8 #)
2001 PCM
Walbro 255 LPH Fuel Pump Rewired with heavy gauge wire directly to pump
Stock Corvette Regulator at 58 psi constant, fuel pressure doesn't drop
-6 Line return and feed
Stock Cam, Stock unported heads
I get about 95% DC at WOT at 6000 rpm with the new injectors (before had 26# stock injectors). Before I was seeing 99% DC at WOT. The pulsewidths are 19.5 or so IIRC. I was hoping the new injectors would drop the DC to at least 8x % DC. I don't see any KR at WOT and the O2's stay fine. I wanted to eventually run a 75-100 hp dry shot or add a pretty big cam but don't feel comfortable with the duty cycles so high.
I only dynoed 302 RWHP recently on a dynojet dyno (unlocked through IRS).
I don't understand how the DC can be so high.. the air fuel ratio wasn't that rich.. low 12's on the dyno. My friend even leaned out the PE enrichment to pull the WOT air fuel down because it was running too rich on a stock tune.
I have heard of 400rwhp through stock injectors and I'm not even close.. in a M6 the car might dyno 340 or so but that still isn't close. I know I can get bigger injectors and it looks like I will but I just don't see why I need to without the power required for them.
I know the air fuel is rich right now but that is with us leaning the car out already off the stock tune where it was commanding 11.x:1.. we changed the commanded AFR to 12.6 or so I believe. Also remember that my car has a raceweight of less than 2900 #'s so the load is not as great as a 3700 # raceweight fbody does so the air fuel doesn't change as much. It still shouldn't be maxing the injectors like it is though.
Teching In
Joined: Sep 2005
Posts: 49
Likes: 0
From: Sydney Australia
Injector Flow Rate vs. KPA Vac Did you reset the IFR (above) in the PCM when you changed the injectors?
to something like: 28.15047 28.5845129.20456 30.7547 31.12673 31.62278 31.99481 32.18082 32.36684 32.67687 32.86288 33.23492 33.79297 34.35101 35.09508 35.90115 36.76923
to something like: 28.15047 28.5845129.20456 30.7547 31.12673 31.62278 31.99481 32.18082 32.36684 32.67687 32.86288 33.23492 33.79297 34.35101 35.09508 35.90115 36.76923
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Teching In
Joined: Sep 2005
Posts: 49
Likes: 0
From: Sydney Australia
Originally Posted by aram
I have heard of 400rwhp through stock injectors and I'm not even close.. in a M6 the car might dyno 340 or so but that still isn't close. I know I can get bigger injectors and it looks like I will but I just don't see why I need to without the power required for them.
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Originally Posted by SRPerformance
re-reading the thread, if you are getting DC off 95% with 28lbs than that would be right as at above 350rwhp they will go 100%.
I don't think there is any fuel restriction.. i got the injectors as take offs from a car and they were low mileage and were good when pulled. The fuel system is a little bit healthier than a stock LS1 fuel system. I just replaced the fuel filter/regulator/pump (walbro 255) about 3000 miles ago.
I guess I'll try out the GTP injectors and see what they will do.