Stock injectors
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 27
Likes: 0
From: Queens,New York 11378
Stock injectors
What the stock injector rating? I mean is an --lbs.
Will moving up to a bigger injector than stock increase torq. or maybe HP?
Or will it just bog down the engine.
The car has a free flowing exhaust, but no headers. { stingers and no cats} :chevy :seeya
Will moving up to a bigger injector than stock increase torq. or maybe HP?
Or will it just bog down the engine.
The car has a free flowing exhaust, but no headers. { stingers and no cats} :chevy :seeya
Drifting
Joined: Jul 2000
Posts: 1,517
Likes: 1
From: Stockholm
Re: Stock injectors (Rockystoy)
The below info is taken from : http://www.vetteguru.com/mods/howto/#injectors As an example the 28.4 lbs/hr is a #28 injector. The hp numbers are the maximum the injector can feed. Hope this helps.
C5 Corvette:
97-98 = 28.4 lbs/hr
80% duty cycle rating: 45.44 Crank HP x 8 = 363.52 Crank HP
100% duty cycle rating: 56.8 Crank HP x 8 = 454.4 Crank HP
99-2001 = 26.4 lbs/hr
80% duty cycle rating: 42.24 Crank HP x 8 = 337.92 Crank HP
100% duty cycle rating: 52.8 Crank HP x 8 = 422.4 Crank HP
Z06 = 28.2 lbs/hr
80% duty cycle rating: 45.12 Crank HP x 8 = 360.96 Crank HP
100% duty cycle rating: 56.4 Crank HP x 8 = 451.2 Crank HP
30 lbs/hr SVO = 36.12 lbs/hr (LS1 at 58psi)
80% duty cycle rating: 57.79 Crank HP x 8 = 462.33 Crank HP
100% duty cycle rating: 72.24 Crank HP x 8 = 577.92 Crank HP
You will not see any increase in hp or tq when changing injectors. If you go to a extreme H/C package, big cubes or blower you will need a larger injector to be able to supply the high power level.
If you have not done it yet, get a high performance airintake as a first mod. Exit28 Motorsports have a GP going on the VaraRam airintake in the following thread: http://forums.corvetteforum.com/zerothread?id=370730
I have not seen you around before so welcome! I think you will find the forum very helpful :yesnod:
:cheers:
[Modified by seanr, 11:38 AM 8/24/2002]
C5 Corvette:
97-98 = 28.4 lbs/hr
80% duty cycle rating: 45.44 Crank HP x 8 = 363.52 Crank HP
100% duty cycle rating: 56.8 Crank HP x 8 = 454.4 Crank HP
99-2001 = 26.4 lbs/hr
80% duty cycle rating: 42.24 Crank HP x 8 = 337.92 Crank HP
100% duty cycle rating: 52.8 Crank HP x 8 = 422.4 Crank HP
Z06 = 28.2 lbs/hr
80% duty cycle rating: 45.12 Crank HP x 8 = 360.96 Crank HP
100% duty cycle rating: 56.4 Crank HP x 8 = 451.2 Crank HP
30 lbs/hr SVO = 36.12 lbs/hr (LS1 at 58psi)
80% duty cycle rating: 57.79 Crank HP x 8 = 462.33 Crank HP
100% duty cycle rating: 72.24 Crank HP x 8 = 577.92 Crank HP
You will not see any increase in hp or tq when changing injectors. If you go to a extreme H/C package, big cubes or blower you will need a larger injector to be able to supply the high power level.
If you have not done it yet, get a high performance airintake as a first mod. Exit28 Motorsports have a GP going on the VaraRam airintake in the following thread: http://forums.corvetteforum.com/zerothread?id=370730
I have not seen you around before so welcome! I think you will find the forum very helpful :yesnod:
:cheers:
[Modified by seanr, 11:38 AM 8/24/2002]
Heel & Toe
Joined: Apr 2002
Posts: 19
Likes: 0
From: san jose ca
Re: Stock injectors (seanr)
You will not see any increase in hp or tq when changing injectors. If you go to a extreme H/C package, big cubes or blower you will need a larger injector to be able to supply the high power level.
----------------------------------------------------------------------------------
Not true, if the engine is running too lean b/c the injectors are too small then it would have too much knock which reduces timing and so going to a larger injector rids the knock and you end up with an increase of performance.
[Modified by fast-Z06, 1:33 PM 8/24/2002]
----------------------------------------------------------------------------------
Not true, if the engine is running too lean b/c the injectors are too small then it would have too much knock which reduces timing and so going to a larger injector rids the knock and you end up with an increase of performance.
[Modified by fast-Z06, 1:33 PM 8/24/2002]
Drifting
Joined: Jul 2000
Posts: 1,517
Likes: 1
From: Stockholm
Re: Stock injectors (fast-Z06)
fast-Z06,
You are correct but why install another error to correct the original error :confused:
If the car runs lean you will have the car running richer by adding laeger injectors but it's a gamble to get it correct. So why not fix the problem instead? Something causes the engine to run lean in your example most likely because of added intake components and/or headers. Get the car to a local shop and have it tuned with LS1-edit or similar.
There is no need of spending money on new injectors on a stock engine or most H/C packages.
Please, no flames intended :D
:cheers:
You are correct but why install another error to correct the original error :confused:
If the car runs lean you will have the car running richer by adding laeger injectors but it's a gamble to get it correct. So why not fix the problem instead? Something causes the engine to run lean in your example most likely because of added intake components and/or headers. Get the car to a local shop and have it tuned with LS1-edit or similar.
There is no need of spending money on new injectors on a stock engine or most H/C packages.
Please, no flames intended :D
:cheers:
Racer
Joined: Jan 2002
Posts: 316
Likes: 0
From: Spanish Fork UT
Re: Stock injectors (seanr)
I agree that changing injectors without tuning is a crapshoot.
Sean do you think I should change to SVO injectors before I go for my dyno tune? For now and for future applications in mind? I am by no means done modding.
[Modified by Horsepower, 4:42 PM 8/24/2002]
Sean do you think I should change to SVO injectors before I go for my dyno tune? For now and for future applications in mind? I am by no means done modding.
[Modified by Horsepower, 4:42 PM 8/24/2002]
Drifting
Joined: Jul 2000
Posts: 1,517
Likes: 1
From: Stockholm
Re: Stock injectors (Horsepower)
If you have big plans in the future and will spend money on a dyno tune anyway I would go with larger injectors. Please be aware about that your car probably will run like crap until you have the car in the dyno shop. Going from #28 to #36 will have your car going very rich if the PCM can't compensate enough :yesnod:
:cheers:
:cheers:
Le Mans Master
Joined: Jul 2000
Posts: 7,758
Likes: 0
From: Fort Worth Texas
Cruise-In II Veteran
Cruise-In III Veteran
Re: Stock injectors (Rockystoy)
What the stock injector rating? I mean is an --lbs.
Will moving up to a bigger injector than stock increase torq. or maybe HP?
Or will it just bog down the engine.
The car has a free flowing exhaust, but no headers. { stingers and no cats} :chevy :seeya
Will moving up to a bigger injector than stock increase torq. or maybe HP?
Or will it just bog down the engine.
The car has a free flowing exhaust, but no headers. { stingers and no cats} :chevy :seeya
When you add for instance larger injectors that the PCM is not calibrated for, you initially induce a rich condition, but this is immediately corrected for by the O2 sensors which the PCM modifies the fuel trims for. What you have in effect done, is changed the perceived load on the engine and modified the timing advance.
The trick of using larger injectors when they are not needed for fuel delivery needs, is to chang the perceived load which changes timing. You need to use in conjunction with this a MAF Translator to further dial in the perceived engine load, to maximize the tuning. However, with the advent of LS1Edit, all these parameter can be changed and programmed into the PCM, without the need for such trickery.
About WOT: If the fuel trims are corrected for an overly rich condition, and they are 0 or negative, then the fuel trims will not be added during Fuel Enrichment mode (WOT). However, if the engine is adding fuel due to an induced lean condition to meet the 14.7:1 stoic ratio, then as a safty measure, the PCM will add the fuel trims to WOT. Many choose to modify the fuel trims to 0 or less than 0, so that no modifications are carried over during WOT operation, providing an easier approach to fine tuning WOT.
Also, remember, that during WOT, the O2 sensors are ignored, and the fuel trims tables are frozen from being updated. The PCM relies on the MAF signal, RPM, Intake pressure and other real time sensors, to perform fuel delivery.
Lastly, another consideration about injectors, you don't want to go overboard when selecting an injector for a specific engine fuel need, because you want to maintain some level of resolution in the digital pulse train sent to the injectors to fire them accuratly.
[Modified by kewlbrz, 6:13 PM 8/24/2002]
Drifting
Joined: Aug 2000
Posts: 1,503
Likes: 0
From: Tupelo Ms
Re: Stock injectors (kewlbrz)
What the stock injector rating? I mean is an --lbs.
Will moving up to a bigger injector than stock increase torq. or maybe HP?
Or will it just bog down the engine.
The car has a free flowing exhaust, but no headers. { stingers and no cats} :chevy :seeya
Some critical points to understand here, is that the engine doesnt run "rich" or "lean" during non-wot no matter what injector or mods you do, because the O2 sensors provide a feedback control to the base injector equation. This is the function of the Fuel trims in the PCM. Which are registers that add or subtract fuel to meet the stociometric correct ratio of 14.7:1 air/fuel no matter what. note: there are limits in the PCM as to how much it can correct for a rich or lean condition after about 20 or 25% it will set codes, and have problems correcting.
When you add for instance larger injectors that the PCM is not calibrated for, you initially induce a rich condition, but this is immediately corrected for by the O2 sensors which the PCM modifies the fuel trims for. What you have in effect done, is changed the perceived load on the engine and modified the timing advance.
The trick of using larger injectors when they are not needed for fuel delivery needs, is to chang the perceived load which changes timing. You need to use in conjunction with this a MAF Translator to further dial in the perceived engine load, to maximize the tuning. However, with the advent of LS1Edit, all these parameter can be changed and programmed into the PCM, without the need for such trickery.
About WOT: If the fuel trims are corrected for an overly rich condition, and they are 0 or negative, then the fuel trims will not be added during Fuel Enrichment mode (WOT). However, if the engine is adding fuel due to an induced lean condition to meet the 14.7:1 stoic ratio, then as a safty measure, the PCM will add the fuel trims to WOT. Many choose to modify the fuel trims to 0 or less than 0, so that no modifications are carried over during WOT operation, providing an easier approach to fine tuning WOT.
Also, remember, that during WOT, the O2 sensors are ignored, and the fuel trims tables are frozen from being updated. The PCM relies on the MAF signal, RPM, Intake pressure and other real time sensors, to perform fuel delivery.
Lastly, another consideration about injectors, you don't want to go overboard when selecting an injector for a specific engine fuel need, because you want to maintain some level of resolution in the digital pulse train sent to the injectors to fire them accuratly.
[Modified by kewlbrz, 6:13 PM 8/24/2002]
Will moving up to a bigger injector than stock increase torq. or maybe HP?
Or will it just bog down the engine.
The car has a free flowing exhaust, but no headers. { stingers and no cats} :chevy :seeya
Some critical points to understand here, is that the engine doesnt run "rich" or "lean" during non-wot no matter what injector or mods you do, because the O2 sensors provide a feedback control to the base injector equation. This is the function of the Fuel trims in the PCM. Which are registers that add or subtract fuel to meet the stociometric correct ratio of 14.7:1 air/fuel no matter what. note: there are limits in the PCM as to how much it can correct for a rich or lean condition after about 20 or 25% it will set codes, and have problems correcting.
When you add for instance larger injectors that the PCM is not calibrated for, you initially induce a rich condition, but this is immediately corrected for by the O2 sensors which the PCM modifies the fuel trims for. What you have in effect done, is changed the perceived load on the engine and modified the timing advance.
The trick of using larger injectors when they are not needed for fuel delivery needs, is to chang the perceived load which changes timing. You need to use in conjunction with this a MAF Translator to further dial in the perceived engine load, to maximize the tuning. However, with the advent of LS1Edit, all these parameter can be changed and programmed into the PCM, without the need for such trickery.
About WOT: If the fuel trims are corrected for an overly rich condition, and they are 0 or negative, then the fuel trims will not be added during Fuel Enrichment mode (WOT). However, if the engine is adding fuel due to an induced lean condition to meet the 14.7:1 stoic ratio, then as a safty measure, the PCM will add the fuel trims to WOT. Many choose to modify the fuel trims to 0 or less than 0, so that no modifications are carried over during WOT operation, providing an easier approach to fine tuning WOT.
Also, remember, that during WOT, the O2 sensors are ignored, and the fuel trims tables are frozen from being updated. The PCM relies on the MAF signal, RPM, Intake pressure and other real time sensors, to perform fuel delivery.
Lastly, another consideration about injectors, you don't want to go overboard when selecting an injector for a specific engine fuel need, because you want to maintain some level of resolution in the digital pulse train sent to the injectors to fire them accuratly.
[Modified by kewlbrz, 6:13 PM 8/24/2002]
Kewlbrz, thanks a million for the above post. Very easy to follow, learned alot. Thanks :yesnod: :cheers:
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