stage 2 question
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Joined: 12-08-07
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From: Whiteman, Missouri
stage 2 question
I've heard and read that with the gm stage 2 kit if you put the 2.8" pulley on the charger it will take care of the running rich and you won't have to retune. Just wondering how much of that is true?
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From: Edmonton
I just got a 2.9 from smoothflowpulleys.com, I have stage 2 already... did you even notice a difference when you changed to a 2.9??
sorry to budge in here, but you're saying that you can put a 2.9 right on a stage2 without having to retune or anything? but then if i added a 2.8 and 60's it would definitely be wise for a tune..
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From: San Jose, CA
Also, to the OP: The only way that a smaller pulley will lean out your AFRs are if they go static, and that is NOT a recommended method for leaning your AFRs.
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From: In a house.
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From: San Jose, CA
lollz
Last edited by SJSchafer; Jun 6, 2008 at 03:48 PM. Reason: Automerged Doublepost
And heat problems. I think a FMIC is a good idea for any pulley smaller then stock 3.35.
Here is a real basic break down of how the LSJ is tuned.
The car is tuned for a certain A/F ratio (comanded A/F) at a particular rpm.
By intalling a smaller pulley their will be more air entering the engine so the ECU will react by adding more fuel to meet the commanded A/F.
And everything is fine.
But if you go with too small of a pulley you might run into problems at the higher rpms.
Since there is more air entering the engine and injectors must work hard to keep up. At higher rpms the small pulley maybe creating so much air that the injectors can not keep up. So the injectors will be maxed out and then your car will go lean.
Which is not good for your engine or your injectors.
When I had a 2.8" pulley installed on my stage 2 kit my engine was happy until 6600 rpms. So I installed a 2.9" pulley and everything is better.
I would get a 2.9" unless you have an Interceptor scan gauge and a wideband sensor to measure your A/F ratio.
Here is a real basic break down of how the LSJ is tuned.
The car is tuned for a certain A/F ratio (comanded A/F) at a particular rpm.
By intalling a smaller pulley their will be more air entering the engine so the ECU will react by adding more fuel to meet the commanded A/F.
And everything is fine.
But if you go with too small of a pulley you might run into problems at the higher rpms.
Since there is more air entering the engine and injectors must work hard to keep up. At higher rpms the small pulley maybe creating so much air that the injectors can not keep up. So the injectors will be maxed out and then your car will go lean.
Which is not good for your engine or your injectors.
When I had a 2.8" pulley installed on my stage 2 kit my engine was happy until 6600 rpms. So I installed a 2.9" pulley and everything is better.
I would get a 2.9" unless you have an Interceptor scan gauge and a wideband sensor to measure your A/F ratio.
And heat problems. I think a FMIC is a good idea for any pulley smaller then stock 3.35.
Here is a real basic break down of how the LSJ is tuned.
The car is tuned for a certain A/F ratio (comanded A/F) at a particular rpm.
By intalling a smaller pulley their will be more air entering the engine so the ECU will react by adding more fuel to meet the commanded A/F.
And everything is fine.
But if you go with too small of a pulley you might run into problems at the higher rpms.
Since there is more air entering the engine and injectors must work hard to keep up. At higher rpms the small pulley maybe creating so much air that the injectors can not keep up. So the injectors will be maxed out and then your car will go lean.
Which is not good for your engine or your injectors.
When I had a 2.8" pulley installed on my stage 2 kit my engine was happy until 6600 rpms. So I installed a 2.9" pulley and everything is better.
I would get a 2.9" unless you have an Interceptor scan gauge and a wideband sensor to measure your A/F ratio.
Here is a real basic break down of how the LSJ is tuned.
The car is tuned for a certain A/F ratio (comanded A/F) at a particular rpm.
By intalling a smaller pulley their will be more air entering the engine so the ECU will react by adding more fuel to meet the commanded A/F.
And everything is fine.
But if you go with too small of a pulley you might run into problems at the higher rpms.
Since there is more air entering the engine and injectors must work hard to keep up. At higher rpms the small pulley maybe creating so much air that the injectors can not keep up. So the injectors will be maxed out and then your car will go lean.
Which is not good for your engine or your injectors.
When I had a 2.8" pulley installed on my stage 2 kit my engine was happy until 6600 rpms. So I installed a 2.9" pulley and everything is better.
I would get a 2.9" unless you have an Interceptor scan gauge and a wideband sensor to measure your A/F ratio.
h/e dude
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Joined: 03-22-07
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From: Still fixing others mistakes.
If you are already tuned for a specific pulley, you do not need to retune for a smaller pulley, unless that pulley causes you to need to pull some timing due to heat. Adding 60# injectors will require a tune regardless.
Also, to the OP: The only way that a smaller pulley will lean out your AFRs are if they go static, and that is NOT a recommended method for leaning your AFRs.
Also, to the OP: The only way that a smaller pulley will lean out your AFRs are if they go static, and that is NOT a recommended method for leaning your AFRs.
