Finished up H/c/i build few ?
08-16-2012, 09:42 PM
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Finished up H/c/i build few ? Car started right up had bad *** oil pressure pretty stoked about that! The car though doesnt like to stay on until warm just seems worse than it should be but yes its untuned.
Now for the questions ...
My map sensor is excessivly loose on the back of intake could this be cause of a vaccum leak..
I read that some silicone can fix this ?
I have the button style valley cover bolts so im going to rule that out and my hose from booster is on and good. And did the gm reccomended of torquing down the intake .
Is there anything else i need to check all wires and coils and plugs are all clicked in and plugged up good. Also car is open headers till i can get the shop to weld up my exhaust again. Thanks for any input guys!
Now for the questions ...
My map sensor is excessivly loose on the back of intake could this be cause of a vaccum leak..
I read that some silicone can fix this ?
I have the button style valley cover bolts so im going to rule that out and my hose from booster is on and good. And did the gm reccomended of torquing down the intake .
Is there anything else i need to check all wires and coils and plugs are all clicked in and plugged up good. Also car is open headers till i can get the shop to weld up my exhaust again. Thanks for any input guys!
Last edited by reeperz28; 08-17-2012 at 08:34 AM.
08-16-2012, 10:02 PM
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Without a tune the idle is probably too low(RPM) , and there is too little idle airflow for it to idle smoothly. It will probably need some fuel pulled out, and some timing added to your idle as well. I have the same cam as you and I needed to move my idle up to 850 RPM and add about 20% more idle airflow in my tune to get it to idle ok. You may have a small vacuum leak, but that is probably minor, compared to how much you will need the idle tuning parameters adjusted. You now have 4 degrees of overlap with that cam at 0.050 lift, considerably different than stock.
08-17-2012, 08:54 PM
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One thing to watch out for is the position of the O2's from the exit of the LT's. Put a set of 8" extension pieces on the collectors for now. The O2's in your case will be only an inch or so from open air, which can skew their readings drastically. The O2's will be measuring some of the air that it picks up from the close opening of the exhaust.
In reality, the idle pumping efficiency of most cams isn't exactly the greatest, it may be around a 10% difference in idle airflow, but it will probably see 20-25% more in the mid to upper regions. Not to mention any idle fuel "short circuiting" which will involve injector event tuning.
Any injector upgrades? If so I'd avoid running it till you get it to a tuner, to avoid washing the cylinders.
Without a tune the idle is probably too low(RPM) , and there is too little idle airflow for it to idle smoothly. It will probably need some fuel pulled out, and some timing added to your idle as well. I have the same cam as you and I needed to move my idle up to 850 RPM and add about 20% more idle airflow in my tune to get it to idle ok. You may have a small vacuum leak, but that is probably minor, compared to how much you will need the idle tuning parameters adjusted. You now have 4 degrees of overlap with that cam at 0.050 lift, considerably different than stock.
Any injector upgrades? If so I'd avoid running it till you get it to a tuner, to avoid washing the cylinders.
Last edited by bayer-z28; 08-17-2012 at 09:09 PM.
08-18-2012, 10:43 PM
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One thing to watch out for is the position of the O2's from the exit of the LT's. Put a set of 8" extension pieces on the collectors for now. The O2's in your case will be only an inch or so from open air, which can skew their readings drastically. The O2's will be measuring some of the air that it picks up from the close opening of the exhaust.
In reality, the idle pumping efficiency of most cams isn't exactly the greatest, it may be around a 10% difference in idle airflow, but it will probably see 20-25% more in the mid to upper regions. Not to mention any idle fuel "short circuiting" which will involve injector event tuning.
Any injector upgrades? If so I'd avoid running it till you get it to a tuner, to avoid washing the cylinders.
In reality, the idle pumping efficiency of most cams isn't exactly the greatest, it may be around a 10% difference in idle airflow, but it will probably see 20-25% more in the mid to upper regions. Not to mention any idle fuel "short circuiting" which will involve injector event tuning.
Any injector upgrades? If so I'd avoid running it till you get it to a tuner, to avoid washing the cylinders.
