Do not get an intake unless you're custom tuning the car!
08-17-2010, 04:00 PM
#1
Do not get an intake unless you're custom tuning the car!
"But someone said ___ intake does not throw off fuel trims"
It does throw them off. It needs to be tuned. This is not some ancient car. The car constantly tries to operate in closed loop, and as such is completely dependent on all of it's sensors to be in accurate working order. Throwing them off by doing things like changing the intake can damage the engine.
"But it doesn't set off the CEL"
Just because it doesn't set of the CEL, doesn't mean it's ok. If you saw the amount of knock and how skewed your fuel trims are, you would be singing a different tune. Literally.
"What if it's just 3-4% off"
3-4% off where? MAF tuning is much more complicated than simply saying it's a few percent off. Let's say it's rich in one spot, the ECU will attempt to remove fuel in surrounding cells. What if it was already lean in those other cells? This car already runs very lean, so if it's off just a little bit, that is not good.
"Someone said they've been doing fine without tuning"
Did they data log? No? Stop right there.
"Can I run GMS1 with an intake?"
No, not if you care about your engine.
"Do I need to get re-tuned if I already have a custom tune?"
Yes, I'm sure your tuner will discount a simple MAF tune.
"What if my tuner doesn't have MAF tuning available?"
Walk away! Just walk away!
"My tuner only tuned the intake on the dyno. Is that okay?"
No, probably not. You need to do a lot of steady state cruising at various RPMs and loads to produce a good MAF calibration.
I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
It does throw them off. It needs to be tuned. This is not some ancient car. The car constantly tries to operate in closed loop, and as such is completely dependent on all of it's sensors to be in accurate working order. Throwing them off by doing things like changing the intake can damage the engine.
"But it doesn't set off the CEL"
Just because it doesn't set of the CEL, doesn't mean it's ok. If you saw the amount of knock and how skewed your fuel trims are, you would be singing a different tune. Literally.
"What if it's just 3-4% off"
3-4% off where? MAF tuning is much more complicated than simply saying it's a few percent off. Let's say it's rich in one spot, the ECU will attempt to remove fuel in surrounding cells. What if it was already lean in those other cells? This car already runs very lean, so if it's off just a little bit, that is not good.
"Someone said they've been doing fine without tuning"
Did they data log? No? Stop right there.
"Can I run GMS1 with an intake?"
No, not if you care about your engine.
"Do I need to get re-tuned if I already have a custom tune?"
Yes, I'm sure your tuner will discount a simple MAF tune.
"What if my tuner doesn't have MAF tuning available?"
Walk away! Just walk away!
"My tuner only tuned the intake on the dyno. Is that okay?"
No, probably not. You need to do a lot of steady state cruising at various RPMs and loads to produce a good MAF calibration.
I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
08-17-2010, 04:15 PM
#3
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I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
Truer words were never spoken. Amen to that.
08-17-2010, 04:26 PM
#6
Senior Member
It skews the fuel trims quite a bit. Even more if you mod the stock snorkel or worse remove it completely. Any intake mods you do to the car will skew the stock sensor because there is no laminar flow straightner (that honeycomb thing most MAFs have in front of them). The LS7 vettes are the same way because they use the same sensor.
Most people on here would know better if the actually read this. It is a sticky so it stays there so no need to search https://www.cobaltss.net/forums/2-0l-lnf-performance-tech-153/thoughts-all-intakes-currently-avaliable-ss-tc-206581/
"But someone said ___ intake does not throw off fuel trims"
It does throw them off. It needs to be tuned. This is not some ancient car. The car constantly tries to operate in closed loop, and as such is completely dependent on all of it's sensors to be in accurate working order. Throwing them off by doing things like changing the intake can damage the engine.
"But it doesn't set off the CEL"
Just because it doesn't set of the CEL, doesn't mean it's ok. If you saw the amount of knock and how skewed your fuel trims are, you would be singing a different tune. Literally.
"What if it's just 3-4% off"
3-4% off where? MAF tuning is much more complicated than simply saying it's a few percent off. Let's say it's rich in one spot, the ECU will attempt to remove fuel in surrounding cells. What if it was already lean in those other cells? This car already runs very lean, so if it's off just a little bit, that is not good.
"Someone said they've been doing fine without tuning"
Did they data log? No? Stop right there.
"Can I run GMS1 with an intake?"
No, not if you care about your engine.
"Do I need to get re-tuned if I already have a custom tune?"
Yes, I'm sure your tuner will discount a simple MAF tune.
"What if my tuner doesn't have MAF tuning available?"
Walk away! Just walk away!
"My tuner only tuned the intake on the dyno. Is that okay?"
No, probably not. You need to do a lot of steady state cruising at various RPMs and loads to produce a good MAF calibration.
I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
It does throw them off. It needs to be tuned. This is not some ancient car. The car constantly tries to operate in closed loop, and as such is completely dependent on all of it's sensors to be in accurate working order. Throwing them off by doing things like changing the intake can damage the engine.
"But it doesn't set off the CEL"
Just because it doesn't set of the CEL, doesn't mean it's ok. If you saw the amount of knock and how skewed your fuel trims are, you would be singing a different tune. Literally.
"What if it's just 3-4% off"
3-4% off where? MAF tuning is much more complicated than simply saying it's a few percent off. Let's say it's rich in one spot, the ECU will attempt to remove fuel in surrounding cells. What if it was already lean in those other cells? This car already runs very lean, so if it's off just a little bit, that is not good.
"Someone said they've been doing fine without tuning"
Did they data log? No? Stop right there.
"Can I run GMS1 with an intake?"
No, not if you care about your engine.
"Do I need to get re-tuned if I already have a custom tune?"
Yes, I'm sure your tuner will discount a simple MAF tune.
"What if my tuner doesn't have MAF tuning available?"
Walk away! Just walk away!
"My tuner only tuned the intake on the dyno. Is that okay?"
No, probably not. You need to do a lot of steady state cruising at various RPMs and loads to produce a good MAF calibration.
I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
Last edited by Terminator2; 08-17-2010 at 04:29 PM. Reason: Automerged Doublepost
08-17-2010, 04:28 PM
#7
Most people on here would know better if the actually read this. It is a sticky so it stays there so no need search https://www.cobaltss.net/forums/showthread.php?t=206581
08-17-2010, 04:42 PM
#11
Senior Member
I have done two LNFs with the K&N SRI and they both need quite a bit of work to get the fuel trims back. Both were off 7-8% on the LTFT and 3-6% on the STFTs. The intake that skews the fuel trims the most is definately CIA's SRI. The two cars I have logged with it show -16.4 to -17.8 LTFTs and -7 to +8 on the STFTs.
08-17-2010, 04:57 PM
#15
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So what your saying is the K&N SRI that I just bought should sit on my shelf until I am ready to tune over the GMS1...which will be in 4 years when the factory warranty is up. I figured it was an easy enough mod to swap on and off when/if I have to bring it in for work....
08-17-2010, 08:31 PM
#20
"But someone said ___ intake does not throw off fuel trims"
It does throw them off. It needs to be tuned. This is not some ancient car. The car constantly tries to operate in closed loop, and as such is completely dependent on all of it's sensors to be in accurate working order. Throwing them off by doing things like changing the intake can damage the engine.
"But it doesn't set off the CEL"
Just because it doesn't set of the CEL, doesn't mean it's ok. If you saw the amount of knock and how skewed your fuel trims are, you would be singing a different tune. Literally.
"What if it's just 3-4% off"
3-4% off where? MAF tuning is much more complicated than simply saying it's a few percent off. Let's say it's rich in one spot, the ECU will attempt to remove fuel in surrounding cells. What if it was already lean in those other cells? This car already runs very lean, so if it's off just a little bit, that is not good.
"Someone said they've been doing fine without tuning"
Did they data log? No? Stop right there.
"Can I run GMS1 with an intake?"
No, not if you care about your engine.
"Do I need to get re-tuned if I already have a custom tune?"
Yes, I'm sure your tuner will discount a simple MAF tune.
"What if my tuner doesn't have MAF tuning available?"
Walk away! Just walk away!
"My tuner only tuned the intake on the dyno. Is that okay?"
No, probably not. You need to do a lot of steady state cruising at various RPMs and loads to produce a good MAF calibration.
I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
It does throw them off. It needs to be tuned. This is not some ancient car. The car constantly tries to operate in closed loop, and as such is completely dependent on all of it's sensors to be in accurate working order. Throwing them off by doing things like changing the intake can damage the engine.
"But it doesn't set off the CEL"
Just because it doesn't set of the CEL, doesn't mean it's ok. If you saw the amount of knock and how skewed your fuel trims are, you would be singing a different tune. Literally.
"What if it's just 3-4% off"
3-4% off where? MAF tuning is much more complicated than simply saying it's a few percent off. Let's say it's rich in one spot, the ECU will attempt to remove fuel in surrounding cells. What if it was already lean in those other cells? This car already runs very lean, so if it's off just a little bit, that is not good.
"Someone said they've been doing fine without tuning"
Did they data log? No? Stop right there.
"Can I run GMS1 with an intake?"
No, not if you care about your engine.
"Do I need to get re-tuned if I already have a custom tune?"
Yes, I'm sure your tuner will discount a simple MAF tune.
"What if my tuner doesn't have MAF tuning available?"
Walk away! Just walk away!
"My tuner only tuned the intake on the dyno. Is that okay?"
No, probably not. You need to do a lot of steady state cruising at various RPMs and loads to produce a good MAF calibration.
I'll go on record as saying that changing the intake is the riskiest bolt on that you can do. You should not swap the intake on any modern car without tuning. If you are unwilling to do this, then go play with the exhaust side, or suspension. Just leave the intake alone.
If this is the case then nobody should drive their car until its tuned because the stock airbox does the same thing 
The car is easily driveable without a tune on the K&N... a tune is in my list but not quite yet. In the meantime I'd rather have the fuel trims Im seeing with the k&N intake than the stock airbox thank you.
Last edited by CudaJoe; 08-17-2010 at 08:32 PM. Reason: Automerged Doublepost
08-17-2010, 08:38 PM
#22
Senior Member
