Odd observation.. see inside.
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From: Woodlyn, PA
Odd observation.. see inside. I have a GWP 3.4" P1SC. The programming is for an all stock car, however I have Grots, cutout and a pair of 3" Y pipes, with and without cats.
I pick up 4 MPG when I use the pipe with cats... and I don't even have the rear 02 sensors in! The simms are still in place. The car is happier down low with the cats, taking off from lights and all (I know... with a 6130 RAM setup is difficult to take off smoothly).
What aspects of programming would make this happen?
I pick up 4 MPG when I use the pipe with cats... and I don't even have the rear 02 sensors in! The simms are still in place. The car is happier down low with the cats, taking off from lights and all (I know... with a 6130 RAM setup is difficult to take off smoothly).
What aspects of programming would make this happen?
Re: Odd observation.. see inside. It's not programming, it's back pressure.
Low end torque usually suffers with a drop in back pressure. Less low end requires more throttle to achieve the same torque compared to when you're capped up w/ the cats
simple as that.
Low end torque usually suffers with a drop in back pressure. Less low end requires more throttle to achieve the same torque compared to when you're capped up w/ the cats
simple as that.
Re: Odd observation.. see inside. Y2khawk is correct <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> At the track, I uncap my exhaust and it does cost me low end torque. I launch at 5500 rpms and do feel a bit of bog with open exhaust. Uncapped exhaust also caused my car to run about 8-10% richer on the dyno. That has proven to be correct at the track as well. Uncap the exhaust and I have to lean the car out 8-10% to get the o2s back dow to the same as capped exhaust.
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From: Woodlyn, PA
Re: Odd observation.. see inside. I understand the compromise between low-end torque and high end power, but what about the gas mileage?
4 MPG can save alot of money... especially when running 94+ octane.
THAT is where the programming comes in is what I meant.
4 MPG can save alot of money... especially when running 94+ octane.
THAT is where the programming comes in is what I meant.
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Re: Odd observation.. see inside. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by cablebandit:
<strong>Y2khawk is correct <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> At the track, I uncap my exhaust and it does cost me low end torque. I launch at 5500 rpms and do feel a bit of bog with open exhaust. Uncapped exhaust also caused my car to run about 8-10% richer on the dyno. That has proven to be correct at the track as well. Uncap the exhaust and I have to lean the car out 8-10% to get the o2s back dow to the same as capped exhaust.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where do your revs drop to when the clutch bites. Just wondering because you said you loose low end with the exhaust uncapped ,and a bog when you launch at 5500 with it open. 5500 does not seem to fall in the low end category though.
Thanks.
Also , i thought cars usually run leaner when you open the exhaust.
<strong>Y2khawk is correct <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> At the track, I uncap my exhaust and it does cost me low end torque. I launch at 5500 rpms and do feel a bit of bog with open exhaust. Uncapped exhaust also caused my car to run about 8-10% richer on the dyno. That has proven to be correct at the track as well. Uncap the exhaust and I have to lean the car out 8-10% to get the o2s back dow to the same as capped exhaust.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where do your revs drop to when the clutch bites. Just wondering because you said you loose low end with the exhaust uncapped ,and a bog when you launch at 5500 with it open. 5500 does not seem to fall in the low end category though.
Thanks.
Also , i thought cars usually run leaner when you open the exhaust.
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Re: Odd observation.. see inside. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Rock:
<strong>I understand the compromise between low-end torque and high end power, but what about the gas mileage?
4 MPG can save alot of money... especially when running 94+ octane.
THAT is where the programming comes in is what I meant.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Like Y2khawk said. Less torque means you have to open the throttle more to get the same torque or the car to move at the same speed. Thats probably why gas milage increases , because you can use less throttle to get the car to move or accelerate to a given cruising speed.
<strong>I understand the compromise between low-end torque and high end power, but what about the gas mileage?
4 MPG can save alot of money... especially when running 94+ octane.
THAT is where the programming comes in is what I meant.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Like Y2khawk said. Less torque means you have to open the throttle more to get the same torque or the car to move at the same speed. Thats probably why gas milage increases , because you can use less throttle to get the car to move or accelerate to a given cruising speed.
