What is recommended next upgrade step?
06-03-2012, 02:19 AM
#26
if you turn your key to the on position and wait ten seconds, you should be able to hear the ic pump kick on and it hums. maybe even right when you turn on the car. that is all setup in your tune. for stock tunes, it takes 10 seconds.
and you can also watch the filler neck with the car on, if the coolant is making bubbles, then its running.
and you can also watch the filler neck with the car on, if the coolant is making bubbles, then its running.
06-03-2012, 02:33 AM
#27
i had jobs when i was in high school and made some money for all that stuff. now im a full time student year round, so 80 dollars means a bit more to me than just for a dual pass. and hp tuners was a birthday present a year ago.
i havent seen any knock yet. im commanding 18* up top. when i first got my car, i had no clue about any of this. i probably ran my car for 40 k miles without a working ic pump back in 07. lol and i know it will rob power. i will not dispute that. but really, how much power are we talking about??
are you in a lsj or a 2.4??
i havent seen any knock yet. im commanding 18* up top. when i first got my car, i had no clue about any of this. i probably ran my car for 40 k miles without a working ic pump back in 07. lol and i know it will rob power. i will not dispute that. but really, how much power are we talking about??
are you in a lsj or a 2.4??
06-03-2012, 02:42 AM
#29
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there have been ppl to make sum ok power without cooling mods ik ther was a thread bout it floatin sumwher but in all honesty do u wanna chance that..these cars heat up real quick so itd b in ur best interest to get a few cooling mods
06-03-2012, 02:49 AM
#30
and i wasnt trying to give out bad info. i just dont think we need to go so far as to say, cooling mods are totally necessary even at a 3 inch pulley or higher. my iat2 never saw over 140 on the 3 inch. some of these threads will make you feel like youll pop a few pistons running at 140*. i just dont see it. i may be wrong though
06-03-2012, 05:22 PM
#31
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Cooling mods will be had. By the end of summer I want ZZP S3(with dual pass endplate), ZZP 3" dp and 3" catback exhaust, and LS4 throttle body.
Then over the winter, Im looking at 2 options, either tvs and meth. Or the 2nd, because my car has a decent amount of miles on it is getting a Ecotec forged shortblock from ZZP with new internals
Then over the winter, Im looking at 2 options, either tvs and meth. Or the 2nd, because my car has a decent amount of miles on it is getting a Ecotec forged shortblock from ZZP with new internals
06-03-2012, 05:31 PM
#32
Cooling mods will be had. By the end of summer I want ZZP S3(with dual pass endplate), ZZP 3" dp and 3" catback exhaust, and LS4 throttle body.
Then over the winter, Im looking at 2 options, either tvs and meth. Or the 2nd, because my car has a decent amount of miles on it is getting a Ecotec forged shortblock from ZZP with new internals
Then over the winter, Im looking at 2 options, either tvs and meth. Or the 2nd, because my car has a decent amount of miles on it is getting a Ecotec forged shortblock from ZZP with new internals
06-03-2012, 05:49 PM
#33
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Anyway, this mod big has got me bad. When I first bought the car last year, I had no intentions on mods. But then watching YouTube vids and thinking about it I got giddy and bought the CAI. Now I got a budget put together to really try to get a lot of mods.
06-03-2012, 05:55 PM
#34
Thank you, I figured the bigger the better with exhaust.
Anyway, this mod big has got me bad. When I first bought the car last year, I had no intentions on mods. But then watching YouTube vids and thinking about it I got giddy and bought the CAI. Now I got a budget put together to really try to get a lot of mods.
Anyway, this mod big has got me bad. When I first bought the car last year, I had no intentions on mods. But then watching YouTube vids and thinking about it I got giddy and bought the CAI. Now I got a budget put together to really try to get a lot of mods.
06-03-2012, 06:05 PM
#35
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Now that I think about it, I remember reading somewhere that a SC runs best with some back pressure. Which would make sense why 2.5 is a better option.
06-03-2012, 06:54 PM
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thers prolly almost no difference in running a 2.5 or a 3"...mayb a couple hp if that but i could be proven wrong with a dyno sheet...i went with a 3" cuz i wanted all the flow i could get with my setup
06-08-2012, 12:28 AM
#37
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you NEVER want back pressure no matter what you're running. There will always be some, but you want to do what you can to decrease it, not maintain it!
Back pressure is the resistance to flow....the ability to flow is the ability to make power
VERY generally speaking exhaust tuning moves your torque peak and your torque band around based on diameter and length changes. Using the 2.5 to 3.0 example, it may very well be that the 2.5 tube lowers your torque peak to a range appropriate for the rest of your engine combo, and that the 3.0 raises it to a point above your appropriate range. In turn then, people see torque drop at lower rpm and equate this to a loss, rather than just a move, and then draw the incorrect conclusion that the smaller tube increases power by causing resistance to flow.
Back pressure is the resistance to flow....the ability to flow is the ability to make power
VERY generally speaking exhaust tuning moves your torque peak and your torque band around based on diameter and length changes. Using the 2.5 to 3.0 example, it may very well be that the 2.5 tube lowers your torque peak to a range appropriate for the rest of your engine combo, and that the 3.0 raises it to a point above your appropriate range. In turn then, people see torque drop at lower rpm and equate this to a loss, rather than just a move, and then draw the incorrect conclusion that the smaller tube increases power by causing resistance to flow.
06-08-2012, 03:52 AM
#38
you NEVER want back pressure no matter what you're running. There will always be some, but you want to do what you can to decrease it, not maintain it!
Back pressure is the resistance to flow....the ability to flow is the ability to make power
VERY generally speaking exhaust tuning moves your torque peak and your torque band around based on diameter and length changes. Using the 2.5 to 3.0 example, it may very well be that the 2.5 tube lowers your torque peak to a range appropriate for the rest of your engine combo, and that the 3.0 raises it to a point above your appropriate range. In turn then, people see torque drop at lower rpm and equate this to a loss, rather than just a move, and then draw the incorrect conclusion that the smaller tube increases power by causing resistance to flow.
Back pressure is the resistance to flow....the ability to flow is the ability to make power
VERY generally speaking exhaust tuning moves your torque peak and your torque band around based on diameter and length changes. Using the 2.5 to 3.0 example, it may very well be that the 2.5 tube lowers your torque peak to a range appropriate for the rest of your engine combo, and that the 3.0 raises it to a point above your appropriate range. In turn then, people see torque drop at lower rpm and equate this to a loss, rather than just a move, and then draw the incorrect conclusion that the smaller tube increases power by causing resistance to flow.
06-08-2012, 03:57 AM
#39
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idt the loss of hp is really much to notice and it prolly depends on ur setup as well some u want to be able to breathe and others u want a little pressure...my car felt alot more responsive and felt lik it ran better when i opened it up to a 3"
06-08-2012, 04:12 AM
#41
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i opened mine to a 3" on a m62...but u may be right i would like to see a dyno or sumtin for my own refrence...most ppl also dont wanna go to a 3" because they think its to loud but its all in the setup on how the exhaust sounds as well
06-08-2012, 12:40 PM
#42
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I didn't say the 3" wouldn't cause a power loss
I said the gain (or lack of loss?) from the 2.5 had NOTHING to do with backpressure
06-08-2012, 03:21 PM
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yes I do, 2 posts here. I just bought my Cobalt SS two weeks ago.
But- I have 20+ years in high performance cars and high performance engines. I teach high performance engine design. My information comes from engineers and physicists in high performance motorsports, not from conjecture and misunderstanding.
I didn't come here to troll, and I didn't come here to get in a pissing match. I came here to read about Cobalts, learn stuff, and offer up what I've learned over the years when I get the chance.
I saw an opportunity to educate about exhaust backpressure, so I tried. You don't want to believe me, that's fine, it wasn't my intent to offend, only to educate.
now that we've completely derailed the OP's thread (sorry dude!) I'll get out, because this is obviously going nowhere
But- I have 20+ years in high performance cars and high performance engines. I teach high performance engine design. My information comes from engineers and physicists in high performance motorsports, not from conjecture and misunderstanding.
I didn't come here to troll, and I didn't come here to get in a pissing match. I came here to read about Cobalts, learn stuff, and offer up what I've learned over the years when I get the chance.
I saw an opportunity to educate about exhaust backpressure, so I tried. You don't want to believe me, that's fine, it wasn't my intent to offend, only to educate.
now that we've completely derailed the OP's thread (sorry dude!) I'll get out, because this is obviously going nowhere
06-08-2012, 03:27 PM
#45
yes I do, 2 posts here. I just bought my Cobalt SS two weeks ago.
But- I have 20+ years in high performance cars and high performance engines. I teach high performance engine design. My information comes from engineers and physicists in high performance motorsports, not from conjecture and misunderstanding.
I didn't come here to troll, and I didn't come here to get in a pissing match. I came here to read about Cobalts, learn stuff, and offer up what I've learned over the years when I get the chance.
I saw an opportunity to educate about exhaust backpressure, so I tried. You don't want to believe me, that's fine, it wasn't my intent to offend, only to educate.
now that we've completely derailed the OP's thread (sorry dude!) I'll get out, because this is obviously going nowhere
But- I have 20+ years in high performance cars and high performance engines. I teach high performance engine design. My information comes from engineers and physicists in high performance motorsports, not from conjecture and misunderstanding.
I didn't come here to troll, and I didn't come here to get in a pissing match. I came here to read about Cobalts, learn stuff, and offer up what I've learned over the years when I get the chance.
I saw an opportunity to educate about exhaust backpressure, so I tried. You don't want to believe me, that's fine, it wasn't my intent to offend, only to educate.
now that we've completely derailed the OP's thread (sorry dude!) I'll get out, because this is obviously going nowhere
06-08-2012, 03:50 PM
#47
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Well my info comes from people that own and tuned cobalts for a living its been posted here many times that if ur not flowing enough to need a 3" u will lose hp. They are dynos posted all over the site that show the same thing im just not gonna dig into pages of info to prove a point over a few hp, I gave the op correct info that on his power level he would make more power on a 2.5 vs 3.
you did give the OP the correct info.
except for the bit about backpressure
the 2.5 offers the right amount of volume and velocity for that combo. The 3" has too much volume, not enough velocity for that combo, and installing it will cause a loss in power. On that we agree.
Lack of velocity of exiting gasses does not create an adequate negative pressure area at the open exhaust valve to completely evacuate the chamber, resulting in residual spent gas left over in the chamber--backpressure. So, again, why would you want that?
06-08-2012, 03:58 PM
#48
dang it! I hate it when I can't let go!
you did give the OP the correct info.
except for the bit about backpressure
the 2.5 offers the right amount of volume and velocity for that combo. The 3" has too much volume, not enough velocity for that combo, and installing it will cause a loss in power. On that we agree.
Lack of velocity of exiting gasses does not create an adequate negative pressure area at the open exhaust valve to completely evacuate the chamber, resulting in residual spent gas left over in the chamber--backpressure. So, again, why would you want that?
you did give the OP the correct info.
except for the bit about backpressure
the 2.5 offers the right amount of volume and velocity for that combo. The 3" has too much volume, not enough velocity for that combo, and installing it will cause a loss in power. On that we agree.
Lack of velocity of exiting gasses does not create an adequate negative pressure area at the open exhaust valve to completely evacuate the chamber, resulting in residual spent gas left over in the chamber--backpressure. So, again, why would you want that?
06-11-2012, 11:44 AM
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wayfarer is correct to the t. i've done alot of trial and error testing with motorcycle exhaust back when i was working as a tech. size, volume , exit velocity all come into play when trying to make power and or tune for power and torque in certain spots of your rpm range. plus i was bored and wanted to add my seven cents to the convo. the 2.75 exhaust is the preferred setup for the cobalt ss/sc. when trying to make big horsepower number with an m62 if horsepower numbers is all you interested in.
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