Questions about performance upgrades

Bulkybear

Bulkybear

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I'm kind of curious. With every car out there, there are aftermarket parts that increase performance. Things like intakes, exhaust, header/downpipes, even just ecu tuning. My question, on performance models (srt, Si, ss, etc) why do the cars not come this way stock? What do the manufacturers try to balance when making a car? I've seen a few people on here fully bolted, with a catted downpipe, fully tuned making between 205 and I think as much as 240 to the wheels. I think our cars make around 180 stock. And they don't seem to have any drastic changes in gas mileage. Rev hang is gone, etc. So I guess I was curious as to why at least the performance models don't come that way. They are obviously coming pretty detuned if you will. Opinions?
 
Some upgrades like intake, downpipe, and exhaust make the car too loud for your average consumer... just my two cents
 
323 said:
Some upgrades like intake, downpipe, and exhaust make the car too loud for your average consumer... just my two cents
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:word:emissions and NVH are a big deal in the new car market and are pretty much the main reason why all cars (even the hardcore performance variants) come pretty watered down. even the most hardcore street legal performance cars are quite different from uncompromised track-only cars.
 
Honest question but would a fully bolted Si not meet the same emissions as stock?
 
Bulkybear said:
Honest question but would a fully bolted Si not meet the same emissions as stock?
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well, that depends what you mean by fully bolted. the biggest emissions issue today isn't the particulate emissions (i.e. smog), but unburned hydrocarbons. if you're talking intake, exhaust, cam, injectors, tune, high-flow or no cat, etc., then it most likely wouldn't meet the same emissions.

take rev-hang for instance. it's actually been around since before drive-by-wire, but it's supposed to reduce unburned hydrocarbons being released by through the tailpipe by burning off any excess gas leftover after the throttle plate closes. reducing rev-hang and letting the revs drop immediately allows more hydrocarbons to escape. most tuning solutions, especially when coupled with high-flow injectors, will increase the amount of gas metered into the combustion chamber, so that also increases the potential for unburned gas to escape.

normally, the reactions that occur in the catalytic converter do help burn off some of the excess gasses, but removing the cat or replacing it with a high-flow version reduces its effectiveness. even installing a cat-back that increases flow reduces the amount of time the stock cat has to burn any excess hydrocarbons, so that also in theory can reduce it's effect.

intakes don't necessarily increase emissions, but they do increase noise, vibration, and harshness. besides the extra noise and vibration, some people also complain of dips or uneven power application after installing intakes. some of that can be fixed with tuning, but the filters on most intakes don't filter as well as the paper filters that come stock, and the increased dirt in the engine can potentially affect long-term reliability. since the intakes don't usually flow a whole lot better than stock and have the potential to introduce other problems, the OEMs figure any benefits won't outweigh the cons, and stick with airboxes with paper filters and tubing designed with resonators that cut out any unwanted noise.
 
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honestly, i understand what you're saying, and I would love it if manufacturers would release no-compromise versions. but unfortunately, in big business, money will always rule. so even if they alienate a few hardcore enthusiasts, if they can keep selling more and more cars by slightly detuning them and making them "more refined" to increase the customer base, they will.
 
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Dang mikey, that's just the kind of talk I was looking for. Thanks for the explanation. Question about intakes, you said they don't filter as well and don't really flow much better than stock paper filters. Have I been wrong in wanting to pick up more power with something like the kn short ram? Should I skip that part and stay with the stock intake?
 
Bulkybear said:
Dang mikey, that's just the kind of talk I was looking for. Thanks for the explanation. Question about intakes, you said they don't filter as well and don't really flow much better than stock paper filters. Have I been wrong in wanting to pick up more power with something like the kn short ram? Should I skip that part and stay with the stock intake?
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k&n makes some great products, and i have used many of their intakes on my cars. they do flow better than stock, but independent testing shows that the extra flow isn't a huge deal greater, and it doesn't filter out nearly as much dirt as stock does. you will probably pick up a few horsepower, but again, it's not a huge difference. 5hp over 201hp stock is only a 2.5% increase. 10hp would be optimistic, and that's only a 5% increase. the problem with k&n intakes is the oiled filter. it relies on the oil to trap the smaller dirt particles, so as long as it's oiled properly, it filters okay. this means it requires maintenance. but depending on how much it's oiled from the factory and how much it's oiled during maintenance, some people have (like me on with of my other cars) have had the maf sensors fouled by oil, causing check engine lights to be thrown. most of the issues i saw with this was after installing new k&n intakes. you can clean the mafs with maf cleaner, and it should work, but i must be getting older, cuz i'm starting to think it's not worth the hassle.

if you do want an intake, look for one that has a dry element. it won't foul up any sensors, but probably won't filter as well either. it's all a matter of preference. if i got an intake on my 9th, it'd be strictly for the more agressive sound than anything else. short rams only make more power at the really high rpms, and in fact a lot of times you'll lose a little tq in the meat of the rpm band. cold air intakes work a little better, but then if you live in really wet areas, there's a (really slight) chance of hydrolock. i've also had issues with that on a SRI on my tacoma when off-roading in mud though, so it really depends.

here's a link with some tests of the k&n vs other filters. http://www.nicoclub.com/archives/kn-vs-oem-filter.html
 
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if i remember correctly, the guy that started AFe is a former k&n engineer, which is why they usually have similar designs for applications that they share. the AFEs usually use dry filters tho, so you wouldn't have as many issues, if any.
 
sorry for the posts, but i just remembered that emissions is also the reason why Honda is switching to the integrated header. it brings the cat up to operating temp a lot quicker, which means it gets to burning excess hydrocarbons quicker. with all the sensors measuring oxygen levels before and after combustion, most combustion in stock cars is actually pretty clean while the cats take care of the rest. but since the cats require really high temps to oxidize the extra gas and neutralize other byproducts of combustion, most of the really dirty emissions happens at startup. so say a car takes a minute to warm up normally, and in that minute releases 90% of it's hydrocarbon emissions. If you can reduce that warm up time to 30 seconds, you cut 90% of the hydrocarbon emissions in half, so effectively a 45% reduction. that's really good for emissions, but sucky for NA performance.
 
I seem to recall the 8thgen Mugen Si didn't sell all that well. Of course the mark up was ridiculous. The dealers eventually had to bite the bullet on the sticker after they were sitting around for a year or more.

I would be very interested to see an American Mugen type r, but I suspect these would be expensive... $45K+
 
Good info definitely. One more question, isn't the k&n short ram for our car a dry filter?
 
Bulkybear said:
Good info definitely. One more question, isn't the k&n short ram for our car a dry filter?
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As far as i know, all their intakes still use their oiled filters. This is from k&n's website:

"Through use of K&N's high flow, oiled cotton gauze air filter, and streamlined intake tube, the Civic Si is no longer gasping for air."

http://www.knfilters.com/news/news.aspx?id=4089
 
If you're thinking about dropping $200 on a SRI... try the drop in K&N filter with the resonator delete. $50-ish and you may get the boost you're looking for.

The only issue you may have with an oiled filter is if there is too much oil and it pulls off onto your MAF sensor it could throw a light. Just get MAF cleaner spray and hit it quick to fix it.
 
Ok. So in conclusion the reason our cars are watered down is strictly for emissions. That sucks, at least tune your performance oriented cars for performance lol. And on the drop in/resonator delete combo you think that would be the equivalent to a sri? Doesn't the stock intake pull air in much the way a cai would? When I was looking at it I saw a tube going from under the filter and it looks like it goes to the front bumper cover or something. If I delete the resonator wouldn't I essentially be cutting off that part of the system and raising my intake air temps?
 
Bulkybear said:
Ok. So in conclusion the reason our cars are watered down is strictly for emissions. That sucks, at least tune your performance oriented cars for performance lol. And on the drop in/resonator delete combo you think that would be the equivalent to a sri? Doesn't the stock intake pull air in much the way a cai would? When I was looking at it I saw a tube going from under the filter and it looks like it goes to the front bumper cover or something. If I delete the resonator wouldn't I essentially be cutting off that part of the system and raising my intake air temps?
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No because you can pull the resonator and still keep that tube that goes into the fender well. It'll draw air from that region ahead of the driver's wheel.
 
Cars are watered down for emissions and so that the average driver of one hundred eleventy years old will be comfortable.

With the res delete it's going to pull air from a similar location to a CAI. The short ram is going to pull hot air from under the hood. With res delete it should give you colder AIT. You would be removing the resonator "box" and leaving the stock piping so you're intake location is now down low behind the bumper. I don't know if the gains would be as much as a short ram but I bet it is close and you won't be spending a couple hundred. The stock intake also draws air from the engine bay. You would be leaving box #10 as your new intake location and removing all the stuff after it. If you look in the images #11 is the stock intake location pointed up into the engine bay.

index.php
 
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Good. I will look up the diy. That delete will probably be my next mod :)
 
I also think besides emissions some customers, maybe more than we think buy these cars for looks and social status. A pure performance version will turn away many customers for being too loud, uncomfortable or too raw. Another considerent is that for a 100k there is always a much more performance oriented beast available and they do not want to undercut it with the lower models. I remember in the 80s when a lot of muscle cars were more affordable, as well as a lot of mid price range japanese sports cars, nowadays not so many. Maybe it is just my impression i did not actually compare how many models and what prices they had.
 
Ok so if I delete the resonator do I have to worry about hydrolock like with a cai?
 
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