X'ed I appreciate that you're trying to show me the error of my ways, however you're comparing the wrong type of car. The rx8 is a rotary and if you look at the chart you refered me to it shows exactly what I described (a FLASH reading). If you look at the other 2 runs he made they were 181 and 178. Using a dyno you Average those readings and even if we allow the first one in its at best a sustainable 181. Thats 6hp from a rotary. If you'll check some of my other posts on this subject, a show on SPEED is doing an upgrade on a Acura RSX-S This car shows 210WHP. They installed a cold air intake specially designed for the car and measured 4-6 WHP with the hope that they will pick up an additional 2 @100mph from ram air effect.

 

Forgive me for what I'm sure is a stupid question, but what does RWHP mean? I'm sure it doesn't mean Rear wheel horsepower, since the RSX (and RSX-S) is a front wheel drive vehicle.

By the way, there is no fundamental difference in how a cold-air intake would affect a rotary engine compared to a piston-driven engine. The rotary engine in effect simply acts as three pistons at once, with the rotor dividing the cylinder into three stages (intake/ compression/combustion, and exhaust). So one shouldn't discount a 6hp increase in an RX-8 simply because the engine is a rotary.

 

i never showed you an rx8. and further, how can you argue with the 9 or 11 whp gain that was shown, its on the freakin graph. no stock rsx is rear wheel drive. where do you get your info from bro? and no rsx-s has ever put anything near 210 F(thats front, not rear) wheel horsepower down.

 

RSX Type S's put down around 170whp down like our crossfires. But intake, race header and hodata, would put you over 200whp. Which would make you rsx run high high 13's. I;m guessing from I believe it was redcrosses 14.4 run, that with chip, intake, and muffler, i mean exhaust. about 185-190ish whp.

 

sorry, i meant stock rsx as there are rsx's putting down hp in the 350whp range daily driven.

 

Sorry Whp. I admit that I don't know who is fwd versus rwd among most of the newer tuner type cars. As far as the rotary being a 4stroke there is considerable debate as to whether it can truly be classed as an otto 4 stroke because it operates as much like a 2 stroke as it does a four stroke. The reason being that it does not have a valve train but simply an induction cycle. Many racing organizations have banned their use for this reason. They have also shown much more affect to changing intake and exhaust systems like a 2 stroke does. If you watch Sports car revolution, on speed you will see that they dyno'd a RSX-S and recorded 210WHP. If you check the spec's from Acura(2005), thats about what they list it at. You provided a link to a site that appeared to be about the RX8. In any case you're missing the point I made about FLASHING on the dyno. Manufactures have been doing it for years in order to support their inflated claims. If you look at the graph, you'll see that the HP reading on the first graph Has a very sharp peak and falls rapidly. Thats whats known as a flash reading. I'm not ignoring whats shown on the graph, I'm simply trying to explain what is being done. I understand that there is a need to think that intake systems on engines are very restrictive. But, without some type of turbo, supercharger, intercooler or changing manifolds or heads or valves, you cannot get the amount of HP back that are being claimed. I too have over the last 40 years seen lots of manufactures claim to have dyno readings to establish that their intake, velocity stack, whatever, does what they say it does. In the end the claims turn out to be just that. If you want to see what you are losing by using a stock intake, simply take it off and dyno the car. Do it with the hood off or open and you'll get less underhood heated air. By the way, I'd like to see one of those 350WHP RSX's that are driven on the street.

 

My previous car was an rsx-s and i lived over in that forum. if you would like any info please ask me.

as far as basic specs, hondata #4, CAI, and exhaust will put you around 180 WHP. The only daily driven 350 WHP type s's are those with turbo and they bump up the boost to race. The jackson supercharger for the s puts down around 250 whp.

the also make a toda kit, which is cams ontop of raceheader and that throws down around 220 - 230.

i had exhaust and intake on mine and it was about 10 HP more than stock i'd estimate.

 

Thanks for the info. I wasn't sure if the RSX-S was stock when they did the dyno run or not, but they stated that they lost 11HP with the stock intake and were trying to get as much back as possible. That is where I got the numbers from, and they do fall in line with my experience over the years in building engines for my dirt track cars. The top engine builders from the last 30 years all advise against buying into the hyped up claims made about intake mods as most are way over the top. Smokey Yunick took a complete chapter in his book to explain what could and could not be done with various tubing and filters ahead of the carb. While a lot of things have changed internally VVT etc. Very little has changed in what can be accomplished with airflow before the carb. I wondered about what was done to get those cars up to that number, I have seen nitrous or supercharged get some really outrageous numbers, but wondered if they were streetable or not. I should have known better because I know a guy here on the Delmarva that actually drives a twin supercharged 69 camaro that turns 7.5 @ 165. I don't think I'd want to drive it from stoplight to stoplight, but he cruises up and down RT1 in the summer at the beach with it.

 

My previous car was also a 2004 Acura RSX Type S. And from what i found on that forum and I have asked they said Race header, intake, and Hondata would yeild around 200whp. They said the exhaust is a minimal gain.

 

man hobbyman you are frustrating. first of all the link says "clubrsx", so where do you get rx8. second, the power drops off at the end because the car has redlined. third, these are dyno runs, not flash runs. whp means power rated at the wheels, not the crank. the show your talking about is probably doing crank horsepower. fact is, its well known that certain cars take to intakes very well. like i said, you dont make 10whp(12 hp to the crank) all the way across the power band but maybe for 5-800rpms. the 11whp gain i showed you would have been at the "peak" gain. there are other cars dyno's i could show you to prove my point, like bullseye said with the cobra and the old b series hondas that got up to 13whp from intakes, but i get tired of arguing with people who dont show me anything empirical as i have done.

 

I agree about those numbers but i think they are closer to around 190 WHP, not going to argue over that. I think the 200 WHP were with type r cams and maybe one or two fluke people. It all depends on the starting dyno. bottom line is with all 4 of those you'd gain between 20 - 25 WHP.

To me I had the AEM V2 and RS-R exhaust. I noticed an increase in MPG and performance. Enough (at least in just sound) to justify my purchases.

 

Sorry, you mentioned the rx8 and I assumed (my fault, I didn't actually look at the site, just the graph) thats the car you were discussing. You are quite correct that the graph shows those numbers, but Please bear with me. If you look at the blue line (the one that shows 186HP) you'll see the hp fall and then rise sharply and then fall again. That is a flash reading. It means the driver backed off slightly and then floored it. When you do that you can FLASH a higher number than the car will sustain at full throttle. The proof of what I'm saying is on the same graph. The other runs do not show a drop and then a sharp peak, but a steady gain until peak Hp and then a gradual drop. Not to beat it to death (afraid I already have) but the actual HP gain is an average of the runs, not the best one. Thats not my idea, that is the rule for all testing. Actually the show I metioned is doing the runs with a Chassis dyno. I may have mislead you by saying a stock RSX-S because it turns out the car was chipped and had some other minor mods Hondata and a exhaust I think. It really doesn't matter because the baseline being higer would only tend to make the gain greater, not less.

 

You regret getting rid of your acura at all? Mine got totaled at 71 miles.

 

The only thing I regret is the fuel economy. I was getting around 40 MPG on the highway. I do miss it a little bit, but the xfire is more refined and more of what i a m looking for (i am almost 29 now). As far as power, i think it is VERY close.

I will also miss the build quality of the acura. i have 2 squeeks in my xfire right now that the dealer supposedly can not fix.

sorry to hear about your type s, what was your screen name over at clubrsx? i was type dougie.

oh the last thing i will not miss, and the main reason for getting rid of the S, was the insurance. can you believe my insuranced raised in one years time from 90/month to 200/month (note not one violation or anything happened to me). they kept telling me the symbol for liability was going up. last i heard it was a 23. the xfire is a 15 or 16 they said. my insuranced dropped by 40% when i got the xfire.

 

Again, this is probably a stupid question, but our car's do not have carborateours (sp?) do they? With fuel injection, there really isn't a purpose for a carb, so what component did you actually mean when stating before the..?

 

Can't remember what exactly it was something DOHCV82Vtec4 something like that. Was on there for a short time. Made that name because I traded in my Mach 1 Call me crazy I'd rather have my rsx back.

 

Well it is kind of silly, its the throttle body. I mean really the limiting factor is the size of the throat feeding the intake manifold, be it a carb or whatever restriction there is.Ultimately of course it is simply the ability of the pump (engine) to inhale and exhale. The more air/fuel mixture you move through the pump, the more power you make. Anything that restricts throughput limits HP. That's the reason most 4 stroke engines don't show much gain when doing intake stuff, the ones that do have either very restrictive air cleaners or have had changes (cams, headers, etc) which require a better intake. Remember naturally aspirated means operating at 1 atmosphere so whatever gravity gives you is all you get. Thats why nitrous and turbo's and superchargers give such impressive gains because they are stuffing the pump!

 

Maybe this is what has me most confused - I'm not sure what the theory is (we're still debating whether intakes work or not, so I'm calling it a theory, but that doesn't mean I'm dismissing the concept - just finding an acceptable middle ground) - is the question that an intake will increase performance due to more throughput, or because it is re-routed to a position within the engine that receives cooler (therefore denser) air? Personally, I don't think that we could really squeeze much performance out of an XFire based solely on increasing the breathing of the engine; it is true that our intake's are somewhat cramped and restrictive - however, I believe that increasing the throughput would have the counter-action of increasing the ambient temperature near the engine (the increased oxygen levels would mean a hotter, purer fuel burn), meaning we'd be pulling in more air by volume, but the density of that air would be less because of the heat...of course, I'm not saying this is what WILL happen, just making a prediction based on my limited knowledge. My understanding of fluid dynamics tells me that if increasing the throughput of the engine would increase HP, then so would those spiral-max things; the "swirled" air would create pressure imbalances similar to the forces which create lift on an airplane wing, accelerating the air down from the spiral-max into the engine. However, from what I've been told, the effect of these SpiralMax devices is so minimal as to be negligible. I don't think that simply providing a bigger opening would provide more air than the spiral max thingie would, since the spiralmax dealie-o also has the added advantage of creating a miniature ram-air effect as previously un-impeded air is now being both sucked through what is basically a smaller opening (the SpiralMax sits in the intake path).

Having said I'll that, I'll be honest and admit I really don't know what I'm talking about I could be forgetting (or not even aware of) some other variable, and it's always a possibility my understanding of fluid dynamics (which I think is mostly what this thread is about) is off.

There's my $0.02

P.S. - Bullseye, out of curiosity why would you prefer the RSX over the xfire? I certainly respect everyone's opinion, but I can't think of a single attribute about the RSX I like more than the XFire - looks, power, RWD, warranty, craftsmanship (I really like the Mercedes feel of the car)...just interested in hearing another view.

 

Actually, you described it pretty well. What you don't get is something for nothing. The intakes that work well do the following, get cooler air from outside the engine compartment whether through the hood, from a wheel well, through the grill (not behind the radiator), or at the base of the windshield. Flow that air unimpeded to the carb/throttle body etc, to be mixed with fuel and then distributed to the cylinders. In a naturally aspirated engine, this all takes place at ONE ATMOSPHERE, the tornado thing is a restriction, air cleaners are a restriction throttle bodies/carbs are all restrictions to the incoming air. They are therefore parisitic devices in that they are limiting flow. There are things on the exhaust side that actually influence what happens on the intake side, for example a well desiged tuned header will get its exhaust pulses to the collecter at different times which creats a vacuum in the collector which causes a vacuum to be siting outside the next exhaust valve so that when it opens that vacuum pulse helps pull the burnt mixture out of the cyclinder. Because of overlap (the intake opens before the exhaust closes ) this vacuum pulse helps pull the fresh charge into the cyclinder helping fill it. Soooooo when you put headers on a NAE you need to do something on the intake side to help. Larger carb, bigger jets, better flow, less restrictions. This is where your K&N filters actually do something. The problem I have with saskins design, is that besides hyping them so much is that he's pulling underhood air. He has put a larger diameter pipe from a box on top the throttle body and run it to two air cleaners hanging in the engine compartment. I'm sure he thinks that by putting them right behind where the normal intake openings are, that he will get outside air. He won't, and you know that, because you descibed it yourself. Hot air is less dense and everything works as the path of least resistance. Because it is less dense, it will flow faster, cooler denser air is slower, the hotter air wins every time. He's actually pulling hotter air than the stock arrangement. The stock arrangement on our cars is actually pretty good. It ducts outside air direct to the throttle body. If he knew what he was doing or was smart enough to ask, he could do as someone else suggested and hang his air cleaners in the wheel wells and he might get somewhere.. OH WELL Hope this helps you make up your mind. Bill
By the way, you mentioned creating lift on the wing of an airplane, negative pressure on top of a wing isn't what causes an airplane to fly, its angle of attack with enough thrust, and anything (see the f-117) will fly.

 

The power between the crossfire and rsx type s is a wash. The gas mileage for one, 30mpg is far better than my 15.4mpg in my crossfire. Also that car has a huge aftermarket, which I love. With bolt-ons you can hit 13's. Also its fwd and would be better in the winter,also wouldnt had to drop 1200 bux in winter wheels and tires. The warranty was longer 4/50k. ANd I wouldnt be in as much negative equity. Maybe only 2k as oppose to 8k. Craftsmanship again is a wash although some aspects of the acura were nicer than the XF. Really all i like better about the XF is the looks and rwd handling aspects. Oh and the insurance is cheaper on XF. My RSX was higher than my mach 1. 2 bux more a month lol. And the payment was cheaper on the acura. Thats about it.