Air intakes?
06-06-2006, 08:42 AM
#11
Member
Join Date: Apr 2006
Posts: 83
^^ free up hp, gain hp, add hp, what does it matter? As long as you get your point across.
Technically I would think it is correct to say add hp if you are talking about a turbo or even a really well designed intake manifold. An intake manifold that allows air to bounce back and forth between rotars and actually creates air pulses equivalent to like 2psi of boost at high rpms is making power that the engine would not normally make, so you are adding power, not just freeing it up. (The stock manifold does that by the way)
I guess technically just changing the intake might be considered freeing up hp, but its not like the stock one is really restrictive or anything, you are really probably just changing the powerband or moving hp around rather than freeing up any hp to speak of.
If you want to get all picky then why are we even talking about hp, why not torque. If an intake adds or frees up hp but costs you some torque then you really havent done anything. I would think a ram air intake is adding hp also, i guess you could call it "freeing up hp" because basically you are just overcoming pumping losses, but at certain times while accelerating there is still more air available than there would be even if you could make an unrestricted intake that changed diameter and length with rpms. Alot of racing classes dont allow ram air and i suspect its because they consider it a power adder. I could debate this with someone or just with myself all day long so why not just look at what people say for what they were trying to say instead of being so nit picky.
I am not trying to **** anyone off, i am just trying to point out that it doesnt matter because you knew what he ment, no one has really said anything wrong here.
Technically I would think it is correct to say add hp if you are talking about a turbo or even a really well designed intake manifold. An intake manifold that allows air to bounce back and forth between rotars and actually creates air pulses equivalent to like 2psi of boost at high rpms is making power that the engine would not normally make, so you are adding power, not just freeing it up. (The stock manifold does that by the way)
I guess technically just changing the intake might be considered freeing up hp, but its not like the stock one is really restrictive or anything, you are really probably just changing the powerband or moving hp around rather than freeing up any hp to speak of.
If you want to get all picky then why are we even talking about hp, why not torque. If an intake adds or frees up hp but costs you some torque then you really havent done anything. I would think a ram air intake is adding hp also, i guess you could call it "freeing up hp" because basically you are just overcoming pumping losses, but at certain times while accelerating there is still more air available than there would be even if you could make an unrestricted intake that changed diameter and length with rpms. Alot of racing classes dont allow ram air and i suspect its because they consider it a power adder. I could debate this with someone or just with myself all day long so why not just look at what people say for what they were trying to say instead of being so nit picky.
I am not trying to **** anyone off, i am just trying to point out that it doesnt matter because you knew what he ment, no one has really said anything wrong here.
06-06-2006, 12:48 PM
#12
Senior Member
Join Date: Aug 2004
Posts: 426
i understand what you're saying, but i don't think you have much experience with the rx8's pcm.
one motor i ported actually LOST, yes LOST hp because the pcm went apeshit and turned the fuel way up. i was able to semi-tune it with the emanage and get more hp than stock, but the computer doesn't like ANYTHING to be done.
step 1: computer
step 2: everything else.
i wouldn't even waste time with a k&n drop-in filter without at least some way to control fuel.
stock rx8 ~165-190 whp (depending on what mood your computer is in
rx8 with intake, no cat, headers, free flowing cat-back: 170-195 whp...
so for the price of your $600 headers, $300 intake, $500 catback, and $200 midpipe, you can just about get the interceptor, or other standalone and make it worth your while.
one motor i ported actually LOST, yes LOST hp because the pcm went apeshit and turned the fuel way up. i was able to semi-tune it with the emanage and get more hp than stock, but the computer doesn't like ANYTHING to be done.
step 1: computer
step 2: everything else.
i wouldn't even waste time with a k&n drop-in filter without at least some way to control fuel.
stock rx8 ~165-190 whp (depending on what mood your computer is in
rx8 with intake, no cat, headers, free flowing cat-back: 170-195 whp...
so for the price of your $600 headers, $300 intake, $500 catback, and $200 midpipe, you can just about get the interceptor, or other standalone and make it worth your while.
06-06-2006, 07:42 PM
#13
Junior Member
Join Date: May 2006
Posts: 11
Originally Posted by Transam kid 01' post='822582' date='Jun 5 2006, 09:39 AM
It frees up HP, not add's. And WHP? are you sure is isnt FWHP?
O and personally, i like the REVi Ram air intake.
it is technically rwhp, it is not front wheel drive. but whp represents the same thing meaning the power isn't measured at the engine.
the rb and revi intakes are the quietest you can buy. HKS, AEM, and the Mazdaspeed, which is coming out in the summer, are the loudest.
06-06-2006, 07:52 PM
#14
Junior Member
Join Date: May 2006
Posts: 11
a high flow cat is the best sound in my opinion. The Rotary Performance super cat is really great and passes emissions.
Rotary Performance Site (rx7.com)
VIDEOS
stock exhaust
same car with cat
take a little while to download but very, very good videos. You should definitly right click video links and click "save target as"
this will give you more power than an intake and a midpipe since I'm pretty sure the ecu must be tuned for midpipes (but not positive).
Rotary Performance Site (rx7.com)
VIDEOS
stock exhaust
same car with cat
take a little while to download but very, very good videos. You should definitly right click video links and click "save target as"
this will give you more power than an intake and a midpipe since I'm pretty sure the ecu must be tuned for midpipes (but not positive).
06-07-2006, 07:58 AM
#16
Member
Join Date: Apr 2006
Posts: 83
I know the computer is aweful, but most people dont know how to tune a car well enough to make it even sorta driveable. It takes like 10 hours. I am not 100% sure but i think the stock computer will eventually learn your mods, it just takes a month or so. The car will make more power if you run 87 octane and drive the **** out of it all the time, not just some of the time. I wouldnt port any engine and try to run it with the stock computer, much less a rotary, i am not saying it cant or hasnt been done, i just wouldnt do it.
I wish there was a computer that you could just hook up and type in 13.2:1 for the a/f ratio and maybe play with ignition alittle and go. Why cant someone make that? It needs a hot wire MAS, a MAP sensor, 2 good knock sensors, a wide band O2 sensor, and maybe even another air temp sensor to go in the TB (even though the MAS basically does the job). Its probably possible to write a program for a microtech or haltech or any of the other computers out there to allow you to do just that, i just wish i knew how. It would probably be very doable for a motech, but then you are spending at least $4000 just on the computer.
I wish there was a computer that you could just hook up and type in 13.2:1 for the a/f ratio and maybe play with ignition alittle and go. Why cant someone make that? It needs a hot wire MAS, a MAP sensor, 2 good knock sensors, a wide band O2 sensor, and maybe even another air temp sensor to go in the TB (even though the MAS basically does the job). Its probably possible to write a program for a microtech or haltech or any of the other computers out there to allow you to do just that, i just wish i knew how. It would probably be very doable for a motech, but then you are spending at least $4000 just on the computer.
06-07-2006, 07:19 PM
#17
Senior Member
Join Date: Aug 2004
Posts: 426
there are a few ecu's with auto tune capabilities, but it doesn't take THAT long to tune a car. a while if you're doing maybe a bridgeport with no basemap to begine with but if you got say the interceptor, you could get it done in an hour or so on the dyno and some street tuning.
but i totally agree with you about not everyone knowing how to do it. but if everyone knew, "tuner" shops wouldn't exist.
but i totally agree with you about not everyone knowing how to do it. but if everyone knew, "tuner" shops wouldn't exist.
06-08-2006, 07:16 AM
#18
Member
Join Date: Apr 2006
Posts: 83
ok, so maybe not 10 hours but it should take alot longer than people usually want to spend on it. I have tuned or help tune 2 or 3 rx8s with interceptors and it takes more than an hour, of course the intake and exhaust were custom and a bit extreme, definately not for street use. That said, we had to fluctuate from the base map quite a bit.
06-08-2006, 08:32 AM
#20
Junior Member
Join Date: May 2006
Posts: 16
Originally Posted by wankelTII' post='822740' date='Jun 6 2006, 09:42 AM
^^ free up hp, gain hp, add hp, what does it matter? As long as you get your point across.
Technically I would think it is correct to say add hp if you are talking about a turbo or even a really well designed intake manifold. An intake manifold that allows air to bounce back and forth between rotars and actually creates air pulses equivalent to like 2psi of boost at high rpms is making power that the engine would not normally make, so you are adding power, not just freeing it up. (The stock manifold does that by the way)
I guess technically just changing the intake might be considered freeing up hp, but its not like the stock one is really restrictive or anything, you are really probably just changing the powerband or moving hp around rather than freeing up any hp to speak of.
If you want to get all picky then why are we even talking about hp, why not torque. If an intake adds or frees up hp but costs you some torque then you really havent done anything. I would think a ram air intake is adding hp also, i guess you could call it "freeing up hp" because basically you are just overcoming pumping losses, but at certain times while accelerating there is still more air available than there would be even if you could make an unrestricted intake that changed diameter and length with rpms. Alot of racing classes dont allow ram air and i suspect its because they consider it a power adder. I could debate this with someone or just with myself all day long so why not just look at what people say for what they were trying to say instead of being so nit picky.
I am not trying to **** anyone off, i am just trying to point out that it doesnt matter because you knew what he ment, no one has really said anything wrong here.
There is difference between adding HP and freeing up. When you add something like and intake or exhaust, you free up HP, b/c the system you are adding is less restrictive. When they test the numbers, they will put on the most restrictive (unless they say as compared to stock) so that it is the most "gain." So in essence, you are "freeing up" HP since it is no longer as restrictive. However, adding a turbo adds HP b/c there is no turbo system on the 8 so there is no way to "free up" the HP.
However, im sure if you said that it "added HP," people would know what you are talking about.