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Topic Review (Newest First)
05-26-2009 08:59 AM
ap72
Quote:
Originally Posted by 83SILVRADO
NO, dont say anything about supersonic or subsonic. it will make him spaz out on you. He's going to say that the speed of sound has nothing to do with anything. how much you wanna bet?

Well at least I taught one person something, the speed of sound does have nothing to do with it.

Also, the effects do not switch on at a certian speed- that is the point. They vary with speed but they do not only work at 100MPH and not at 70mph, I don't know who gave you that silly notion. It's like saying brakes will stop you from a 15 MPH roll, but if you go over 35MPH you can't stop.
05-26-2009 08:31 AM
83SILVRADO NO, dont say anything about supersonic or subsonic. it will make him spaz out on you. He's going to say that the speed of sound has nothing to do with anything. how much you wanna bet?
05-26-2009 08:25 AM
Deez This 'switch', could it apply to sonic and supersonic?

If you have a supersonic somethingorother and it ONLY works at supersonic speeds... It will not work at subsonic.

So there is your switch.

When a rocket ship reaches escape velocity from planet earth, is there a switch?

Mad Max had a switch.

Now, go fetch that hickory switch...
05-26-2009 08:17 AM
83SILVRADO
Quote:
Originally Posted by Deez
My point from waaay back was that for your car, if the ram air had no positive effect until your car reached 100MPH. What good would it do you if you NEVER drove past 70MPH?
Exactly, ram air in terms of motion and not a supercharger/turbocharger sucks. just get over it.
this thread makes me wanna puch a baby. its that aggravating
05-26-2009 08:15 AM
ap72
Quote:
Originally Posted by Deez
WAIT, the earth is out of orbit, when I count three, everybody in the western hemisphere jump. DANG, there just wasn't enough to make a difference. Oh well, at least the universe is Flat.


Umm, what switch? Never said anything about a switch. Maybe fetch me a switch LOL My point from waaay back was that for your car, if the ram air had no positive effect until your car reached 100MPH. What good would it do you if you NEVER drove past 70MPH? That last question will be the most important one for you to answer yet. It's kind of like having overdrive on a car that will increase fuel mileage if used, but if never shifted into overdrive it won't do you one bit of good no matter how you claim it will.

"no positive effect untill 100mph" indicates that at 100mph there is somehow a switch in the systems function. Just like until you flip a switch the light is off. you claim that speed acts as the switch.
05-26-2009 07:46 AM
cobalt327
Quote:
Originally Posted by Deez
WAIT, the earth is out of orbit, when I count three, everybody in the western hemisphere jump.
That reminds me of the deal where the chicken farmer was going to market w/a truck load of hens.

When he got bogged down, he had his helper get out and wail on the side of the truck w/a big stick to make the birds fly around inside their cages- lightening the truck enough to get it unstuck.
05-26-2009 07:41 AM
Deez WAIT, the earth is out of orbit, when I count three, everybody in the western hemisphere jump. DANG, there just wasn't enough to make a difference. Oh well, at least the universe is Flat.

Quote:
I do have 1 question for you though, why would there be an on/off switch at a particular speed?
Umm, what switch? Never said anything about a switch. Maybe fetch me a switch LOL My point from waaay back was that for your car, if the ram air had no positive effect until your car reached 100MPH. What good would it do you if you NEVER drove past 70MPH? That last question will be the most important one for you to answer yet. It's kind of like having overdrive on a car that will increase fuel mileage if used, but if never shifted into overdrive it won't do you one bit of good no matter how you claim it will.
05-26-2009 06:49 AM
ap72
Quote:
Originally Posted by Deez

this is one example, on one application. This is not an across the board power gainer and most will find the time and money invested will have been a fruitless endeavor. Racing is about ingenuity (fun, and winning), finding what works for a given application. I don't think the OP will benefit at all from ram air anything unless he's able to attain speeds at which ram air will have a positive effect. Until those speeds are reached the ram air deal is a novelty type thing.

that was my point- no matter how many test results point towards the siginificant gains of RA some people will refuse to accept the simple science behind it. regardless of how much testing is done it can never be complete. I do have 1 question for you though, why would there be an on/off switch at a particular speed? The effects of RA start as soon as the car is put into motion, they increase significantly with more speed (v^2) but there is no point at which it begins to have a positive effect- it always has a positive effect even if it is ever so slight at 5 MPH.
05-22-2009 08:48 PM
Deez Good to see someone pipe up with actual usage. There are however a couple of point to consider in all of this.

Quote:
It is quite obvious no one in this thread has ever done back to back testing to find the best spot to gain an advantage by utilizing these high pressure areas to boost engine output.

I did just such a thing on my 1981 RX7 GT3 car and I picked up 15 mph on a 1/3 mile straightaway...my top speed down that straight went from 110-125mph
Your gains are much as stated below just on a road race app.

Quote:
It does make a HUGE difference, street driven vs track driven. The engine doesn't know squat, but if it's intended purpose was for drag race only, the builds are night and day different. One may never see 4000RPM or speeds at which Ram Air would have any use at all, whereas a drag race only engine may operate at or near 8500RPM, at speeds 3-4 times (or more) the street driven. If you had no net increase below 100mph, it would be senseless to utilize such thing for a road car if no increase until 100mph+.
For a race car where rules (if any) allow, sure you could try, and it might work as did for 4jaw. He has certainly benefited from what he has tried. Very good.

BUT

this is not the rule - there are exceptions to the rule(s)

AND

this is one example, on one application. This is not an across the board power gainer and most will find the time and money invested will have been a fruitless endeavor. Racing is about ingenuity (fun, and winning), finding what works for a given application. I don't think the OP will benefit at all from ram air anything unless he's able to attain speeds at which ram air will have a positive effect. Until those speeds are reached the ram air deal is a novelty type thing.
05-22-2009 09:21 AM
cobalt327 If you can get alcohol permitted as well, all bets are on the "oil burners". Even w/o alky, my money would be on one of Otto's finest.

But you and I both know that when they see what they're capable of, here comes the dump truck full of lead ingots to hold you back...

Just ease up to it on them- don't show your hand until it counts... Then pull the trigger!
05-22-2009 09:14 AM
4 Jaw Chuck Well, the mod was completely illegal and was a blatant breaking of the rules..so when I went through tech inspection I was sure to ask if it was against the rules.

After consulting the rule book, concerned browbeating and consultation it was pronounced a non-forced air device. Since the guys I was racing against would be the ones who would protest, I polled them all individually to see if any objected...no one said a thing!

Seems all of them had the same opinion of ram air...it doesn't work. LMAO!

I raced the car three more times after that and won by a large margin, lapping the last 3 cars in the class at most of the events. On the last race I blew an apex seal on the motor which sidelined the car until I could find another motor (kinda blew a shift into third and the motor hit 8200 rpm..whoops!). Unfortunetely the VTEC Hondas came in the next year and dominated the class I ran in since I had to run a 300 pd weight penalty for running a rotary. I quit racing that same year. Too expensive to keep up with the Hondas, 200HP stock from such a small motor is pretty hard to beat when they can run 300 pds lighter. Peripheral porting the 12A would have put me into another class, so ended the fun.

The good thing was, at the next club meeting I managed to get turbo diesels allowed in the same class with unrestricted blowoff valves and propane injection allowed. Seems none of the guys in the club think a diesel could be any competition for the Hondas.

Maybe one day I will give the class another run with a late 80's Rabbit turbodiesel running 40psi of boost and staged propane injection.

Rabbit Diesel versus BMW M5

Shhh don't tell anybody.
05-22-2009 06:16 AM
cobalt327 Ain't going near that one!

So, after this mod, did you clean house in your class?

I'd be real surprised if you weren't protested- bet your *** I would be- if suddenly you came ripping around me w/an extra 20-25% extra HP from the race before!!
05-22-2009 06:09 AM
4 Jaw Chuck
Quote:
Originally Posted by cobalt327
It seems to a non-mathmatician that the 10 second decrease in lap times and the incredible HP increase that would need to go along w/the higher trap speed could not be solely from R/A.

I believe there is another component- possibly aerodynamic in nature- that accompanies and enhances the gains seen.
I think you might be right, maybe it was the carb suction pulling the car through the air.

Mmmm...suction.
05-22-2009 05:44 AM
cobalt327 It seems to a non-mathmatician that the 10 second decrease in lap times and the incredible HP increase that would need to go along w/the higher trap speed could not be solely from R/A.

I believe there is another component- possibly aerodynamic in nature- that accompanies and enhances the gains seen.
05-22-2009 02:08 AM
4 Jaw Chuck I forgot to mention the most significant effect I found with an RA setup was in throttle response. The "tip-in" response improvement I experienced was huge especially at the end of the 1/3 mile straight where I had to get off the gas and set the car into the corner and then get on it hard to throttle steer the car through the corner. Weight transfer during road racing is very important and an increase in throttle response means you can gain time exiting a corner.

In all I measured a 10 second improvement in my track times, I went from 1':30" to 1':20" in one day and was challenging cars that had huge advantages over my car in HP. This was on a track where 750 Superbikes turn 1':06" times and Formula Toyota 2.0L winged cars turn 1':00" flat.

Here is a pic of the track as it exists today, except for changing corner 9 to more of a hairpin configuration (the old section was very rough and hard on tires) it is the same track I raced on. The road racing runs counterclockwise and uses the drag track as the front straightaway. As you can see lots of highspeed areas on this track.



BTW you may have seen a clip of this track on the TV show "Mayday", it became famous because a Boeing 737 made an emergency landing on the track at lunch time break. I wasn't there as it was before my time but the plane became known as the Gimli Glider, here is a pic from 1983 of the plane on the tarmac behind the road race start/finish line. Luckily it stopped before turn 10 allowing racing to continue! If it hadn't I'm sure those guys would have found a way to move it off the track to keep racing.



Mayday - Gimli Glider
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