Are you For or Against the Stock Air Box - Check This Out!
Registered User
Joined: Oct 2007
Posts: 961
From: Elk Grove, CA
Rep Power: 89
That's becasue some of the "results" for the claimed HP gains are done on the cumulus nimbus dyno which is calibrated by the sigmoid dynometer.....which means they pull the numbers out of the sky or out of their A$$.
For me, personally, and one reason I was such a proponant of the OEM air box, it boils down to physics, simple math, and the restrictions of every design out there...
The name of the game is storage of AIR. In every box sold, you use the same diameter primary tube feeding the TB, So you are truly limited at the "funnel". I've always claimed "why bother"... Until I saw the Sportec, and now Dan's option here... This works, not because volume is increased. It isn't... However, the "feed" of the air charge is better, more constant, and because it uses the stock air box base, you benefit from the larger surface area of the OEM size filter, which was another pet pieve of mine...
Dan, are you reading my mind???
Now let's talk about those brake rotor hats!!!
Mike
The name of the game is storage of AIR. In every box sold, you use the same diameter primary tube feeding the TB, So you are truly limited at the "funnel". I've always claimed "why bother"... Until I saw the Sportec, and now Dan's option here... This works, not because volume is increased. It isn't... However, the "feed" of the air charge is better, more constant, and because it uses the stock air box base, you benefit from the larger surface area of the OEM size filter, which was another pet pieve of mine...
Dan, are you reading my mind???
Now let's talk about those brake rotor hats!!!
Mike
Registered User
Joined: Nov 2007
Posts: 598
From: San Diego
Rep Power: 71
Well when I did the independent test with my M3, the K&N filter was bigger, claimed to have better airflow and the primary inlet tube was larger than stock. So seemed like a no brainer. It would have to yield more hp but in actuality, I lost 12 hp. I bet the engineers at BMW that get paid a whole bunch of money could explain to me why I lost hp.
Somethings are just more complicated than they seem.
Somethings are just more complicated than they seem.
Registered User
Joined: Jun 2007
Posts: 2,141
From: CIR PCA Region
Rep Power: 133
I think the next step, and a simple one at that given Agency Power's prowess, is to add "scoops" like what the GT3 and GT3RS have just behind the deck area to "pull" air into the box.
Would probably be easy. Just some sort of glue to hold them on and it would be done. Charge another $50 over the box as an option and perhaps 100 without a box.
Jeff
Would probably be easy. Just some sort of glue to hold them on and it would be done. Charge another $50 over the box as an option and perhaps 100 without a box.
Jeff
Last edited by jcb-memphis; Sep 12, 2008 at 06:45 AM.
Registered User
Joined: Aug 2004
Posts: 215
From: Orlando, FL
Rep Power: 30
I think the next step, and a simple one at that given Agency Power's prowess, is to add "scoops" like what the GT3 and GT3RS have just behind the deck area to "pull" air into the box.
Would probably be easy. Just some sort of glue to hold them on and it would be done. Charge another $50 over the box as an option and perhaps 100 without a box.
Jeff
Would probably be easy. Just some sort of glue to hold them on and it would be done. Charge another $50 over the box as an option and perhaps 100 without a box.
Jeff
Registered User
Joined: Jun 2007
Posts: 197
From: Nashville, TN
Rep Power: 32
Intake dyno
Having owned and operated a Chasis Dyno for the last 10 years, just wanted to add a few commments:
Independent dyno testing is great and necessary, but there are so many variables even when you try to keep everything exactly the same within reason run after run. Especially on Chasis Dyno. Engine dyno's are much more precise in controlling the environment, and take a ton of driveline components out of the equation.
8-10 HP fluxuations are common on chasis dyno's, especially when your talking 400-500-600 hp or more. Just because you bolted something on and the next run was 10hp down does not necessarily mean it was the primary cause. 20 hp is another story and should show up every time as something.
You need more that a couple of runs for a baseline. It must be stabalized. I often have to run my TT 5 or 6 times to get repeatable numbers. Changing nothing between runs, with idential cool down periods etc, and using an infared thermal gauge to check intake component temps, intercooler teimps and water and head temps, it often is the 4th or 5th run before the HP and TQ peak out. Whenever I see product claims with dyno run 001 comparing dyno run 002 or 003 I am skeptical. I want to see 5 or 6 runs with no change, then 5 or 6 with the mod. Pain in the *** but reality.
Traction can be an issue on these cars with this kind of HP unless you have a hub dyno and this will effect numbers, look at the graph carefully with rpm for slippage.
As far as intakes are concerned I have tried a bunch of them on the dyno on just about every of car that I have owned (who wouldn't, unlimited dyno time at my disposal)
THERE IS NO WAY TO SIMULATE OVER THE ROAD AIRFLOW on a chasis dyno and get it anywhere close to what a car is doing at 100mph, or 50 mph for that matter. Low pressure areas, intercooler effecientcy, all kinds of things change.
If you want to see if you intake filter set-up is a restriction, take the damn thing off and dyno, done that many times and sometimes see a change, and sometimes not. Just because on your dyno sitting still in the shop with a big fan on it does not make any more HP does not mean it will not flow better in real road conditions.
Give me as much cool, unrestricted air as possible because when we are flying down the road flooring it, it a a huge amount of air being requested. The Vivid airbox looks great to me, and the price makes it more attractive, and it sure looks like it will provide more available cool air than the stock design, if your motor needs it at the time.
Independent dyno testing is great and necessary, but there are so many variables even when you try to keep everything exactly the same within reason run after run. Especially on Chasis Dyno. Engine dyno's are much more precise in controlling the environment, and take a ton of driveline components out of the equation.
8-10 HP fluxuations are common on chasis dyno's, especially when your talking 400-500-600 hp or more. Just because you bolted something on and the next run was 10hp down does not necessarily mean it was the primary cause. 20 hp is another story and should show up every time as something.
You need more that a couple of runs for a baseline. It must be stabalized. I often have to run my TT 5 or 6 times to get repeatable numbers. Changing nothing between runs, with idential cool down periods etc, and using an infared thermal gauge to check intake component temps, intercooler teimps and water and head temps, it often is the 4th or 5th run before the HP and TQ peak out. Whenever I see product claims with dyno run 001 comparing dyno run 002 or 003 I am skeptical. I want to see 5 or 6 runs with no change, then 5 or 6 with the mod. Pain in the *** but reality.
Traction can be an issue on these cars with this kind of HP unless you have a hub dyno and this will effect numbers, look at the graph carefully with rpm for slippage.
As far as intakes are concerned I have tried a bunch of them on the dyno on just about every of car that I have owned (who wouldn't, unlimited dyno time at my disposal)
THERE IS NO WAY TO SIMULATE OVER THE ROAD AIRFLOW on a chasis dyno and get it anywhere close to what a car is doing at 100mph, or 50 mph for that matter. Low pressure areas, intercooler effecientcy, all kinds of things change.
If you want to see if you intake filter set-up is a restriction, take the damn thing off and dyno, done that many times and sometimes see a change, and sometimes not. Just because on your dyno sitting still in the shop with a big fan on it does not make any more HP does not mean it will not flow better in real road conditions.
Give me as much cool, unrestricted air as possible because when we are flying down the road flooring it, it a a huge amount of air being requested. The Vivid airbox looks great to me, and the price makes it more attractive, and it sure looks like it will provide more available cool air than the stock design, if your motor needs it at the time.
Registered User
Joined: Oct 2005
Posts: 3,577
From: tampa florida
Rep Power: 211
looks like it will go well with my "duel ram air deck"
Dan send me one!!
Registered User
Joined: Nov 2007
Posts: 598
From: San Diego
Rep Power: 71
Having owned and operated a Chasis Dyno for the last 10 years, just wanted to add a few commments:
Independent dyno testing is great and necessary, but there are so many variables even when you try to keep everything exactly the same within reason run after run. Especially on Chasis Dyno. Engine dyno's are much more precise in controlling the environment, and take a ton of driveline components out of the equation.
8-10 HP fluxuations are common on chasis dyno's, especially when your talking 400-500-600 hp or more. Just because you bolted something on and the next run was 10hp down does not necessarily mean it was the primary cause. 20 hp is another story and should show up every time as something.
You need more that a couple of runs for a baseline. It must be stabalized. I often have to run my TT 5 or 6 times to get repeatable numbers. Changing nothing between runs, with idential cool down periods etc, and using an infared thermal gauge to check intake component temps, intercooler teimps and water and head temps, it often is the 4th or 5th run before the HP and TQ peak out. Whenever I see product claims with dyno run 001 comparing dyno run 002 or 003 I am skeptical. I want to see 5 or 6 runs with no change, then 5 or 6 with the mod. Pain in the *** but reality.
Traction can be an issue on these cars with this kind of HP unless you have a hub dyno and this will effect numbers, look at the graph carefully with rpm for slippage.
As far as intakes are concerned I have tried a bunch of them on the dyno on just about every of car that I have owned (who wouldn't, unlimited dyno time at my disposal)
THERE IS NO WAY TO SIMULATE OVER THE ROAD AIRFLOW on a chasis dyno and get it anywhere close to what a car is doing at 100mph, or 50 mph for that matter. Low pressure areas, intercooler effecientcy, all kinds of things change.
If you want to see if you intake filter set-up is a restriction, take the damn thing off and dyno, done that many times and sometimes see a change, and sometimes not. Just because on your dyno sitting still in the shop with a big fan on it does not make any more HP does not mean it will not flow better in real road conditions.
Give me as much cool, unrestricted air as possible because when we are flying down the road flooring it, it a a huge amount of air being requested. The Vivid airbox looks great to me, and the price makes it more attractive, and it sure looks like it will provide more available cool air than the stock design, if your motor needs it at the time.
Independent dyno testing is great and necessary, but there are so many variables even when you try to keep everything exactly the same within reason run after run. Especially on Chasis Dyno. Engine dyno's are much more precise in controlling the environment, and take a ton of driveline components out of the equation.
8-10 HP fluxuations are common on chasis dyno's, especially when your talking 400-500-600 hp or more. Just because you bolted something on and the next run was 10hp down does not necessarily mean it was the primary cause. 20 hp is another story and should show up every time as something.
You need more that a couple of runs for a baseline. It must be stabalized. I often have to run my TT 5 or 6 times to get repeatable numbers. Changing nothing between runs, with idential cool down periods etc, and using an infared thermal gauge to check intake component temps, intercooler teimps and water and head temps, it often is the 4th or 5th run before the HP and TQ peak out. Whenever I see product claims with dyno run 001 comparing dyno run 002 or 003 I am skeptical. I want to see 5 or 6 runs with no change, then 5 or 6 with the mod. Pain in the *** but reality.
Traction can be an issue on these cars with this kind of HP unless you have a hub dyno and this will effect numbers, look at the graph carefully with rpm for slippage.
As far as intakes are concerned I have tried a bunch of them on the dyno on just about every of car that I have owned (who wouldn't, unlimited dyno time at my disposal)
THERE IS NO WAY TO SIMULATE OVER THE ROAD AIRFLOW on a chasis dyno and get it anywhere close to what a car is doing at 100mph, or 50 mph for that matter. Low pressure areas, intercooler effecientcy, all kinds of things change.
If you want to see if you intake filter set-up is a restriction, take the damn thing off and dyno, done that many times and sometimes see a change, and sometimes not. Just because on your dyno sitting still in the shop with a big fan on it does not make any more HP does not mean it will not flow better in real road conditions.
Give me as much cool, unrestricted air as possible because when we are flying down the road flooring it, it a a huge amount of air being requested. The Vivid airbox looks great to me, and the price makes it more attractive, and it sure looks like it will provide more available cool air than the stock design, if your motor needs it at the time.
I am just playing devils advocate. I also have an aftermarket CAI on my 996TT.
Registered User
Joined: Jun 2007
Posts: 197
From: Nashville, TN
Rep Power: 32
Hey Torresmd, sorry if it came across as doubting your testing, not meant that way at all, I believe your numbers, especially if they were repeatable like that. I have seen some strange things. Would have liked to have seen your same test with no filter out of curiousity.
Registered User
Joined: Nov 2007
Posts: 598
From: San Diego
Rep Power: 71
No worries, definitely did not take it personally. The M3 was a real pain in the *** to modify. I still have a lot to learn about the 996tt. I learn something new everyday on this forum.
