With all due respect: RPI (you guys) posted this "
This is correct. A tuft test (putting small pieces of yarn in the duct and seeing which way they blow) shows the air flows up into the airbox through this duct, so the blockoff will not affect brake cooling." in this thread: RPi Block off Intake Plates... Final Verdict? . You clearly state that you did see airflow coming upwards into the airbox from that lower duct.
I have a lot of respect for you guys and what you do, however, after talking to a few BMW advisers today (who race their cars) they indicated that in fact your assessment of creating pressure in the box may help at LOW speed, however, at higher speeds, the vacuum effect created may actually be pushing the needed air over the hood and not into the scoops, thus the need for those lower ducts. They all raved about the scoops but recommended not using the plates if you wanted peak performance at higher speeds. In fact, the exact recommendation was charcoal filter delete and RPI scoops with no block off plates. I know you guys dyno the cars,etc. and your process seems EXTREMELY well done, far and above that of many of the tuners out there, and your engineering obviously is top notch, so I am wondering if you can tell me if when you Dyno you are able to very accurately replicate both situations (low and high speed) in order to have equally accurate findings on this. When I say "low and high speeds" I am referencing wind force, vacuum effect, etc. that would be present at the front of the car during high speed runs, where a vacuum may occur from wind forces near both the outer edges of the front end of the car and wind directly into the grill, and low starts where little air would likely be flowing to actually "pressurize" the box.
Thank you for your comment. I have to disagree though because we have tested speeds up to 205mph (vbox confirmed) and we saw no drawbacks to the use of the block off plates. The runs only supported what we believe is happening during the dyno tests. I have only seen more air at higher and higher speeds. The vbox tests discounts the idea that the scoops do not work or hurt performance on the top end at high speeds.
Quote:
Originally Posted by khyber
They were down here awhile back for a presentation on the 991 @ Autogallery. They worked for Porsche GmbH (R&D Powertrain), I think there back in Germany or the Czech Republic; building another street legend. Glad you did a lot of work with engineers; speaks volumes about your products. The engineers I talked to really didn't base things on speculation or opinions but based there assessment on the facts/data. If a yarn test is data, then so be it.
Still have the the RPI intake system on my car, there is a reason I still have it on the car; I think its because deep down I want to believe it works and hope it does work. I'm not a expert on car engineering (though I like to think I am) but I leave that too you and trust you develop and sell products to owners of these amazing cars that work and not some $200 placebo effect.
To be honest, dont put a product on your car just because you "hope" it works. There were a lot of people on the forums that tried products "hoping" it would work. Do your research, talk to all the engineers you know and make your own decision. Rabdog, ACG, ECF, Keang24, etc. have never lost to other M5s. Thats not a placebo effect but if you believe it might be, make the changes. Nobody is going to hate you for it. Your buddy came to take a class with me and thought all the stuff his friends taught him would work. Im sure he hoped it would but in FOF training, we saw how he got lit up. :P
Quote:
Originally Posted by bayerischemotor
The block-off plates aren't completely airtight, would it make sense to tape over them so that they are completely tight?
They cover about 95% of the bottom hole. We did not see a need to cover the entire hole. It was intended to just slow down any pressure loss that might be there at higher speeds. It also helps with any moisture that is in the box.
To be honest, dont put a product on your car just because you "hope" it works. There were a lot of people on the forums that tried products "hoping" it would work. Do your research, talk to all the engineers you know and make your own decision. Rabdog, ACG, ECF, Keang24, etc. have never lost to other M5s. Thats not a placebo effect but if you believe it might be, make the changes. Nobody is going to hate you for it. Your buddy came to take a class with me and thought all the stuff his friends taught him would work. Im sure he hoped it would but in FOF training, we saw how he got lit up. :P
I'll be doing some date logging in the next couple of weeks on the block-off plates; I'll call it the "HOPE TEST"
Most people that have bought your scoops/block off-plates have based that purchase on hope; from the E9X community to even here everyone is very skeptical of what it really does. Dinan Stage 2 suspension, I know what its doing in reality, I don't need hope. My exhaust, I know what its doing, no hope needed. Block-Off plates, I have no idea if there doing anything. Yes, I will be removing them and will find out for myself in the coming week.
btw, how does the Dinan air-box deal with moisture if it is completely closed from the bottom? Your involvement in this thread does speak volumes about your products. Thanks
Quote:
Originally Posted by RPIpower
Your buddy came to take a class with me and thought all the stuff his friends taught him would work. Im sure he hoped it would but in FOF training, we saw how he got lit up. :P
What does that have to anything? I'm assuming your talking about Jay. What he and his friends learned playing Call of Duty wouldn't translate well into reality.
Hopefully you taught him some valuable skills while lighting him up.
block off plates to me are rubbish. I had them in, then took them out. I think I actually lost power with them in. From an engineering standpoint, they just don't make sense.
I figured Rpi test everything they sell. And Dinan did not have the lower air duct in theirs. So I ended up going to Home Depot and buying a piece of sheet metal from the roofing section for $ 2.99 It was big enough to make 2 block off plates.
Dinan is not the gold standard guys. Frankly, from real experience, you get very little performance boost for the expense. I invested $10k+ in engine, clutch, flywheel and suspension in my 2008 550i 6M Sport and the only measurable difference was the suspension. Dinan can make monstrous leaps with turbo cars but normally aspirated not so much. Honestly, I got more performance on my M5 by just removing the charcoal filters. Don't know about you but somehow I tend to lean towards trusting that BMW engineers have the airflow design down to a science. I took out my block off plates and am running scoops and charcoal filter delete. Growls at low revs and screams at high. I felt I lost power with them in as well however the old butt dyno is pretty innaccurate. But isn't this debate sort of silly? We are arguing about $12 pieces of metal that you REALLY won't notice a difference either way. Now when I am needing to shave a hundredth of a second off of the land speed record I'll worry about the 2-3 hp I MAY get.
Prob better suited to practice our shifting than think about plates. Will make a lot more diff in the end. Personally I think mods should be done that you notice. If you like the sound of an exhaust, buy it. If a tune makes your car rev higher, buy it. If you feel block off plates give you more confidence, buy them. Just enjoy your car. Modding is fun but I am just a guy who really prefers to do things that make me smile. Little plates hidden in the airbox that I never see or feel....nah.
I sense there are quite few medical professionals on here with "HOPE" and "Gold Standard" being thrown around...and the skepticism too . I've always felt that BMW M has always left a little room for improvement in past generation M cars and engines, but I really think they've maxed things out this generation with the N/A engines in the S54, S65 and S85. Hence the move to turbo charging. Not much left to improve on with the S85 for the tuners unless its custom software and/or FI.
__________________ 2008 Sepang Bronze / Portland Full Leather
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Last edited by JT///M5; 13th August 2012 at 00:14.
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