RPI (Race Precision Inc.) Intake Scoop For The 06+ Non-Z4M ! ! !

[BimmerZealot]

Hey guys, I'm sure a lot of you guys have been following my research in the Z4M thread about the RPI scoops. Well as you guys know Eloy tried out the scoop on two different Non-Z4Ms and the scoop did NOT fit.

Well upon many hours of research, I discovered they changed the piece that the hood latch brace bolts onto. This was done 01/2006. So any car built after 01/2006 the scoop WILL fit your car. The Z4 and Z4M share the same identical front bumper components and mounting points, same reason why the Z4M bumper is a direct fit.

So I went up to RPI in Paramount, CA this morning and we test fitted the scoop, success! Fits perfectly, even better then the Z4M because of a little bit more room behind the Non-M front bumper vs the Z4M. Of course Eloy wasn't happy with it just fitting it's gotta produce gains.

So we put my car on the dyno and did 3-4 runs to get the highest stock HP. Keep in mind my car is completely stock (engine wise) except for I removed my carbon filter.

The car dynoed at a peak horsepower of 202.8 HP technically this number might be lower because we had already taken off the stock intake scoop (a.k.a dubbed Half-Bra) so with the more restrictive stock scoop in place the numbers would have been slightly lower. None the less it was our base run data.

Next Eloy installed the scoop in a few minutes, very simple install. I opted for the red scoop and to tell you the truth its barely noticeable on my car, of course black would be invisible. I like the look of the red scoop peeking from behind the grills

So, back onto the dyno the car went. The car was dynoed once again, I think this time it was 4-5 times. The first run was the same as the base HP, then the following run the HP dropped, normal as the ECU was shocked by the sudden influx of air. Each run after that provided us with a higher and higher number. Finally on the 5th run I think it was we settled on a final number of, 208.1 HP. Keep in mind the car was dynoed with the hood closed and one run after the other. You know you have a great part when you can run the car multiple times and still get performance gains. A combination of heat soak, the ECU learning, and the heavy concentration of exhaust gases as opposed to fresh air in the shop led us to see these numbers as underrated.

But, none the less, clearly the scoop is doing a great job in boosting top end HP and torque. With just a few minutes of the ECU adapting we averaged a gain of about 6 HP. I have no doubt that driving around for a week or two and dynoing it again the numbers would be even better.

All in all, I just wanted to let you guys know that the scoop DOES fit the 01/2006+ production cars, that includes the Z4 3.0i Roadster, Z4 3.0Si Roadster and Z4 3.0Si Coupe along with the Z4M line as well. As you guys can see the performance numbers are there so what're you waiting for, call Eloy and order yours today!

On a side note, I think there was a combined HP in that shop of well over 1000HP between the two M5s, two Nobels, and Eloy's turbo charged Saturn Sky, my lowly 3.0Si was definitely the odd ball out. The guys are RPI run a top notch shop with great customer service. Eloy even ordered some pizzas when lunch time rolled around while we waited. Great people, great service, great parts, and a strong dedication to proven performance. Not much more you can ask for from a shop.

For you pre-01/2006 guys if someone is local and wants to drop their car off for a few days, I think Eloy may be willing to designed a new scoop for you guys.

I took a few videos of the dyno run with my camera phone but I doubt its even worth posting so I just attached the dyno sheets for your viewing pleasure.

Thanks Again Eloy

[vachss]

Thanks for making the effort and good to see that the scoop does work, though I have to admit a bit of disappointment in seeing about half the gain in HP achieved with the M and that essentially all the gain occurs above 5500 rpm. Oh well, for $125 it's still a good deal.

[BimmerZealot]

Well like I said, given more time for the ECU to learn and with breaks between dyno runs rather then run after run after run, or I should just say real life. The gains would be higher and more prominent, I wouldn't be surprised if after a week or two the dyno numbers would be better, especially on a fresh day when my engine hadn't had 5+ previous dyno runs. In total, my car feels much more responsive throughout the RPM range, I drive mostly with the SPORT button off, with the scoop in place the car feels much closer to with the SPORT button on, haven't tested it with the button on yet.

Like you said for a little over 100$ the gains are probably the best bang for the buck you're gonna find for our cars.

[RPIpower]

One of the problems with our tests is that the shop quickly fills up with carbon monoxide during our baseline runs. We've seen how air quality, heat soak, etc. can hurt an engines performance. Does the scoop make more power? Maybe, maybe not. We certainly never want to over rate the hp gains. I would rather under rate them and thats why we conduct the tests the way we do. On a conservative dyno, we still see a $21.50 per WHP ratio which isnt too bad. People are spending $1000+ on exhaust systems that net 0whp.

[Maroon]

Was the test done with their BMC air filter or just with the stock filter?

[BimmerZealot]

Stock filter with carbon filter removal only no other engine mods

[Incompatible]

Hey BZ, As was mentioned earllier, thanks for all the research and effort looking into this, many forum members will benefit from your efforts. Looks like it's time to order a scoop for my ride. Thanks again.

[PANDJZ4]

Thanks from me too! Can (or will) the BMW dealer install, or can I do it myself? Also, what is a good air filter to use with the scoop? I'm sure the filter for the M won't fit on my si............Thanks again!

[RPIpower]

Originally Posted by PANDJZ4

Thanks from me too! Can (or will) the BMW dealer install, or can I do it myself? Also, what is a good air filter to use with the scoop? I'm sure the filter for the M won't fit on my si............Thanks again!

The stock airfilter works pretty well. I can find out if BMC makes one for the Si. Earl has already shown us how well the stock filter can perform with the scoops (11.8whp gain).

[Dammmittt]

Originally Posted by RPIpower

One of the problems with our tests is that the shop quickly fills up with carbon monoxide during our baseline runs. We've seen how air quality, heat soak, etc. can hurt an engines performance. Does the scoop make more power? Maybe, maybe not. We certainly never want to over rate the hp gains. I would rather under rate them and thats why we conduct the tests the way we do. On a conservative dyno, we still see a $21.50 per WHP ratio which isnt too bad. People are spending $1000+ on exhaust systems that net 0whp.

That's crazy...no exhaust fan in the shop?

[PANDJZ4]

Thanks...I'm sold. But, where can I get it installed? I live close to Boise, Idaho.

[RPIpower]

Originally Posted by Dammmittt

That's crazy...no exhaust fan in the shop?

Nope. You should come by one day and see how we test stuff. We really put ourselves in a disadvantage which I dont mind. We want to test in the worse conditions. When I lose a race, Im not going to say, "hey wait a minute, let me open my hood and let everything cool down first," or "hey, there was a car in front of me that ran no cats causing my engine to suck up all his crap."

We use a Patterson fan that was made for Dyno Dynamics. Its flow rate is 70mph at 8ft from the car. We dont dyno with the hood open and we dont use a fan that you can go parasailing with. I'm sure if we tested things like that, we would see a better gain.

[BimmerZealot]

http://www.raceprecision.com/forums/...php?f=13&t=126

There are really only about 5 steps to installing the scoop. If you can turn a screw driver you can install the RPI scoop yourself. Check out the link; it's as easy as taking off your grills, removing the stock intake scoop, positioning the RPI scoop, bolting it in with self-tapping screws (provided) and reinstalling the grill. If you run into any problems along the way RPI can help you out their only a phone call away. I dont think the dealership would be willing to do the install for you, if they did they would probably charge an arm and a leg.

Thanks everyone for the "thanks" I'm glad I was able to debunk the mystery. Wasn't going to let the Z4Ms have all the fun =] It took awhile digging through pictures and realoem schematics but I'm glad it all worked out. Enjoy guys!

[Zeddy4Me]

awesome... great news! Thanks to BimmerZealot, the NON M's will have fun too... THANK YOU! and THANK YOU RPI for such a wonderful product.... WE LOVE YOu ELOY!!hahaha

[EdmM3]

It looks to me like there is absolutely no gain until 5500 rpm.

Given that you won't be above this for more than a second or two when accelerating, I really wonder if there is going to be any real world benefits from this.

Comments?

[PANDJZ4]

5500 rpm and above is where you want the gain. The only time I need extra HP is when I'm accelerating. It looks to me like I'll get a little extra HP when it's time to have some fun, but still maintain fairly good gas mileage when I'm just cruising.

[BimmerZealot]

As mentioned multiple times the scoop is for TOP END gain. So it's no surprise that it is above 5500RPM. Keep in mind the RPI fan used for the dyno runs is rated at 70 mph 8 feet from the car. If you were on the freeway at 80-90 MPH roughly around 3,000RPM you would be getting even better flow and performance 2500 RPM from where the paper gains start. The problem with trying to show gains on the scoop with dyno runs is that ram air systems benefit the most when the car is moving, that is hard to show with a fan and a stationary car. I noticed my 6th gear pulls on the freeway to be much more responsive and easier to do, passing is effortless.

[veryhuman]

Great read! I'd be onboard if a scoop was available for my year/model.

Originally Posted by BimmerZealot

Stock filter with carbon filter removal only no other engine mods

Is the carbon filter the black layer infront of the stock filter (with orange border)?

[BimmerZealot]

Yes it should be on top of the original orange filter. Mine was part of the top half of the intake box, had to pry it out with a screw driver.

[laidback]

Congrats!... any gain (hp/tq) IMHO from the RPI dyno machine is alot (as Eloy stated that they dyno the cars pretty conservatively)...Me and the guys at M5board.com call the RPI Dyno Dynamics the "HeartBreaker" ...

[2K5 325i]

Subscribed for later,
-Chris

[OH FO SHO]

i want one ... BimmerZealot upon your research, do you think there is any way to "mod" the scoop to fit the earlier model z4's? or maybe if RPIpower can chime in?

TIA