Kzang

Kinda ironic coming from a BMW owner

OP, throw in a sprint booster! People here claim that it will increase HP by .00001%!

sdg1871

I loved my 2003 540i Sport. Even more so than my 550i Sport. It was incredibly responsive off the line -- still a million times more responsive than my 550 with SprintBooster. Turn off the traction control and you could easily smoke the tires in the 540. Not so with my 550. It felt more connected to the road and more involving than my 550.

But, of course, the 550 has significant advancements over the 540. The 550 is much faster -- especially in terms of highway passing power. The 550 has more grip and higher cornering limits than the 540 did -- I can go faster in the twisties in the 550 than I could or would with the 540. The 550's Steptronic is much more responsive and faster than my 540's Steptronic was. The 550 has more room than the 540. The 540's "upgraded" DSP sound system was a total POS. The 550's Logic 7 stereo is a million times better (although not up to par with my Infiniti M45's 14 speaker Bose sound system in all areas other than bass response and bass power). The 550's interior seems much higher quality than my 540's was. The 540's electronics are downright primative when compared with the 550. But despite all the 550's advancements over the 540, I always felt more emotionally connected to the 540. But if you forced me to chose between the two as my daily driver, I would chose the 550.

Also, as much as I like my Carbon Black color, I miss the easy maintenance of the Titanium Silver color than my 540 had.

Tom650

I read the whole thread and although I am not sure what is the issue with the dyno, my experience is positive with dinan. I have a 2006 650i with SMG and stage 3 engine mods, stage 1 suspension mods and 20" Radenergie R10s (by the way the R10s with non runflats weight 48lbs less than the stock ones).

The car feels much more responsive than stock and quicker off the line and I am very happy with my overall package. After the mods I cancelled an M6 on order (not that I compare the two) because the car performed exactly the way I liked it and there was no reason to get an M6 yet. I am looking for a supersprint catback exhaust system now to finish my mods.

I did not dyno my car but did use my ipod track software to time it (for whatever accuracy it has) and from stock it showed consistent gains in both calculated power (from avg 370 filtered to 420 Hp) and 0-60 etc times. So I recommend going to the track to verify performance because on the road it does not matter what the dyno shows but what you track improvements are.

I would welcome input from members that have 1/4 mile numbers before and after mods.

Here are a couple of articles, non dinan, on the ram air effect:
http://www.caranddriver.com/features/04q2/...ing_-tech_stuff

http://www.worksevo.com/article2.php

...To prove his point, Dinan bolts to his Dynopack one of his 2003 Dinan M5s, heavily tweaked to make a claimed 470 horsepower at the crank (he expects about 415 at the wheels). With the hood closed and no external fan blowing air into the radiator, the car wheezes out just 334 horsepower at the wheels. An LCD data logger on the dashboard reveals the air-fuel ratio from the engine computer. Approaching redline, the BMW's computer richens the mixture all the way to 9.5:1 as the underhood temperatures soar.

That's one thick mix, practically charcoal briquettes blowing out of the tailpipe. But then, with the M5 running in fifth gear (the 1:1 gear ratio with the least friction, preferred by dyno testers), the computer expects 159 mph worth of cooling wind blast around the horsepower peak. It's getting nothing, and it knows.
Now Dinan opens the hood and turns on a small Home Depot shop fan blowing about 10 mph worth of air. The M5 is allowed to shed some excess heat and then run again. This time the computer finds another 37 horsepower, or 371. Things are looking up, but the M5's output is still nowhere near Dinan's expected number of 415.

"I can't claim something I can't measure," says Dinan, so the crew then wheels out the big gun: a $7000 electric fan that looks like it should be hanging on the wing of a Boeing 737. It blasts 38,000 cubic feet per minute of air at 75 mph down a narrow duct, right into the M5's radiator. The fan roars, the M5 howls, the computer twinkles, and the graph paper ticka-ticks out of the printer. It says 411.4 horsepower, the best run of the day.

"I'd pick up four or five more horsepower if I came back tomorrow morning and ran it at 70-degree room temperature," says Dinan. The room is currently 81 degrees.

"Basically, what horsepower would you like? I can give you anything from 330 to 420 with the same car," Dinan says. "Blowing air with a fan isn't the same as creating a bow-pressure effect over the whole front of the car. BMW can simulate that because it has billions to spend on wind tunnels. We don't, but we can come close by spending $250,000 to $300,000 on a climate-controlled room."

That's Dinan's next step. It's a huge expense for a boutique parts-maker, but BMWs aren't getting any stupider. The trend says the cars rolling into a tuner's shop will have more and smarter sensors with each passing model year. BMW may be at the leading edge of electronic engine controls right now, but the rest of the industry is sure to follow.

When it does, the "brag-ability" of dyno numbers will get even more dubious as dyno printouts become merely a reflection of what a particular car does on a particular dyno under a particular set of conditions. What happens on the street could be another matter altogether. As in Vegas, sure bets are in short supply when you measure horsepower.

I hope this helps....

Regardless, I am a very happy customer of dinan....

v_therussian

WOW! You should DEFINITELY try to have Dinan resolve this - 4 g's for better sound is a rip off!!!

tex_phil

Thats a good point I really haven't thought of. You can increase any cars horsepower if you have a blower off a jet going into the radiator, and less if you have a smaller fan obviously. I guess a test would be on a dyno with no fan and a dyno after with no fan to see exactly what it increased.

John@Motorcepts

THat's so true too.

dusandimic

Or you can use the exact same fan both times like I did.

Tom650

The point is that if the airflow is not high enough to correspond to the design requirements (eg traveling at 70mph or more) then even with the same fan you will not see the gains. You did not mention the size of the fan and what speed it might simulate.

However, you can check on the gains by taking your car on the track or the drag strip and measure real life performance, that is improvement in your 0-30, 0-60, 0-100mph and 1/4 mile runs...

gildagjg

I have owned 3 Dinan cars prior to my car now and my dad currently has a 2001 Dinan 7 all work was performed at Habberstad BMW in Huntingting NY (they are a Dinan retailer) and they have and still honor my dads BMW warranty whenever he brings it in for something.

As for performance my cars as well as my dads had and have a substanial gain in horsepower, throttle and performance overall. I dont recall which S package my cars had since I bought them with it already installed but I do know what my dads has since it was done not so long ago. He currently has the S3 Package - Sport without hll and there is a huge I mean HUGE difference in the cars horsepower and performance.

What Stage Signature Package did you get and who installed it for you?

Michelle@RPI

Sorry to hear your story.

I must feel discouraging, but know this, there are a few honest companies producing mods that do work.