M5Board.com

So at last I went back to beautiful California to go to "car guy Mecca" in Monterey as well as visiting the great members of the The Unofficial BMW M5 Homepage Messageboard community. On the program was also visiting US largest BMW-tuner Dinan as well as Race Marque Systems which is one of the few companies that put a supercharger on the E39 M5. Dinan is also particurlary interesting since they have a 470 HP package to the M5, normally aspirated. Also on the program was going along the beautiful Highway 1 that goes along the pacific coast.

I landed in San Fransisco on a Friday should stay a week. Member chunpng (Pong) who was very nice to pick me up at the airport and we went to Los Altos to pick up the Miata I was about to borrow for the trip. The Miata had a supercharger and serious roadholding modifications. The only thing that was missing was maybe grippier tyres. A convertible is a perfect car for California. In five days we drove 1700 miles.

Here Im having a Cobra in front of me on Highway 1 on my way to Halfmoon Bay. It can't get any better.

Beautiful roads, the only thing you could wish for is maybe a little less traffic. I drove here at midnight then it was completely empty of cars and a very fun drive but not as nice since you couldn't see as much.

Here we see the brand new Lamborghini Gallardo beofre the US-premiere in Monterey the upcoming Friday. This was on the streets of San Fransisco and it was actually getting towed!

After a weekend in SF we had a meeting with Dinan at their Morgan Hill headquarters. We were greeted by their very knowledgable salesman Chris who gladly showed us around the facilities. We were lucky to meet up with the founder himself, Steve Dinan who drove his personal M5 with the S2 package, the red one. We also met up with member beetlem5 aka Bailey, his friend and his LeMans blue M5.

Chris is explaing above their work with the E36 with the US M3 supercharged engine. Our visit started with a tour of a white race E36 M3 US-version with a Vortech supercharger that greets us in the lobby. We discussed some reliability issues regarding superchargers and we learned that some parts as bearings are critical to the longevity of the supercharger. Since the supercharger spins with around 40-50 000 rpm the brand and quality of the bearings are very important. The quality have varied since the manufacturer uses different bearings at different times. I also noticed the full carbon doors on the E36 which looked very interesting but were too costly for commercial production.

Then we saw a 5-series E34 with a 540i engine with a Garrett T04 turbocharger. This was the Dinan 540i Turbo World Challenge and had around 650 HP. Chris mentioned that Dinan said they quit racing since the rules changed alot. They put $5000 on the suspension setup only to have it illegal next week. After that they were fed up with racing in that class.

We then moved on to look at an M3 E46 that got the S2 package. Along that there were two red Mini Cooper S that Dinan were developing products for. They also worked on a Z4. I told them how much I liked the Hartge Z4 5,0 and they seemed to understand why that was the case. We got the opportunity to look close on the Dinan exhausts that uses uses stainless steel inside out. But for some exhaust with weird bends or otherwise very difficult to produce Dinan buys the OEM-exhaust and cut them open and make the needed modifications. In alot of parts (such as clips etc.) Dinan uses the BMW OEM parts since BMW continiously updates the parts and the parts develop over time during the product cycle. By using BMW-parts Dinan takes advantage of BMW product knowledge.

He also told us Dinan had no plans for a supercharger for the 330i since those people who would buy those would rather have an M3 which makes sense.

Then we were shown the Dinan headers for the M5. The reason because their $7999 price is: their complex shape that requires alot of welding work, enirely made of stainless steel, expensive CNC-milled adaptors are made to connect from the squarish block to the round header with a free flow and the headers uses a 4-2-1 design and the flow combiners are complex to make. Finally, alot of research was done to find out the optimal length of the headers. The length was tweaked to tkae advantage of the secondary wave of back pressure that is created when gas goes from 4 to 2 and then to 1 the secondary wave of back pressure arrives exactly back into the block so it acts as a vacuum and thus increases the amount of air being drawn in. The reason why BMW did not do this desgin oon their own headers was according to Dinan because of it would be too expensive and time consuming to manufacture. BMW have constarins like they have to design the vehicle for a large market and also have to consider manufacturability. The headers will increase the peak horsepower gain from 6500 rpm to redline with 28 HP.

After we went on to the dyno room where Dinan had installed a new Dynapac dyno from New Zealand. This connects the directly to the wheel hub so you're eliminating the tyreslip. We spent alot of time speaking about dynos and by this time Steve Dinan himself came and joined us. Before we only were with the our initial contact Chris. Steve Dinan is a very positive person who really takes prides in his products and explained all the variables a dyno measurement can have. Steve showed us a graph that hade 4 different rund of an E39 M5. One simple thing such an opened hood rendered around 5-10 HP difference because of heat and how the engines electonice cut the power when it feels its overheated. He explained the problems with that you never can replicate the air movement of a normal highspeed run. Since the engine feels liek its too hot on a dyno it will give the engine more fuel to cool it down which wil lresult it lower power and hte car running too rich of fuel in the fuel/air ratio. In fact there was a huge fan in the dyno room but that couldn't replicate true conditions according to Dinan. I asked why just you don't do a "before tuning" and "after tuning" dyno run and Steve explained that there were so many variables you cannot replicate to have the same at those two runs. He said all the cars fluids has to be the same temperature since a fluid gets more "fluid" (increased viscousity) at higher temperatures and that affects the power alot. He also explained to me the great lengths he went to in the earlier years to try to do perfect dyno test, involving stroboscobe to see if the tyre was slipping against the rolls of the dyno and so on. Also the M5 engine management program interfears when it feels its to hot and cuts the power.

So that is also why you might see some big increases sometimes because at the particulat testing moment the M5 did not cut the power since the sensors weren't as hot. Steve Dinan are writing some white papers on the dyno variations and the car for these papers and dyno runs will be an E39 M5. It will be published an article about this in the US-magazine Car and Driver this fall. It actually started out with Car and Driver asked Dinan which dyno to buy and Steve told about his expeiences with dynos. So expect a white paper in the future of the dyno and the M5.

After the dyno room we weht into a conference room and he discussed why the M3 with the full Dinan kit (the S2 M3) only had one pair of the four exhuast pipes working. It was because more power. On the V8 in the M5 it's logical to have a a pair ofexhaust on either side but on the straight-six of the M3 it does not make sense. Regarding the M5 Dinan had a thought of changing the cams but came to the conclusion that it would be a too big risk letting the dealers do the conversion. They decided not to have products that involves dissassemply of the engine. I asked about what Steve Dinan thought about the Nowack M5 that changes the camshafts and the overall power of the Nowack N500 under ideal circumstances. Steve gave them credits for changing the camshafts and other itnernal work. He then showed us a formula he always uses as a preliminary tool to see what theoretically is feasible for naturally aspirated engines:

Which is pretty close to what the tuner Nowack states. And with a 7780 rpm redline that the nowack N530S package has its 562 HP. And Nowack claims 520 HP. Notice that that is the theoretical limit and as Dinan said doesn't tell you how you acheive it only that it is achievable... I guess you shouldn't put too much belief into that formula, but it's was a interesting one. You can change the air pressure to reflect if you have a supercharger or turbo which you of course can have even more power. But as stated, only in theory.

After alot of talk I was excited to see what the S2 package for the M5 did to the performance. Steve claimed they had sold over 120 kits for the M5. The parts for the S2 costs $26 456 and after labour it totals around $35 000 and adds 70 HP to the M5. This includes:

So basically this package increases the engines breathing capability, as well as more efficient exhaust. Also a lighter flywheel. Also very critical to the power-result was the reporgramming of the software. Finally a shorter final drive. Since this final drive is coupled with a higher rev-limiter the shift points are nearly identical to the standard M5 up to around 130 mph. But it goes to the redline in 5th and 6th gear with the differential. Of course it's derestricted too. At 7300 rpm at 6th gear the top speed is 191 mph (306 km/h). Interestinlgy enough this package does not include better brakes.

To our luck we had a 2001 LeMans Blue M5 with us completely standars except a Dinan exhaust and also a DV-camera. So I asked Dinan if we could take a spin and do a comparison, setting aside all variables of dyno and heat problems. Sure, but he wanted to drive. That was OK with me as long as I could witness it!

So off we go, it is Steve driving the Imola Red M5 with the DINAN license palte that been featured in many magazines vs. a almost completely standard 2001 M5. On our way to the straight I asked Steve what his favourite BMW was and it was the M3 E46 that is a more drivers car than the M5. He tells me he "everything with an engine" except boats. He flies airplanes too. We decided to do the race with inspiration from the Saudi M5 videos that was featured on the The BMW M5 Messageboard lately. You are each in one lane and then one car honks, then the other car honks as a confirmation that it's good-to-go and then the first car honks again and then the race is on after the third honk on the horn. We did two runs and we were three in the S2 M5 and they were two in the LeMans Blue M5. Rolling start from first gear and then floor it to say 130-135 mph. We do that twice and we each stay in each others lane. Both of the times the S2 clearly pulls away, most noticably in the lower gears. The shift points are almost identical at lower speeds since both cars hit the rev limitet at 1st gear since the rev-limiter lags on the M5. At over 120 mph there must be at least 5+ carlenghts between us. This can be watched from the videos that will be on the site.

The questions is how much the rear differential contributes to the difference and how much the rest of the engine package contibutes. My hunch is that a raised rev-limiter and a 3,45 differential would do some significant changes. but of course not as good asa complete S2 package.

The spontaneous race was very fun and I think Steve enjoyed it as well, especially considering the outcome. I wanted to do some runs more but Steve thought we had proven them point which I beleive he was right with. I'll say there is no better way to benchmark a car than a side-by-side comparison in each lane at high speeds. However you have considerations as which make of tyre since some are more sticky than others etc. butin reality it's the side by side comparison that counts.

After Dinan we said by to Steve, Chris as well as out member with the LeMans Blue M5 when he dusted us on the highway. We set sight for Palo Alto were we should have a dinner with fellow members of the site.

There are alot of traffic, lanes and many, many cars in California. I guess that is true for Germany as well.

Here we had a dinner with alot of members in Palo Alto. We had the chance to take a spin in BeastPowers S2 M5 which was inspiring at 130 mph. Rollcage and almost anything you can imagine it was equipped with.

After a dinner in Palo Alto along with some high-speed runs on the Freeway, finally without any traffic it was back to San Fransisco.