BMW M5 Forum and M6 Forums banner
1 - 4 of 4 Posts

49,475 Posts
Discussion Starter · #1 ·

2/23/2005 - Interview by David Haueter (Photos by David Haueter and courtesy Grand Am, Synergy Racing) More pictures.

Founded in 1979, Dinan is most well known for their high performance BMW products and have established themselves as North America's premiere BMW tuner. Unlike many "tuners" that simply resell parts made by aftermarket suppliers, Dinan engineers and manufacturers many of their own parts. Their attention to detail, engineering and performance backed by a warranty that matches the factory has made them the only North American BMW tuner that has their products distributed through select BMW dealerships (similar to the relationship AC Schnitzer and Alpina have with BMW in Germany). Steve Dinan also has a passion for racing, which has led to his involvement in Grand Am. He has been building the engines for G & W Motorsport (now Synergy Racing) since Daytona Prototypes debut season in 2003, a relationship which continues through this year. Dinan also picked up Finlay (Ten) Motorsports as a client for 2004, building both their Daytona Prototype engine and the powerplant for their Grand Am Cup M3. We talked with Steve Dinan about Grand Am, his BMW engine and the future of the series.

How did you first get involved in building engines for Daytona Prototype?
I've know Price Cobb for a long time, and he had been impressed by the straight-line speed of the BMW 540i I raced in World Challenge. He knew that I had been building V8 engines for years, so he called me and asked if I was interested in building the engines for the G & W Motorsport (now Synergy Racing) DP. I read the rules and talked with Grand Am on the phone, and they were very serious about sticking to the rules. I have to give them an A - they've been doing a good job, and that's why the series is growing so well. That's not to say more money won't win. Ganassi won last year and they also outspent everybody, but in Grand Am, the impact of that money is smaller than it would be in other series.

As more of the bigger racing teams and manufacturers get involved in Daytona Prototypes, do you think it will be harder for a smaller shop like Dinan to stay competitive on the engine side?
If Grand Am does a good job of holding to the rules, I don't think it will be harder. I got out of racing in 1996 and one reason I got out was that I got tired of political issues where a manufacturer would come along and give the sanctioning body a lot of money, and all of a sudden have a rules advantage. As long as Grand Am sticks to the rules, we have a shot at it, and I've never seen a racing series create a level atmosphere like Grand Am has. We're glad we got in on the ground floor, and we're making a series investment to stay competitive. I don't think we're getting beat by anybody in terms of straight-line speed, weight or reliability.

Tell me about your facility. . .
We have two facilities that support our BMW road car business, as well as the racing programs. We have a whole new engine machine shop that's in our Morgan Hill facility, and hired another engine builder that has experience building engines for Honda in Champ Car and IRL.

What is it about the V8 from the BMW M5 that makes it a good racing engine?
It's the only engine in the series that comes with a throttle plate per cylinder, like real racing engines in F1 do. It's also one of only two 5-liter, 4-valve motors (the Ford being the other), so it's one of the largest displacement 4-valve motors and has great torque. Also, even though it's a 5-liter engine it doesn't weigh any more than the Toyota engine, which is only 4.3-liters. One of the reasons I love BMW is that they invest money to try and make things better, and the BMW motor is technically superior to any motor in the series in terms of the original design. It's also been very reliable and is near the highest top speed on the radar gun at just about every race track (fastest speed recorded in a Dinan-powered DP so far is 184mph at Daytona). We recommend 40-50 hours per racing motor before a look-over, but last year G & W ran the engine for 70 hours and it was fine.

What's a typical race weekend like for you?
We're responsible for monitoring the telemetry on the engine, to keep an eye out for anomalies. Usually, after each session we'll pull the plugs and check inside the engine with a scope to make sure everything is healthy. We're also responsible for monitoring the traction control track to track, as the coefficient of friction changes. We work on development throughout the year to reduce weight, lower the center of gravity, improve gas mileage and reduce friction inside the engine. (Note: It should be said here that Dinan engines have only had one mechanical failure and that was due to a bad circuit board, not to the engine itself).

Are there any weaknesses of the BMW V8, as a racing engine?
If the engine has an Achilles heel, it would be if you needed it for high-rpm applications, but in Grand Am that's not a factor, as the rules are made to keep the rpm down so the motors last a long time. The reason the BMW V8 wouldn't be ideal for high rpm running is because the firing order of the engine causes a lot of torsional wrapup on the crankshaft. When a front cylinder is fired, the crank twists the whole length and then oscillates back and forth until it reaches equilibrium. The Pontiac engine fires a front cylinder and then a back one, which gives the crank a chance to dampen out before firing another one at the front. That's the secret to making a V8 that can handle higher rpm, but for some reason, BMW didn't go with that firing order - I don't know if it's because they don't have as much experience with V8's or because they feel it makes more torque that way, but the design doesn't work well with higher rpm.

Do you think we'll see the BMW V10 engine (from the new M5) in a Daytona Prototype? (the new M5 motor in stock from makes 507hp)
I'm pretty certain you won't see it in 2005 - I'm not sure about 2006. It really depends on whether it's important to BMW. That may not be a great motor for Grand Am anyway, since we're only allowed to turn 7,000rpm. The V8 motor has more stroke than the V10 and makes more low-end torque, which makes it a better fit with the rules. With the way the V10 is designed, it would have no horsepower advantage in Grand Am since the rev limit would have to be lowered, and would make less torque.

Do you think Grand Am will eventually allow more horsepower in the Daytona Prototypes?
They told us a while ago that they were going to bump everyone up by 100hp to 600hp once Porsche came out with a larger displacement engine, but since then they've decided that around 500hp is a reliable number and they're going to stay with it. The Porsche actually has the highest amount of peak horsepower, but they don't have the torque to pull it out of the corners. All of the competitors would like to see wider rear tires, more downforce and another 100hp on the car. I think they could do that and it would still be a cost-effective series - it probably wouldn't add more than $100K a year to a $2million budget, but that's not the direction Grand Am wants to head. Right now, you can run the whole racing season and spend less than $200,000 on racing engines, which is extremely reasonable for a big-time racing series.

With the rules making the cars so equal, do you think the role of the driver becomes more important in Grand Am?
We're seeing more big name drivers showing up in Daytona Prototypes, because the teams are realizing that the only place they can get a real advantage is by putting the best driver behind the wheel. Teams are finding out quickly that what they got away with last year, they're not going to get away with this year. When the level gets as high as it has in Grand Am, you need a top level driver to be competitive.

Do you think Grand Am has better racing than ALMS right now?
The problem with ALMS is that only one team ever gets the right parts and almost everybody else is an also-ran. We had a team that we were supposed to be an engine supplier for this year in Daytona Prototype (Pacific Coast Racing) and they went to ALMS to run the C5R Corvettes. I think their budget for ALMS is $5 million and their budget for Daytona Prototype was around $2 million. So, they're going to spend well over twice the amount of money to go out and get beat by factory teams. I'm not sure if I understand the point. The cars are cool and exciting to watch, but the racing is a yawn. In almost every Grand Am race last year, they were really racing and were going at it right until the end of the season, and the field is going to be even deeper this year.

What do you think of the way Grand Am GT is headed, with the tube frame cars coming in?
We're very concerned about that. The Europeans don't like tube-frame cars, and my concern is that Grand Am will chase the European manufacturers away if they start pushing that too much in GT. The problem is that with the American cars, the chassis' are usually so bad, that if they don't make tube-frame cars they're not competitive, but the Europeans don't like them. So, we wind up with two different prep rules, which makes it hard to keep the cars equal. I think if Grand Am had to choose between the two, they would go to tube-frame. From a racing standpoint, a tube frame chassis is a superior product, as it's more rigid, has better weight distribution and a lower center of gravity, but the European manufacturers would resist and they don't want to lose them - there's a lot of Porsches out there. Porsche and BMW are both at a disadvantage with the new rules and I hope the goal is to keep them even.

Are you hoping to expand your racing engine business outside of Grand Am?
We would like to do more World Challenge, Grand Am Cup and BMW CCA Club Racing engines. For BMW CCA Club Racing, we went out and bought a bunch of E36 and E46 M3 core motors, with the idea of making 3-4 different levels of engines based on the various classes they can compete in.

More information:

Here you can find my article about Dinan:

Super Moderator
10,465 Posts
Interesting article. I wonder how high of an rpm dinan is thinking when he says the v8 is not a good high rpm engine? In other words, is it good for 7k, 8k? How high is high rpm in his book.
The stock M5 engine seems (to me at least) to be pretty strong and smooth thru the 7k limit we typically use on the street, which seems like a pretty high rpm for a street engine.

767 Posts
It's always enjoyable (for me) to read Steve Dinan's comments, and certainly these ones. I was most interested in his thoughts on the M5 V8 and V10 torque given the mandated RPM range, and stress on the crank due to firing order. Definitely "North America's premiere BMW tuner".
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.