Mosler MT900

Back in the day: When the MT900 came out, Dan told the folks at Mosler that he’d develop a twin turbo system for them to make these things really fly. They said “No thanks, they’re fast enough.” Shortly after they brought one to his door asking for help. This was the beginning of a fun collaboration that had its ups and downs. The original turbo car needed some work. Dan helped Mosler sort through the issues and developed an EFI calibration that met emissions standards and made these cars extremely quick. Even with the rear wing mounted, the cars would light the tires while rolling and accelerating at anything below 120 mph. Quick. Very quick.
Mosler didn’t sell a lot of cars, but the customers were discriminating. Dan kept making improvements to the powertrain software with every bit of data he could obtain. A fair number of these cars were sold in Europe, including Germany, where the owners used the cars for what they were designed for: high speeds and track days. The owners loved the drivability of the powertrain and the smooth, predictable power generated with track day driving style in mind. Transient throttle application was unparalleled, the chassis stiff and responsive.
You might recognize this white car if you read Car & Driver back in 2008. It went on to win the Lightning Lap challenge that year. You can read about it here. If you scroll to the bottom of the article, you’ll find the write-up on the winning Mosler. They indirectly complimented Dan’s handy-work by indicating that they could feather the throttle and thus control this monster on the bumpy portions of the track. You couldn’t do that with a poorly sorted powertrain. And yes, it is effing fast!
The car is gorgeous from any angle, with or without bodywork.
Testing and R&D was thorough. For one particular German customer, the German distributor for Mosler asked Dan to run his car near 200 mph and to be sure that his particular MT900S could run at top speed for an entire fuel tank-full. “No problem” was the reply. And we made it happen. Wild day on the dyno, that.
Here, a similar white MT900S with the carbon wheels gets tested, tuned and flogged before delivery.
Stunning. Notice the new roof-top scoop.
As with any luxury product, these cars are bespoke. The owner of this red MT900 wanted more power and thus it was fitted with an Eaton supercharger. Again, full development was performed to make sure the powertrain met all goals for power output, exhaust emissions, fuel economy (you better believe it!), transient throttle response, idle quality and of course, durability and reliability.
A little bit of ice to help cool the puffer between test rounds.
This is the “Merlot” car, Dan’s absolute favorite. No picture can do this car justice for how beautiful it looked in reality with it’s deep red merlot color. This car was chosen to represent the Mosler brand at the Festival of Speed. “Great choice!” was Dan’s reaction. He went home after working on this car on one particular day and told his wife he wanted to buy this very car. She wasn’t thrilled about the price.
After “Merlot” came back from the Festival of Speed, Dan was asked to go to the Mosler factory to take care of an MT900 GT headed to Europe that had been fitted with a carbon triple disc clutch. The idle needed tweaking with the new lightweight clutch. By this time, Dan had managed to get his wife to acquiesce on the purchase of “Merlot” which he knew would be back at the factory. When he got to the factory, he couldn’t believe what he saw. There, in the back of the factory, was Merlot sitting on two pallets, broken in half. “What happened?!” asked grief-stricken Dan. “‘Name-withheld’ crashed it while on a test drive with a client; spun it and sent it into a pole, cracked it in two” was the answer. “Name-withheld” was the same person who warned Dan to try not driving the cars much as they “may get him in over his head”. Irony knows no bounds. Dan didn’t buy Merlot, and “Name-withheld” never lived down his “professional” driving.
Here is the car known as the Dubai car. This was another twin turbo 7.0L.
Some new things were tried by the factory on this car: fuel system, exhaust, turbos, waste-gates, etc.
Here’s a great shot of the plumbing that has to get shoe-horned into the back of the MT900.
Dan saw the size of the two turbos on this engine setup and voiced his concern about them being too small. The engine builder knew it as well, but there was no convincing the chief engineer. At that time, between Dan and Mike (the engine builder) there were at least 50 years of high-performance powertrain development experience in the dyno room but nobody listening to them. Okay, let the test begin. The turbos were producing over 9 psi of boost at just over 1200 RPM with only 64% throttle and the waste-gates fully open. Good thing we were billing by the hour.
When the car was assembled, the same turbos were still being used. The little Garretts spin up quickly with their ceramic ball-bearings. A lot of exhaust work went into bypassing the turbine, but that wouldn’t stop excessive heat from being generated in the compressor.
As with most things made by the good folks at Mosler, the work was gorgeous. You’d need a garage made of glass to truly appreciate the craftsmanship.
Testing on the dyno, you could see the beauty of the engine bay and the warnings on the tires…
As you can see, the tires were getting blown off the dyno. No matter how hard the car was strapped down, the rears would just light up and let go. Lots of wheel spin and tire graining.
More data collection and sensor integrity testing. You don’t want things failing at 220 mph with boost on the boil. Although ultimately it did fail. A defect in a connecting rod bolt caused a rod to fail and the engine came apart. The manufacturer of the bolt supported the findings and sent the engine builder a new set of bolts (gee, thanks).
Next up was the Mosler Photon, an evolution of the MT900S. The Photon had a naturally-aspirated 7.0L, a Hewland sequential transmission, narrower rear bodywork and narrower rear tires. This car would go on to win the 2011 Car & Driver Lightning Lap (you can read about that here) although it was slower than the 2008 car (for a number of reasons…)
The one and only Photon was Warren Mosler’s personal car.
Here we have it at Palm Beach International Raceway for testing prior to it going to Virginia International Raceway for the Lightning Lap.
This is Dan (left) and Mike (the engine builder, to the right) working on the car. It needed some sorting to say the least.
The Photon’s potential is huge, but there are things Dan didn’t agree with as far as parts used and setup incorporated. But, as Dan says, when you’re the hired help, you can only insist on what you’re asked to help with. The rest, well, you can advise, but you can’t insist. Shame. There was a ton of speed and grip left on the table.
Above is the “China” car under development. This was the new “Raptor GTR” design that was being developed by we-don’t-know-who. Rumors started circulating about tensions and trouble within the Mosler factory. We just did our job and tried to help develop the troubled car.
We realized quickly that the fuel system wasn’t sufficient along with other issues that couldn’t be left to stand.
We did what we could to put as much information in the hands of the Mosler staff as possible, but this is when we learned that this wasn’t a true factory car. At this point, we were told that an independent investor(s) were involved with this car.
We did what we could and sent the car back.
The car later returned. It had been “modified and repaired” according to the investor. We did the best we could with what we had been given.
Ultimately this was the last Mosler vehicle we would see. All told, Dan’s hands touched virtually every Mosler that left the factory after 2007. Things apparently fell apart at the factory with the “China” car and the involved investor(s). It was covered in the press (read about it here) and it wasn’t pretty. This was a truly shameful ending to what should have been one of the greatest success stories of an American car company that started small and offered great performance. It wasn’t to be. The good thing is that there are some pretty amazing cars out there being driven by some very fortunate people. Warren Mosler had a great vision and his Mosler MT900S was an amazing (if brief) piece of American automotive history built by some truly amazing and talented people who Dan had a lot of respect and love for. Dan and his crew feel privileged to have been a small part of this unique, ill-fated story.