| Author |
Message |
van2001ko
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 10, 2004 - 11:56 pm: | |
Hello I have a question about the Detrot Diesel 50
Transit version. I am a transit fan that is intique on how bus engines are setup..well anyways here are a few
questions.
1. When SEPTA had there buses set to only 40mph do
there engines still rated @ 275hp? And is it possible to set a Allision B-400R-4 Speed to 75mph?
2. On a typical transit bus what's the highest speed
can the governs be set to? And what MAX RPM are they
typical govern to?
3. What kind of Rear End does SEPTA mainly uses on
their Nabi and New Flyer Buses?
Thank you ! |
Earl-8-Ky
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 11, 2004 - 10:10 am: | |
A transit bus is usually geared low. The engine RPM does not allways control the speed.The 50 series engine can be set at 300 HP or better. |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 13, 2004 - 12:44 am: | |
Stand by, van2001ko.
I will get you some specific answers on Monday about rear-end gear ratios.
My gig is up here in Toronto, Ontario.
It is possible to spec a top gear lock-out switch, which might explain the 40 mph top speed you refer to.
The B400 Allison World transmission is typically shown to the driver as a 5 speed automatic.
275HP is a popular power setting for transit buses. Series 50 materials of the vintage I'm familiar with suggest they can be set up to 315HP. But, torque is king, and this little, shaking beast makes a ton of it. I'll see if I can find a chart somewhere.
Series 50, typical of Detroit Diesel, can spin up into the lower half of the 2000 rpm range, depending on who wants to pay for the rebuild. (faster you let it spin, the faster it wears out, nothing changes!)
Series 50 is a four cylinder, turbo-charged, after-cooled design, and cylinder parts are interchangeable with its 60 series big brother, as is the tradition with this engine builder.
With everything electronically controlled in these modern drivetrains, "governor settings" can, and often are, different for each gear. There really isn't an engine "governor" anymore, the computer controlled electronic injectors do it all.
Gear ratios still make all the difference to top speed and acceleration, even with the huge power available today.
happy coaching!
buswarrior |
patkylekenny
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 14, 2004 - 12:47 am: | |
Yes thanks for the reply. Well I've seen the charts of the DD50 before pretty impressive. However I dont know what SEPTA does to there buses govern to 40mph they have 4 gears only and from my perspective as a rider I can tell you this. The 40mph buses has a really raw sound. And I know that the accelaration is less greater plus the gears are way smaller all of them. So my guss is that the TA took a few parts away from the engine and part special modifed parts on? Or put another DDA cartige in that only limits the engine horsepower to 250hp or maybe less..
I know that there was one bus a NABI with 4 speed that really fast and it was govern to 60 sometimes and 75mph. And it reach 75mph like a bat out of hell and making lots of noise. It started to get loud like around 60mph. my guess it was ungovern in speed and the engine horsepower was booted up. And the Accelaration indicated by the speedometer was like 2mph/s at higher speeds eg..50mph. And the bus sounded like really powerful. than all sudden the TA got to the bus and made a really raw sound and than they govern it down to 40mph.
So anyways how much does the engine max rpm settings in each gear is usally differ?
Thanks |
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