A barage of technical questions

[speedracer1407]

Hi folks. This is my first post, and I apologize in advance for the ridiculous number of technical questions to follow as well as the length of this post. I'm an avid automotive nut, and I'm familiar with how most pieces of transport engineering work, but I've had a hard time finding details about the CTA buses I ride every day to work despite a bit too much time dickin around on manufacturer websites, google searches, forum searches, etc.

1. Newflyer engines: The first few batches of Newflyers (1000-1700), as I understand, have Cummins ISL 6 cylinder engines with a variable-vein turbocharger, which accounts for the instantaneous spool-up you can hear from inside and outside of the bus as it pulls away from a stop. Which power/torque version do they have?

2. Recent press releases from the CTA say that 1700 and above models (I think) are equipped with a "smaller and more efficient" engine. Which engine is this? As an observer, I notice only that it makes a slightly different noise from out side, but produces a very noticeable turbo waste gate "burp" between 1st and 2nd gear, as well as on throttle lift-off. This is a sound that doesn't' happen on the pre-carbon steel-chassis NFs.

3, What in the WORLD is wrong with the NABI articulateds? Nowadays I ride the 147, and am therefore cursed with riding the artics most of the time. But once in a while, glorious relief comes in the form of a Newflyer, or even, a TMC. The softness and solidity of the brand new NFs is expected, but even old TMCs rattle less, and are softer-riding along the bumpy stretch of LSD I travel every day. I've read various passing comments about "problems" with the NABI when they were first delivered--suspension cracking and such. But what's been done to fix this? They're brutally stiff-riding in the best condition, and down right injurious when the air suspension bags on the rear frequently deflate. Surely, if cracks showed up early, they're showing up even more now that they've got a few years under their unyielding belts, but what has (or is being) done to fix the problem?

4. Which engine(s) do the Nova's use? Although I don't get to ride them much (haven't gotten a chance to ride the two currently assigned to NP), I assume that their unique engine position is part of what makes it hard for me to identify the engine noise. Frankly, I like the fact that, from a curbside observation, they're the only CTA buses whose engines make a proper ball bearing-in-a-rotating-drum clatter at idle. But what confuses me is that some Novas have a particularly narrow exhaust stack, while others have a larger one much like the 1000 Newflyers and some 5800s. Is the different exhaust stack indicative of a different engine, or merely a modification to the engine (or exhaust) of later Novas?

5. Simple and stupid question: I can't seem to pinpoint whether 1991 TMCs and Flxibles were ordered with the 6v71, 6-71 or 8v71 Detroit Diesel engine. And also, did some Flxibles have8v92 engines?

6. Continuing with the older buses, this past spring I had several peculiar sightings. Between maybe March and April (when I was commuting downtown from the north shore), I came across 4 2-stroke Detroit-powered TMCs and Flxibles that had what appeared to be some sort of problem engaging the transmission. In each case (often on the 120 and 121), the bus would stop to pick up passengers, try to accelerate, and find that no acceleration was available. The driver would then, presumably, put the bus in neutral, and floor the throttle for a good 15-30 seconds of insanely loud, governor-topping revving. Then he'd try to engage a drive gear. In each case, the driver would have to repeat this cycle 2-5 times to get the bus moving. I am sure that this process of high revving in neutral wasn't elective, as one of the most memorable moments was a 121 turning right onto lower Illinois from Lower Michigan. It couldn't make it, backed up, and then had some sort of failure that necessitated a good 2-3 minutes of foot-to-the-floor-in-neutral revving before a drive gear could be selected and the huge traffic jam could be relieved.

Now, all of these revving instances happened on the unusually cold days we had this past spring. But I also rode and observed countless 2-stroke 1991 buses throughout the previously and unusually frigid winter, and I never saw this, nor have I seen it since. Any ideas about what happened?

7. One final question. Do the 5800 Newflyers have the Detroit series 50? They certainly sound similar to the NABIs in some circumstances. If this is the case, is the only difference between the two engines a quicker-spooling ceramic turbo charger on the NABIs? The 5800s seem to take ages to spool up to full boost, but man did I love the outrageously loud turbo on a recent 5800 147 ride I had recently in the back seat. A treat, for sure.

Thanks in advance for any replies, an I certainly hope there are some technically-minded folks on this forum who can answer the questions i have on this ridiculously long post.

[Busjack]

The only things I can say is that any differences with the New Flyers start with 1630, which is the first of Option 3. CTA announced then that they were carbon steel and had smaller engines.

Also, the complaints about the NABIs (at least as stated in the Tribune) was that the Alabama assembly force wasn't too good, and there are problems with the suspensions, in the frame around the articulation joint, and the rear door engines. Other complaints have been rumored about. There was one Pace driver who said that all NABIs are junk, him dealing with the 40 and 35 foot ones at Pace.

Also, while there was a debate here, it was established that the 5800s got new engines when they were rebuilt.

[artthouwill]

6. Continuing with the older buses, this past spring I had several peculiar sightings. Between maybe March and April (when I was commuting downtown from the north shore), I came across 4 2-stroke Detroit-powered TMCs and Flxibles that had what appeared to be some sort of problem engaging the transmission. In each case (often on the 120 and 121), the bus would stop to pick up passengers, try to accelerate, and find that no acceleration was available. The driver would then, presumably, put the bus in neutral, and floor the throttle for a good 15-30 seconds of insanely loud, governor-topping revving. Then he'd try to engage a drive gear. In each case, the driver would have to repeat this cycle 2-5 times to get the bus moving. I am sure that this process of high revving in neutral wasn't elective, as one of the most memorable moments was a 121 turning right onto lower Illinois from Lower Michigan. It couldn't make it, backed up, and then had some sort of failure that necessitated a good 2-3 minutes of foot-to-the-floor-in-neutral revving before a drive gear could be selected and the huge traffic jam could be relieved.

Now, all of these revving instances happened on the unusually cold days we had this past spring. But I also rode and observed countless 2-stroke 1991 buses throughout the previously and unusually frigid winter, and I never saw this, nor have I seen it since. Any ideas about what happened?

Thanks in advance for any replies, an I certainly hope there are some technically-minded folks on this forum who can answer the questions i have on this ridiculously long post.

[sw4400]

7. One final question. Do the 5800 Newflyers have the Detroit series 50? They certainly sound similar to the NABIs in some circumstances. If this is the case, is the only difference between the two engines a quicker-spooling ceramic turbo charger on the NABIs? The 5800s seem to take ages to spool up to full boost, but man did I love the outrageously loud turbo on a recent 5800 147 ride I had recently in the back seat. A treat, for sure.

Thanks in advance for any replies, an I certainly hope there are some technically-minded folks on this forum who can answer the questions i have on this ridiculously long post.

Yes, the 5800's do have the Detroit Series-50 Diesel Engines.

[BusHunter]

Here's a question. Why would a sign for bus #5808 display the words check file on the destination? Is it possible for a bus to lose it's sign program?

[Busjack]

Here's a question. Why would a sign for bus #5808 display the words check file on the destination? Is it possible for a bus to lose it's sign program?

Sure, why not? No more strange than the signs that were twice as high as the actual sign (I mean the bottom of the message was cut off, and said something like Message A?) or "CTA Program 1/10/07" (or whatever date). Remember, on that bus, you are dealing with a 1995 vintage flash memory.

[MT0851]

As far as I know the earlier D40LFs have the Cummins ISM as they have the extended rear cap which only comes with the ISM. So the latest ones should have the Cummins ISL.

The Nova LFSes have the Cummins ISC engine.

Anyways, does anyone know what tranny the CTA's D40LFs have?

[Busjack]

Anyways, does anyone know what tranny the CTA's D40LFs have?

Someone had posted, 3 years ago, and based on a press release on the web, that it was ZF.