Jump to content

Recommended Posts

Randy

Good story. I am NOT calling BS!!! I am assuming that 309 was a 4 lane that went over the mountain where 78 does today as 78 was not built until into the late 80's?? I was not in the area til the mid 70's.. And we had to go thru town on old US 22.

Brocky

Mackdaddy

I agree with you.. I drove one for Matlack in 1970. Could come out of Albany NY grossing in the high 70's on the NY Thruway, get in 5th, and never shift all the way to Syracuse.

It was a combo that a newbie could not kill, and the old hand could sit back and relax..

  • Like 1

Brocky

I got into driving trucks shortly after the Maxidyne came out, and driving one was a real treat. All of the competition, even the 335 Cummins and 8V-71s, were torqueless wonders with a narrow powerband that you always had to stay on top of. In town you could do all your driving with just 2 or 3 gears instead of the at least half dozen the competition required. On the highway you could get over 90+ percent of the hills without even downshifting, while a conventional engine would have you making at least one if not two or three downshifts.

Excellent story, thanks for sharing it! Driving a truck with a high torque rise engine back then must have been mind boggling for those who were experiencing it for the first time. I had the pleasure of driving Maxidyne/Maxitorque equipped trucks for 4 1/2 years at my previous job, 3 years in R models and 1 1/2 years in a CH. That drivetrain was and always will be in a class by itself.

  • Like 1

Jim

Thanks for sharing. Those were good times at Mack back then.

I know Mack still advertises a maxidyne as an option but they all have more gears than just 5

Will these new electronic Maxidynes pull thru a 5 speed or they don't lug down like the old ones could.

I recall a 605hp maxidyne for the Titan. Did that ever come about?

Thanks for sharing. Those were good times at Mack back then.

I know Mack still advertises a maxidyne as an option but they all have more gears than just 5

Will these new electronic Maxidynes pull thru a 5 speed or they don't lug down like the old ones could.

I recall a 605hp maxidyne for the Titan. Did that ever come about?

The Maxidynes are still available, but Volvo doesn't promote them. The engine with the broadest power curve, the mislabeled MP7 "Maxicruise" at 395 HP, is the most like the old Maxidynes with a power range from around 1100 to 2000 RPM. Mack still makes a 6 speed Maxitorque with gathered ratios, I've plotted out the gradability and such and it'd work well with this engine. Unfortunately the fleet customers are obsessed with fuel economy and want the governors set to 1800 RPM or so, too low to allow a Maxidyne to work with just 6 speeds. But the reality is that most trucks spend their driving time in the top 2 gears, and the wide ratio Maxitorques have only a 40% split between the top two gears, same as the close ration 9 and 10 speeds. Thus a good driver could keep the revs down for good economy in the top 2 gears while making only half as many shifts in the lower gears, where even Volvo has programmed their AMTs to skip gears for better economy.

A Maxidyne + 6 speed Maxitorque combination that saves weight, is easier on the driver, and lasts darn near forever... What's not to like? But it wasn't invented in Goteberg and Volvo has a competing AMT, so Volvo's gonna keep it a secret and hope it goes away...

  • Like 1

I remember the first maxidnes and some of them did not have a muffler but did have cast into the exhaust side of the turbo words saying muffling device.I guess this was legal until they started the sound test on the road.

glenn akers

cool story thanks for sharing,,,,i owned a maxidine ,,,didnt really care for it,,,but i admit it was a good idea,,,and alotta people did like them,,,drive a kenwoth now,,with a automatic,,,love it...no more shifting...woohoo.would prefer a mack,,,but least its not a volva.lol..bob

I remember the first maxidnes and some of them did not have a muffler but did have cast into the exhaust side of the turbo words saying muffling device.I guess this was legal until they started the sound test on the road.

In the early days of the Maxidyne, Overdrive did a comparison test with two F models pulling identical loads. one truck was equipped with a 250 Cummins and a 10 speed RR, the other with a 237 and a 5 speed. Natutrally the 237 walked away from the Cummins on the hills. Maybe Cummins should have brought a 335 to the party. :)

Anyway, they mention the lack of a muffler and said there was a sticker (or plate or something) that read "turbo muffler" that could be applied near the exhaust manifold that would satisfy the authorities. This is the first mention I've heard of this in a long time.

Jim

I have seen turbos with a id tag stammped to it that would have "muffling device" noted in the specs of the turbo.

I thought some of the orders state laws may have even been written that turbochargers were infact considered a muffling device?

WOW what a great read some one over that way should get an old Maxidyne load it up go out on the roads and do some time trials add it the story I think a lot of us might be surprised and would add a modern touch to a great read

I think a lot of people would be surprised how well these pull even now

even better do some trails against some modern trucks of the same class I think there would be some shocked faces even more so if you add the fuel figures

and that Maxidyne bark OH baby sounds so much better than some young boys cruising around with there DOOF DOOF music going

great read thanks for sharing

Paul

  • 2 weeks later...

There was a great story in Bulldog about a test Mack did with 3 F models. they were numbered 318, 335, and 325..........you know what they are. They did a run from Allentown to San Francisco and compared fuel, speed, and number of times shifted. the maxidyne did an amazing job winning in all 3 categories. they also have a video from a helicopter of a lot of the run. I will find the article and post it when I get a chance. I also have the promotional barrels that they compared with fuel usage. The blue was Mack white Cummins and red Detroit. I cannot remember the # of shifts but the Detroit was many X more than the Mack.

I recall seeing a write up on this. I thought it was in a old overdrive mag? Maybe they just were telling the same story that Mack published?

I think it had a brake down of the overall stats at the end and your right. the Mack powered tractor had something like 1/2 as many shifts as the other two trucks combined.

Would like to see that if you find it.

  • Like 1

Great story, I'm sure we can get something together for Double Clutch with some gathered up photos.

Mack was such an innovator in the industry. The talented staff was the reason for their success for decades.no other brand can claim industry changing innovations as Mack can.

I have a movie highlighting the Maxidyne comparison, that corresponds to the fuel barrel promotional item, it is a fantastic film.

  • Like 1

Interested in Old Trucks? Check out:

www.antiquetruckclubofamerica.org

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...