Tundra 5.7 Magnuson Supercharger Towing Report

[katanapilot]

Just returned from an 2000 mile trip from Atlanta to Oshkosh WI towing the Oliver Elite II with our 2011 Tundra - recently modified with the Magnuson Supercharger.

The truck did very well and I'm happy with the performance of the supercharger. Towed up and over Monteagle in Tennessee with no issues.

Pros (opinion of course) -

• Adds a great deal of power i if you want to use it.  Specs say 550 hp and 550 lb-ft of torque
• No discernible change in fuel mileage.  I don't have a heavy foot, but if I did - I would expect the mileage to decrease.
• Helps reduce some downshifting on mild grades.

Cons -

• Noticeable supercharger whine when you accelerate. No real difference just cruising along.
• Requires premium fuel.
• Will probably shorten the life of the driveline (but Tundras, like most Toyotas are known for going 200-300K miles with no issues).
• It's still not a diesel.  To get the higher power, you still have to increase the RPM's. Torque at low end does not change much.
• Not an inexpensive mod.

Hoping to do the Colorado mountains in a month or so - where the boost should help restore some of the lost power at altitude.  I'll provide an update after that trip.

[rideandfly]

Great report. Was wondering how fuel economy would work out, that's good news with a supercharger! Looking forward to hearing about the CO trip, too. 

[Mike and Carol]

When I had the TRD Supercharger installed on my 2012 Tacoma I had about the same pros and cons.  I never towed without it so I can’t comment on towing improvement.  Non-towing power was fun.  At the time I had a 2002 Mini Cooper S that was supercharged as well so the whine seemed pretty normal. Mike

[ChrisMI]

2 hours ago, katanapilot said:

It's still not a diesel.  To get the higher power, you still have to increase the RPM's. Torque at low end does not change much.

The movie on the Magnuson website shows a 2x torque increase in the 2-3k range (from under 200 to over 400). I’d say that’s a huge increase for towing especially with the parasitic drag the supercharger puts on the engine. Great to hear the mpg isn’t affected too much unless you want to go fast. 

[katanapilot]

44 minutes ago, ChrisMI said:

The movie on the Magnuson website shows a 2x torque increase in the 2-3k range (from under 200 to over 400). I’d say that’s a huge increase for towing especially with the parasitic drag the supercharger puts on the engine. Great to hear the mpg isn’t affected too much unless you want to go fast. 

 I haven't looked recently at the charts to see the curves. Not sure if chassis dyno test simulate real world (less than full throttle) driving conditions.

To me, the power is noticeable above 3000.  I only saw 4000 RPM once or twice and that was a downshift to pass a slow poke. Redline is close to 6000, but I still feel like I'm abusing the engine anytime I'm much above 3500.  I know I'm not, this Lexus designed engine can probably run all day at redline.

[John E Davies]

Have you considered putting a slightly smaller driven pulley on it, that will provide more low end boost? I assume that there is some kind of internal blow off protection to keep it from getting too high. I have no experience, but I am surprised that you are not seeing tons more low end power. Boost from a supercharger is pretty linear.  I think you should put the truck on a dyno to make sure it is running as designed. I want more power but I will probably do it with gears, if at all. I need to be able to run cr@p gas.

This chart doesn’t help much, can somebody post one that shows down to 2000 rpm?

John Davies

Spokane WA

[katanapilot]

I am sure the supercharger is working as designed. As mentioned, I do not have a heavy foot - so although there is plenty of boost is available at the lower RPM’s, it is very much an “ on demand” system. The vacuum operated valve on the supercharger modulates based on throttle position - so you don’t get all the boost available at that RPM unless you are wide open throttle. 

I still have not done a full throttle launch. I’ve seen the videos of that and I’m trying to save my Michelin tires for our 11,000 mile Alaska trip next year. 😉

[John E Davies]

Thanks, are you confident about finding premium gas everywhere? There are occasional small town gas pumps even in Washington that only carry regular and diesel. I know a lot of truck engines say “recommend premium” but they will adjust for lower octane with a slight reduction in power. The Toyota 5.7 engine is noticeably snappier with mid range ethanol free and gets 10% better mpgs, but not enough for me to seek it out and pay the much higher price….

We are going to attempt the Canada border crossing on Tuesday if our Covid tests come back negative, but we have decided that four crossings would be pushing our luck, so we are going to Whitehorse and poke around there, then u-turn. And we will not attempt the Dempster at all. Another place you probably would not find premium…

John Davies

Spokane WA

[ChrisMI]

I’m curious how long the transmission will hold a gear?  It would be nice if it would hold 2.5k rpm in third and reach close to max torque before dropping down a gear. Does the selector allow locking it to a gear or just set a limit to the highest one?

[katanapilot]

Not worried about finding premium fuel.  Before I did this mod and with the Alaska Highway trip in mind - I downloaded the chart of all services available and verified that gas stations with premium fuel were no further than 200 miles apart. Generally, they are much closer together than that.  I do have the small fuel tank (26 gallons) on my Tundra, but we will carry two five gallon Jerry cans just in case. I contemplated doing the larger fuel tank mod, but decided it really wasn't worthwhile.  I need to stop every couple of hours anyway to stretch and find a bathroom.

As to the transmission - you cannot force the transmission to stay in any gear (other than first).  You can manually select a gear, but it will still downshift to a lower number gear if you apply enough throttle.