General Supercharger Thread

I know that this is probably coming from a place of being more familiar with VFTuner since I use it regularly, but I think it's solid to use and provides a lot of tables, although I do respect the arguments for HPT.

 

That's my main concern. I'm sure I can figure out how to do it with VF, but then I could be screwed if I try to take it somewhere for dyno tuning. Gear lock works great on mine though.

 

If you already have it (missed that part) then why switch? Have @mZiggy or someone tune it. The buy in for HPT is another $600 just to even touch your vehicle, plus having someone tune it. If VFT wasn't an absolute cluster fuck when it first came out I would still be running it, it's theoretically more capable and it's not chump change to swap software.

 

Just having some analysis paralysis because there are several options and there isn't one that's clearly "the best", just like harrop vs magnuson vs whipple. They all do the job and the prices are fairly close, so it comes down to the minor details.

 

That's where I'm at too...I'm on the OVT tune, love it, compared to the ole BD tune...Direct Shift works well as well as the Gear Lock...for as many times as I tried to get the stated "custom tune" they promised...they never helped out and went radio silent despite me being polite...now I have injectors, fuel pump and the Sniv 2.2 and my only hold up is the tuning ... I hate having to sway around like an orphan at Christmas for tuning software but HPT likely will be the one I choose...out of necessity.


*No offense to any orphans...

 

One of the things I appreciate the most about using VF is the transmission control side of things. VF's got a ton of engine side goodies of course, and while its 3rd party diagnostic tools integration is effectively non-existent still, it's supposedly coming in the future and it's not like the lack of those kinds of ancillary features makes it impossible to tune with. Just means the tuner (and tester) have to be a bit more flexible with how data is compiled.

2007-17MY Tundra tables need a bit more touching up in my opinion but they're not terribly far off from the level of ease of use I get with the 2018-21MY ECUs.

I'd still like to see VF release a properly functional and expanded ethanol learning disable patch, which Mat told me is coming sometime in the future. We'll see.

Regardless, the software has definitely come a very very long way since launch in 2020. Obviously the OVT flasher existed prior to that but that's really a separate discussion since it was just a tune flasher, not a tuning suite.

 

How big of a performance hit will the magnuson or whipple take living at 7000'?

 

PSI-wise, you'll lose about half of the 7-8psi Magnuson claims. I'm running the older 1900 Maggy and on a great day would see 4.1psi. I'm regularly between 6,300-7,100 feet. IIRC, somewhere in this thread, I believe Sniv provided a calculation of 27HP per 1psi (someone please correct me if I'm wrong).

 

A lot, supercharged engines lose power with elevation twice as bad essentially. Your base horsepower from the engine alone goes down, and the amount of air the supercharger pumps also goes down. So you end up using more boost to make up for the altitude, and overall make less boost, so your end result of power beyond stock (relative to a sea level engine) gets tanked pretty bad. This is why I recommend high elevation (especially at 7000ft) to run the smallest pulley possible. Even then, you'll be lucky to make the same power that a stock supercharger will make at sea level.

Just to throw some numbers around, a stock 1900 Magnuson makes ~7psi at sea level with 2.45" pulley. My truck at 5500ft with a 2.0" pulley (considered extremely small and a huge step up in boost) is lucky to see 8psi after making up for the altitude deficit. I am pumping as much power from the Magnuson as possible essentially, and only at 5500ft (not that high even) my truck has the same performance as an off the shelf blower on the beach.

I don't want to plug my derpy website, but it is the one place I put all the elevation data I've compiled. I have a lot of graphs I've put together and shown here: https://www.snivspeedshop.com/pulley-sizing

Ignore the pulley numbers, but the 2.45" stock pulley size lines should be a close representation for all Tundra superchargers, and the other pulley lines if you scale them should be somewhat close as a rough approximation.

 

And another post, just because high elevation is overlooked usually.

If you drive over some passes, you won't even measure boost at all. Most boost gauges are reading absolute pressure, so if they read 4psi like @PolishedTRD said, his supercharger is putting out 5-6psi, but the sensor is looking at it as if it was at sea level. So a boost of 0 on a gauge is really the same as being at sea level where the base intake pressure is 14.7psi. I've had times (like driving over Eisenhower on I-70 in Colorado) where at the top at WOT the truck reads 0psi. The blower is working it's butt off, but the truck is making effectively the same power as a bone stock truck at sea level. Of course, the truck is still making WAY more power than a naturally aspirated truck at that elevation, so don't get confused---the boost IS doing something. But how I approach it is how much am I stressing the engine beyond a proven limit, the proven limit is a stock engine with a stock supercharger at sea level. If you crank the pulley size, the supercharger is pumping out 10-12psi, but you have 4psi of altitude deficit, well the engine's actual horsepower is only in the 6-8psi range if you were at sea level. Smaller pulley = lots of boost at any elevation, but lots of boost doesn't mean lots of power at high elevation. My supercharger puts out 11psi, but I read 8psi on the gauge, so my truck is about as fast as a stock ~7psi supercharger at sea level. @Mdl or @Fastlane47 make 11psi at sea level, their 11psi from the supercharger is a lot different than the 11psi from my supercharger because my engine is really making 8psi of power. Same boost, drastically different amount of horsepower and subsequently stress on the engine.

I think I said the same thing a few different ways there, but I think it's cool to think about. And if you look at the pulley offerings on the market, NO ONE thinks like that. I had the smallest pulley they offered on my supercharger since day 1, and I never even saw 6psi. Because of that, I decided to make my own pulley just to try and get the same feeling that a guy in LA feels with a bolt on supercharger. And it makes a BIG difference. I can't even imagine how fast the above guys at sea level are. Excuse my ramblings.

 

Ah that's right! Great consideration! My PSB-1 reads vacuum (engine off) at my elevation, but I never bothered converting it to PSI from inHg - around 3-4psi of vacuum.

 

So can you just slap a smaller pulley on an otherwise stage 1 setup and make up for it? What happens when you take your 8psi at 6000' pulley down to 1000'? Ejecto-rods-o cuz?

 

Exactly. In the PSB-1 settings there's even "altitude compensation" to correct for that offset so the gauge reads true boost off the blower, but imo that's kind of pointless, though to each their own. If you change elevation you'd have to change the altitude compensation too.

Yes! Fueling is based on raw airflow, ie sea level equivalent boost for all purposes. So you could run a smaller pulley, without any changes and potentially even stock injectors. With that said, it all depends on the pulley size and how much boost you make. My dad is installing a supercharger on his 4Runner as we speak actually, and he lives at 9000ft, and I told him to buy the smallest pulley URD sells and don't even worry about touching the fuel system.

And you are spot on with your second question. If you don't change the pulley, you will now make a lot more power as the engine base power increases and so does the boost the blower puts out. This is why hub style systems where you can quickly change the pulley size are nice, which all modern Tundra superchargers are that way. I always run my small pulley, but I have a larger pulley in the glovebox for any time I go below ~2000ft so I can drop the power level to a reasonable amount. Which on that note, boost is not an on/off switch. You can run a small pulley that makes a lot of boost and just be cautious with the throttle so it doesn't make a lot of boost in case you run to a lower elevation and don't have the ability/opportunity to change pulley size. The boost ramp in is proportionate to throttle more or less, so if you stayed to say 70% of full throttle you would stay in the lower amount of boost. Again, all dependent on your specific setup though.

 

Smallest pulley at sea level problem solved at other elevations lol

 

not so loud, some of us small pulley/sea level folks might hear you.

 

That's actually very helpful. Looks like I could drop down a size or two and get a decent gain at 7k and not be too far into the Danger Zone if I happen to go down to phoenix, as long as I don't beat on it. Or change the pulley out like you said. Leaning towards the maggie 2650 at this point, which looks like it has a bolt on pulley, not pressed on like the 1900

 

The unfortunate part is nobody sells a pulley for the Maggie TVS 2650 tundra kit other then Magnuson who will in turn void your warranty. SCOL said they can custom make one. Said they had to check one last thing and would get back to me. Never heard back, even after sending another email asking if they had any update

 

If you’re looking for a boost in performance at elevation that is over what could be found on a base setup at sea level, best bet right now for high elevation would be the Harrop with a 65/70/75mm pulley, or the Whipple (Rey probably knows the smaller size options but I believe there is many to choose from.) Magnuson 2650 could also be viable once the pullies are better established. Being that the 2650s and 2.9s are inherently larger they will move more air once you start getting the smaller pulleys than even a 2.0 on a 1900 without having to go crazy spinning them at RPMs above what they’re rated for, and running it far out of its efficiency range and turning it into a heat pump. At 65mm on a 2650 with the engine spinning at 6200rpm will be spinning the rotors around 14,800RPM and still be in a good efficiency range. A 1900 with a 2.0 pulley with the engine spinning 6200RPMs will be spinning the rotors at 19,000RPM > the efficiency will suffer, and those poor, poor bearings lol. I think most of these blowers are not supposed to surpass the 18-20k RPM range.

 

I could reverse engineer one but I don't have one, or if someone can pull me dimensions that are accurate I can get some made too.

 

So, living at elevation is the main impetus for me looking at blowers. Years ago, one of my coaches put a blower on his pickup for the same reason - he was basically a hotshot and pulled up and over two passes everyday. Medium duty and above trucks are restricted from driving one of those passes 5 or 6 months out of the year which is how he kept busy as a hotshot. I didn’t really understand it at the time, but it always kind of made sense. The way @snivilous explained it shows why it really makes sense. It’s not that the blower isn’t doing anything, it’s just that you start at a lowered air pressure and have to make a certain psi just to get back to sea level pressure. The blower does that and usually more.

The few times I’ve driven my truck to the coast I’m always surprised when I start chirping tires without flooring it until I remember that air density is restoring power that I usually go without.

If you feel like looking more in to some historical tidbits about supercharging, look up fighter planes from wwii. They started supercharging and turbo charging them them to make up for lost air density before jet propulsion became a thing.

@Silver17 brings up a point I want to explore more: how blower volume affects efficiency and the affects altitude has on blower volume. I’m looking at the Whipple partly because it has the largest blower volume; I don’t know HOW much difference that makes compared to a smaller blower volume, but it would seem intuitive that it should be more efficient and better able to compete with the air density lost from altitude.

 

I did notice the lack of 2650 pullies on the magnuson website. Whipple has 11 sizes for the tundra.

edit: looks like 5 or 6 smaller size for the whipple

 

I would suspect some of the Magnuson ones work with the Tundra Magnuson, albeit they might not advertise them. It would seem like you'd design the blower to use the same pulleys as your other offerings so they aren't unique to each blower.

 

There is also the overdrive crank pulley. Prospeed is 7 inches and good for 2 to 2.5psi.
I'm running the ASP overdrive crank pulley which is 6.71 inches. I saw a 2psi increase with it.

 

Magnuson show none. It wasn't until I spoke to a sales rep that said I could order a 80mm...

 

Exactly! Has anyone tried Magnuson GM offering on the Toyota2650?
Not sure if they are 8 or 6 rib or even feasible.

 

After closer examination, other than there not being recesses for the bolt heads the way the Harrop pulleys are, these look pretty identical to the Harrop pulleys. I wonder if using the Harrop style bolts would allow you to use the Harrop pulleys on a magnuson. It’s probably unlikely the alignment with the belt would be identical though. I’m sure it could be determined with some measuring.

 

Here's what I sent to scol. Ours are the 8rib

 

Magnuson said only digits 57-99-08-diameter# would only work for our application

 

I'm sure SCOL or another company would say just put so and so pulley on...

 

ZPE said if I ship them mine they could cast up some ... I may just do that so us tvs dudes have some options