General Supercharger Thread

I love this.

My unit is scheduled for delivery around Thanksgiving, if someone hasn't sent you a pulley before that, I'll send you mine.

 

Well apparently like an idiot I spoke to soon .... SCOL is on it

 

If you can read/understand it these are the pulley Harrop measurements I just grabbed with a cheapo caliper. I used metric instead of freedom units, but can be converted by dividing 25.4/x measurement.

 

I live at ~1000ft elevation, but I travel to 9k+ every year. I would love to do with a medium travel trailer as well.

Sounds like the smallest pulley that I can safely run at home will also help the most at altitude.

 

Additional/updated measurements edited to the post. Not sure if that’s all of them. They’re really just to give a rough idea if by some chance they are compatible if the Harrop style bolts were used.

 

I too live around 1k’ in my local area, which is where I’ve been doing the dragy testing and such. I’d recommend a 77.5-80mm pulley on a 2650 if you would like to straddle the line of reliable and a little extra saucy. I tow my 32’ 7k+ TT with this setup no problems, super effortless….almost comical.

 

https://maine.craigslist.org/cto/d/dover-foxcroft-2018-toyota-tundra-turbo/7684136146.html

 

That's a steal for what has been done to the truck.

 

Oooh, the water pump and filter under the truck, are a nice touch!

 

So,,, this was never sold? He was opening a new shop so I think it is the same guy. He explained to me that since the turbo was mounted low they were having troubles with the pump for the oil. It would allow oil to get back to the turbo and on start up it would smoke something awful. He stated the ProSpeed was helping figure out how to solve the problem.

it has two gas tanks and three pumps. It took a lot to do all that and I am not surprised it took a year or more to finish the project. To me it just has way to much specialized pieces to make it a practical application.
It has the L480 trans and they had to machine an adapter to bolt up to the motor, then parts made to keep the shifter stock.

 

Anyone off hand know existing crankshaft pulley diameter? 6"?

 

Looks like 6.25"

 

I have 2 on the shelf but no decent caliper to get OD over lip and 6.25 as @armyoffoo sounds about right. You have to remove the oil sender for ASP and Prospeed needs a relocation nipple. Not sure if ASP has any in stock but they do have the smaller water pump pulley for $75. Also a 2013 highlander tensioner pulley is 1/4 inch smaller than the Tundra and will give an extra 1/8 inch to get belt on for TVS1900 owners. Other models shouldn't have an issue.

 

Right on thank you guys!

 

Ok... so, I've gone thru a full tank with the 77.5mm pulley.

my MPG has not changed. what kind of sorcery is this?

It just goes to show you if you don't aggravate the blower bypass, it matters not what size pulley you have....and consequentially, the duty cycle of the motor is unaffected.

and if you do aggravate the bypass, magic happens.

the only anomaly I've seen is the IAT delta....it used to be ~27 degrees (80mm pulley)...now it's ~29degrees.


Taking a road trip today (400 miles round trip) to see the kids @ school. I'm guessing I'll avg 18mpg for the whole trip. almost all hwy.

 

This thing has been passed around more than my ex.

 

So you’re saying this 77.5 is just for sea level stuff and I need to go to ‘stage 5k’ and get the 65mm pulley on at my 10,000ft? Absolutely reckless recommendation I love it

As I was driving my kid to school last Monday and hit -25° for a part I was reminded how important temp is when relating to air density.

When in the 5,000ft range like quite a few of us on here hang on a 20° day the air density is the same as others at sea level with 95° moist air. Same with -10°@5,000ft and 69°@sealevel. So our best days are on par with their worst case or normal conditions.

My question is if it was properly tuned for a much smaller pulley at high altitude and temporarily went to sea level with really cold temps would paying careful attention to throttle input, aka no WOT, keep the truck in a safe place?

Seems like if you lived in a place that rarely got below 60° it could also warrant a small bump down in pulley size?

 

my layman's view is = the MAF should account for most of this density variation and adjust the tune accordingly?

my truck is acting fine. however; if I get into it, it will shit & get. I'm quite sure I could break something if I drove deep into the pedal.

but as of now, this smaller pulley is ideal. as long as I drive "relatively" sane. it appears the tune/MAF are doing the job.

 

since we don't have a map sensor, is there a way to set up a boost cut with HPtuner? Just in case, for example, you put the small pulley on then drive down the hill and "accidently" floor it?

 

I discovered this last year, they would be willing to make an adapter to fit your application I’m sure. It’s expensive, but would accomplish the boost limiting goal. https://www.tundras.com/threads/general-supercharger-thread.85513/page-124#post-2949126

 

Are you a fellow pirate/irate retard?

Completely agree, it's really a density function.

You could keep it in a safe place, but you'd have to think about it. In my experience the truck ends up making boost a lot faster, so you might end up making more boost than you're comfortable with before power enrichment kicks in, and when PE kicks in you're making significantly more than you're accustomed to. So there's a few factors to account for, premature boost effectively and more boost overall. It's certainly workable, I actually found that downshifting was the easiest way to control boost because the shift points are kind of screwed up for what you want since you're limited to such a low throttle. If you downshift then you need less boost since the engine is making more power revved up a bit, so kind of ironically lower gears and manually shifting it keeps the boost from getting high. That's my experience driving down to Las Vegas since I'm too lazy to swap the pulley usually.

As for the tune, I haven't noticed a significant issue going to lower elevation. Since the MAF is just reading raw airflow it doesn't really care or know how the blower is performing. The real issue is knock retard starts to increase I've found just due to the fact of more airflow at lower load than normal, and then the aforementioned delay of power enrichment from what you'd otherwise use. Now if you tune for a small pulley at low elevation, I've noticed no issue whatsoever going to higher elevation, with knock feedback decreasing and then premature over fueling from PE since the truck hasn't entered boost yet.

Not that I'm aware of, since boost is effectively slaved to TPS. Boost sensors can output a boost cut that you could use to control something, like the electronic actuator @Silver17 posted or some other methodology.

 

That's a pretty cool idea.

 

Without the whine and more (turbo) sucking?

 

Discount code: 5OffWBDyno

 

Yes! Putting on a smaller pulley is the equivalent of fitting a smaller exhaust housing on the turbo. Limiting the max boost like mentioned and referenced is the equivalent of a wastegate on a turbo thats hitting max boost too early and kind of what I’m thinking. Regardless of altitude could be really cool if setup properly.
It’s possible that it’s my specific combo of 37” tires, 3.3 diffs, 8-speed making me want more boost and torque lower in the rpm band.

Looking at the sizes and what IIRC @snivilous said they make at altitude. Probably goofed, but thought it was half.
Pulley - psi - high altitude psi
85 - 7 - 3.5
80 - 9 - 4.5
77.5 - 10 - 5
75 - 11 - 5.5
70 - 13 - 6.5
65 - 15 - 7.5

A 65mm pulley and a wastegate set at 10-11 psi looks cool for my setup but would that be ridiculous at sea level for most people? My experience is more with turbos and diesels so learning about blowers and gassers.

 

How early does the boost come in?

edit: I realize boost is linear but what rpm do you feel it in the seat of the pants dyno...

 

Depends on the pulley, smaller pulley would build boost at lower RPM, not sure on the break over points

 

I don't have @snivilous email to me but he was explaining with my setup, at sea level, was making 4 to 5 psi much lower in RPM range and had to have PE come in alot earlier.

 

We have similar setups except for the SC. Are you also building psi earlier on or is the larger Harrop keep it in higher RPM range? I'd imagine so since the 1900 is a lot smaller.

 

I haven't put on the 77.5 pulley yet, I figured I would need to get my tune updated when I do, so that PE can be adjusted.