General Supercharger Thread

I believe he is running the OE Box, 3.5 if not mistaken

 

Yup

 

Just to share something stupid I just did. I switched to the maggy box and 75mm pulley. And my tuner wanted me to get the AEM wideband so I can log it in HPt. I had the Innovative Motorsports one already and when I put the new one on, I put that little plastic cap on the IM wideband and just zip tied it down there because that’s the one I was going to keep in there after I’m finished logging….. I forgot they heat up and it melted the cap on the sensor

 

I bet you can save it, maybe propane torch the sensor so the plastic can melt all the way off? assuming there's some stuck in the sensor ports.

 

That’s a good idea… I can probably cut the zip tie and let it hang and see if it’ll drip out. I’m going to go try rn.

 

For anyone running the Innovate Motorsports PSB-1 A/F & Boost gauge, there's a Custom Offset for Altitude Compensation. Unless you're already aware of this and you've changed it, yours is likely set to default (@snivilous) .

With the engine OFF and the key in RUN (or so the gauge is powered on depending upon how you've wired it), press and hold the LEFT button until whatever's in the display changes to BOOST CUT PRESS (for turbo applications, so nonapplicable for our use).

You're now in a menu that allows you to make some custom settings. Press the LEFT button again to scroll to ALTITUDE COMP (AC). If you pass it, keep scrolling until you make the loop of options or press the other button to go back. Beneath AC it probably says DEFAULT OFFSET 0kPa.

Press and hold the LEFT button until DEFAULT OFFSET begins to flash. Using either button you can now toggle between DEFAULT OFFSET and CUSTOM OFFSET. As far as I've been able to determine, CUSTOM OFFSET will automatically set to whatever your present elevations air pressure is relative to sea level or relative to whatever the default offset is set to I suppose. That will become your new ZERO (0) boost pressure reference point.

While either of these choices are flashing, you can continue to toggle between them. If you don't toggle for 15 seconds, the device will time out and "set" to whichever setting was flashing in the display (If you don't want to wait, you can set it by pressing both buttons at the same time. Good luck with that, I was never able to get it timed right).

After 15 seconds the gauge will revert to whatever you have it set to for normal driving.

 

What's funny is I had no idea how to do any of that until literally this morning since I wanted to turn the O2 and Boost cut messages off, and then saw that setting in there I didn't adjust that yet though. It's awesome you can adjust everything through the buttons, I always thought you needed a laptop.

I don't really follow why or what the compensation does. Is it measuring absolute or relative pressure? Mine reads -5.5in with the truck off which matches for the altitude which makes it seem like absolute pressure measured, but then why do you need an altitude compensation? Plus that'd mean we're making absolutely insane boost. 8psi sea level equivalent at 5500ft? That seems wrong.

 

ideas to help this fella? https://www.tundras.com/threads/problems-installing-supercharger.114839/#post-2955203

 

If anyone has helpful input for him there is another thread he started that is getting more traction. May be better to consolidate answers to one place. https://www.tundras.com/threads/no-idle-stall-after-installing-supercharger.114840/#post-2955332

 

Okay, the only information about if it's reading in PSIA or PSIG is from a review about a different innovate product that is just a boost sensor, and one of the reviewers said that sensor measured in absolute pressure. Which makes sense for why you'd have altitude compensation, and why I'm seeing a "vacuum" ie less absolute pressure when the engine's off. So I could altitude compensate so it reads 0 with the truck off, which would mean I'm making more boost since everything would shift "up". So then you'd see an accurate boost number, though since I always convert to absolute pressure for a reference with a sea level truck, then not adjusting the compensation will give a raw number for what a sea level equivalent truck would see boost wise (and represent how much "stress" the engine is experiencing beyond stock power).

So for example, I'm at 12.0psia at my house. Today I measured 8psi, that's 8psi equivalent if I'm at sea level and really 10.7psi (14.7 - 12.0 + 8) that the supercharger is making. If you altitude compensated the sensor, it'd measure 10.7psi, but the actual stresses the engine is seeing is if it was at sea level at 8psi.

I'm going to call them to confirm this on Monday, but that's a huge deal if what I said is true! That means reading 0psi over Eisenhower is really like 5psi of boost that the supercharger is making.

 

Yep.

I thought of another way to think of this, not for any particular reason other than to try to simplify or condense the whole concept.

If you're 6ft tall from the bottom of your feet to the top of your head but stand in a three foot hole, you're still 6ft tall but only three feet above the ground. The altitude compensation allows us to decide if we're placing the end of our tape measure at the bottom of our feet, or from ground level. I set my tape measure to always measure from my feet no matter how deep the hole is, you elect to always take into consideration the depth of the hole and measure your height from ground level no matter the hole depth.

I think that we could say that my reference is relative and yours is absolute? (I'm only half way through my coffee.... but I think we're on the same wavelength...)

 

Yes sir, that's a perfect analogy!

 

So sounds like at your altitude your absolute pressure at the manifold with that 2” pulley is the same as my absolute pressure at the manifold closer to sea level with my 80mm pulley. That sounds about perfect at that elevation. Are you leery of coming down to sea level, or even 2500’ as that puppy will really be making some jam? I know you said some fuel upgrades are in the plans. I’m also wondering if some belt slip will reveal itself at lower altitudes and stop overboosting from being a concern anyway. If so you may benefit from one of those gates green fleetrunner belts.

 

@snivilous what belt did you end up using? Sounds like you didn't need any pulley wrap mod to make the 2" pulley work

 

Excuse another long post, but for anyone looking to downsize their pulley this has a lot of thoughts:

Exactly, and all of this makes a lot of sense: I'm close to maxing out the MAF and injectors since my manifold absolute pressure is now higher than a stock supercharger would be, and my dragy times are similar to you guys at sea level.

My current thoughts: the 2.0 pulley seems great for the mountains, probably 4000+ elevation it makes up for the altitude deficit and then some. If you live in Utah, Colorado, Wyoming, Idaho, or anywhere where you won't go under 4000ft I think it's awesome. I just so happen to live in the one corner where the altitude drops away, so at 2500ft it really becomes borderline. With the 2.35" pulley the boost seemed to scale with the altitude pressure which makes sense, so extending that math to the 2.0 pulley I'm making 10.7psi from the supercharger at 5500ft (8psi at sea level) so at 2500ft theoretically will make 12psi from the supercharger, which will effectively be ~10.7psi at sea level which is really getting up there. Drive down to sea level, and now we're talking 13psi of boost

Back to your question, i go down to 2500ft once a week on average, if I just don't go WOT it's totally safe. Even if I did WOT a few times, like my normal driving of interstate merging and stop lights, I think with an updated tune that's still relatively safe. If I lived at 2500ft, I'd upsize the pulley though. Since most of my life is at 5500ft or higher, the 2.0 has added a ton of pep and the engine at WOT is only stressed 1psi beyond a stock supercharger at sea level.

If I plan to drive into Nevada or California, I plan to swap the 2.0 for the 2.3 though. While I'm sure people can make a smaller pulley work down there (Viktor has proven that), that is beyond what I want to do. The alternative is prevent the bypass valve from closing, or don't go WOT, but for the latter the boost is coming on so early that it will make 6psi before it even gets enough throttle to want to shift so it becomes difficult to manage that much boost imo (ie prevent getting into high boost by controlling your foot).

In regards to fueling, I do think I'll bump to the 750s and the 4.5 intake. If I was strictly at 5500+ I'm on the limit but it seems safe, but I think if I get into it at 2500 it'll lean out, throw MAF codes, etc. So since I'm in the gray zone of lots of different boost levels in my radius of weekly travel, it'll be safer and more reliable to go with the larger setup.

And lastly about the belts, I looked at gates and dayco and anyone else I could find and none of them made a smaller belt that was in the size I wanted. I think the optimal for the 2.0 will be a 112.0 or little smaller belt, but the only belts I've been able to find are 110, and then jump to 112.4 (what I'm currently running, and what I recall the gates size was). Hopefully I'm wrong and find more options, but the flip side as you said is right now I don't seem to have belt slip and frankly if I do at lower elevation that's fine, and any other scenario is probably for someone else to solve

Might be worth starting a new thread about just pulley sizes to not clog this thread sorry everyone, that was a novel

 

So 2.30 pulley it is lol

 

The 2.3 should be about 9psi at sea level. So a POTENTIAL sea level break down:

2.0 - 13psi
2.1 - 11.6psi
2.2 - 10.3psi
2.3 - 9psi

 

@snivilous , with all your experience and science, when can we start making these optimized pulleys? 2.3" sounds right for me now as I'm at 4500-6000ft elevation all day long...until road trips to CA, WA, ID, etc...regardless, a new thread on just Pully sizes would be another incredible idea!

 

Started a thread for the Magnuson pulleys, if you have an interest at all check it out: https://www.tundras.com/threads/pulleys-for-magnuson-trd-supercharger.114871/

 

I richened the tune out yesterday, and as expected nothing happened and the injectors went to 100% duty cycle. So I just ordered the Prospeed 750cc injectors and their 4.5" intake!

I also called Innovate and they confirmed the sensor measures absolute pressure as we concluded.

 

Makes me happy to read as I'm getting the 4.5" intake and 750cc injectors installed with the Harrop next Monday. Glad it's worth the $$ it sounds like!

 

LMK if you would decide you’re interested in selling the Magnuson intake to recoup some cost once you swap it out. I may be interested, as I have no plans to put a smaller pulley on in the future.

 

Good thing you mentioned that, since I 100% plan to sell the Magnuson intake once I have the tuning for the Prospeed intake working correctly! I paid $260 new not including the filters (which I have both the K&N and the AFE) for reference, so around there minus a bit.

 

Nice! Just PM me when the time comes and we can figure it out.

 

Are you currently on 650s and a 450 fuel pump? I already ordered the 450 dw fuel pump, but have not yet ordered injectors.

 

Correct. I have the TRD greens which I thought were 650s, but Viktor has a video and they're actually 535cc, so the 750s are really a 40% flow increase. The 450 I think is fine for just about everything, the guy at Prospeed asked what pump I had and didn't question it. If you haven't ordered injectors I'd go straight to the 750s, I never data logged duty cycle with the TRD greens but I suspect they were approaching the 80% rule of thumb (or going over) even with the URD 2.35 pulley.

The intake I'd be fine with the Magnuson 4", but it's getting close to the limit so figured may as well bump it. Obviously the MAF hitting 5V isn't a huge deal, running out of injector IS a huge deal though.

 

You currently have 650cc injectors installed? They aren’t the Deatshwerks are they?

 

I corrected the post so it's more clear, I have the TRD green injectors which I thought were "650" but they're actually 535cc.

 

Straight to 750cc it is! I currently have the Stillen stage 2 intake which has something like a 5" opening tapering down to the 3.5" stock. Plan is to just cut part of the intake tube away and replace with a larger coupling. Then swap over to the AFE s/c intake once it's developed and released. Hopefully they offer it in the 4.5" tube

 

so, If I'm tracking correctly with all the smaller pulley talk...

keeping stock airbox & 3.5"inlet:
I could run a 75mm pulley (now=80mm), and I would be fine up until...say 5000 rpm or 5volt MAF...whichever came first. I'm sure there is some math involved to get a closer guesstimate than my 5000 rpms. I presently can hit 5 volts near 6k on a good dense humid day... I have hit it twice so far*.




or

just get a 75mm pulley & damn 4.5" inlet in the spring.



*as I think about this...I never hit the 5volts during my Dragy runs....y'all hold your disparaging comments please.