General Supercharger Thread

Well... Now I'm more confused than ever as far as if I should do headers or not. I'm in no rush being that I'm still waiting for parts from ProSpeed anyway.

 

do it.

they look better.

 

Makes quick take off during corner much more stable, no more inner tire try to do chirping, AND it makes snow driving better (don't think you get same amount of snow down in TX as we do up here)

it pulls like a wild ape with gears and s/c, even during normal driving everything feels so effortless, it's actually more relaxing to drive.

when in doubt, do it, it makes the truck sound really good.

 

Just got done installing my Harrop yesterday and went right to the stage 2. Huge difference in the power, acceleration and has given me plenty of smiles so far.

Next mod is the ProSpeed Air Box.

 

I asked them why the disclaimer about the plugs and coils. This was the response:

“Thats a generic line that we put on all cars that have added forced induction. I confirmed with the tuner that there was no cause for concern with your current setup.”

So just a little CYA.

 

I may have to hit that shop up for some dyno runs once my stage 2 tune is dialed in, it would be cool just to have some numbers. Are they a very busy shop? The couple places closer to me are all too busy to just do some runs without also tuning it. Also, are you on stock sized tires?

 

assuming you have a stock inlet 3.5"?

I am interested in your numbers for stage 2.

I was told I am maxed out on my MAF @ 477/517.



see...there's that damn 4.5" inlet calling my name.

 

Yes stock intake with an AFE dryflow. It will be interesting to see if DAP comments on maxing out the MAF voltage. I mentioned it on emails previously and he didn’t comment on having issues before, only that the stock intake with an SABM works better than any aftermarket cold air intake. I’m curious though if he has mainly tuned Magnusons with the larger magnuson intake or if the Harrops he tuned all had an aftermarket intake. Guess we will find out. I can actually view the voltage with the HPtuners software while I’m doing data logs but haven’t done any full throttle pulls yet to view it under that scenario. Once he gives me the instruction to data log a WOT pull maybe I can keep an eye on that.

 

I plan to go back there just for dyno runs once I put the 80mm and injectors in and remote tune with HP.

Yes, it seems they are a busy shop but they said now is a slower time of year for them. I placed my order, they got the charger in a couple weeks and I was installed about a week or 2 after that. I find that turnaround time very reasonable.

I’m not on stock tires. Mine are 295-70-18 which is roughly 2” taller than stockers. They are Toyo AT3 on TRD Pro forged rims so while being heavier than stock, it’s not a 100 pound setup.

 

That’s probably just a touch bigger than my 295/70r17s. Mine are a total of 91 lbs per tire/wheel with the method 314s and the grabber X3 tires. Shouldn’t be terribly far off from your setup. I’ll have to give R/T a call and see what they say about some Dyno pulls. I just did some 60 and 70% throttle data logs. At about 67% throttle I was at 4.73 volts on the MAF and around 7psi. It’s gonna be close!

 

My wheel and tire comes out to 89 pounds, roughly 34.3” tall.
I’m not sure if the overall height or the weight, or both lower the dyno numbers.

What voltage does the MAF max out at?

 

question for the hive:

So i have an issue My MAF is supposedly maxed @ stage 2 (80mm) - stock air inlet.

question...

What is the biggest Hp/Tq numbers y'all have gotten with a stock airbox/inlet?


and/or...what's the air math for reaching the 5volts?

 

I had an interesting conversation yesterday with my tuner. As it turns out there is ways around the MAF voltage ceiling and it doesn’t really matter. Basically he said even a lot of trucks with the magnuson kit reach that 5volt max. He says it doesn’t even matter because it doesn’t look at MAF in open loop > full throttle and close to it. The only issue is that it can give the P0101 code, which just gets disabled in the tune. He said many of the Toyota TRD tunes actually also disable the P0101. Essentially it’s a non issue. As for the intake in his testing it doesn’t sound like there is anything to be gained going to a 4.5” intake. It bottle necks back down anyway at the supercharger inlet. Per his testing the stock intake actually has better thermal properties than a particular 4.5” intake out there which lead to about 40 degrees cooler intake air and more power. He was not bashing any other companies, but laying out what he has found in tuning over 1000 tundras.

 

so, what Hp/Tq numbers are possible? stock intake/inlet.

and...if the MAF maxes out the 5 volts...does the tune "leave the map" and rely on the open loop? then, what parameters are being used to keep the motor together?

what if I hit 5 volts before WOT?

not arguing....just try to put the pieces together.

I'm going down this rabbit hole to make sure my tuner knows what is what.

like how am I limited to 477/517? did he limit something in the tune? is that possible?

 

I can’t say that I know, but I’ve seen trucks with the Harrop stage 2 put down over 500whp on the stock intake. The Harrop truck was like 517whp, and I saw another one make over 530. So it must just vary truck by truck. Some trucks also never even hit that ceiling for whatever reason. I’m also probably oversimplifying and misrepresenting what he was explaining so I won’t bother trying any further lol. I don’t want to make it sound like he said anything he didn’t say. It’s mostly over my head.

 

I too am curious how your power is “limited” @nobodyintexas. Did he actually tell you it’s limited at that because of the MAF? If so what does he do in the tune to hold back the airflow through the MAF to below the 5v max? What control does a tuner have over the airflow through the intake other than lowering the max the throttle body will open to allow flow? The supercharger doesn’t give a crap, it just wants to move all the air the throttle body will let it. Unless the intake timing limits it? Man, I wish I knew things lol.

 

we are thinking the same now...

yes..he said I am maxed out because of the MAF voltage. I would need to make big changes to my air inlet stuff to get more power.

which is fine if true...

but I see some of you guys (Harrop included) throwing out bigger numbers than my 477/517.

I'm not bitchin' (yet)

I just can't get my head around it.

I'm thinking the only thing with a limit is this tuner's ability to work around the MAF.

or he is correct & is using my guidance on building a SAFE tune.

now, how he can make an 80mm tune stay under 5 volts is beyond my pay grade.

the blower is gonna simply move more air into the motor. it's all it knows to do. a tuner is certainly not limiting air flow.

the blower moves X amount of air...it's the tunes job to make the correct AFR & timing crap happen.

@ViktorG or @snivilous educate us a tad.

I think I have some horses left in my tune.



I'm bored stiff dealing with our auditors....so, my questions are flowing.

 

One thing I’d keep in mind though is not all dynos read the same. Your tuners Dyno may just read lower which is why they always do a baseline run and then look at the delta. Your truck would probably hit 500whp on some other dynos. Didn’t you pick up at least 40-50hp from stage 1 untuned to stage 2 tuned? That’s pretty much on par with what you should expect.

 

I think so.

n/a base was ~287/328? mustang dyno

untuned stage 1 405/433 mustang dyno

untuned stage 1 418/440 dynocom

tuned stage 1 453/486 dynocom

tuned stage 2 477/518 dynocom



see how stage 2 hp didn't grow much....






and the Tesla took 2 hours to fix. bad A/C connection. wife is off my back now...

 

I think @snivilous or someone else addressed it earlier. MAF plays a role in adjusting fuel based on what is going in to the engine but it doesn't have a high level of fidelity within certain ranges. ECU also adjusts fuel based on what is leaving the exhaust; I don't remember what it is called at the moment.

 

that's supports my theory that the MAF ain't the issue. I would guess at WOT it better be using AFR as the metric to adjust fuel/timing.

 

Looks like the gains are on par with what DAP told me. He said 40-50hp gain just from tuning the 85mm with bigger injectors, and the smaller pulley is good for an extra 20-30hp on top of that. Basically expect a delta of 60-80hp going from untuned stage 1 to tuned stage 2 which looks like what you got.

 

Aside from engine/transmission getting up to temp, loosely speaking closed-loop is steady state and light to medium throttle, switches to open-loop medium/full throttle so maybe the MAF doesn’t matter? Not every tuning platform can disable codes, maybe your at the limit of throwing the P0101 with the tuning platform?

 

I appreciate the patience/civility from y'all.

good discussions.

I have no complaints with the truck. it's a beast.

it's like a diamond...the longer you have it, the smaller it gets.

 

I agree.

I can watch open/closed loop on my scanguage. and I agree, AFR & timing do a dance when it goes open.

I think you are onto something.

 

or...it may be as @snivilous so gracefully pointed out.

I am not putting the spurs into it hard enough.

 

Take what I say with a grain of salt, Victor knows far more than I

I guess this makes some sense. My understanding is the MAF is only taking readings during closed loop (cruising) and actively adjusting the fuel based on the airflow (voltage) and AFR it's seeing since it wants to maintain stoichiometric. Once power enrichment happens (open loop) which is based on throttle angle, the truck "blindly" dumps fuel based on rpm and a multiplier of stoichimetric. Power enrichment is based off throttle angle and rpm, so once it's enabled (throttle angle) it appears to look at the engine rpm and open the injectors longer to richen the truck out to a prescribed value. However, it doesn't actually know how far it's richening it since as we know the stock AFR sensors don't read very rich, so the truck seems to dump more fuel (a specific amount) but it's not aware of what AFR that's achieving. That makes me think the MAF isn't doing much at that point, because without the AFR sensor then knowing airflow doesn't help anything since you're missing half the variables to calculate fuel (and we know fuel is blindly and dumbly controlled in power enrichment).

This also goes inline with what I've read and done in the past: the MAF voltage gets tuned, and then power enrichment gets tuned. The MAF is not being tuned at higher throttle levels, it's (relatively) in the weeds where it matters which is cruising. So it seems logical then, that you can "work around" the MAF voltage, since if it maxes out right when you hit power enrichment then it doesn't really matter since it's no longer being utilized. You end up blowing the code for the MAF out of bounds, but I'm sure as most of us know that code doesn't seem to do anything either and can be reset on the fly (with that said, I've never heard of or seen evidence of being able to disable that code).

With all that said... that's assuming the MAF is completely unutilized once power enrichment happens, which I find hard to believe. What is power enrichment multiplying? There has to be a fuel map that it's multiplying and it seems like you need the MAF to tell you how much fuel you need for stoichimetric, and now you multiply that level... so you're still taking input from the MAF to get that base fueling that power enrichment now works off of. Unless there's some other fuel map that has nothing to do with the MAF and just gets multiplied, which seems like a dumb way to do it when you still have plenty of sensors giving feedback. It also seems wrong to me that you can just disable (or ignore) the MAF code just because you've entered power enrichment. If that was fine, why didn't Toyota make it so when power enrichment is activated the MAF is "turned off" and doesn't blow a code? Why make the MAF reading all the time if it doesn't matter? Why make it have a range that extends into the airflow regime where power enrichment is happening? Seems like a lot of shit could be simplified by saying "power enrichment active, ignore the MAF and if it goes out of bounds we don't care" but that's not what Toyota did. You could argue "PE/WOT is where you're most likely to find an issue in the system since that's under the highest stresses, so that's why the MAF is being monitored and can blow a code" but I have a hard time buying that...

Long post as usual, nothing to conclude, trust your tuner I guess?

 

I, for one, appreciate your long posts. Even if that means I have to run to get a second cup of coffee to make it through them And as usual, here's another useless non-contributing post from me!

 

Hahaha I appreciate it! I'm known among my friends for writing really long messages. And I'm like bro, if you don't want a thorough answer to your question, don't ask! Posts like that is what helps people learn instead of a simple one liner, and no point holding information back when some random little nugget is what they've been needing to find and can help them move forward.

 

appreciate your thoughts & questions.

We are on the same page. You have validated my quandaries.

and it helps to see it written & realize what I still don't know.

all of these variable are inter-related & when i'm told they are not, I glitch. your ideas about the MAF being ignored are dead on. it can't be ignored - it takes away too much of the equation and it no longer balances.

I wish I could sit in front of the dyno info and see every variable available. This would help me understand - i think.