OVTune 3.5L Tacoma Supercharger and Twin Turbo Systems

Considering it’s not currently available to order - I’m gonna go with no

 

Yeah i figured it couldnt hurt to ask!

 

Maybe it will come out while the discount is going on

 

My plan(and should work after some quick measurements) is to install a second OEM Airbox where the battery sits. Main battery would just get relocated to the passenger side closest to firewall. It looks like I can just spin it 180° and drop the intake side down to the turbo. This way I can retain the OEM filters for both sides.[/QUOTE]

I am already moving my battery and would love this setup as well

 

I’ve been here for years and have never used the ignore feature. Your total lack of comprehension is enough for me to use it. It’s one thing to be a newbie and wanting to learn. It another to be.

 

? Not what I expected but certainly your right. It's regrettable, because I truly am trying to understand the assertions made. Perhaps my questions were poorly phrased and insufficiently direct... that's what comes from posting in airport terminals.

I'll do away with analogies as they are serving us poorly, they were what I was provided with and while I'm personally a fan of them, they sometimes fail us. Instead I'll use the fundamentals, and I assure you I have sufficient knowledge to comprehend the fundamentals of math and physics. Where I may have naiveté, or perhaps even ignorance, is on the specific measurement points, or assumptions others are familiar with but I am not.

This is the specific reference I'm having a hard time understanding:

"PSI is just a number... these turbos at 5psi are forcing far more air into the motor than the atmospheric pressure ever could, many times over."

This reference is implying that the cylinders are now filling with a mass of air 3 or more times the non-FI state.... perhaps MANY more times; i.e. 5, 7,10? He didn't say twice, or even thrice, but specifically said many times over. I was guided to some relevant threads, which I read. They are decent discussions on the relative merits between small/large, and single vs. double, and of course some of the inefficiencies inherent to the process. Even some discussion on back pressure effects. But neither of them answered my question.

I'll ignore the following for their real but small effects:
Real Gas Law concerns for heated air
Deviations from sea level standard air
Inefficiencies of supply air induction
Turbulent air flow at intake/exhaust ports
Dynamic air pressure differentials because of flow
Volumetric efficiencies
Any other inefficiencies caused by turbos, or things constant across turbo sizes

I'm now left with a simple static system where I can assume a turbo increases manifold pressure above ambient by a known value. I've always assumed that when a tuner references lbs of boost, he's talking about a number taken at a point relevant to the intake valves. And perhaps that's my mistake. Referencing lbs of boost specific to a turbo's port means we have to use rules of thumbs, or industry norms, or some other conversion to our specific use. And maybe that's the way it's done... all tuners reference lbs of boost so everyone can understand how hard the turbos are working, or how capable they are compared to other turbos, e.g. it's a comparative value between turbos.

Simple math tells me that it takes 14.7 PSI of boost to double the usable O2 on each cycle. I'm simplifying of course, and exhaust gas partial pressures and all the exclusions above modify this conclusion. But those are second or third order effects. Caveat: unless exhaust gas residual is a significant partial pressure, which I don't think it is.

I truly thought I had a fundamental understanding of forced induction (while necessarily glossing over some of the nuances of design efficiency and performance). If I'm this far off, and a 5PSI boost is more than tripling the amount of usable O2, then this is an eye-opener for me and I clearly don't understand fundamental turbo mechanics, or worse, my math and physics fundamentals are poorly retained.

So my question still stands: At 5PSI of boost, what is the ratio of usable mass of air in each cylinder compared to non-FI?

 

Ok, bye!

 

Wow

 

Went sideways a little, I’ll own it if my original posts were off tempo, wrong, or simply came off as an ass. It certainly wasn’t my intent. I was just trying to get clarification. If manifolds are under an imperfect vacuum, ie @ 10 PSI, then the efficiency goes up faster than the earlier math assumptions. 6 lbs would be 60% increase.

Perhaps it’s best to let this tangent die as its contribution to the thread isn’t productive at the moment.

 

Ya'll can keep arguing while I zoom past with my whistle tips.

 

Are you up running on the twins?

 

negative

 

Dam was hoping you had a jump on us all.

 

Yeah we all chomping at the bit for any crumbs OV wants to throw out videos, dyno numbers, expected timeline... anything no big rush but my birthday is coming up

 

I've been bouncing back and forth between finishing 2.0 and tuning fueling for our truck.

We will definitely be developing a better High pressure cam pump.
Stock one just sucks even splitting injection when you're pushing high boost 18+psi.

The direct injectors have no issue.
This explains why both the 2URGSE and the V35A use dual high pressure pumps.

This pump doesn't even look to be "scaled" for engine size. Toyota just made "a" pump and threw it on everything. (Could be wrong, hard to really find info)

I'll be ripping one apart next week to start design on ours. Unfortunately they look to be sealed units so upgraded "internals" is likely not an option.


My birthday is also soon

 

So quick question about the tune and larger tires... Does it make any correction for tire size in any way? I have 33s and an using the hypertech

 

No

 

Uncalled for, the both of you. Rush is just trying to understand, and it very well may be true, but I was also curious about why 5psi was equivalent to a many times over atmospheric pressure.

Keep in mind that not everyone on this forum knows everything like you guys do, it’d would be more helpful to explain than to look down upon.

 

Turbocharger pressure (boost) is any pressure measured above current atmospheric.
So let's say you're at sea level, and you floor your truck. The intake manifold now has sea level air pressure inside (around 14.7 psi)
Then, any pressure higher, is "boost"
And boost psi is total pressure minus atmospheric.

So, 5psi is 19.7psi total ( if you're measuring from complete vacuum).

But, if you're trying to use pressure to calculate power, you can't, because it's pressure and CFM at that pressure.


I know in your mind you think, well 5psi is 5psi. But there is variance in density at that psi, for one. (Temp)

Also, the hard concept to think here is that the pressure measured is a measurement of what the engine is NOT getting. (Because if the engine was consuming 100 percent of all flow, there would be total vacuum).

Boost psi is only part of the equation. The exhaust makes a big part of it. You can take the same turbo, change the outside to larger (lowering exhaust restriction) and make more power.
Because now the engine is able to consume and expel more air.

In this case you actually see boost DROP and power rise. (Think, how much boost do you get if engine is consuming 100 percent of given air? None!. But you're making a shit ton of power if it's consuming 100 percent of what the turbo is giving it, you'll also surge and blow up well before that but anyways)
That's how "adding a downpipe or full exhaust) can make huge power differences on turbo engines.


A concept that goes against the internet "I'm running 10 psi bro" mentality lol.

 

Think of this to wrap your head around...
There are exhaust setups out there that use genius scavenging techniques to fill cylinders with more than 100 percent cylinder full, with no turbos or supercharger.
Because flow out controls flow in.

I actually helped design a Miata header on the ND that produced world record HP results using this conception.

now, our turbo kit uses 2.25 inch downpipe mated to stock Y pipe, stock exhaust, stock secondary cats.

How much the tacoma can make with a full, larger exhaust will be significantly more on the same "boost."
Why? Because the engine is consuming more air, and to maintain the same psi, the turbo must spin faster, forcing more air into the manifold. The engine is "eating more" so pressure will go down unless the turbo spins faster providing more air to meet that desired "boost"
And the engine is getting more air all the while... because more exhaust is getting out.

There is actually pressure in the exhaust, a lot.

This is why you hear about turbos "running out of steam" in high rpm. But...they are still making boost? How can it be out of steam. You can see 15 psi at 7000 rpm and power dropping. Why? Because the hot side of the turbo is restricting flow out. As flow out is restricted, flow in is restricted, and the turbo can maintain pressure with less air, because the engine can't "eat it" because it's now constipated. Now throw a big hot side on the turbo, and you just gave it a laxative. But with that laxative comes a con. Turbo lag.
That's why big turbos make huge power but have shit spool. The outside must accommodate all flow OUT.



Trying to explain in easy to understand terms.

Sorry my phone is autocorrect hot side to outside.

It also gets way more complex with compressor maps, compressor sizing to exhaust, etc etc. But this is generally how it works.

So you think, I'll just put a bigger hot side on a small turbo. Not so fast. Are you sure that tiny compressor can now flow enough? (Yes, if your boost is super low...But you want power!). So you crank it up to 20psi, with all this additional flow that tiny compressor is spinning way outside its efficiency and likely past mechanical limits and will break the shaft. (Hello K04 mazdaspeeds!)