General Supercharger Thread

I’m just saying, maybe it is related to the MAF of TB harness and not your fueling at all. I’m still suspect of mine but haven’t tried swapping them yet to new ones. It didn’t happen to me for a while.

 

I’m not using the TB harness adapter. I took mine out after it kept throwing that code. Since I was able to make it reach I’ve just kept it like that. Hopefully if Amazon drops the last package off in time I can try it again and have an update. hopefully the regulator is the solution.

Even if I had to just shift every gear at 5500 I would do it. The normal drivability is really nice with the 75mm

 

The IAT breakout loom/MAF connector would be the more likely culprit actually. So what Is your current fuel pressure regulator situation? Do you have the modified FPR that came in the kit installed, and is it boost referenced? What is the Amazon package you’re waiting on?

 

Ya I just have the FPR that came with the kit. I ordered the evil energy 6AN FPR,lines, and fittings

I also ordered plugs because i think I’m about at 15k miles on these ones.

 

I’d be hesitant to use an aftermarket FPR because they usually bleed down the fuel pressure when the truck is off. The stock fuel system maintains pressure after shut down so there is always pressure on the lines for startup. An aftermarket FPR could lead to extended crank times at startup while you wait for pressure to build, pretty sure the tundra fuel pump only gets power once the starter is cranking. Prospeed actually makes a jumper of sorts for use with aftermarket FPRs to energize the pump in the ON position of the ignition, but then if you get in an accident and the fuel system has a rupture somewhere, the pump can keep running and pumping all of the fuel out of your tank which is hazardous.

 

Is it weird that I'm really excited for this to be tuned?! Haha the combination of 'happy bits" is amazing!!

 

This. You effectively have to calculate gear and its specific ratio vs rpm to determine what speed you'll shift at, and then adjust so your result is below your fuel cutoff limiter.

Not to mention Toyota's implementing of their fuel cutoff results in dead pedal weirdness until the tach falls to a pre-determined level

 

Is it some type of check valve in the rail or return line? I hadn’t of that issue.

 

I personally don’t know the design difference that the stock one holds pressure and the aftermarkets dont. It’s the FPR itself not an external check, so there must be a check in the factory FPR.

So I did some digging up of old posts by the very knowledgeable Matt Smith on Facebook. Just for you! Here is some pertinent info on FPRs:

Factory FPR without boost reference - 43psi at all times.

Modified Harrop provided FPR with boost reference - 33psi at idle and in full boost will be about 50psi.

OEM FPR supplied for an FFV truck with boost reference - 46 psi at idle and about 60 psi at full boost.

OEM FPR supplied for an FFV truck without boost reference - 50psi at all times.

On a stage 2 Harrop with a 450lph, He hooked up factory fuel rails in parallel with a factory FFV regulator on each rail and the tuner said it had TOO MUCH fuel being boost referenced, and actually had to tune it without boost reference to cut back on the fuel a bit. Here are pictures he posted for reference.

If anything I’d try doing that if I were you. Order 2 OEM FFV regulators and figure out how to pipe it all together in parallel.

 

Good to know about the boost reference could possibly be too much.

 

Indirectly explains the new conrods:
https://youtu.be/C_YNn3ZkJmU

 

Anyone know if he ran it factory into the bucket and measured ? I'd like to see it.

You're not getting more fuel hooking it up like this but you are getting better pressure (consistant) at each injector, thats a good thing. Keeps the last injector from getting starved for fuel. The limiting factor would be the injector itself.

 

Viktor told me you just run the boost pressure line to the regulator and now it's boost referenced. I haven't done that but plan to. Not sure how much of an increase that gives.

 

Did the 750s come with the injector data for tuning?

 

On sale if anyone needs one.

AEM 30-4406 -30-35 PSI Boost Gauge

$153 AEM 30-4406 -30-35 PSI Boost Gauge

https://www.amazon.com/dp/B001DX7KMY

 

No sir.

 

@4firemandan I saw on the Toyota Repository thread you talked about scaling the injector constant and inv constant for your 650 injectors, did that end up working for you?

 

Mine came with a flow test sheet

 

But it doesn't give injector constants and shit like that?

 

Ignorant question incoming:

If the passenger side fuel rail tends to run lean, would it make any difference at all to put the higher flow tested injectors on that side and the lower ones on the driver's? Even though they're only like a few cc apart

 

I don't think it'd make any difference. The pressure loss will happen regardless since those injectors are down stream.

Maybe those injectors would unintentionally try to flow a bit more, so I guess it couldn't hurt but waste of time imo.

 

Not an ignorant question, but with setups like this where one bank runs leaner, it is *typically* not a deficiency with the injectors but with the rail design.

On the 3GTacoma for example, the passenger side runs lean because the port injection fuel rail system is less capable than the DI side of the fueling system, and it runs in sequence from front driver (cyl 2) to the back and then around to the front on the passenger side (cyl 1). The result is 2-4-6-5-3-1. As you hit each subsequent injector/cylinder, you observe pressure loss as fuel is provided to that injector and then continues on.

The same exact motor in the Lexus utilizes a dual pump system and feeds equally, and suffers no pressure loss or fueling deficiencies.

 

This

 

My 650s came with this. So the Prospeed injectors are really 725s basically?

 

I was thinking the same thing when I saw the different flow values.

 

My injectors are sitting at home so tonight I'll look at them and HPT. From reading it looks like the injector constant is something you just scale based on the injector flow, and then there's the battery offset which is the charts you guys posted. Hopefully just linearly scaling is all that's needed to make the injectors run correctly out of the box.

 

allright...changed my Wix filter.

no sweat, right?

well, I broke the rear tab that holds the lid in place. it still works, but is now quite sketch.

this is more than adequate reason to move to a new airbox, right?

 

The only question is, which one?

 

'zactly.

my quandary is which would be the least trouble.

What could I get away with without re-tuning?