Totaled Tacoma - Rebuild in Process!

I don't know much about forced induction, but to me this bypass valve is not working as intended. I took a video showing how it only opens for a second under heavy throttle, even if you stay in the throttle. And it won't open at all under light throttle.

Also, it does not make the super charger wine. Every other video on YouTube, the whine is very loud when revving at idle. The only time I hear the super charger whine is in 3rd gear under load. No other gear makes the whine.

https://youtu.be/gcd9W_fyCgo?si=wajdaxFZXNJQAMkR

Anyone else have any opinions? The truck is back at the shop again as well.

 

Have you confirmed your findings with a boost gauge? Looks like it’s working properly in your video. There is no engine load in idle, so it would be very difficult to build boost to see the bypass open for long periods of time.

 

I understand there is no load on idle and the valve should be open in that case, however, the valve closes and then opens immediatly even when the throttle is still open and the engine is at high RPM.

Shouldn't it stay open until you release the throttle and the engine goes back to idle?

Edit: The shop will be hooking up a boost gauge to check if boost is being made.

 

Since manifold pressure is proportional to engine load, you cannot build manifold pressure (to hold that bypass closed) reving the engine with no load.

I changed from the MP62 to the 1320 supercharger, and these newer chargers build boost earlier and more effortlessly(obviously design) and are not as loud as the older MP62 units. I prefer the 1320 units as it seems to build power at lower rpms.

 

Thank you. Did not know that about manifold pressure.

Still odd that you can't hear it at all revving it from the engine bay, while every other video on YouTube of the new tvs1320 you can clearly hear the whine.

Also, it's only audible in gears 1-3, with 3rd gear being the loudest by far (1st and 2nd are more of a whisper). 4th and 5th have zero whine, and the truck feels like an old dog below 3k rpm in any gear, so there is no low rpm improvement being felt. There is also still the fact that I can hear a lot of escaping air/wooshing sound when on throttle and accelerating.

The shop has checked for vacuum leaks so far today and found nothing. They did a smoke test as well.

They have emailed Gadget at URD for advice and will be hooking up the boost gauges for a test drive later to see if boost is even being made.

 

Have you considered using a standalone ECU?

What you are describing seems to be similar to my experience with the URD 7th injector. I was never able to get the URD 7th running properly even after countless hours of “tuning”. Going to a Haltech standalone is one the best mods I have done to date.

 

I did look into the Haltech you mentioned earlier, seems a bit over the top for what I need right now. Plus, I have to hold off on large purchases for the next month until I close on my new home (hoping final build inspection happens the last week of June).

The shop owner has done 2 previous installs of this supercharger from URD, including on one of his personal vehicles, and he did not run into any issues with those.

The only thing new with my install is the use of the 7th injector kit. His best guess right now is something with the tuning box may be wrong (or possibly the wireing plugs for the box), and he is hoping Gadget can shed some light on what to check.

I did read on another thread someone saying the tuning box couldn't read the engine RPMs, but that was on an older 1996 Tacoma, and that URD said it should not effect newer Tacomas.

But we'll keep investigating. I'll continue to use this thread to post my thoughts. If I say something that makes no sense or sounds dumb, let me know, I'm not the most knowledgeable when it comes to engines or tuning.

 

Almost 1 year to the day that I ordered the Yota1 rebuilt 5VZ she's in and purring. It's amazing how much less NVH there is with the rebuilt.

I don't know if there's a way to find out the exact core I have, but I'd like to think it's yours, thanks!

 

That is awesome! Looks great.

I don't know how easy it is to see, but a Google search shows someone mentioning the VIN being rivited on the driver's side of the engine block.

 

Haha, you're going to love this.

The shop owner met some Magnuson engineers at an offroading event he went to recently and called one of them for help.

They said to get rid of the 7th injector kit, lol. They said when it works, it works well. The problem seems to be getting it to work correctly, it's a pain to dial in.

We are still going to see what URD/Gadget says first before deciding what to do next. We do have a way of disabling the 7th injector and cutting power to the tuning box to basically test how things run without the 7th injector kit. I'm curious to see if it makes more boost with the 7th injector kit disabled.


The shop did hook up some boost gauges and found out the engine is under-boosted, making only about 3psi under WOT. He did say it does not fluctuate/flutter, and that it stays at a constant 3psi, but it should be in the 6-7psi range according to the magnuson engineer with the stock pulley size.

So right now we think it's probably something with the tuning box. We will wait to see what URD/Gadget recommend.

Edit: Forgot to mention the shop owner also put a go pro under the hood and saw that the bypass valve was working as intended and fully closing under throttle.

 

The Magnusson engineer said the TVS1320 is supposed to get 6-7 psi? I think the engineer may have mispoken there and confused it to the MP62 units.
I believe the TVS1320 units are 4.5-5lbs of boost on the stock pulley consistent with what I have seen. Keep in mind that at 1lbs of boost, the TVS1320 pushes more volume of air than the MP62. This is why the TVS1320 @ 4.5-5.0psi and the MP62 @ 6.5psi make the same amount of horsepower.

Anyways, I'm not suprised Magnusson isn't a fan of the URD kit. The problem with the URD kit is that the stock ECU is always trying to work against the changes that the URD 7th controller makes, so it is difficult to have consistent performance with that system, and I spent so many years messing with it. I'm just glad I jumped on the Haltech as soon as it was avaible for the 5VZ, and didn't waste any more time. Really felt like the Haltech (proper fueling and ignition) added another 50 HP to my already supercharged engine. It is that drastic!
Anyways, I'd check to see that you don't have any boost leaks in the vacuum/boost lines, or the gasketed mating sufaces of the lower intake plenum.