Topgunz full supercharger kits!!

"Z"en

Sounds like a plan. Keep us posted if possible. I'd still suggest you have an EGT gauge and sensor installed. Will help you keep your engine and exhaust in check under WOT.

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610whp/462wtq A2A- 6.8s@100-200km (stock motor) / IG: minized123456 / 淬 Custom VQ Vortech-based supercharger parts made to order! https://www.instagram.com/p/CFUjDc5H...d=m0unws28pvk4

Senna-F1

So we decided to upload tune anyway to see if it would get rid of these codes, and it did. Just FYI for future searches.

DrBacon

I think the drop in boost at high rpms is from the supercharger side belt slipping. I ran my hand under under the belts and on serpentine side it's clean, but once I touch that supercharger side belt my hand is covered in black dust which I assume isn't normal and due to it slipping. I can tighten that tensioner, which looks like a real pain in the *** to get to while still in the car, however if it's already making 13psi with belt slip I really don't want to know what it will do once it's tightened. Boost gauge arrives next week and I should be able to verify with that the MAP sensor readings just to make sure. Also new clutch is going in next week as well

redondoaveb

Chances are it isn't going to make any more boost, it'll just make 13 psi all the way to redline. Keep an eye on the supercharger side and see if you start to get dust build up around the pulleys and bracket.

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
750whp/700ft.lbs

DrBacon

There's definitely belt dust around on the backside. Correct me if I'm wrong, but I thought centrifugal superchargers built boost linearly to RPM unless there's a restriction. I suppose that filter is a pretty heavy restriction though. I'm going to attempt to tighten that belt tomorrow. Any idea on how tight it should be? I guess until it stops slipping, however there's already only a very, very small amount of movement when I push on the belt as is.

redondoaveb

That's a pretty significant amount of dust. Yep, the filter is a pretty big restriction. Even with a turbo guard screen, my car made 16.4 psi @7400 rpm. Boost started falling off before redline and I had zero belt slip. I hope someone else chimes in on belt tension. I believe somewhere in this thread there's an explanation. I believe it's based on how much you can twist the belt in the top section between the sc pulley and jackshaft pulley.

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
750whp/700ft.lbs

"Z"en

Belt slip is what I expected in the beginning, although it is not visible in the first attached pic you showed to us (the surface of the backside is shielded). Try to tighten the belt as tight as possible until it is foiled in any attempt to flip it. I've had a hard time in dealing with my friend's build (which was mainly built by me, my mechanic, and my tuner) of the 928 wheel and filter. We found belt dust around the bracket and even used heat gun to check these two belts.
https://www.instagram.com/p/BxOYNS6n...=1efdk158o36mp
https://www.instagram.com/p/BxUEwWjF...d=nccm677eqi3i
We used a larger lower idler custom one off and RPM belt on the supercharger side to solve it. He's having the similar setup on the serpentine side as yours.
https://www.instagram.com/p/ByDHTcPA...d=1cjlg185ac4b
or
https://www.instagram.com/p/Bx5Al-in...=1ukdsx8trl0zy

Back to your problem, I think the Omni MAP sensor shouldn't be that fragile unless it was damaged during installing it. And yes the filter is indeed a restriction. You'll loose at least 3 psi roughly when putting the filter on. Your system will be more susceptible to the belt slip with the filter on, like you wear a mask to breath. You will have to breath (spin it) harder and that's exactly the case your blower is undergoing. I personally think it's barely possible to achieve more than 15ish psi if your using the filter along with the poor little V3 Sci/Si trims of the 8-rib drive pulley. Will be busy dealing with belt slip in addition to the supercharger oil potentially coming out of the head unit. Try to use 36225 lower idler if you still see the dust after every effort you have done to tighten the supercharger belt. I'm assuming your using the Gates 7pk2642 belt on the serpentine side. I'd not suggest you consider using the RPM belt if your running the stock self-lubricated Vortech internals and the current pulley combination (shouldn't be needed to use the RPM belt right now).

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610whp/462wtq A2A- 6.8s@100-200km (stock motor) / IG: minized123456 / 淬 Custom VQ Vortech-based supercharger parts made to order! https://www.instagram.com/p/CFUjDc5H...d=m0unws28pvk4

DrBacon

I made a quick video showing the current belt tension. I have a friend who has a vortech 350z and he said my belt is already much tighter than his is. I haven't tightened the belt yet. Curious to see how this compares https://youtu.be/MWe5_cB3SBc

redondoaveb

I can tell you that my belt is tighter than yours, it twists about half as much as yours does.

__________________
Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
750whp/700ft.lbs

"Z"en

Still too loose.

__________________
610whp/462wtq A2A- 6.8s@100-200km (stock motor) / IG: minized123456 / 淬 Custom VQ Vortech-based supercharger parts made to order! https://www.instagram.com/p/CFUjDc5H...d=m0unws28pvk4

DrBacon

I tightened it about one full turn of the bolt, I marked it before starting. The belt doesn't "seem" any tighter but I didn't want to overtighten it. I did one pull and the boost peaked at 7,000 rpms (at 12.2psi) and stayed pretty constant all the way to 7,700 this time, not dropping off anymore. I'll do a few more pulls some time later to confirm but I think it's fine for now. New clutch goes in on thursday, then I'll do the break in miles and get it on a dyno fairly soon after.

Senna-F1

]

Well, I'm making 12.3 psi boost. Stock pulley, Motordyne LTH, Helmholtz test pipes, Motordyne exhaust. Seems pretty high. Eugene says Im at 77% duty cycle on pump gas on my Walbro 480/1050cc combo which was supposed to already be an upgrade pump wise just to be safe. We need to check fuel pressure under boost. So, plenty of boost, but no room for E85 at this duty cycle.

DrBacon

Welcome to my world, now you understand? . Out of curiosity how consistent is your boost over different WOT pulls? I have about a 1psi variance, I've seen as "low" as 11.8 to 12psi and as high as 13psi, with no changes.

Senna-F1

I didn't have any issues understanding. So my runs are consistent boost wise. Although I think my Innovate gauge might read a bit lower...maybe 10's? we just got it working so I need to check that. The issue with duty cycle was a kinked vacuum line which is why boost gauge wasn't working, and FPR wasn't raising pressure. But duty is still 70%.

What are folks setting idle fuel pressure to? 41-42? Or more like 52? CJM says 1050's are for cars making less than 700WHP. Im way below that. Going to take a video of the fuel pressure to see what it's doing.

"Z"en

Depends on whether your tuner uses the vacuum line or not. Most of the tuners like to set base pressure as 43-45 and to use the vacuum line. There are three kinds of pressure - regulator pressure (set with the adjuster screw), manifold pressure (for those of the vacuum line hooked up), and pressure at the injectors. Mine was set as 52 for the idle fuel pressure. With the fuel return, duty cycle, and recorded pressures under WOT, one can actually confirm if the fuel pump is capable of supporting the power under WOT, based on the fuel your using.

__________________
610whp/462wtq A2A- 6.8s@100-200km (stock motor) / IG: minized123456 / 淬 Custom VQ Vortech-based supercharger parts made to order! https://www.instagram.com/p/CFUjDc5H...d=m0unws28pvk4