Boost Issue with new Supercharger
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Cruising
Joined: May 2017
Posts: 14
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Finalist 2020 C7 of the Year -- Modified
Boost Issue with new Supercharger
Looking for any input in order to make sure I'm educated before accepting my dyno results. Mods added include Magnuson supercharger with secondary Z06 drive, upgrade to 70mm pulley, LT4 fuel pump and injectors, haltech stinger air intake and finally kooks 2 inch long tube headers with green catted xpipe. After tune only getting 515rwhp and the boost hits 9psi and the drops to 5.5 psi. Shop vacuum test for boost leaks, double checked bypass valve checked for belt slip. The shop is going to consult with the place I bought the items from to see what the suggest . Current speculation is the free flowing exhaust may be the issue or need even a smaller pulley to get the boost up. The issue is I should have gotten 515rwhp with just adding the basic magnuson and so all the other upgrades appear to be for nothing.
Live just above sea level in central Canada
Live just above sea level in central Canada
Last edited by Pumpkinodin8844; May 28, 2017 at 02:31 PM.
Melting Slicks
Joined: Oct 2009
Posts: 2,004
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From: Long Island New York
Do you live at a high altitude? Those numbers seem really low, even if the only mod was your blower. I've seen stage 2 Edelbrock e forces like I have on my car make high 500s with no other mods, but that was at sea level.
Last edited by BlueDevilZ51; May 28, 2017 at 12:45 AM.
Thread Starter
Cruising
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Finalist 2020 C7 of the Year -- Modified
No I live in central canada so elevation is just above 200 meters. I've also heard similar results with many people reporting closer to 580 rwhp and I'm really hoping that my local shop can get to the bottom of it but I figure I would be proactive and see if I can come to them with some suggestions as well.
I'm Batman..
Joined: Apr 2014
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From: Lehigh Acres FL
Tech Contributor
Who is the tuner? Sounds like they have no clue how to tune this car. The E92 ECM is a major change from the LS motors. Sounds like you should get your money back and go to someone who knows what they are doing..
Ant
Ant
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Cruising
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Finalist 2020 C7 of the Year -- Modified
I don't want to say yet as they are working on it so if it's fixed all is good. I can tell you there well known so you might be surprised if they can't fix it.
I'm Batman..
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From: Lehigh Acres FL
Tech Contributor
Le Mans Master
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From: cookeville tennessee
with this & Ant with no boost leak in the tune. These cars are totally diff than the LS set up. Robert
Le Mans Master
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From: Redmond WA
Always cracks me up that Eastern Canada calls itself "Central". Saskatchewan is central!
Anyway, I'm almost morally certain it's one of two things:
a) Belt slip, or
b) Torque demand tables now being exceeded by actual torque production so the TB is closing to bring power down to the table's value
I've seen this in person on an NA motor, watched the blades do it on the dyno.
[Edit: I see a couple of people already said this, so just consider mine a vote for theirs!]
Anyway, I'm almost morally certain it's one of two things:
a) Belt slip, or
b) Torque demand tables now being exceeded by actual torque production so the TB is closing to bring power down to the table's value
I've seen this in person on an NA motor, watched the blades do it on the dyno.
[Edit: I see a couple of people already said this, so just consider mine a vote for theirs!]
Last edited by davepl; May 28, 2017 at 03:27 PM.
Thread Starter
Cruising
Joined: May 2017
Posts: 14
Likes: 6
Finalist 2020 C7 of the Year -- Modified
Always cracks me up that Eastern Canada calls itself "Central". Saskatchewan is central!
Anyway, I'm almost morally certain it's one of two things:
a) Belt slip, or
b) Torque demand tables now being exceeded by actual torque production so the TB is closing to bring power down to the table's value
I've seen this in person on an NA motor, watched the blades do it on the dyno.
[Edit: I see a couple of people already said this, so just consider mine a vote for theirs!]
Anyway, I'm almost morally certain it's one of two things:
a) Belt slip, or
b) Torque demand tables now being exceeded by actual torque production so the TB is closing to bring power down to the table's value
I've seen this in person on an NA motor, watched the blades do it on the dyno.
[Edit: I see a couple of people already said this, so just consider mine a vote for theirs!]
Advanced
Joined: Feb 2017
Posts: 99
Likes: 3
Looking for any input in order to make sure I'm educated before accepting my dyno results. Mods added include Magnuson supercharger with secondary Z06 drive, upgrade to 70mm pulley, LT4 fuel pump and injectors, haltech stinger air intake and finally kooks 2 inch long tube headers with green catted xpipe. After tune only getting 515rwhp and the boost hits 9psi and the drops to 5.5 psi. Shop vacuum test for boost leaks, double checked bypass valve checked for belt slip. The shop is going to consult with the place I bought the items from to see what the suggest . Current speculation is the free flowing exhaust may be the issue or need even a smaller pulley to get the boost up. The issue is I should have gotten 515rwhp with just adding the basic magnuson and so all the other upgrades appear to be for nothing.
Live just above sea level in central Canada
Live just above sea level in central Canada
Instructor
Joined: Oct 2002
Posts: 219
Likes: 68
From: MI
Whoa! Did you say LT1 with Z06 drive and Maggie 2300?
Who suggested that pulley? Is this on pump gas?
Stock pulley for the kit with dedicated drive is 98mm which delivers 6.5-7 psi. Other options are as follows:
95mm - about 7.5 psi - Max for pump gas.
90mm - about 8.5 psi - Max for stock fuel system and good gas.
80mm - about 12 psi
75mm - about 14 psi
70mm - about 16 psi
I don't know what octane fuel you're using or what fuel system you're using but it had better be serious.
I'm running a 75mm on a 6th gen Camaro which makes 730RWHP and just ran a 9.93@140MPH.
Hopefully the throttle didn't open, other wise you might have a more serious issue with your engine.
Who suggested that pulley? Is this on pump gas?
Stock pulley for the kit with dedicated drive is 98mm which delivers 6.5-7 psi. Other options are as follows:
95mm - about 7.5 psi - Max for pump gas.
90mm - about 8.5 psi - Max for stock fuel system and good gas.
80mm - about 12 psi
75mm - about 14 psi
70mm - about 16 psi
I don't know what octane fuel you're using or what fuel system you're using but it had better be serious.
I'm running a 75mm on a 6th gen Camaro which makes 730RWHP and just ran a 9.93@140MPH.
Hopefully the throttle didn't open, other wise you might have a more serious issue with your engine.
Last edited by 2highpsi; May 30, 2017 at 12:16 PM.
Thread Starter
Cruising
Joined: May 2017
Posts: 14
Likes: 6
Finalist 2020 C7 of the Year -- Modified
Update
Looking for any input in order to make sure I'm educated before accepting my dyno results. Mods added include Magnuson supercharger with secondary Z06 drive, upgrade to 70mm pulley, LT4 fuel pump and injectors, haltech stinger air intake and finally kooks 2 inch long tube headers with green catted xpipe. After tune only getting 515rwhp and the boost hits 9psi and the drops to 5.5 psi. Shop vacuum test for boost leaks, double checked bypass valve checked for belt slip. The shop is going to consult with the place I bought the items from to see what the suggest . Current speculation is the free flowing exhaust may be the issue or need even a smaller pulley to get the boost up. The issue is I should have gotten 515rwhp with just adding the basic magnuson and so all the other upgrades appear to be for nothing.
Live just above sea level in central Canada
Live just above sea level in central Canada
1. Got a new tuner so hopefully that helps
2. Turns out the shop I used for install is using dyno dynamic vs dynojet. My understanding is the dynojet leans toward a higher value so much that on average dyno dynamics aka the heart breaker is 13% lower. So 515 rwhp is 590rwhp on the dynojet.
Thread Starter
Cruising
Joined: May 2017
Posts: 14
Likes: 6
Finalist 2020 C7 of the Year -- Modified
I got it all worked out. Main issue was the tune. New tuner did there thing and I went from 5 psi to 14 psi which was way to much for the Lt1 so I then moved to a 85mm pulley bringing it to 9psi. On top of that i was experiencing misfiring which was a result of bad plugs and wires and coil pack. Once I got this fixed my cats starting acting up so I went cattless. Now on the dyno I'm 640rwhp 9psi and it runs great. My advice is pay the $$$ and find a good reputable company. In Canada I ended up using Davenport but if I was in the USA my choice would be a place like lingenfelter and I'm pretty sure they offer remote tuning. Costs a bit more but I wasted 1500 on a bad tune.
Last edited by Pumpkinodin8844; Jun 28, 2019 at 03:50 PM.
Race Director
Joined: Mar 2001
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From: Bonneville Salt Flats
Boost is going "somewhere," not mixing with fuel in the engine. I've used turbos and assorted superchargers, and If the boost is falling off at higher rpms, something is wrong... little boost = little powers.
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