Boost lvl for a 2650R / 90mm Pulley / OEM Lower / 103mm TB / 2" Longtubes - Page 2

laynlo15 · 07-20-2021, 07:26 PM

Quote:

Originally Posted by Camaro1973

That definitely isn’t right. You can see many posts from other tuners all over where the 90mm, stock lower are all hitting 16psi. (Sea level) my log as well.

Depends on other mods, elevation, etc. Mine with a 90 and stock lower only made 14 psi with Lt4.

*radz28* · 07-21-2021, 08:10 AM

I know of a car set-up close to your combo, minus LTs and running a ported 95 TB (ported stock Maggie snout) and it'll make up to about 15.5-psi here in the Summer (around 85* ambient). Car has stock exhaust, minus secondary cats. That car has seen as much as 18-psi in boost-weather with the same set-up. I think cam timing changes since the boost weather runs have probably lowered boost a little, but all of that's on stock lower and a 90 upper.

PureZL1 · 07-21-2021, 10:40 PM

I don’t really know whats going wrong with my setup, 14 psi with a 85mm.. really couldn’t figure out whats the issue.

Camaro1973 · 07-22-2021, 12:06 AM

Quote:

Originally Posted by PureZL1

I don’t really know whats going wrong with my setup, 14 psi with a 85mm.. really couldn’t figure out whats the issue.

Where are you getting this reading from??

PureZL1 · 07-22-2021, 01:36 AM

My tuner, he didn’t mention having any problems, i am currently sitting on 720 whp with a cai/Lts jms booster, meth and the 2650 with 85 upper. *14psi*

laynlo15 · 07-22-2021, 07:51 AM

Seems like we are beating this horse to death. No one will have the same results every time. No motor is exact even though GM says the specs are the same. You can take the same 2 motors and run a compression check and its doubtful you'll get the same data out of both that were checked. Each time you make a change thats relative to back pressure to the engine you'll change the boost level. You can log your car in two different places or two different dynos in different cities or states and you'll get a different boost level. A guy at sea level will see as much as 2 lbs of boost difference then a guy in Denver, or New York or Missouri where I'm at. For every 1000 ft of elevation you may see .5 lower boost level. I worked for Magnuson and raced for them for 4 years and I heard these questions everyday. Why does my car have a different boost level then my buddies and we have the same ride? Because nothing mechanical is exactly the same every time even though its advertised to be the same. Between the 2300 and the 2650r I've been thru about every pulley ever built for these two blowers and I'm telling you don't get caught up in what the other guy has, the same for dynos, its not going to be the same.

*radz28* · 07-22-2021, 07:52 AM

Check your bypass

laynlo15 · 07-22-2021, 08:06 AM

Quote:

Originally Posted by radz28

Check your bypass

Good point I forgot to mention that. You rarely see them fail to fully close when you go WOT but it does happen.

FoundNemo · 07-28-2021, 08:09 AM

Quote:

Originally Posted by PureZL1

I don’t really know whats going wrong with my setup, 14 psi with a 85mm.. really couldn’t figure out whats the issue.

It likely has to do with you using the stock TB and snout. Are you running the stock airbox?

*radz28* · 07-28-2021, 09:36 AM

Quote:

Originally Posted by laynlo15

Good point I forgot to mention that. You rarely see them fail to fully close when you go WOT but it does happen.

It was just the adjuster bolt that was holding it open slightly, like the OEM bolts sometimes do from the factory

PureZL1 · 07-28-2021, 12:31 PM

I have the regular magnuson snout and the 87mm oem tb, rotofab cai not the big gulp, the regular one but i’ve seen cars completely stock except for the maggie doing 14+ psi on 90mm..yet i got 13 on 90mm and 14 on 85mm, also the gains are not that much of a work, i barely got 720 whp with intake/LTs meth and a jms booster *85mm* pulley..

07-21-2021, 08:10 AM	#16
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crazy Coast Posts: 15,186 View My Garage	I know of a car set-up close to your combo, minus LTs and running a ported 95 TB (ported stock Maggie snout) and it'll make up to about 15.5-psi here in the Summer (around 85* ambient). Car has stock exhaust, minus secondary cats. That car has seen as much as 18-psi in boost-weather with the same set-up. I think cam timing changes since the boost weather runs have probably lowered boost a little, but all of that's on stock lower and a 90 upper. __________________ '20 ZL1 Black "Fury" A10, PDR, Exposed CF Extractor Magnuson Magnum DI TVS2650R // RFBG // Soler 103 // TooHighPSI Port Injection // THPSI Billet Lid // FF // Katech Drop-In // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs

07-22-2021, 07:51 AM	#20
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,860	Seems like we are beating this horse to death. No one will have the same results every time. No motor is exact even though GM says the specs are the same. You can take the same 2 motors and run a compression check and its doubtful you'll get the same data out of both that were checked. Each time you make a change thats relative to back pressure to the engine you'll change the boost level. You can log your car in two different places or two different dynos in different cities or states and you'll get a different boost level. A guy at sea level will see as much as 2 lbs of boost difference then a guy in Denver, or New York or Missouri where I'm at. For every 1000 ft of elevation you may see .5 lower boost level. I worked for Magnuson and raced for them for 4 years and I heard these questions everyday. Why does my car have a different boost level then my buddies and we have the same ride? Because nothing mechanical is exactly the same every time even though its advertised to be the same. Between the 2300 and the 2650r I've been thru about every pulley ever built for these two blowers and I'm telling you don't get caught up in what the other guy has, the same for dynos, its not going to be the same. __________________ 2022 Lt1 6.2 A10, Maggie 2300, THPSI Port Inj/10 rib, Rotofab, E, Nickey, SCOL, Griptech, RC Bandits, Hoosiers/MT 9.80@142.96 1.44 60ft, 6.34@112 707/669 RWHP/TRQ. 16SS Maggie 2650 9.41@147 1.35 60ft, 5.99@119. 16 C7 A8 10.90@128 Bolt on stuff Last edited by laynlo15; 07-22-2021 at 08:04 AM.

07-22-2021, 07:52 AM	#21
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crazy Coast Posts: 15,186 View My Garage	Check your bypass __________________ '20 ZL1 Black "Fury" A10, PDR, Exposed CF Extractor Magnuson Magnum DI TVS2650R // RFBG // Soler 103 // TooHighPSI Port Injection // THPSI Billet Lid // FF // Katech Drop-In // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs

07-21-2021, 10:40 PM	#17
PureZL1 Drives: 2018 A10 ZL1 Join Date: Oct 2020 Location: Kuwait Posts: 21	I don’t really know whats going wrong with my setup, 14 psi with a 85mm.. really couldn’t figure out whats the issue.

07-22-2021, 01:36 AM	#19
PureZL1 Drives: 2018 A10 ZL1 Join Date: Oct 2020 Location: Kuwait Posts: 21	My tuner, he didn’t mention having any problems, i am currently sitting on 720 whp with a cai/Lts jms booster, meth and the 2650 with 85 upper. 14psi

07-28-2021, 12:31 PM	#25
PureZL1 Drives: 2018 A10 ZL1 Join Date: Oct 2020 Location: Kuwait Posts: 21	I have the regular magnuson snout and the 87mm oem tb, rotofab cai not the big gulp, the regular one but i’ve seen cars completely stock except for the maggie doing 14+ psi on 90mm..yet i got 13 on 90mm and 14 on 85mm, also the gains are not that much of a work, i barely got 720 whp with intake/LTs meth and a jms booster 85mm pulley..

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