Dumb Question about boost - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Valkyrie14 · 02-24-2021, 07:39 AM

When does an LSA create boost? At what rpms?

I ask because on a recent log I sent to my tuner he said I didn’t make any boost. The log was taken on a regular drive, did not get on it at all, but did hit 4,000 rpms.

My pulleys are spinning the rotors all the time. My understanding is that at a certain rpm the actuator opens the blade to the rotors and the additional intake of air begins to flow in to the heads. I’m sure I have simplified this.

I bought a used blower and I have always been skeptical of it. My recent concerns with a boost gauge not reading boost has me running down a rabbit hole. So I start at the top and see if the blower is working first.

I am doing a new log today on a stretch where I can go a little faster.

I am starting to feel like a hypochondriac.

hillshooter · 02-24-2021, 10:22 AM

give him 3 shifts all to redline, second third and 4th.

larry_g · 02-24-2021, 10:26 AM

Here's another thought...

gtstorey · 02-24-2021, 10:35 AM

Put it on a dyno and compare the curves to other's.

Silver14 · 02-24-2021, 10:40 AM

Are you logging boost in HP Tuners? If so, post the log here for others to look at.

Batmanntexas · 02-24-2021, 12:57 PM

Boost is generated when a load is placed on the engine, regardless of RPM (mostly). For example, you could run the motor to 6000RPM and still be at 0 psi or in vacuum. Conversely, if you are tooling along a flat road at 1500RPM in 6th gear and stand on it, you should see almost full boost (PD style blower) instantly.

I'd verify that you are logging the correct parameter, that you are running at least a 2-BAR MAP sensor, and the tune is adjusted correctly for said MAP sensor.

Sparko · 02-24-2021, 02:32 PM

As long as your vacuum bypass is working properly, as you open your throttle plate you will start building. A good way to watch for function is just simply watching manifold pressure.

Setting up HPT to read your MAP sensor in kpa is the simplest measure. 0-100kpa will be under vacuum, >100kpa is boost. A simple, cheap, combination vac/boost gauge (I like mechanical gauges when troubleshooting if possible), will do the job too. As you roll the throttle you'll see the gauge move from full vac through 0 into boost.

TheFlyingBananaSS · 02-24-2021, 03:22 PM

Eliminate the possible bad gauge by trying a different gauge. Maybe a friend has one. Put on the car and see if you are only reading vacuum or if it goes + into boost.

Silver14 · 02-24-2021, 03:32 PM

You can test your gauge with a bicycle or other hand air pump if you think it's the issue.

eLeSthree · 02-24-2021, 03:37 PM

Quote:

Originally Posted by larry_g

Here's another thought...

Good call. Additionally he is missing that second actuator and has one of his bypass valves vacuum ports plugged.

Valkyrie14 · 02-24-2021, 06:09 PM

Thanks everyone for the answers. My tuner told me based on past logs I am making boost, I think I made him laugh a little. I am definitely going to adjust the angle of my actuator after seeing this video.
This puts me back to the gauge and my location. As others have pointed out my gauge is reading vacuum and sets back to 0 so it is reacting to pressure from the line. So I guess so am not on a boost point? The upper stem is what I am using for the gauge, my Hobbs and the fuel regulator.
I used to have the lower stem capped off and had the actuator running off of the upper stem and T’d off lines for gauge, Hobbs and regulator. Now the actuator is off of the lower stem, which may be vacuum?
I really appreciate all of the help in getting this all figured out.

Silver14 · 02-24-2021, 06:42 PM

If you share the log here I’d be happy to show you how to read the boost on it.

larry_g · 02-24-2021, 08:38 PM

As mentioned above, are you loading it enough to generate boost? Even when my gauge goes from vacuum to zero, I still need to put my foot into it considerably more before it shows boost.

Sent from my Pixel 5 using Tapatalk

RupertPupkin · 02-24-2021, 09:00 PM

Maybe..... you think you have no boost, Bc you’re used to the power now.

02-24-2021, 07:39 AM	#1
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	Dumb Question about boost When does an LSA create boost? At what rpms? I ask because on a recent log I sent to my tuner he said I didn’t make any boost. The log was taken on a regular drive, did not get on it at all, but did hit 4,000 rpms. My pulleys are spinning the rotors all the time. My understanding is that at a certain rpm the actuator opens the blade to the rotors and the additional intake of air begins to flow in to the heads. I’m sure I have simplified this. I bought a used blower and I have always been skeptical of it. My recent concerns with a boost gauge not reading boost has me running down a rabbit hole. So I start at the top and see if the blower is working first. I am doing a new log today on a stretch where I can go a little faster. I am starting to feel like a hypochondriac. __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

02-24-2021, 10:22 AM	#2
hillshooter Drives: 2015 Camaro SS commemorative Join Date: May 2015 Location: Utah Posts: 425	give him 3 shifts all to redline, second third and 4th. __________________ 2015 Camaro SS, LS3 Stroker, PRC heads,CUSTOM CAM. AGP 68/68 with custom Hot and Cold side. Fore triple pumps, Holley terminator X. BMR drag suspension with carlyle brake kit. 15" ET drags and 17" skinnies. ZL1 3.73 gears , aluminum driveshaft. TH400 with circle D converter.

02-24-2021, 12:57 PM	#6
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	Boost is generated when a load is placed on the engine, regardless of RPM (mostly). For example, you could run the motor to 6000RPM and still be at 0 psi or in vacuum. Conversely, if you are tooling along a flat road at 1500RPM in 6th gear and stand on it, you should see almost full boost (PD style blower) instantly. I'd verify that you are logging the correct parameter, that you are running at least a 2-BAR MAP sensor, and the tune is adjusted correctly for said MAP sensor. __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

02-24-2021, 02:32 PM	#7
Sparko Drives: 2010 Camaro 2SS Join Date: May 2019 Location: Rochester, NY Posts: 152 View My Garage	As long as your vacuum bypass is working properly, as you open your throttle plate you will start building. A good way to watch for function is just simply watching manifold pressure. Setting up HPT to read your MAP sensor in kpa is the simplest measure. 0-100kpa will be under vacuum, >100kpa is boost. A simple, cheap, combination vac/boost gauge (I like mechanical gauges when troubleshooting if possible), will do the job too. As you roll the throttle you'll see the gauge move from full vac through 0 into boost. __________________ 2010 Camaro 2SS 2018 Charger GT+ 2005 Cavailer LS S/C - Sold '87 HD FXRT - Wrecked pending repair

02-24-2021, 03:22 PM	#8
TheFlyingBananaSS Evil Genius of Chevrolet Drives: 2017 Z06, 2019 XTS, 2013 SS Join Date: Feb 2017 Location: New York Posts: 3,260	Eliminate the possible bad gauge by trying a different gauge. Maybe a friend has one. Put on the car and see if you are only reading vacuum or if it goes + into boost. __________________ GPI SS2 VVT cam, ECS Novi 1500 supercharger, Corsa Extreme, Detroit Speed and BMR suspension, Circle D triple disc, Melling oil pump, LS2 chain tensioner, ATI 10% UD, DSX E85 kit, High Energy coils, BTR springs, LS2 Lifter trays, Titanium retainers, hardened push rods, FIC 1000 injectors, ZL1 pump, Mighty Mouse catch can, AEM gauges, Tial BOV, Richmond 3.91 gears, Custom gauge bezels, Speed Engineering headers, Stainless Works HF cats, DSX Aux pump, 710rwhp on E85.

02-24-2021, 10:35 AM	#4
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,155	Put it on a dyno and compare the curves to other's.

02-24-2021, 10:40 AM	#5
Silver14 Drives: 2014 SIM 2SS Join Date: Sep 2015 Location: Charlotte, NC Posts: 925	Are you logging boost in HP Tuners? If so, post the log here for others to look at.

02-24-2021, 03:32 PM	#9
Silver14 Drives: 2014 SIM 2SS Join Date: Sep 2015 Location: Charlotte, NC Posts: 925	You can test your gauge with a bicycle or other hand air pump if you think it's the issue.

02-24-2021, 06:09 PM	#11
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	Thanks everyone for the answers. My tuner told me based on past logs I am making boost, I think I made him laugh a little. I am definitely going to adjust the angle of my actuator after seeing this video. This puts me back to the gauge and my location. As others have pointed out my gauge is reading vacuum and sets back to 0 so it is reacting to pressure from the line. So I guess so am not on a boost point? The upper stem is what I am using for the gauge, my Hobbs and the fuel regulator. I used to have the lower stem capped off and had the actuator running off of the upper stem and T’d off lines for gauge, Hobbs and regulator. Now the actuator is off of the lower stem, which may be vacuum? I really appreciate all of the help in getting this all figured out. Attached Images __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

02-24-2021, 06:42 PM	#12
Silver14 Drives: 2014 SIM 2SS Join Date: Sep 2015 Location: Charlotte, NC Posts: 925	If you share the log here I’d be happy to show you how to read the boost on it.

02-24-2021, 08:38 PM	#13
larry_g Drives: 2014 1SS/1LE Join Date: Nov 2015 Location: Louisville, KY Posts: 826	As mentioned above, are you loading it enough to generate boost? Even when my gauge goes from vacuum to zero, I still need to put my foot into it considerably more before it shows boost. Sent from my Pixel 5 using Tapatalk __________________ 830 WHP 700 WTQ, Whipple 2.9 @ 13lbs Boost, Flex Fuel Tune by Blevins Tuning, LSA SBE, 3.5 GripTec, ATI LS3 Damper, AFR 260cc Mongoose, ARP Studs, Yella Terra Ultralites, Johnson 2110R, BTR PDS Stage 3, Melling 10355, Improved Racing Baffle, ID1050X, DSX Triple Fuel Pump, RotoFab CAI, NW 103mm TB, Stainless Works 1-7/8" LTH to 3" Speed Eng w/ X-pipe to NPP, Powermaster 9509 XS, Detroit Speed Motor Mounts, MGW, Monster LT1-S, ZL1 Calipers, DBA Rotors & Pads, Bilstein B6 Struts & Shocks, BMR 1.25" Drop Springs & Adj Rear Bar, Pegasus Solid Bushings, Z/28 Wheels, other misc parts.

02-24-2021, 09:00 PM	#14
RupertPupkin Drives: 2014 Camaro SS 1Le Join Date: Feb 2016 Location: IL Posts: 1,606	Maybe..... you think you have no boost, Bc you’re used to the power now. __________________ 2014 SS 1LE Money Pit/ Forged 402 CAM 22X/24X, .619/.617, 113 LSA/ LS9 Heads FIC 1200cc/DSX Aux Pump//McLeod RXT Clutch 730whp: 630Trq