ZL550 Supercharger Blow off? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

z76232 · 07-22-2015, 04:35 PM

Hi
I bought a 2010 ZL550 a few months back and have just drove it around town. I took it on the freeway the other night and was cruising at 80 and every few minutes it felt like the car power was backing off a little and you would hear an air noise. It only has 1700 miles on it. Is this just a normal SC blow off valve noise or should I get it checked out? Another question I have, is there a way to have the rev limiter raised up or removed from it?
Thanks
Dave

2010reddevil · 07-22-2015, 04:39 PM

The air whooshing sound is probably the s/c bypass opening up and venting. You can raise the rev limiter but definitely don't want to remove it. You'll be buying a new engine quicker than you can read this post.

z76232 · 07-22-2015, 04:49 PM

Thanks, I was thinking that but have no knowledge of supercharged engines. It has a paddle shifted auto in it and I hit the limiter going through the gears and it seemed to hit right a 6K, right where I was going to shift. Like to have a little leeway. I think if it was raise to 6500 it would be fine. Does anyone know a dyno tune shop and someone who can do this in the Phoenix area?
Thanks

z76232 · 07-23-2015, 01:38 AM

The L99 should be good for 6500 RPM's don't you think. Had a old Boss 302 that was limited to 8K.

SS PANTHER · 07-23-2015, 01:49 AM

The rpm is set to 6200rpm. You have a L99 motor and that valve train is suspect to failure at high rpms. Even stock L99's have afm lifter failures. The ZL550 does not come with an aftermarket cam. If you changed the cam and the entire valve train you would have a more durable and reliable motor that you could raise the rpms up to 6500. Nice car by the way. The SLP cars are some of the most tastefully done Camaros.

z76232 · 07-23-2015, 06:03 PM

I thought I shifted at 6k but like Comrado said, the tach and speedo must not read correct in 1st gear. I think I'll just leave it in drive and let the computer do all the work. I sold my 06 Z06 because of engine problem scares, don't want to do the same with this one.
Now I'm not condoning street racing but I couldn't help myself. It was a Mustang messing with me and the street was long, empty with no entrys. I left it in drive. He was no problem at all. Was surprised to see him pull into my neighborhood after our short little street race and I met him at the mailboxes and talked. He said he usually has no problem spanking Camaros. Typical Ford guy. Tells me he knew I wasn't stock when he punched it and I blew by him like he was standing still. Nice car but I like the Camaro better. Said he was running 430hp.

rebelyell22 · 07-23-2015, 11:46 PM

430 at the crank or wheels?

Batmanntexas · 07-24-2015, 08:22 AM

With a positive displacement (PD) supercharger, like your Magnuson, you should not have a "blow off" noise during operation. The "by-pass" valve is in place for steady state operations, i.e. cruising on the freeway, poking along city streets, etc., where there little to no load being placed on the motor. It allows the blower to "free spin", for lack of a better term, so that it is not continually compressing air, that you don't need, to minimize drag on the engine, increasing fuel economy.
Long explanation short, you might want to look into the bypass valve and see that it is working properly/correctly adjusted.
On PD equipped cars, pulley size(s) are what determine boost limits, if you weren't aware. Enjoy the new ride!!

Zaproy · 07-24-2015, 12:28 PM

Haha those 15 5.0s are slow stock. My friend has a yellow gt pp with a cai and I still pull away and I'm all stock. I love hurting those 5.0s feelings, they all think they spank camaros and then when they can't pull away they always come up with "oh you must be tuned or something."

z76232 · 07-25-2015, 04:43 PM

Quote:

Originally Posted by Batmanntexas

With a positive displacement (PD) supercharger, like your Magnuson, you should not have a "blow off" noise during operation. The "by-pass" valve is in place for steady state operations, i.e. cruising on the freeway, poking along city streets, etc., where there little to no load being placed on the motor. It allows the blower to "free spin", for lack of a better term, so that it is not continually compressing air, that you don't need, to minimize drag on the engine, increasing fuel economy.
Long explanation short, you might want to look into the bypass valve and see that it is working properly/correctly adjusted.
On PD equipped cars, pulley size(s) are what determine boost limits, if you weren't aware. Enjoy the new ride!!

I will admit I know nothing about super charges, this is all new to me. I think I will try to find a decent tune, dyno shop here in the Phoenix area and bring it over to them. Like I said, cruising around town under 50mph you don't hear or feel anything but the whine. It was when I was driving down the freeway for 10 miles at 80mph when I heard and felt something.
Thanks

z76232 · 07-25-2015, 04:44 PM

Quote:

Originally Posted by rebelyell22

430 at the crank or wheels?

Exactly, I haven't seen or talked to him yet. The way it ran it had to be at the crank if it really had that much.

07-22-2015, 04:35 PM	#1
z76232 Drives: 2010 ZL550 Join Date: Mar 2015 Location: United States Posts: 11	ZL550 Supercharger Blow off? Hi I bought a 2010 ZL550 a few months back and have just drove it around town. I took it on the freeway the other night and was cruising at 80 and every few minutes it felt like the car power was backing off a little and you would hear an air noise. It only has 1700 miles on it. Is this just a normal SC blow off valve noise or should I get it checked out? Another question I have, is there a way to have the rev limiter raised up or removed from it? Thanks Dave

07-22-2015, 04:39 PM	#2
2010reddevil Drives: 2010 Camaro 2SS Victory Red 6M Join Date: Apr 2015 Location: Gulf Coast, TX Posts: 1,424	The air whooshing sound is probably the s/c bypass opening up and venting. You can raise the rev limiter but definitely don't want to remove it. You'll be buying a new engine quicker than you can read this post. __________________ 2011 2SS 6A Red Jewel Metallic, Vararam Tune CAI, Magnaflow 3" Competition c/b, Speed Engineering 1-7/8 LT's, Circle D 5C, M/T 275/40R20 S/S, HPTuners tune by Ryan@GPI 12.3 @ 112 ACM as of 12/22/19 Gone on 12/28/19 R I P 2010 2SS 6M Victory Red/Black (old ride) CAI intake, Speed Engineering 1 7/8" LT's, X4 base tune, Flowmaster Outlaw axle-back. 12.6 @ 115 SAR as of 9/19/15 Gone but never forgotten.

07-23-2015, 11:46 PM	#7
rebelyell22 Drives: 2011 SIM 2SS/RS LS3 Join Date: Sep 2013 Location: Tupelo, MS Posts: 5,902	430 at the crank or wheels? __________________ 2011 2SS/RS built 8/24/10

07-24-2015, 08:22 AM	#8
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,375 View My Garage	With a positive displacement (PD) supercharger, like your Magnuson, you should not have a "blow off" noise during operation. The "by-pass" valve is in place for steady state operations, i.e. cruising on the freeway, poking along city streets, etc., where there little to no load being placed on the motor. It allows the blower to "free spin", for lack of a better term, so that it is not continually compressing air, that you don't need, to minimize drag on the engine, increasing fuel economy. Long explanation short, you might want to look into the bypass valve and see that it is working properly/correctly adjusted. On PD equipped cars, pulley size(s) are what determine boost limits, if you weren't aware. Enjoy the new ride!! __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

07-22-2015, 04:49 PM	#3
z76232 Drives: 2010 ZL550 Join Date: Mar 2015 Location: United States Posts: 11	Thanks, I was thinking that but have no knowledge of supercharged engines. It has a paddle shifted auto in it and I hit the limiter going through the gears and it seemed to hit right a 6K, right where I was going to shift. Like to have a little leeway. I think if it was raise to 6500 it would be fine. Does anyone know a dyno tune shop and someone who can do this in the Phoenix area? Thanks

07-23-2015, 01:38 AM	#4
z76232 Drives: 2010 ZL550 Join Date: Mar 2015 Location: United States Posts: 11	The L99 should be good for 6500 RPM's don't you think. Had a old Boss 302 that was limited to 8K.

07-23-2015, 01:49 AM	#5
SS PANTHER Drives: 2013 SS Supercharged Convertible Join Date: May 2013 Location: SoCal Posts: 2,714	The rpm is set to 6200rpm. You have a L99 motor and that valve train is suspect to failure at high rpms. Even stock L99's have afm lifter failures. The ZL550 does not come with an aftermarket cam. If you changed the cam and the entire valve train you would have a more durable and reliable motor that you could raise the rpms up to 6500. Nice car by the way. The SLP cars are some of the most tastefully done Camaros.

07-23-2015, 06:03 PM	#6
z76232 Drives: 2010 ZL550 Join Date: Mar 2015 Location: United States Posts: 11	I thought I shifted at 6k but like Comrado said, the tach and speedo must not read correct in 1st gear. I think I'll just leave it in drive and let the computer do all the work. I sold my 06 Z06 because of engine problem scares, don't want to do the same with this one. Now I'm not condoning street racing but I couldn't help myself. It was a Mustang messing with me and the street was long, empty with no entrys. I left it in drive. He was no problem at all. Was surprised to see him pull into my neighborhood after our short little street race and I met him at the mailboxes and talked. He said he usually has no problem spanking Camaros. Typical Ford guy. Tells me he knew I wasn't stock when he punched it and I blew by him like he was standing still. Nice car but I like the Camaro better. Said he was running 430hp.

07-24-2015, 12:28 PM	#9
Zaproy Drives: 2014 Camaro SS/RS Join Date: Mar 2015 Location: North Posts: 133	Haha those 15 5.0s are slow stock. My friend has a yellow gt pp with a cai and I still pull away and I'm all stock. I love hurting those 5.0s feelings, they all think they spank camaros and then when they can't pull away they always come up with "oh you must be tuned or something."