Lowering Boost - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Ron_Robinson1 · 01-22-2014, 04:50 PM

I havent asked my tuner yet, but was curious if anyone has ever lowered their boost levels with out changing their tune.

Its not my daily driver in the Summer, but I drive it quite often.

-So I'm currently at 11.5lbs of boost at the top of the pull, and I wanna raise a pulley by .10 or .15 to lower my boost to max 10lbs. Will this throw off my tune or just run me a little rich? I have always read if you pulley down and raise boost you need to retune, but what about the opposite, pulley up and lower the boost do you need a retune? I dont mind getting it retuned but I would like to keep this tune so when Im at the track I can just pulley down and be good to go.

-Or I can just leave it alone, I have a great tuner, everything looks good on the dyno, I have plent of fuel/injector, and I should stop worrying over nothing. If it blows I will just rebuild, but If I can hold off on rebuilding tell next winter then I will be a happy camper.

jrpimp00 · 01-22-2014, 05:28 PM

Wont affect your tune unless your tuner doesn't know what hes doing.

jessrayo · 01-22-2014, 06:21 PM

I'm not a tuner but I would think you would want a new tune for the pulley change. With a smaller pulley the engine will have less air at any given rpm and may tend to run rich.

Slowhawk · 01-22-2014, 06:27 PM

Should be fine.

Bo White · 01-22-2014, 06:38 PM

Yep, fine.

Ron_Robinson1 · 01-22-2014, 06:50 PM

Quote:

Originally Posted by jessrayo

I'm not a tuner but I would think you would want a new tune for the pulley change. With a smaller pulley the engine will have less air at any given rpm and may tend to run rich.

I totally agree with your statement, logically it makes sense. But I couldn't find actual data to prove this. But I have received a lot of answers saying I will be good to go. I think if I was dropping from 12lbs to say 6lbs it could be a different story, but I'm only talking 1-2 lbs, which I know doesn't seem like much but I really hope to drop the RWTQ a little bit.

Thanks SlowHawk and Bo White for chiming in.

jessrayo · 01-22-2014, 07:22 PM

Quote:

Originally Posted by Ron_Robinson1

I totally agree with your statement, logically it makes sense. But I couldn't find actual data to prove this. But I have received a lot of answers saying I will be good to go. I think if I was dropping from 12lbs to say 6lbs it could be a different story, but I'm only talking 1-2 lbs, which I know doesn't seem like much but I really hope to drop the RWTQ a little bit.

Thanks SlowHawk and Bo White for chiming in.

Well you learn something everyday....lol. I'm sure those guys know a lot better than I do.

RankSS · 01-22-2014, 09:21 PM

It would be no different than running your car at a higher altitude.

Unreal · 01-23-2014, 09:56 AM

Won't be an issue.

Will have less air, so the MAF reads less air and sprays less fuel. The reason to tune when boost goes up is you get into areas of the maf curve/timing map etc that haven't been tuned yet or checked to be safe so it is smart to retune. If you are going down then all those cells should have been tuned already.

Basically say 11psi is hitting 10khz and 9psi hits 9.2khz. Car uses the maf transfer curve to tell how much air that is and adjust fuel. All should be good. Now if you turn it up and are now hitting 11khz and car has never been tuned there you may have issues. Then again maf curves are fairly predictable and it probably won't be bad but it is always safe to check and retune for more boost/power.

Ron_Robinson1 · 01-23-2014, 10:23 AM

Quote:

Originally Posted by Unreal

Won't be an issue.

Will have less air, so the MAF reads less air and sprays less fuel. The reason to tune when boost goes up is you get into areas of the maf curve/timing map etc that haven't been tuned yet or checked to be safe so it is smart to retune. If you are going down then all those cells should have been tuned already.

Basically say 11psi is hitting 10khz and 9psi hits 9.2khz. Car uses the maf transfer curve to tell how much air that is and adjust fuel. All should be good. Now if you turn it up and are now hitting 11khz and car has never been tuned there you may have issues. Then again maf curves are fairly predictable and it probably won't be bad but it is always safe to check and retune for more boost/power.

Thanks man, really appreciate the info. Actually you broke it down to even my level of understanding.

dreksnot · 01-23-2014, 11:37 AM

Think about the guys running boost controllers. I asked my tuner the same question. I run my max boost at 9.5# - tuner set the car to run like that. I can turn my boost down to 4# and still run happily and safe. Also by lowering the boost, you're putting less stress on everything. You should be just fine. Just for saving grace - talk to your tuner.

01-22-2014, 04:50 PM	#1
Ron_Robinson1 Drives: A Static line to a pack tray & ZL1 Join Date: Feb 2011 Location: Centeral NY Posts: 2,277	Lowering Boost I havent asked my tuner yet, but was curious if anyone has ever lowered their boost levels with out changing their tune. Its not my daily driver in the Summer, but I drive it quite often. -So I'm currently at 11.5lbs of boost at the top of the pull, and I wanna raise a pulley by .10 or .15 to lower my boost to max 10lbs. Will this throw off my tune or just run me a little rich? I have always read if you pulley down and raise boost you need to retune, but what about the opposite, pulley up and lower the boost do you need a retune? I dont mind getting it retuned but I would like to keep this tune so when Im at the track I can just pulley down and be good to go. -Or I can just leave it alone, I have a great tuner, everything looks good on the dyno, I have plent of fuel/injector, and I should stop worrying over nothing. If it blows I will just rebuild, but If I can hold off on rebuilding tell next winter then I will be a happy camper. __________________ 2017 ZL1 A10: 8.84 @ 156 PB 2017 ZL1 A10: Previously FBO 756/761 (9.6 @ 143 1/4) SOLD-2013 ZL1 M6:BTR,LTs,IDs,ATI,RotoFab10.84@129 SOLD-2011 SS M6: Blower, Cam, Alky, LTs.

01-22-2014, 05:28 PM	#2
jrpimp00 Drives: '10 Black/IOM Camaro SS/RS Join Date: Mar 2010 Location: Fayetteville NC Posts: 532	Wont affect your tune unless your tuner doesn't know what hes doing. __________________ 2010 Camaro 2SS/RS Black/IOM //// 1998 Pontiac Trans AM 819 RWHP @ 12 PSI (Turbo)

01-22-2014, 06:21 PM	#3
jessrayo Speed Freak Drives: 2013 ZL1 Camaro, 2016 Camaro SS Join Date: Jun 2013 Location: Ardmore, OK Posts: 2,637 View My Garage	I'm not a tuner but I would think you would want a new tune for the pulley change. With a smaller pulley the engine will have less air at any given rpm and may tend to run rich. __________________ 2016 SS -AGP twin Borg Warner 7163 EFR's, LT4 mechanical pump, LT4 injectors, Walbro 255 low side, Castrol SRF. 734whp/759 tq 2013 ZL1 -ADM - 427 LSX 6 bolt, O-ringed block built by LME. Twin PT6466 turbos. RPM custom manual trans, RPS Quad carbon clutch, 9" Hendrix rear diff & axles. ADM/squash fuel system, Ron Davis radiator, Spal fans, AGP air to air, turbo plumbing. LPE oil cooler, rear bushing upgrade, roll bar...etc. rwhp 1400+... 212.5mph, best Texas mile to date.

01-22-2014, 06:38 PM	#5
Bo White Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012 Location: Vance Alabama Posts: 8,090	Yep, fine. __________________ Retired wanna be cylinder head porter 2015 2SS 1LE Clutch reservoir, Vararam DRX, ported TB, TSP 2" headers, MGW shifter, stage 4 cam and Wilkes 11° 65cc heads Totalled: 2010 1SS Wilkes Performance/Eagle 416 shortblock, TSP custom valvetrain, PRC 260 heads, Edelbrock Pro Flo 102, th400 swap, 8" PTC 5500 stall= 535/435 at the wheels tuned Gen 3 Performance and Dyno 10.97 @ 124 full weight in 3100 DA CamaroFest X

01-22-2014, 09:21 PM	#8
RankSS Drives: 2010 Camaro SS Join Date: Oct 2013 Location: Saskatoon SK Can. Eh Posts: 365	It would be no different than running your car at a higher altitude. __________________ 2010 Camaro SS RS, Maggie with 3.4" pulley, 60# injectors, ADM dual fuel pumps, ADM Stage 2 Cam with Brian Tooley springs and pushrods, black CAI intake, Stainless Works long tube headers w/gutted cats, ZL1 Diff w/offset bushings, Pfadt lowering springs, Pfadt sway bars, Pfadt solid sub frame mounts, BMR trailing arms and toe rods, Hurst short throw shifter, Painted on Hugger Orange stripes, Forgestar F14 Piano Black wheels, Nitto NT05 rubber.

01-22-2014, 06:27 PM	#4
Slowhawk Drives: 1999 Trans Am Join Date: Jul 2009 Location: Bridgewater,Ma Posts: 2,018	Should be fine.

01-23-2014, 09:56 AM	#9
Unreal Drives: 2006 Z06 Join Date: Oct 2010 Location: Gilbert, AZ Posts: 5,712	Won't be an issue. Will have less air, so the MAF reads less air and sprays less fuel. The reason to tune when boost goes up is you get into areas of the maf curve/timing map etc that haven't been tuned yet or checked to be safe so it is smart to retune. If you are going down then all those cells should have been tuned already. Basically say 11psi is hitting 10khz and 9psi hits 9.2khz. Car uses the maf transfer curve to tell how much air that is and adjust fuel. All should be good. Now if you turn it up and are now hitting 11khz and car has never been tuned there you may have issues. Then again maf curves are fairly predictable and it probably won't be bad but it is always safe to check and retune for more boost/power. __________________ Nick Corvette Z06 -1200ish rwhp

01-23-2014, 11:37 AM	#11
dreksnot Served USN - Atomic Chimp Drives: 2021 Camaro ZL1 1LE A10 (stock) Join Date: Jul 2012 Location: Fort Collins, CO Posts: 1,706 View My Garage	Think about the guys running boost controllers. I asked my tuner the same question. I run my max boost at 9.5# - tuner set the car to run like that. I can turn my boost down to 4# and still run happily and safe. Also by lowering the boost, you're putting less stress on everything. You should be just fine. Just for saving grace - talk to your tuner. __________________ > > 2021 Camaro ZL1 1LE A10 > > Past Builds: 2013 Twin-Turbo LSX434 M6 - 1,359rwhp daily