Exhaust versus Power versus HP - ZR-1 Net Registry Forums

Paul in SC · 05-02-2013

Quote:

from secondchance in previous thread

Re: Group Buy Stainless Works.
With headers, no cats and 94 stock exhaust it registered 1.4 psi @ 6000 rpm.
Same with free flow exhaust (OBX in this case) dropped to 1 psi.

Yun,

Let's start there and the first question I have is what mods and HP for the engine tested?

Thanks for adding comments. I hope you don't mind the new thread.

Paul

Meanmyz · 05-02-2013

From the SW thread... Paul I guess I was asking because I was considering the pros and cons of doing this myself (headers, cats, and stock resonator and mufflers).

So again the question to anybody will to chime in: If Marc H lists 5 HP as the difference between the second design stock exhaust vs. a freer flowing exhaust, does this difference widen as you modify the car for more power, such as 500HP?

...with the answer leading to "yes it only makes sense to also add a free flow exhaust because you are only mitigating the effects of some of your mods" or "no, there won't be a noticeable difference".

secondchance · 05-02-2013

Quote:

Originally Posted by Paul in SC

Quote:

from secondchance in previous thread

Re: Group Buy Stainless Works.
With headers, no cats and 94 stock exhaust it registered 1.4 psi @ 6000 rpm.
Same with free flow exhaust (OBX in this case) dropped to 1 psi.

Yun,

Let's start there and the first question I have is what mods and HP for the engine tested?

Thanks for adding comments. I hope you don't mind the new thread.

Paul

94 405 hp stock motor. Headers and OBX exhaust w/ Marc Heibeck chip turned 363 rwhp and 340 rw lb-ft.
OBX is 2-1/2" stainless steel system.

secondchance · 05-02-2013

Quote:

Originally Posted by Meanmyz

From the SW thread... Paul I guess I was asking because I was considering the pros and cons of doing this myself (headers, cats, and stock resonator and mufflers).

So again the question to anybody will to chime in: If Marc H lists 5 HP as the difference between the second design stock exhaust vs. a freer flowing exhaust, does this difference widen as you modify the car for more power, such as 500HP?

...with the answer leading to "yes it only makes sense to also add a free flow exhaust because you are only mitigating the effects of some of your mods" or "no, there won't be a noticeable difference".

Conventional wisdom is to go to 3" exhaust once above 450 hp. To answer your question - yes. Difference will widen. Higher hp means more exhaust volume.

efnfast · 05-02-2013

1990, 375 stock hp. Headers, no cats, OBX exhaust, Marc H chip. 353 rwhp.

1990 quasar blue · 05-02-2013

1990 ported plenum/injector housings. SSW headers, random technology cats, flowmaster catback. HAT tune. 390 rwhp/360 rwtq. SAE.

Fully Vetted · 05-03-2013

1994 ported, SSW headers, no cats, Magnaflow catback, Corey Tune. 430 rwhp/392 rwtq

WARP TEN · 05-03-2013

350, Haibeck 510 pkg minus Fidanza and plus ceramic cats. Top end/head porting, 63 mm throttle body, SSW headers, Corsa. 413 RWHP. Fidanza aluminum flywheel would add 13 RWHP and no cats would add another 10 or so.--Bob

Raptor Twin Turbo · 05-03-2013

Stock 405 HP 93'

360 rwhp & 340 rwtq

No port, No headers, stock CATs & exhaust.

MS/Raptor ECM with MS tune.

Paul Workman · 05-04-2013

It is all in my signature except to add this re the exhaust

3" dual exhaust (except mufflers...but that is going to change!)

05-02-2013	#1
Paul in SC Join Date: May 2012 Location: Bluffton, SC Posts: 151	Exhaust versus Power versus HP Quote: from secondchance in previous thread Re: Group Buy Stainless Works. With headers, no cats and 94 stock exhaust it registered 1.4 psi @ 6000 rpm. Same with free flow exhaust (OBX in this case) dropped to 1 psi. Yun, Let's start there and the first question I have is what mods and HP for the engine tested? Thanks for adding comments. I hope you don't mind the new thread. Paul __________________ 1993 ZR-1 - "The Green Thing", LPE/LSV 385; 2021 HTC, Red Mist Metallic, Cool gray interior, stainless dual stripes; ZR-1 Net Registry #1376

05-02-2013	#2
Meanmyz Join Date: Feb 2006 Location: Springfield, Minnesota Posts: 446	Re: Exhaust versus Power versus HP From the SW thread... Paul I guess I was asking because I was considering the pros and cons of doing this myself (headers, cats, and stock resonator and mufflers). So again the question to anybody will to chime in: If Marc H lists 5 HP as the difference between the second design stock exhaust vs. a freer flowing exhaust, does this difference widen as you modify the car for more power, such as 500HP? ...with the answer leading to "yes it only makes sense to also add a free flow exhaust because you are only mitigating the effects of some of your mods" or "no, there won't be a noticeable difference". Last edited by Meanmyz; 05-02-2013 at 06:15 PM.

05-02-2013	#5
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,463	Re: Exhaust versus Power versus HP 1990, 375 stock hp. Headers, no cats, OBX exhaust, Marc H chip. 353 rwhp.

05-02-2013	#6
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Re: Exhaust versus Power versus HP 1990 ported plenum/injector housings. SSW headers, random technology cats, flowmaster catback. HAT tune. 390 rwhp/360 rwtq. SAE. __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19

05-03-2013	#7
Fully Vetted Join Date: Sep 2012 Location: Rockwall, Tx Posts: 1,510	Re: Exhaust versus Power versus HP 1994 ported, SSW headers, no cats, Magnaflow catback, Corey Tune. 430 rwhp/392 rwtq __________________ _________________ 1994 AB/Grey #141 430 RWHP/392 RWTQ FBI Lyposuction / Secondaries relieved of duty / SW Long Tube Headers / Corsa Exhaust / FIC SS Injectors / MSD Coils / Lightweight Pulleys / Corey tuned B & M Shifter / Aluminum Flywheel / Samco Hoses / Shelby Series One's / C4 No Flex Frame Stiffener BBC - Bling By Carter: Custom ZR-1 Center Caps / Custom Plenum Plate / Air Box Knobs / TB Cover / Oil Filter Cover

05-03-2013	#8
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,089	Re: Exhaust versus Power versus HP 350, Haibeck 510 pkg minus Fidanza and plus ceramic cats. Top end/head porting, 63 mm throttle body, SSW headers, Corsa. 413 RWHP. Fidanza aluminum flywheel would add 13 RWHP and no cats would add another 10 or so.--Bob __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough"

05-03-2013	#9
Raptor Twin Turbo Join Date: Apr 2013 Location: Roy UT Posts: 8	Re: Exhaust versus Power versus HP Stock 405 HP 93' 360 rwhp & 340 rwtq No port, No headers, stock CATs & exhaust. MS/Raptor ECM with MS tune. __________________ [B]Ron Hanselman [COLOR="Blue"]Raptor LLC, Corvette Twin Turbo's[/COLOR] [url]www.raptorllc.net[/url][/B]

05-04-2013	#10
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Exhaust versus Power versus HP It is all in my signature except to add this re the exhaust 3" dual exhaust (except mufflers...but that is going to change!) __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry Last edited by Paul Workman; 05-04-2013 at 06:10 AM.