Open lid? - ZR-1 Net Registry Forums

KILLSHOTS · 05-09-2014

Hey guys,

Marc seems to feel that there is no real benefit to going with an open air filter lid. I certainly trust Marc, but I also know that there are a lot of you guys who run them. I can't really imagine the stock vented lid being a bottleneck. What are your thoughts?

Kevin · 05-09-2014

I have an open lid, no idea if it helps or not

PhillipsLT5 · 05-09-2014

I have a open lid, Locobob did a dyno test some years back, seem to remember SLP Claw being the best HP

GOLDCYLON · 05-09-2014

I have an open lid as well.

Karl · 05-09-2014

It's free and it increases the surface area that the engine can suck in fresh air.

Goldcylon, do you have a link or the dyno numbers to share?

GOLDCYLON · 05-09-2014

Quote:

Originally Posted by pushrod-v8

It's free and it increases the surface area that the engine can suck in fresh air.

Goldcylon, do you have a link or the dyno numbers to share?

yes this is what locobob posted up over at Corvette forum many years ago.

locobob

Here is the old post from the CF. Results for peak HP were within margin of error but notice the average HP and Torque numbers show a small gain.

Today myself and forum member/dyno owner TJ Wong set out to find the truth regarding C4 air intakes. We dyno tested 3 different air intakes on my Lingenfelter 368cid LT5. Tested today were: stock with paper element, stock with K&N element and a cut lid, and finally SLP's "claw" tri-cone filter design. All dyno pulls were made with starting coolant temps at 195 degrees F. Here are the results.

Stock with paper, two identical pulls: 477rwhp. Avg. peak HP 477

Stock with K&N and cut lid, three pulls: 471, 475, 480rwhp. Avg. peak HP 475.3

SLP tri-cone "claw", three pulls: 477, 478, 481rwhp. Avg. peak HP 478.7
It would appear that the naysayers are mostly correct about C4 air intakes, not much to be gained here. Both Tom and I were rather suprised with the results. We had expected to see some small but visible gains with the cut-lid and SLP, instead we got a bunch of tests with peak numbers being basically the same or well within normal dyno pull to pull variation. The SLP unit does seem to have a small advantage over the others but suprisingly it's in mid range power not peak (see dyno graph average power #'s).

Sorry folks the image of the Dyno Graph is NLA

Karl · 05-09-2014

Seems odd with the k&n and cut lid combo the horsepower started low and kept climbing. I like the 480 number...seems more realistic. If it made 480 once it can make 480 again.

KILLSHOTS · 05-09-2014

I think my theory on the C4 in general has always been that the bottleneck is the filter itself, not the lid. In essence, open the lid more and the air still gets held up at the filter itself. Since we can't really increase the flow through the filter (a K&N doesn't flow better than a clean stock filter, for instance) I question whether we really increase airflow by a worthwhile margin by going from a vented lid to a full-open lid. That said, I'm totally open to being shown otherwise and I would definitely switch to an open lid for a few HP and better breathing characteristics overall.

Has anybody ever noticed a difference in intake noise when switching from stock to open? Maybe that would indicate a difference in airflow.

Karl · 05-09-2014

Yes there is a obvious sucking/suction noise when the throttle is opened.

PhillipsLT5 · 05-09-2014

All I hear is LT5 music

05-09-2014	#1
KILLSHOTS Join Date: Feb 2014 Location: AZ Posts: 860	Open lid? Hey guys, Marc seems to feel that there is no real benefit to going with an open air filter lid. I certainly trust Marc, but I also know that there are a lot of you guys who run them. I can't really imagine the stock vented lid being a bottleneck. What are your thoughts?

05-09-2014	#2
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,633	Re: Open lid? I have an open lid, no idea if it helps or not __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

05-09-2014	#3
PhillipsLT5 Join Date: Aug 2005 Location: Scottsdale, AZ Posts: 2,450	Re: Open lid? I have a open lid, Locobob did a dyno test some years back, seem to remember SLP Claw being the best HP

05-09-2014	#4
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,153	Re: Open lid? I have an open lid as well. __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

05-09-2014	#5
Karl Join Date: May 2013 Location: Chicago Posts: 977	Re: Open lid? It's free and it increases the surface area that the engine can suck in fresh air. Goldcylon, do you have a link or the dyno numbers to share? __________________ 1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black Sold 1985 L98 Blue On Blue Sold

05-09-2014	#7
Karl Join Date: May 2013 Location: Chicago Posts: 977	Re: Open lid? Seems odd with the k&n and cut lid combo the horsepower started low and kept climbing. I like the 480 number...seems more realistic. If it made 480 once it can make 480 again. __________________ 1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black Sold 1985 L98 Blue On Blue Sold

05-09-2014	#8
KILLSHOTS Join Date: Feb 2014 Location: AZ Posts: 860	Re: Open lid? I think my theory on the C4 in general has always been that the bottleneck is the filter itself, not the lid. In essence, open the lid more and the air still gets held up at the filter itself. Since we can't really increase the flow through the filter (a K&N doesn't flow better than a clean stock filter, for instance) I question whether we really increase airflow by a worthwhile margin by going from a vented lid to a full-open lid. That said, I'm totally open to being shown otherwise and I would definitely switch to an open lid for a few HP and better breathing characteristics overall. Has anybody ever noticed a difference in intake noise when switching from stock to open? Maybe that would indicate a difference in airflow.

05-09-2014	#9
Karl Join Date: May 2013 Location: Chicago Posts: 977	Re: Open lid? Yes there is a obvious sucking/suction noise when the throttle is opened. __________________ 1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black Sold 1985 L98 Blue On Blue Sold

05-09-2014	#10
PhillipsLT5 Join Date: Aug 2005 Location: Scottsdale, AZ Posts: 2,450	Re: Open lid? All I hear is LT5 music