I figured it would go down, and I was right... With the ZZ4 cam in there, I was getting about 230-250 miles per 13 gallons. Now I'm lucky to get 200 miles. But I'm still tuning the car, playing with the PROM values, so who knows if it'll go up.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

I'm going to be swapping cams soon and was going to use a zz4 cam. I have to pass emissions here did you pass with the zz4 cam, and what were your HC and CO readings. You have the dyno testing in Ca right.

thanks

 

I pulled 70ppm HC and 0.00% CO last year on the NJ tailpipe sniffer. Specs are on the page in my signature.

The emissions guys couldn't believe it, checked 2x for exhaust leaks. I'm running 1.6:1 rockers and it idles kinda choppy.

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1982 Z-28

See http://www.mycar.net/mafb/registry/detail.cfm?id=276 for details

 

Try invoking Highway Mode and Highway Mode Spark Advance.

 

I didnt dyno with the ZZ4 cam, I cheated, I pulled that engine out and rebuilt it into its current setup, and put an iron headed engine in there with an LT1 cam for smog. It passed perfect.

Glenn, I was waiting for your write-up on how to do that.

 

You made 70 on the HC holy **** my standard is .80. Was it the dyno test or the idle test?

 

Here are my ZZ4 cam smog test results:
Passed with flying colors!

2500 rpm
HC PPM Max allowable 0140 measured 0000
CO% Max allowable 1.00 measured 0.00

Idle rpm
HC PPM Max allowable 0120 measured 0006
CO% Max allowable 1.00 measured 0.00


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87 GTA, 350 TPI, auto, 3:27 gears, rebuilt engine, ZZ3 cam, LT4 valve springs, pocket ported stock heads, edelbrock intake, TPIS air foil, AFPR, high flow air cleaner, modified stock air canister, relocated air intake sensor, tb bypass ported plenum, modified MAF (screens removed), edelbrock headers, hi-flo cat, flowmaster muffler.

 

heh, your gas mileage is good compared to mine. i got a whopping 100 miles, yes, 100 miles on a full tank of gas (leaving about 1/4 in there). I use to go 215 miles before a refill, but my gas mileage in the winter is always worse than in the summer. or maybe something is wrong with my car heh.

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Gutted cat
-!AIR

 

Well, I know I average about 10-12 MPG in the city; I just can't stop hitting the gas hard. On the highway, I get about 22-25 MPG doing 75 MPH and above. I haven't been able to pass emissions test since I removed my cat back in '94.

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'88 GTA 350 Full of Leprosy (rust)
Headers, catback, free mods, Xtreme energy cam, intake pieces and 2100 RPM TQ

13.39@102.50 MPH
1.90 Sec ----- Best 60FT
104.23 MPH -- Best Trap Speed
AIM HIGH!

 

branz28, are you running a 160degree thermo?
if so, thats probly your problem with the bad gas mileage in the winter.



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1987 IROC-Z L98,SuperRam,EB 6085's,LPE 219/219 Roller, Crane 1.6RR, EB TPI Base, 58mm TB, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, MSD 6AL, MSD Blaster 3, Aluminum DS, 94 Disk Rear, Adjustable Valve, Precision 3.73 Gears, Sub-Frame Connectors, Hotchkis Lower Control Arms, KYB Shocks/Struts, Suspension Techniques Lowering Springs, Polyurethan Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm,

To see the ROC, Check out the webpage Here

 

Dsouthern, I think your test is different than mine, do they have the IM240 dyno test in CA?

 

No dyno test in Calif.
Just a visual under hood inspection and then two tests, one at idle rpm and one at 2500 rpm. Both tests were done with the car sitting still and in park.

 

In Los Angeles and Orange County, they definitely have the IM240 dyno test. In Central and Eastern CA, they just have the idle test.

And I'm still only getting about 210 miles before I have to stop for gas...

 

I do not have a TPI but I have an L31 Vortec 350 with the Hot cam kit and a 750 cfm edelbrock, tremec 5 speed and 4.10 gears. I have gotten 20 mpg on the highway at 70 mph. Just switched back to 3.23 should be better.

 

In San Diego, we also have the dyno test. You have to live in the mountains and farm areas to not have the dyno test around here.

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1989 IROC-Z 5.7L