Beast_305

I was just wandering because I am very close to getting them (one of them for sure this week). I am going with the Hooker Comp. for header's and a Dyno-Max Catback. I can get one of them right now but which one should i get? Also the headers I'm getting dont have a slot for my O2 sensor, will this mess up my car? or can i run without the O2 sensor?

Beast_305

Also i almost forgot what power increases can i expect, i heard from a few people that headers and catback will get you atleast 40 HP is this true? TIA

R Defever

If it's an L69 then your car should run fine w/o the O2 sensor. Performance wise, the L69 already has a better exhaust than the LG4, but headers and a y-pipe would help it to breathe better and rev more freely. I've heard as much as 20-25 horsepower from this mod and i wouldn't doubt it if you have a descent exhaust.

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85 Z28 (Soon to be GMPP 350 HO)
Headman Hedders and matching y-pipe, Edelbrock Performer, Ram Air, Accell cap and rotor, Accell Supercoil, Bosch 8mm wires, 160 stat, highflow Catco converter, absolutely no other smog equipment, B&M shift kit, Rapidfires, numerous carb mods, and flex-a-light fan.

"If you think education is expensive, try ignorance."-Ben Franklin

Dan87IROC-Z

40 hp is with a good exhaust set up. Such as TES and American Thunder, I would not expect more than 30 hp from Hooker headers and Dynomax cat-back. If I were you, I would save my money and buy a better brand.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission

Current Mods: Edelbrock TES Headers, Hooker Cat-Back System, Performance Resource Chip, 160* Thermostat, Accel 8.8mm Ignition Wires, K&N high flow air filters, gutted air box, gutted MAF sensor, Throttle Body Coolant By-Pass, Homemade Ram-Air, Falken ZIEX Z-Rated Tires.

1/4 mile times without chip:
Best ET: 15.7 @ 89MPH
Best Corrected ET: 14.5 @ 96MPH

ws6transam

You'll probably see less improvements than, say, an LG4. The L69 has a 2.75" cat-back with wide-mouth oval catylitic converter, and a mandrel-bent Y-pipe, along with wider diameter exhaust manifolds. Still there will be improvements. 20 HP, perhaps?

I've taken off my stock exhaust and now use VHT-coated Edelbrock TES with a Carsound 3-inch catylitic converter, and Hooker Aerochamber cat-back. I like the sound, and everyone's complimenting me on it.

Of course, I did the exhaust at the same time as the heads, cam, & intake, so I'm maybe 100 HP better than last fall. YMMV.

Sounds of the exhaust on my 305HO are on my website. http://www.isthq.com/~dan/fcar.html


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Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines,
5-point racing harness, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Speed-sensitive steering conversion, underdrive pulleys, Crane Hi-6 & more. 1.05g skidpad verified.

Beast_305

I will only see a 20 HP increase? I see what you mean but I dont have the L69 exhaust I have the stock Exhaust from the LG4, the engine that was in my car before the L69. Will I still get a 20 HP increase even though I dont have L69 exhaust?

Ed Maher

First of all, Defever is an idiot, every thirdgen has a computer and as such requires an O2 sensor. Period. If you don't weld in a bung for the O2 sensor you will never make it more than 5 minutes with the SES light coming on, leaving you in limp home mode, running like hell, and burning lots of extra gas.
With that out of the way, i also don't believe the L69 had any better manifolds then the LG4, just the bigger cat and intermediate pipe.
Just make sure when you get the dynomax cat-back that you don't order the 2.5" system with opposite side outlets. Their 3" system has both outlets on the driver's side, like SLP.
ed


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Ed Maher - Moderator @ the Carb Board
85 Z28 - 357c.i. - stolen 12/24
Click Here for the Rest
'83 Grand Prix - low miles
Only mods...Homemade open element, 2.5" cat and exhaust, CK-B metering
and the way out ******* style in effect
stock 14" wheels w/ wire hubcaps in front
snowflake 15" alloys in the back

Beast_305

Ok, so if i get these header's I need to somehow get the O2 sensor in or else it will run like crap? How much would one of those "bung" things cost to get and have someone install. I have no welding expierience and am not about to learn. Also the Dynomax cat back im getting is the 2.75 catback.

ws6transam

Find a welding shop to weld them in for you. Most shops can do little jobs like that for twenty bucks. I recently got my Hooker Aerochamber repaired for $20 at Bannasch Welding in Lansing. I called ahead, and the guy said he was just finishing up a trailer. I ran it down, he did the welding, and I was out of there in 15 minutes. You'll need an oxygen sensor bung, and probably pre-drill the hole yourself. Once done, the welding is trivial for them.

Ed, the L69 exhaust featured a 2, or 2 1/4 inch outlet on the exhaust manifold(I forget which) , and a 2.75 inch intermediate pipe, in addition to the mandrel bent Y-pipe and wide mouth catylitic converter. --Wish I'd kept the manifold bits, but I sold them to an LG4 owner who swears they were bigger than his.

Whatever.