L-48 performance Q!!!

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Feb 15, 2003 | 01:50 AM

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Racer

Joined: Apr 2002

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From: Atascocita TX

L-48 performance Q!!!

what does a stock L48, standard 4spd., run in the 1/4? what would it run with 3.70:1 gears, an aggressive cam, and a set of hedders w/ side pipes (4")? thanks in advance.

Feb 15, 2003 | 03:07 AM

Justin79-L-82

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From: WInnipeg Mb

Re: L-48 performance Q!!! (ry)

Bones stock probably high 15's. WIth headers, cam and gears i would guess about 15.6. You won't really gain alot without changing the heads on the l-48's

Feb 15, 2003 | 09:58 AM

American Boy

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From: Quebec

Re: L-48 performance Q!!! (Justin79-L-82)

You would gain at least a full second on the 1/4 mile. The L48 are restricted in order by the exhaust, cam, heads and intake. I gain 30 hp at the engine by tuning the timing advance, rejetting the carb and taking off the cat. Heads would help with smaller combustion chamber to get the compression up. An important note is to build an engine as a final package. Big cam don't like low compression. Think about the final result and make change to get there.

Stephan

Feb 15, 2003 | 04:14 PM

Jvette73

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Joined: Jun 2001

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From: Severna Park Md

Re: L-48 performance Q!!! (American Boy)

Before I changed the heads and cam on my L48 I ran a best of 14.99. At the time I was running a TH400 with 2500 stall 3.08 rear gear. The only engine mods were pertronix ignitor , re-curved dist. and 1.6 to 1 rocker arms. 14.99 was achieved thru cast iron manifolds and stock exhaust.

Feb 16, 2003 | 01:38 AM

tnt76vette

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Re: L-48 performance Q!!! (Justin79-L-82)

Gotta take issue with Justin's remarks about not gaining much without a head change on L-48's. B4 I got rid of my 882s, I was DDing 296HP + 355ft/lbs. of torque, with just a mild cam and a TRUE DUAL exhaust system, truly a decent gain Since adding my ceramic headers and reworked 416 heads I now DD 355HP and 410ft/lbs of Torque. BTW my Corvette Black Book lists 882 heads as being used on both L-48s AND L-82s for a few years......... :D . As "Ganey's Exhaust Paper" states: The exhaust system (2 Y Pipe) is the biggest drawback.......not the 882 heads............ :cheers:

Feb 16, 2003 | 09:33 AM

Ganey

Race Director

Joined: Apr 1999

Posts: 11,520

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From: CORVETTE 77 385 C.I. TEXAS

Re: L-48 performance Q!!! (tnt76vette)

As your 73 should have duals, what it really needs is more cam. tnt76vette & others are aware we have been over this many times. After the following is heads.

Comp Cams 268H is a good min. for your 4spd. & max. for the stock valve springs. Add an al. intake, crossover pipe, Dynomax Cerma headers & mufflers (about 300 HP) & it will start running like a CORVETTE.

:cool:

Feb 16, 2003 | 09:56 AM

redwingvette

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From: Waterford Mi

Re: L-48 performance Q!!! (Ganey)

:iagree: DD shows my setup close to 300Hp at 5000RPM.s and 376ft/lbs torque between 3000 and 3500RPM's. That is a pretty good gain from stock.

Feb 17, 2003 | 08:34 PM

Chris O'

Burning Brakes

Joined: May 2000

Posts: 958

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From: Brisbane, Australia 1985 Coupe

Re: L-48 performance Q!!! (tnt76vette)

I don't take that much faith in DD! Spend a couple of bucks and get a "real world" claim.

I dynoed my '77 with a cam/port matched intake/bigger valves & flow work/recurved dist/dual ex with stock manifolds and I got 154.3rwhp. I added headers and dual exhaust and got 226.1rwhp. This was done on the same dyno!

You gotta make 'em breath! Either dual exhaust or better flowing heads (even stock ones).

:cheers: