Differences between L83 and L98
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 3,194
Likes: 27
From: Monroe Twp, NJ
Differences between L83 and L98
Been reading about the 84 and 85 Corvette road tests. Seems the 85 was almost one second faster in the quater mile than the 84 and only rated at 25 more horsepower.Im wondering if the only difference in the two engines was the fuel injection system or were valves and heads different? I also wonder if the 25 horses was underated?
Team Owner
Joined: Sep 2001
Posts: 62,127
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Heads are the same, as the camshaft is close to the same (to my knowledge, i only have the 84's lift specs), like the exhaust system.
Its in the intake and injection system, and the HP rating is pretty accurate.
Its in the intake and injection system, and the HP rating is pretty accurate.
Last edited by vader86; May 6, 2007 at 11:11 AM.
Drifting
Joined: Feb 2004
Posts: 1,277
Likes: 1
From: Santa Maria CA
its pretty close to a second. 14.1 to 15.1 E/T's. Like any car the L83 will drop in ET with minor mods.....as does the L98. The Crossfire intake kindof
hard to get past mid 13's. Takes alot of work unless you spray.
hard to get past mid 13's. Takes alot of work unless you spray.
Drifting
Joined: Jan 2002
Posts: 1,606
Likes: 1
From: Las Cruces NM
I think the extra 40 ft/lbs of tq also helped the L98.
I've never seen a dyno sheet on a stock L83, so this is just a guess, but I wonder if the L98 had more below peak. In other words, it was only a 25hp difference at peak, but there may have been a greater difference at, say 3000rpm.
C
I've never seen a dyno sheet on a stock L83, so this is just a guess, but I wonder if the L98 had more below peak. In other words, it was only a 25hp difference at peak, but there may have been a greater difference at, say 3000rpm.
C
Drifting
Joined: Feb 2004
Posts: 1,277
Likes: 1
From: Santa Maria CA
205hp v.s. 230hp isn't much difference in a race if torque is the same.
Now torque on the other hand is L98's friend big time,theres not only 25hp more but 40 more ft/tq more aside the hp. Thats a big jump in power all around.
Now torque on the other hand is L98's friend big time,theres not only 25hp more but 40 more ft/tq more aside the hp. Thats a big jump in power all around.
Drifting
Joined: May 2003
Posts: 1,647
Likes: 28
From: Woodbridge NJ
After Chevrolet approved port fuel injection, Ron Midgley and his V-8 engine team was able to increase nhp by 12%, from 205 to 230 at 4000 rpm while torque was increased by 14%, from 290 to 330 ft. lbs. at 3200 rpm. This was achieved while meeting heighten emission standards, not to mention an 11 percent increase in fuel ecomony.
The torque increase was due to the dry manifold, using tuned length intake runners.
From my readings, this was Chevrolet's first step in recapturing the performance peak of 1970.
The torque increase was due to the dry manifold, using tuned length intake runners.
From my readings, this was Chevrolet's first step in recapturing the performance peak of 1970.
Burning Brakes
Joined: Jan 2001
Posts: 1,133
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From: Joplin, MO, USA
Yes, torque is the main difference. I went from an L98 to an LT1, didn't notice much "seat of the pants" difference, because the low end thrust was there, although the quarter mile times are much different, because the LT1 breathes easier in the top end.
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