1991 corvette cam question !!
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
My ride
A4 3.07 ,100K L98 .Heads never been off
ZZ4 cam , 1.5 roller tip rockers ,home ported intake/ plenum,SLP big tubes.LT's,No cat.
Original injectors / spark wires/ dist /etc.
Runs 13.0X -13.1X all day in street trim.Never been correctly tuned.
Best 12.98 (3 times)
1.70 60ft's on MT DR's
"Not that much" of an improvement over 14.2 stock
A4 3.07 ,100K L98 .Heads never been off
ZZ4 cam , 1.5 roller tip rockers ,home ported intake/ plenum,SLP big tubes.LT's,No cat.
Original injectors / spark wires/ dist /etc.
Runs 13.0X -13.1X all day in street trim.Never been correctly tuned.
Best 12.98 (3 times)
1.70 60ft's on MT DR's
"Not that much" of an improvement over 14.2 stock
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
My ride
A4 3.07 ,100K L98 .Heads never been off
ZZ4 cam , 1.5 roller tip rockers ,home ported intake/ plenum,SLP big tubes.LT's,No cat.
Original injectors / spark wires/ dist /etc.
Runs 13.0X -13.1X all day in street trim.Never been correctly tuned.
Best 12.98 (3 times)
1.70 60ft's on MT DR's
"Not that much" of an improvement over 14.2 stock
A4 3.07 ,100K L98 .Heads never been off
ZZ4 cam , 1.5 roller tip rockers ,home ported intake/ plenum,SLP big tubes.LT's,No cat.
Original injectors / spark wires/ dist /etc.
Runs 13.0X -13.1X all day in street trim.Never been correctly tuned.
Best 12.98 (3 times)
1.70 60ft's on MT DR's
"Not that much" of an improvement over 14.2 stock
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
ZZ4 has same heads as L98 (113) .ZZ4 is rated 355Hp with carb.
Obviously lose some hp with TPI but pickup on torque hense the good 60 ft.
"Untuned " defined as never been on a dyno; track adjustment of inital advance only.Has generic chip mods for spirted driving.
Still maintain ZZ4 cam /basic porting /exhaust mods excellent budget upgrade.
Want me to send you my time slips?
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
The online calcs show about 310 chp @3450lb race weight so nearer 70hp increase.
ZZ4 has same heads as L98 (113) .ZZ4 is rated 355Hp with carb.
Obviously lose some hp with TPI but pickup on torque hense the good 60 ft.
"Untuned " defined as never been on a dyno; track adjustment of inital advance only.Has generic chip mods for spirted driving.
Still maintain ZZ4 cam /basic porting /exhaust mods excellent budget upgrade.
Want me to send you my time slips?
ZZ4 has same heads as L98 (113) .ZZ4 is rated 355Hp with carb.
Obviously lose some hp with TPI but pickup on torque hense the good 60 ft.
"Untuned " defined as never been on a dyno; track adjustment of inital advance only.Has generic chip mods for spirted driving.
Still maintain ZZ4 cam /basic porting /exhaust mods excellent budget upgrade.
Want me to send you my time slips?
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
The online calcs show about 310 chp @3450lb race weight so nearer 70hp increase.
ZZ4 has same heads as L98 (113) .ZZ4 is rated 355Hp with carb.
Obviously lose some hp with TPI but pickup on torque hense the good 60 ft.
"Untuned " defined as never been on a dyno; track adjustment of inital advance only.Has generic chip mods for spirted driving.
Still maintain ZZ4 cam /basic porting /exhaust mods excellent budget upgrade.
Want me to send you my time slips?
ZZ4 has same heads as L98 (113) .ZZ4 is rated 355Hp with carb.
Obviously lose some hp with TPI but pickup on torque hense the good 60 ft.
"Untuned " defined as never been on a dyno; track adjustment of inital advance only.Has generic chip mods for spirted driving.
Still maintain ZZ4 cam /basic porting /exhaust mods excellent budget upgrade.
Want me to send you my time slips?
I don't doubt your 13.0 but did you actually run 14.2 with your own car or did you take that from somewhere as the stock figure for your year? I mean maybe your car was faster to start with? BTW. do you still run stock converter (if A4 trans)?
I thought you need 10hp to make 0.1sec improvement? 1.2 sec would then need a lot more than 70hp.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
When I first got car ran 14.2ish; couple of 14.1's
Lt's , hi flow cat,freeflow mufflers, air pump delete and freeby mods took it down to 13.7ish I recall.Cat was stuffed which could account for less than startling performance.
Replacing cat with test pipe for track days worth good 1-1.5 sec.
Did cam/ intake at same time;took it to 13.2 ; no traction on street tyres.
The DR's dropped the 60 ft times from 1.9 to consistant 1.7's.
Ambient temps at track (sea level ) rarely below 80 , usually into 90's.
Best times was late in day with 1/4 tank with track still warm but air temp down.
Has 2K convertor
Lt's , hi flow cat,freeflow mufflers, air pump delete and freeby mods took it down to 13.7ish I recall.Cat was stuffed which could account for less than startling performance.
Replacing cat with test pipe for track days worth good 1-1.5 sec.
Did cam/ intake at same time;took it to 13.2 ; no traction on street tyres.
The DR's dropped the 60 ft times from 1.9 to consistant 1.7's.
Ambient temps at track (sea level ) rarely below 80 , usually into 90's.
Best times was late in day with 1/4 tank with track still warm but air temp down.
Has 2K convertor
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Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
First recommended modification for L98's
Hookers #2151 popular
http://speeddemonmotorsports.com/catalog/exhaustC4.html
Hookers #2151 popular
http://speeddemonmotorsports.com/catalog/exhaustC4.html
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Seriously though, I like tuning speed density more than MAF, but it's a fact the more cam you have, the less resolution you end up with.
Some interesting advice in the thread. Guess a lot of you guys are really into budget builds. Thats cool! I don't think you'll ever catch me wasting my time with stock heads + intake unless its a plow truck or tow rig.
-- Joe
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
"Guess a lot of you guys are really into budget builds. Thats cool! I don't think you'll ever catch me wasting my time with stock heads + intake unless its a plow truck or tow rig."
Joe ,
in the backblocks of the world where you pay US$20K for a 20yr old Vette and cams are $600+/ heads $2500 pr you do what it take.
You can tell from the doubter's that I've done allright.
Got 11;1 383 HSR now.
Joe ,
in the backblocks of the world where you pay US$20K for a 20yr old Vette and cams are $600+/ heads $2500 pr you do what it take.
You can tell from the doubter's that I've done allright.
Got 11;1 383 HSR now.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
"Guess a lot of you guys are really into budget builds. Thats cool! I don't think you'll ever catch me wasting my time with stock heads + intake unless its a plow truck or tow rig."
Joe ,
in the backblocks of the world where you pay US$20K for a 20yr old Vette and cams are $600+/ heads $2500 pr you do what it take.
You can tell from the doubter's that I've done allright.
Got 11;1 383 HSR now.
Joe ,
in the backblocks of the world where you pay US$20K for a 20yr old Vette and cams are $600+/ heads $2500 pr you do what it take.
You can tell from the doubter's that I've done allright.
Got 11;1 383 HSR now.
-- Joe
