C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

HP Guesstimate

Thread Tools
 
Search this Thread
 
Old Feb 8, 2005 | 09:45 AM
  #1  
COMMANDER370's Avatar
COMMANDER370
Thread Starter
Burning Brakes
 
Joined: Apr 2004
Posts: 814
Likes: 2
From: WESTLAKE LA
Default HP Guesstimate

Sunday i drove my car for the 1st time in 12 years. I have been working on it in my spare time for the last 6-8 months.Young guy in Honda with a fart can the size of a small bbq pit pulls up along side me at red light and asked"hey, how many h.p. you got".I told him enough, but i really do not know.Any ideas how much h.p i have?
1980 L-82,now running headers,2-1/2" dual w/o cat.Weiand stealth, 4160 Holley 600cfm and CompCam 270H cam.Stock heads(this will be my next change when piggy bank gets refilled)
Reply
Old Feb 8, 2005 | 09:53 AM
  #2  
SpyderD's Avatar
SpyderD
Pro
15 Year Member
 
Joined: Sep 2002
Posts: 690
Likes: 1
From: near Memphis TN
Default

About 40HP over stock, most benifited from the addition of the dual exhaust and the cat removal. You have a good street setup, next step as you probably know is to get new heads and then start reaping the benifits of the headers and manifold. Hint - get some heads that increase that lame stock compression by a point or two.
Reply
Old Feb 8, 2005 | 10:05 AM
  #3  
oregonsharkman's Avatar
oregonsharkman
Melting Slicks
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2004
Posts: 2,165
Likes: 950
From: Keizer Oregon
Default

guessing about 245@the flywheel net. Heads should make a real difference since you already have the cam.
Reply
Old Feb 8, 2005 | 10:25 AM
  #4  
mandm1200's Avatar
mandm1200
Melting Slicks
Supporting Lifetime
 
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Default

I'm not sure of what the 80 had for an exhuast system, but the earlier C3's with a cat could pick up 50hp by changing the exhaust system. Add a few more ponies for the cam. If the engine was put on a dyno without accessories I would think in the neighborhood of 315-330hp.
What some people don't realize is that a 69 350hp when dynoed by todays procedures would only put out 320hp or maybe even less. Throw a restrictive cat exhaust system on it and it would be well under 300hp. It just sounds good to say 350hp versus 270hp. Same engine just tested differently.

Edit
The 80 L-82 started out as a 230hp engine.

Last edited by mandm1200; Feb 8, 2005 at 10:31 AM.
Reply
Old Feb 8, 2005 | 10:30 AM
  #5  
Matt Gruber's Avatar
Matt Gruber
Race Director
Active Streak: 30 Days
Community Influencer
Liked
Loved
 
Joined: Oct 2000
Posts: 14,996
Likes: 79
From: central FL, near the beach.
Default

my guess 280
200 rwhp
Reply
Old Feb 8, 2005 | 11:15 AM
  #6  
COMMANDER370's Avatar
COMMANDER370
Thread Starter
Burning Brakes
 
Joined: Apr 2004
Posts: 814
Likes: 2
From: WESTLAKE LA
Default

Originally Posted by SpyderD
About 40HP over stock, most benifited from the addition of the dual exhaust and the cat removal. You have a good street setup, next step as you probably know is to get new heads and then start reaping the benifits of the headers and manifold. Hint - get some heads that increase that lame stock compression by a point or two.

What heads do you recommend?
Reply
Old Feb 8, 2005 | 01:27 PM
  #7  
SpyderD's Avatar
SpyderD
Pro
15 Year Member
 
Joined: Sep 2002
Posts: 690
Likes: 1
From: near Memphis TN
Default

Originally Posted by COMMANDER370
What heads do you recommend?
You will get many recommendations on that. I will just say what I have on mine - L98 aluminum heads that have been ported and polished. The previous owner put them on and I kept them when I replaced the engine. I like them - it will raise your compression to around the 9.7 range with the small chambers, they are lightweight, they are relatively cheap from GM (they come stock with ZZ4 engines). There are better flowing heads for more money out there BUT these heads got me to the low 13's in the quarter mile and that's good enough for me. I think they would be a good match for your cam's lift.
Reply
Old Feb 8, 2005 | 02:43 PM
  #8  
COMMANDER370's Avatar
COMMANDER370
Thread Starter
Burning Brakes
 
Joined: Apr 2004
Posts: 814
Likes: 2
From: WESTLAKE LA
Default

Originally Posted by SpyderD
You will get many recommendations on that. I will just say what I have on mine - L98 aluminum heads that have been ported and polished. The previous owner put them on and I kept them when I replaced the engine. I like them - it will raise your compression to around the 9.7 range with the small chambers, they are lightweight, they are relatively cheap from GM (they come stock with ZZ4 engines). There are better flowing heads for more money out there BUT these heads got me to the low 13's in the quarter mile and that's good enough for me. I think they would be a good match for your cam's lift.
Spyder,thanks for the info.Will keep my eyes open for a deal
Reply

Get notified of new replies

To HP Guesstimate

Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-1

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski




All times are GMT -4. The time now is 09:14 PM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE