Advanced Engineering Tech For the more hardcore LS1TECH residents

Advanced Guru's Only Please Respond! Copied From Nitrous Section

Thread Tools
 
Search this Thread
 
Old Mar 6, 2007 | 08:50 PM
  #1  
bshonda's Avatar
Thread Starter
Teching In
iTrader: (1)
 
Joined: Aug 2005
Posts: 38
Likes: 0
From: Memphis, Tn
Default Advanced Guru's Only Please Respond! Copied From Nitrous Section

in the motor section i notice alot of talk that goes on about DCR ratios and how important it is to get to 8.5 to keep running pump gas. and everyone should select a cam and heads setup to get you to this mark. but what i dont see is anyone talking about how nitrous will affect this ratio. if im going to get a cam and head setup for nitrous, then what should i shot for in a DCR ratio? how much does a 100 shot affect that DCR ratio? what will a 200 shot do to it? how much will more or less valve overlap change this with lower or higher lobe seperation? if i have less lift with more duration, will my DCR rise less or more than it would if i had high lift and long durartion? alot of questions i know, but what bothers me is that i cant find where anyone has ask these questions. and lastly, piano, can you come up with a chart that you could input a nitrous shot and compute what the DCR would rise too?
GO TO WORK GUYS!!!
Reply
Old Mar 7, 2007 | 07:04 PM
  #2  
XBR24's Avatar
Teching In
 
Joined: Dec 2006
Posts: 15
Likes: 0
From: Crown Point, IN
Default

DCR should not be the End-all number... infact.. it seems to be QUITE overrated on this forum.

DCR is a basic calculation that has NOTHING to do with rpm. The DCR is only calculated by intake valve closing and basic geometric calculations for piston location.

Your DCR vs SCR will tell you what type of engine you have... if your SCR is 15:1 and your DCR is 7:1, you will have a high rpm engine... likewise if you have a 8:1 SCR and a 7.9 DCR.. you will have a low rpm engine.

Your IVC is critical for rpm selection, espeially NA because your trying to capture all the momentum of the air charge, the higher the target rpm, usually you will want a later IVC.

If you put to much empahsis on the DCR number you will not get the big picture!!
Reply
Old Mar 8, 2007 | 09:18 AM
  #3  
bshonda's Avatar
Thread Starter
Teching In
iTrader: (1)
 
Joined: Aug 2005
Posts: 38
Likes: 0
From: Memphis, Tn
Default

Originally Posted by XBR24
DCR should not be the End-all number... infact.. it seems to be QUITE overrated on this forum.

DCR is a basic calculation that has NOTHING to do with rpm. The DCR is only calculated by intake valve closing and basic geometric calculations for piston location.

Your DCR vs SCR will tell you what type of engine you have... if your SCR is 15:1 and your DCR is 7:1, you will have a high rpm engine... likewise if you have a 8:1 SCR and a 7.9 DCR.. you will have a low rpm engine.

Your IVC is critical for rpm selection, espeially NA because your trying to capture all the momentum of the air charge, the higher the target rpm, usually you will want a later IVC.

If you put to much empahsis on the DCR number you will not get the big picture!!
funny you should say all that, cause the comp cams gods just said the exact same thing. thanks for the input!!!
Reply
Old Mar 9, 2007 | 11:45 AM
  #4  
koolrayz's Avatar
8 Second Club
iTrader: (26)
 
Joined: Nov 2002
Posts: 2,644
Likes: 3
From: mansfield ohio
Default

Originally Posted by bshonda
the comp cams gods
Thats like saying "military intelligents"
oxymoron
Reply
Old Mar 9, 2007 | 12:04 PM
  #5  
brad8266's Avatar
TECH Senior Member
iTrader: (23)
 
Joined: Aug 2005
Posts: 8,797
Likes: 0
From: Watertown, NY
Default

Originally Posted by koolrayz
Thats like saying "military intelligents"
oxymoron
Reply




All times are GMT -5. The time now is 04:50 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE