it seems like the XE-R lobes...
Thread Starter
TECH Senior Member
iTrader: (7)
Joined: Nov 2001
Posts: 9,491
Likes: 1
From: Bethesda, MD
it seems like the XE-R lobes... I was talking with Chris Pippy and he observed that it seems like the XE-R cammed cars are showing peak HP at lower rpms then we anticipated.
For example my car with a 224/224 114 peaked at 6100 rpm (locked converter). I would have guessed 6300 with a 114 LSA.
Do others concur with this observation?
For example my car with a 224/224 114 peaked at 6100 rpm (locked converter). I would have guessed 6300 with a 114 LSA.
Do others concur with this observation?
Re: it seems like the XE-R lobes... How many degrees of advance do you have ground in? My 224/224/112 LSA XE-R peaked at 6,550 with 2 degrees ground in. It's pretty flat from 6300-6800, but the actual peak is 6550.
__________________
Thread Starter
TECH Senior Member
iTrader: (7)
Joined: Nov 2001
Posts: 9,491
Likes: 1
From: Bethesda, MD
Re: it seems like the XE-R lobes... Trevor:
I think it is 2 degrees but I never got the cam sheet.
I am within 10 HP of peak from 5700 - 6600. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
If the converter isn't locked, the rpm is skewed with a high stall converter, because the dyno samples during the shift extension and computes an incorrect rpm/mph factor.
Unlocked, my dyno rpm goes 300 rpm beyond my rev limiter <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />
<small>[ August 29, 2002, 03:19 PM: Message edited by: Ragtop 99 ]</small>
I think it is 2 degrees but I never got the cam sheet.
I am within 10 HP of peak from 5700 - 6600. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
If the converter isn't locked, the rpm is skewed with a high stall converter, because the dyno samples during the shift extension and computes an incorrect rpm/mph factor.
Unlocked, my dyno rpm goes 300 rpm beyond my rev limiter <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />
<small>[ August 29, 2002, 03:19 PM: Message edited by: Ragtop 99 ]</small>
Re: it seems like the XE-R lobes... my 230/230 111 LSA cam peaked at "only" 6450 rpms. i was happy with that.
also i thought with teh convertor locked "it slips" and shows a higher peak than in reality.
also i thought with teh convertor locked "it slips" and shows a higher peak than in reality.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Re: it seems like the XE-R lobes... Dependant upon where you put the lobe, that will affect the peak. 2 cams that are identical, one on a 112 and the other on a 114 will have a different peak. Like the B1 and T1. Same grind, different LSA, you will find that the T1 will peak higher.
The XE-R lobe is just that, a lobe. Where you have that lobe placed (duration, Lift, advance, LSA...ect..) will determine where it peaks at.
Remember, Cylinder heads also change the peak dependant on port size, ect.
The XE-R lobe is just that, a lobe. Where you have that lobe placed (duration, Lift, advance, LSA...ect..) will determine where it peaks at.
Remember, Cylinder heads also change the peak dependant on port size, ect.
Thread Starter
TECH Senior Member
iTrader: (7)
Joined: Nov 2001
Posts: 9,491
Likes: 1
From: Bethesda, MD
Re: it seems like the XE-R lobes... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by G2 LS1:
<strong>The XE-R lobe is just that, a lobe. Where you have that lobe placed (duration, Lift, advance, LSA...ect..) will determine where it peaks at.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That was my assumption, but I wasn't sure if the ramp rates and the shorter total duration (i.e. advertised duration of an XE-R lobe is about 4 degrees less than an XE lobe of similar duration at .050) were causing a couple hundred rpm change.
Head flow characteristics could definitely be a factor and explain why the ARE SII cars like mine perform well with bigger cams.
<strong>The XE-R lobe is just that, a lobe. Where you have that lobe placed (duration, Lift, advance, LSA...ect..) will determine where it peaks at.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That was my assumption, but I wasn't sure if the ramp rates and the shorter total duration (i.e. advertised duration of an XE-R lobe is about 4 degrees less than an XE lobe of similar duration at .050) were causing a couple hundred rpm change.
Head flow characteristics could definitely be a factor and explain why the ARE SII cars like mine perform well with bigger cams.
