Thinking about trying a BIG reverse split
08-16-2002, 09:25 AM
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Thinking about trying a BIG reverse split I am going to be swapping cams in September sometime and am considering the following three cams.
230/230 112LSA .6xx lift intake and exhaust
or
234/230 112LSA .6xx lift with a little advance in. (probably 2 degrees if PtoV is ok)
I'll even consider a 236/230 112LSA .6xx lift if I can get it in without clearance issues. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Would be on a lobe slightly more aggressive than the XE-R.
I am also 360ci so I can get away a little bigger than stock ci cars and maintain a decent idle.
My custom ROSS pistons (10.8:1 comp) are in the hole slightly and have valve reliefs so I can run big duration and lift numbers.
What do you think? I think it should make MAD power and peak around 6500rpm. I'll shift around 6800rpm and run it out to 7000rpm at the traps (Depending on my gear/tire height.)
My goal in this car is 125mph in good DA with the 360 cubic inch shortblock and ARE 2.02 1.57 5.3L heads on slicks. I have already gone 122.6mph in good air with the automatic so I think 125mph with the cam change, six speed and a little more weight out is definitely possible.
Your thoughts are welcome..
Cheers,
Chris
230/230 112LSA .6xx lift intake and exhaust
or
234/230 112LSA .6xx lift with a little advance in. (probably 2 degrees if PtoV is ok)
I'll even consider a 236/230 112LSA .6xx lift if I can get it in without clearance issues. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Would be on a lobe slightly more aggressive than the XE-R.
I am also 360ci so I can get away a little bigger than stock ci cars and maintain a decent idle.
My custom ROSS pistons (10.8:1 comp) are in the hole slightly and have valve reliefs so I can run big duration and lift numbers.
What do you think? I think it should make MAD power and peak around 6500rpm. I'll shift around 6800rpm and run it out to 7000rpm at the traps (Depending on my gear/tire height.)
My goal in this car is 125mph in good DA with the 360 cubic inch shortblock and ARE 2.02 1.57 5.3L heads on slicks. I have already gone 122.6mph in good air with the automatic so I think 125mph with the cam change, six speed and a little more weight out is definitely possible.
Your thoughts are welcome..
Cheers,
Chris
08-16-2002, 09:27 AM
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Re: Thinking about trying a BIG reverse split that's freak'n huge, I say TRY IT!!!!
that's almost as big as I'm trying on my 382. Maybe I should have went a few degrees bigger. 236/232 112lsa
that's almost as big as I'm trying on my 382. Maybe I should have went a few degrees bigger. 236/232 112lsa
08-16-2002, 09:31 AM
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Re: Thinking about trying a BIG reverse split God Damn, two weeks ago you were preaching the benefits of the almighty standard split on an LS1 <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
I'd say go for it, but remember you have ARE heads which supposedly need to have the exhaust crutched to make halfway decent numbers.
I'd say go for it, but remember you have ARE heads which supposedly need to have the exhaust crutched to make halfway decent numbers.
08-16-2002, 09:34 AM
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Re: Thinking about trying a BIG reverse split I know of a couple of ARE cars with big single patterns making 445+RWHP.
230 on the exhaust side is still a lot of duration especially on the new style lobes.
Just an experiment to see what happens <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris
230 on the exhaust side is still a lot of duration especially on the new style lobes.
Just an experiment to see what happens <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris
08-16-2002, 09:41 AM
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Re: Thinking about trying a BIG reverse split I'm going to go out on a limb and say that's probably too big. It's gonna idle extremely hard and rev quite a ways up in the rpm band.
Good to see someone with the ***** to try it though. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Good to see someone with the ***** to try it though. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
08-16-2002, 10:25 AM
#6
Re: Thinking about trying a BIG reverse split Chris,
I think you're right on track with the 236/230 cam. The LS6 intake/ported heads combo seems to dictate about a 6 degree reverse split for maximum hp and torque under the curve. Thunder Racing has done extensive testing on reverse-split cams and found some interesting results. On high compression motors with great cylinder heads (like yours) the 230/230 cams made very good power on 346s, but the 230/227 cams made a little more power and torque and the 230/224 made the most. Pretty wierd huh?
The 6 degree reverse-split seems to strike a good balance with the intake side and the exhaust (provided you have very free-flowing exhaust). The end result is more overall tq and hp under the curve with no downsides. I say go for it!
I think you're right on track with the 236/230 cam. The LS6 intake/ported heads combo seems to dictate about a 6 degree reverse split for maximum hp and torque under the curve. Thunder Racing has done extensive testing on reverse-split cams and found some interesting results. On high compression motors with great cylinder heads (like yours) the 230/230 cams made very good power on 346s, but the 230/227 cams made a little more power and torque and the 230/224 made the most. Pretty wierd huh?
The 6 degree reverse-split seems to strike a good balance with the intake side and the exhaust (provided you have very free-flowing exhaust). The end result is more overall tq and hp under the curve with no downsides. I say go for it!
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08-16-2002, 10:30 AM
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Re: Thinking about trying a BIG reverse split </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Chris ARE 360:
<strong>I know of a couple of ARE cars with big single patterns making 445+RWHP.
230 on the exhaust side is still a lot of duration especially on the new style lobes.
Just an experiment to see what happens <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where are these 445+ rwhp ARE cars? Most of the strokers they do don't top that <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> j/k
What do you mean "espcecially on the new style lobes"? 230 on an XE-R is more like a 226 XE just looking at the advertised duration.
Also, where are you going to get lobes more aggressive than XE-R stuff?
<strong>I know of a couple of ARE cars with big single patterns making 445+RWHP.
230 on the exhaust side is still a lot of duration especially on the new style lobes.
Just an experiment to see what happens <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Where are these 445+ rwhp ARE cars? Most of the strokers they do don't top that <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> j/k
What do you mean "espcecially on the new style lobes"? 230 on an XE-R is more like a 226 XE just looking at the advertised duration.
Also, where are you going to get lobes more aggressive than XE-R stuff?
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08-16-2002, 10:45 AM
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08-16-2002, 10:57 AM
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Re: Thinking about trying a BIG reverse split I say for the 236/230.It looks to be the most promising of the 3.I say you can get away with it because of your compression and you have a few more cubes over the 346 it responded well to a 230/230 cam.
08-16-2002, 10:57 AM
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Re: Thinking about trying a BIG reverse split Go with the 236/230. Maybe drop it down to a 110 or 111 lsa?
We really havent found the upper limit with big duration cams on close to stock cubes yet, have we? I wonder if you can stuff a 240/234 in there? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
We really havent found the upper limit with big duration cams on close to stock cubes yet, have we? I wonder if you can stuff a 240/234 in there? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
08-16-2002, 01:04 PM
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Re: Thinking about trying a BIG reverse split How about 234/228? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
It will be interesting to hear from Fireball on this. My impression is that going from the MMS 229 cam to his current 232/232 cam has produced a noticable drop in drivability. Maybe it was in part due to the head swap or lack of time to tune it. Just wondering if 230 on the intake is the start of the cut-off as far as streetability goes.
It will be interesting to hear from Fireball on this. My impression is that going from the MMS 229 cam to his current 232/232 cam has produced a noticable drop in drivability. Maybe it was in part due to the head swap or lack of time to tune it. Just wondering if 230 on the intake is the start of the cut-off as far as streetability goes.
08-16-2002, 01:28 PM
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Re: Thinking about trying a BIG reverse split Chris I don't think it will net you much over what you have now, maybe 5hp max? Spend the effort on something else imho.
08-16-2002, 01:41 PM
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Re: Thinking about trying a BIG reverse split </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong>How about 234/228? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
It will be interesting to hear from Fireball on this. My impression is that going from the MMS 229 cam to his current 232/232 cam has produced a noticable drop in drivability. Maybe it was in part due to the head swap or lack of time to tune it. Just wondering if 230 on the intake is the start of the cut-off as far as streetability goes.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Brian's idle would be much more managable if he had a 232/232 ground from a more aggressive lobe series like the XE-R.
<strong>How about 234/228? <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
It will be interesting to hear from Fireball on this. My impression is that going from the MMS 229 cam to his current 232/232 cam has produced a noticable drop in drivability. Maybe it was in part due to the head swap or lack of time to tune it. Just wondering if 230 on the intake is the start of the cut-off as far as streetability goes.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Brian's idle would be much more managable if he had a 232/232 ground from a more aggressive lobe series like the XE-R.
08-16-2002, 02:13 PM
#14
Re: Thinking about trying a BIG reverse split The faster lobes will help, but a 236 XE-R will have the same duration at .006 as fireball's 232 XE cam (285) so the intake will be same although the exhaust will be shorter. (285 vs. 279).
He also went down in LSA so that didn't help things either. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
<small>[ August 16, 2002, 02:14 PM: Message edited by: Ragtop 99 ]</small>
He also went down in LSA so that didn't help things either. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
<small>[ August 16, 2002, 02:14 PM: Message edited by: Ragtop 99 ]</small>
08-16-2002, 03:30 PM
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Re: Thinking about trying a BIG reverse split I'm still waiting on my cam, but when it goes in & I come over to tune, you can stop by & see how a 230-236-112 works out <img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" />
08-16-2002, 04:33 PM
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Re: Thinking about trying a BIG reverse split </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong>The faster lobes will help, but a 236 XE-R will have the same duration at .006 as fireball's 232 XE cam (285) so the intake will be same although the exhaust will be shorter. (285 vs. 279).
He also went down in LSA so that didn't help things either. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I was just pointing out in my previous post that saying "230 might be the cutoff point" is very misleading since that is only the duration @ .050 and has nothing to do with idle quality and overlap of a cam. You are right in that a 236 XE-R will be nearly identical to a 232 XE lobe.
<strong>The faster lobes will help, but a 236 XE-R will have the same duration at .006 as fireball's 232 XE cam (285) so the intake will be same although the exhaust will be shorter. (285 vs. 279).
He also went down in LSA so that didn't help things either. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I was just pointing out in my previous post that saying "230 might be the cutoff point" is very misleading since that is only the duration @ .050 and has nothing to do with idle quality and overlap of a cam. You are right in that a 236 XE-R will be nearly identical to a 232 XE lobe.
08-19-2002, 08:38 PM
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Re: Thinking about trying a BIG reverse split Back from Holidays... <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
I am going to be talking/stopping by ARE this week to discuss what they think. Going to look at my flow sheets/port volume intake and exhaust and see what we can come up with.
A 234/230 112LSA .6xx/.6xx lift is what I am seriously considering right now. With an 975-1100rpm idle it will be perfectly fine idling. I have 4.11 gears and even with the old style 226/234 cam have PLENTY of torque.
Should be a fun experiment. I am hoping the stock clutch can hold up to it on the dyno heheheh <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Chris
I am going to be talking/stopping by ARE this week to discuss what they think. Going to look at my flow sheets/port volume intake and exhaust and see what we can come up with.
A 234/230 112LSA .6xx/.6xx lift is what I am seriously considering right now. With an 975-1100rpm idle it will be perfectly fine idling. I have 4.11 gears and even with the old style 226/234 cam have PLENTY of torque.
Should be a fun experiment. I am hoping the stock clutch can hold up to it on the dyno heheheh <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Chris
08-19-2002, 09:32 PM
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Re: Thinking about trying a BIG reverse split I asked Nick about a reverse split in my 422 but, he recommended staying with a single pattern 240/240 .6XX .6XX 114(idle in a auto)
It'll be interesting to see what you gain by increasing intake dur. 8°, decreasing exhaust dur. 4°, going with more aggressive lobes, and going with more lift. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
When are you going to ARE this week? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
John
It'll be interesting to see what you gain by increasing intake dur. 8°, decreasing exhaust dur. 4°, going with more aggressive lobes, and going with more lift. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
When are you going to ARE this week? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
John
08-20-2002, 07:08 AM
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Re: Thinking about trying a BIG reverse split </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong>It will be interesting to hear from Fireball on this. My impression is that going from the MMS 229 cam to his current 232/232 cam has produced a noticable drop in drivability. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Rag...I believe it was more of the LSA that caused the drop in drivability... Going from the 114 to the current 112 really chopped up the idle quality <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Have a hard time believing that the 2 extra degrees of duration did that <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
<strong>It will be interesting to hear from Fireball on this. My impression is that going from the MMS 229 cam to his current 232/232 cam has produced a noticable drop in drivability. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Rag...I believe it was more of the LSA that caused the drop in drivability... Going from the 114 to the current 112 really chopped up the idle quality <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Have a hard time believing that the 2 extra degrees of duration did that <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />