Twins v. Compounds
07-10-2009, 07:55 PM
#2
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I may not be correct, but from what I think I know is that in order to have true twin turbos you have to have one turbo on each side of the exhaust manifold(each of the same size) which isn't possible on a truck like ours. Its more of something that you see on gas vehicles with two headers. Compounds are what our trucks really run. One smaller turbo that feeds a much larger turbo. I say I have twins for two reasons. Its faster to say, and a lot of people have no clue what compound turbo's are.
07-10-2009, 09:18 PM
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exactly what he said people slang the term "twins" on cummins but they are in fact compound turbocharging different sized turbos in series. twins on the V8s and any V engine twin turbos 1 bank 1 turbo. same sized turbos in parrallel. don't get hung up on the terminology. theres enough of the grammer and etiquette police around.
07-10-2009, 11:35 PM
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One smaller turbo that feeds a much larger turbo
07-11-2009, 12:04 AM
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that is correct. follow the compressor path. I do know that. I was in a rush. point there was unequal charger sizes in SERIES in compounding. Equal chargers in PARALLEL in twins.
07-11-2009, 12:17 AM
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Yea, my bad. I knew I was going to mess something up in my explanation. I can put the stuff together pretty well, but explaining how it works isn't my strong point.
And I have one question for y'all that are good with compound tweaking. I would like to get a little better low end spool. I've heard that I want to tighten my waste gate a little bit. Is that correct?
Main reason I ask is because if I get on it to get goin when I pull out in traffic I will smoke out a city block and I don't feel like being responsible for an accident. And I cannot turn down my fuel anymore or I will loose my top end.
And I have one question for y'all that are good with compound tweaking. I would like to get a little better low end spool. I've heard that I want to tighten my waste gate a little bit. Is that correct?
Main reason I ask is because if I get on it to get goin when I pull out in traffic I will smoke out a city block and I don't feel like being responsible for an accident. And I cannot turn down my fuel anymore or I will loose my top end.
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07-11-2009, 10:28 AM
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Just a idea but how would it work if you were to split the manifold and and run true twins. I know there would be more to it than just that but in my head atleast it sounds good.
07-11-2009, 07:55 PM
#10
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Yea, my bad. I knew I was going to mess something up in my explanation. I can put the stuff together pretty well, but explaining how it works isn't my strong point.
And I have one question for y'all that are good with compound tweaking. I would like to get a little better low end spool. I've heard that I want to tighten my waste gate a little bit. Is that correct?
Main reason I ask is because if I get on it to get goin when I pull out in traffic I will smoke out a city block and I don't feel like being responsible for an accident. And I cannot turn down my fuel anymore or I will loose my top end.
And I have one question for y'all that are good with compound tweaking. I would like to get a little better low end spool. I've heard that I want to tighten my waste gate a little bit. Is that correct?
Main reason I ask is because if I get on it to get goin when I pull out in traffic I will smoke out a city block and I don't feel like being responsible for an accident. And I cannot turn down my fuel anymore or I will loose my top end.
That will get them to spool faster.
If you are smoking that bad, you need to adjust your pre-boost fuel on the back of the pump. It will not effect full fuel at all. If they are smoking that bad, you are actually hindering spoolup by "putting ou the fire".
07-11-2009, 08:23 PM
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Is it possible that I have any bit of a timing issue. I have tried different star wheel adjustments for probably about 12 hours and too low I run out of fuel and too high it snuffs it out like you said.
07-11-2009, 10:08 PM
#12
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You take your afc off, use shop air where the afc boost line goes into and adjust the starwheel so it afc arm will slide forward at 25psi.
On the back of the afc right next to the boost line is anothe metal cap with 2 screws one being tamper proof. Cut that cap off and that is the pre boost screw. Loosening it cuts fuel down before boost hence pre-boost fuel.
Your starwheel controls WOT full fuel load.
The pre-boost fuel screw controls the fuel before boost.
Hope this helps.
If you cant find it, I will take a picture for you as I have an extra AFC. PM me and let me know.
Also, have you done all the AFC mods?
07-11-2009, 10:12 PM
#13
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Here is an excellent thread about AFC mods and the 4th pic. shows the pre-boost screw without the cover on it.
http://competitiondiesel.com/forums/...ad.php?t=11047
http://competitiondiesel.com/forums/...ad.php?t=11047
07-11-2009, 10:12 PM
#14
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No AFC modification done at all. I have a good feeling that may be my main issue. If possible could you please send a picture of that screw you are talking about. My email is Laxboy3211@hotmail.com if that makes it easier.
Thanks a bunch for your help!
Thanks a bunch for your help!