Backpressure - Can big wastegates help?
12-22-2010, 09:09 AM
#41
TECH Apprentice
12-22-2010, 09:20 AM
#43
TECH Apprentice
no, he never knew you said / asked the question..
i asked him awhile ago... chatting about air flow dynamics..
he did major in that, in mechanical engineering..
i'll find my serect squirrel note book
i asked him awhile ago... chatting about air flow dynamics..
he did major in that, in mechanical engineering..
i'll find my serect squirrel note book
Last edited by crashly; 12-22-2010 at 09:28 AM.
12-22-2010, 10:32 AM
#44
If i were to re-do my hot side, what would be the ideal sized pipe diameter? Remember i am using T3 exhaust housings. I ask this because if the high hp front mount guys can run 2.5" from the motor to the turbo, surely my pipe is too large for my rear mount. My goal would be to improve spool while not chocking up the motor. I have dual 2.5 from motor to the turbo's now. I have the larger exhaust housing coming so hopefully that takes care of my backpressure issue. Anymore opinions? Thanks!
Last edited by TracyRR; 12-22-2010 at 10:45 AM.
12-22-2010, 11:13 AM
#45
phil first of all im sure that you don't care about my opinion on what would be optimal but more like your trying to troll me
and in all honesty there should be way more engineering involved with your build for me to even start to tell you what you need
but i honestly hope everything works well for you and im sure your car will be sick
and in all honesty there should be way more engineering involved with your build for me to even start to tell you what you need
but i honestly hope everything works well for you and im sure your car will be sick
12-22-2010, 11:21 AM
#46
If i were to re-do my hot side, what would be the ideal sized pipe diameter? Remember i am using T3 exhaust housings. I ask this because if the high hp front mount guys can run 2.5" from the motor to the turbo, surely my pipe is too large for my rear mount. My goal would be to improve spool while not chocking up the motor. I have dual 2.5 from motor to the turbo's now. I have the larger exhaust housing coming so hopefully that takes care of my backpressure issue. Anymore opinions? Thanks!
as far as what front mounts do is a completely different ball game and there a lot of variable that don't apply to you
from a engineering stand point i don't see benefits from downsizing your hot side if somebody has one i would love to hear it
12-22-2010, 12:14 PM
#47
phil first of all im sure that you don't care about my opinion on what would be optimal but more like your trying to troll me
and in all honesty there should be way more engineering involved with your build for me to even start to tell you what you need
but i honestly hope everything works well for you and im sure your car will be sick
and in all honesty there should be way more engineering involved with your build for me to even start to tell you what you need
but i honestly hope everything works well for you and im sure your car will be sick
12-22-2010, 12:25 PM
#48
If i were to re-do my hot side, what would be the ideal sized pipe diameter? Remember i am using T3 exhaust housings. I ask this because if the high hp front mount guys can run 2.5" from the motor to the turbo, surely my pipe is too large for my rear mount. My goal would be to improve spool while not chocking up the motor. I have dual 2.5 from motor to the turbo's now. I have the larger exhaust housing coming so hopefully that takes care of my backpressure issue. Anymore opinions? Thanks!
having looked at multiple engine builds and worked with more than enough people around the country with AMS-1000 tuning, I've documented more setups than you can shake a stick at as far as spooling speed, boost ramp rates, exhaust setups, turbine housings, and many other things. With that being said for a 370" motor that would make about 20# of boost, you'd have a couple options for sizing
Headers, using a straight header 1 5/8" or a stepped 1 5/8" to 1 1/2" produces a airflow speed of 229cfm or 229cfm to 276cfm based on the header sizing chosen
Connection pipes, 2.25" tubes yeild 480cfm at peak boost.
Without getting too deep into my findings those numbers would providing faster spooling than larger lower CFM setups.
There is a correlation between header/crossover size and spooling time. Other factors will also move the spool time up and down.
I'm sure tripleblackLS1 will say that 2.25" pipes are not big enough to make 1000hp but its about velocity. If 2.25" pipes can't support 500hp(1/2 of 1000total HP), than how can 2.5" can support 1250(1/2 of 2500hp).
Last edited by Phil99vette; 12-22-2010 at 12:49 PM.
12-22-2010, 01:09 PM
#49
Connection pipes, 2.25" tubes yeild 480cfm at peak boost.
Without getting too deep into my findings those numbers would providing faster spooling than larger lower CFM setups.
There is a correlation between header/crossover size and spooling time. Other factors will also move the spool time up and down.
I'm sure tripleblackLS1 will say that 2.25" pipes are not big enough to make 1000hp but its about velocity. If 2.25" pipes can't support 500hp(1/2 of 1000total HP), than how can 2.5" can support 1250(1/2 of 2500hp).
Without getting too deep into my findings those numbers would providing faster spooling than larger lower CFM setups.
There is a correlation between header/crossover size and spooling time. Other factors will also move the spool time up and down.
I'm sure tripleblackLS1 will say that 2.25" pipes are not big enough to make 1000hp but its about velocity. If 2.25" pipes can't support 500hp(1/2 of 1000total HP), than how can 2.5" can support 1250(1/2 of 2500hp).
12-26-2010, 06:12 PM
#58
Just a quick clip from 40mph to ?mph....i was trying to lug it in 2nd gear only for a backpressure test. the 335 r888's broke loose around 18 pounds of boost. Backpressure was 39 pounds at 18 pounds of boost...little over 2.1:1 b/p ratio. I have larger exh housings coming so i will followup with another test next week. Not sure if i attached the link properly but it is in my photobucket. Tracyrr-corvette. p.s... excuse the quality... my buddy must have been drunk.
http://s1008.photobucket.com/albums/...t=M4H00068.mp4
http://s1008.photobucket.com/albums/...t=M4H00068.mp4
12-26-2010, 10:49 PM
#59
Just a quick clip from 40mph to ?mph....i was trying to lug it in 2nd gear only for a backpressure test. the 335 r888's broke loose around 18 pounds of boost. Backpressure was 39 pounds at 18 pounds of boost...little over 2.1:1 b/p ratio. I have larger exh housings coming so i will followup with another test next week. Not sure if i attached the link properly but it is in my photobucket. Tracyrr-corvette. p.s... excuse the quality... my buddy must have been drunk.
http://s1008.photobucket.com/albums/...t=M4H00068.mp4
http://s1008.photobucket.com/albums/...t=M4H00068.mp4
This is with the old pipe setup?
