Uncontrollable boost; check this manifold out..
#1
Honda-Tech Member
Thread Starter
Uncontrollable boost; check this manifold out..
Just want to get some opinions on this manifold and see if anybody can spot something out of the ordinary. I just installed a brand new Precision PW46 gate, 9psi spring, take it out for it's first run and I'm seeing around 12-13psi steady untill around 6k when it starts to creep and finally around 7k it just shoot right up to 20+psi.. Tried 3 different wastegates, various springs, running it right off the comrpessor housing to the bottom port etc.. at this point, the only thing I can think of is that there is something wrong or altering exahust flow to the wastegate outlet, which is why I'm posting these shots up. LMK!
#3
Honda-Tech Member
iTrader: (4)
Join Date: Apr 2005
Location: South, Texas
Posts: 12,903
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
the wastegate may not be opening, that the top off the wastegate and confirm you have only a 7 psi spring in there. Someone recently was having similar issue witha tial wg that supposed to come with 9 psi spring and when he opening it up there was two springs inside that equaled over 20 psi
#5
Honda-Tech Member
Thread Starter
Re: Uncontrollable boost; check this manifold out..
the wastegate may not be opening, that the top off the wastegate and confirm you have only a 7 psi spring in there. Someone recently was having similar issue witha tial wg that supposed to come with 9 psi spring and when he opening it up there was two springs inside that equaled over 20 psi
#6
Honda-Tech Member
Join Date: Mar 2000
Location: Toronto, ON, Canada
Posts: 2,859
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
Bench test the wastegate.. Supply it with an air source and an inline pressure gauge, and test it for valve movement. You'll be able to discover that it is the wastegate's fault or the manifold.
Don't keep using your engine for testing, because it's not wise to keep hitting that unintented boost.
Don't keep using your engine for testing, because it's not wise to keep hitting that unintented boost.
#7
Honda-Tech Member
Thread Starter
Re: Uncontrollable boost; check this manifold out..
Bench test the wastegate.. Supply it with an air source and an inline pressure gauge, and test it for valve movement. You'll be able to discover that it is the wastegate's fault or the manifold.
Don't keep using your engine for testing, because it's not wise to keep hitting that unintented boost.
Don't keep using your engine for testing, because it's not wise to keep hitting that unintented boost.
Trending Topics
#8
Honda-Tech Member
Join Date: Aug 2010
Location: Olympia,Wa
Posts: 4,592
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
#9
Honda-Tech Member
Join Date: Mar 2000
Location: Toronto, ON, Canada
Posts: 2,859
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
If the wastegate is opening, and is opening fully, then I would look at the boost signal source for the wastegate (kinks, line blockage, etc..) as the next potential problem.
Over retarted ignition timing and rich AFR's can also cause boost creep.. I had cases which boost creep was present (15 PSI creeps to 20+ PSI), but simply dialing up the timing have brought it down to acceptable levels (15 PSI creeps to 17 PSI). The amount of timing you can run will depend on your setup though, so an hour at the dyno can help you further troubleshoot.
Over retarted ignition timing and rich AFR's can also cause boost creep.. I had cases which boost creep was present (15 PSI creeps to 20+ PSI), but simply dialing up the timing have brought it down to acceptable levels (15 PSI creeps to 17 PSI). The amount of timing you can run will depend on your setup though, so an hour at the dyno can help you further troubleshoot.
#10
Honda-Tech Member
Join Date: Aug 2010
Location: Olympia,Wa
Posts: 4,592
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
This is what Im thinking as well thats why I asked. A buddy of mine ran his vacumme source for his waste Gate off his compressor housing for some dumb *** reason and it creeped like a mother fvuker until her ran the line all the way to the intake manifoild and it solved the problem.
#12
Honda-Tech Member
Thread Starter
Re: Uncontrollable boost; check this manifold out..
If the wastegate is opening, and is opening fully, then I would look at the boost signal source for the wastegate (kinks, line blockage, etc..) as the next potential problem.
Over retarted ignition timing and rich AFR's can also cause boost creep.. I had cases which boost creep was present (15 PSI creeps to 20+ PSI), but simply dialing up the timing have brought it down to acceptable levels (15 PSI creeps to 17 PSI). The amount of timing you can run will depend on your setup though, so an hour at the dyno can help you further troubleshoot.
Over retarted ignition timing and rich AFR's can also cause boost creep.. I had cases which boost creep was present (15 PSI creeps to 20+ PSI), but simply dialing up the timing have brought it down to acceptable levels (15 PSI creeps to 17 PSI). The amount of timing you can run will depend on your setup though, so an hour at the dyno can help you further troubleshoot.
60-1
Since I removed the manifold I took some shot of the collector and the wastegate exit. This manifold was sold to me as a 'Full Race' unit, i've never seen another one but maybe somebody can take a look at the pics and tell me if everything looks as expected:
#13
Honda-Tech Member
iTrader: (4)
Join Date: Apr 2005
Location: South, Texas
Posts: 12,903
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
not to be a jerk but the manifold doesnt look to be of the best quality. there are cracks, the collector isnt done very well and the w/g opening is severely restricted. fix the issues with the manifold or find a suitable replacement. The short collector and the blocked wg opening is really going to hinder boost control with a manifold that doesnt have a priority design
#14
Honda-Tech Member
Join Date: Aug 2010
Location: Olympia,Wa
Posts: 4,592
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
Yeah I would ditch the manifold It has cracks and shitty welds and the exit to the waste gate is a horrible design and it alone could be causing boost creep.
#16
Honda-Tech Member
Re: Uncontrollable boost; check this manifold out..
no question... its the entrance on that wastegate elbow...
if exhaust gas is equal to an elephants d*** the entrance for exhaust gas to reach the wastegate is an ants p****....
either fix that manifold or get a new one...
if exhaust gas is equal to an elephants d*** the entrance for exhaust gas to reach the wastegate is an ants p****....
either fix that manifold or get a new one...
#18
Honda-Tech Member
iTrader: (5)
Re: Uncontrollable boost; check this manifold out..
yeah thats the issue. manifold is pretty shitty on the inside.
i was hitting 25psi on a 38mm mvs with a 7psi spring on my ramhorn. i had a 44/46mm flanged put on and it would only go 2-3psi above spring pressure.
check the drag racing forum classifieds, my manifold/downpipe is for sale if youre interested
i was hitting 25psi on a 38mm mvs with a 7psi spring on my ramhorn. i had a 44/46mm flanged put on and it would only go 2-3psi above spring pressure.
check the drag racing forum classifieds, my manifold/downpipe is for sale if youre interested
#19
Honda-Tech Member
Thread Starter
Re: Uncontrollable boost; check this manifold out..
Apprieciate the feeback folks, justed ordered up a new Blueridge Motorsports Ram & DP combo now.. do it right or don't do it at all eh?
Thanks!
Thanks!
#20
Re: Uncontrollable boost; check this manifold out..
that manifold will work just fine. anyone who thinks thats bad is either a gifted fabricator with high standards or a rich kid.
im thinking installer error with the WG.
im thinking installer error with the WG.
#21
Honda-Tech Member
Thread Starter
Re: Uncontrollable boost; check this manifold out..
#23
Re: Uncontrollable boost; check this manifold out..
The WG port looks very inefficient. You could attempt to hog it out and try to make it better but honestly it might not get any better. A lot of people teardrop the WG runner to give maximum flow and sometimes this doesn't even stop boost creep.
#24
Honda-Tech Member
Re: Uncontrollable boost; check this manifold out..
He has a huge crack on the elbow of the wastegate!! That's his problem! Look in the second picture in the second set he posted.
#25
Honda-Tech Member
iTrader: (4)
Join Date: Apr 2005
Location: South, Texas
Posts: 12,903
Likes: 0
Received 0 Likes
on
0 Posts
Re: Uncontrollable boost; check this manifold out..
Crack in wg elbow won't cause boost creep. Any cracks would cause poor turbo operation ie spooling. And hus problem is boost spike