boost creep fix
#1
Honda-Tech Member
Thread Starter
boost creep fix
I am using a heat treated peakboost "ac" ramhorn with a 38mm wastegate flange with a 38mm to 44mm vband adapter connecting my 44mm tial wastegate...
i am using a t1 turbo blanketed precision 6265 turbo and the wastegate has a 9psi spring that is crepping to 13/14psi.
if i cut off the 38mm flange and replaced it with the proper vband to have a direct fit 44mm tial wastegate would that difference be enough to stop the creep i am experiencing?
my additional concern is that i want to modify my dump tube to recirculate into my 3" down pipe... would this make boost creep even worse?
i am using a t1 turbo blanketed precision 6265 turbo and the wastegate has a 9psi spring that is crepping to 13/14psi.
if i cut off the 38mm flange and replaced it with the proper vband to have a direct fit 44mm tial wastegate would that difference be enough to stop the creep i am experiencing?
my additional concern is that i want to modify my dump tube to recirculate into my 3" down pipe... would this make boost creep even worse?
#2
Honda-Tech Member
iTrader: (1)
Join Date: Sep 2008
Location: wilmington, ca, usa
Posts: 1,216
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
Maybe that 9lb spring is really a 15lb spring.
The wastegate adaptor shouldnt have anything to do with that creep..
A wategate is quite a simple working part . Keeps closed to hold boost in opens to release extra exhaust
Maybe a boost controller issue.
The wastegate adaptor shouldnt have anything to do with that creep..
A wategate is quite a simple working part . Keeps closed to hold boost in opens to release extra exhaust
Maybe a boost controller issue.
#3
Honda-Tech Member
Re: boost creep fix
LOL. Creepboost strikes again!
In all seriousness, though, have someone lob the 38mm entry off the manifold completely, and replace it with a proper 44mm gate entry and flange.
In all seriousness, though, have someone lob the 38mm entry off the manifold completely, and replace it with a proper 44mm gate entry and flange.
#4
Honda-Tech Member
Join Date: Jan 2007
Location: Oahu, HI
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
If its the peakboost ramhorn I'm thinking of the WG placement on those already isn't very good. Adding an adapter onto it will only make it worse. I would definitely have someone redo the flange.
As for rerouting your dumptube, I'm not to sure.
As for rerouting your dumptube, I'm not to sure.
#5
Honda-Tech Member
Thread Starter
Re: boost creep fix
the 38mm flange opening measures 37mm and the 44mm v band flange opening 42mm. i wonder how much 5 mms would help? anyone have any ideas because id hate to do that work and it still not fix the car... wonder if anyone has been in this dilemma..
#7
Honda-Tech Member
Join Date: Jan 2007
Location: Oahu, HI
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
If you don't want to take the risk of doing the work and it not working I would just get a different manifold. Just by the design of the manifold the WG has somewhat poor placement
Trending Topics
#8
Re: boost creep fix
My setup is very different than yours (I have a GT3076 on a cast DRAG manifold) but I had boost creep issues before. Some ways back I looped my wastegate back into my downpipe. Surprisingly, the boost creep went away and now my boost falls off at higher RPM. I have no explanation why, but that was my experience.
#10
Honda-Tech Member
Join Date: Jan 2007
Location: Oahu, HI
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
My setup is very different than yours (I have a GT3076 on a cast DRAG manifold) but I had boost creep issues before. Some ways back I looped my wastegate back into my downpipe. Surprisingly, the boost creep went away and now my boost falls off at higher RPM. I have no explanation why, but that was my experience.
Maybe? Just a guess
#11
Honda-Tech Member
Join Date: Sep 2007
Location: NJ
Posts: 1,739
Likes: 0
Received 0 Likes
on
0 Posts
#12
#13
Honda-Tech Member
Join Date: Jan 2005
Location: Lower Right Hand Corner, PA
Posts: 5,643
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
Like a chain is only as strong as it's weakest link, an exhaust is only as open as it's smallest diameter. In this case, while you're running a 44mm gate, it's only effective as a 38mm.
And yes, the 5mm will make a HUGE difference.
I would guess that helped because the velocity from the exhaust in the downpipe helped to evacuate the fumes from the wastegate.
Maybe? Just a guess
Maybe? Just a guess
#14
Honda-Tech Member
Join Date: Mar 2000
Location: Toronto, ON, Canada
Posts: 2,859
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
My setup is very different than yours (I have a GT3076 on a cast DRAG manifold) but I had boost creep issues before. Some ways back I looped my wastegate back into my downpipe. Surprisingly, the boost creep went away and now my boost falls off at higher RPM. I have no explanation why, but that was my experience.
However, this elevated exhaust pressures is also raising your EGT's and lowering your overall power. That's why wastegate dumped to atmosphere increases power.
Having a wastegate dumped to atmosphere is like having a 3.0" + 1.75" exhaust in terms of exhaust flow capacity (under boost). Recirculating back into the downpipe is similar to downsizing your exhaust, thus, also lowering power and increasing EGT's/exhaust pressures.
#15
Honda-Tech Member
Thread Starter
Re: boost creep fix
I appreciate everyones input, I think i am just going to cut off the 38mm flange and weld in a 44mm direct flange for my wastegate and hope for the best
with the additional input on the power losses of a dumptube... i think im going to debate on this further to see if its worth it... i am looking for ways to reduce sound so that is a huge reason why as well as reducing the horrid smells from up front... what an increase in diameter of the dumptube benefit me more and locate it further down to the bottom of the oil pan to recirculate?
with the additional input on the power losses of a dumptube... i think im going to debate on this further to see if its worth it... i am looking for ways to reduce sound so that is a huge reason why as well as reducing the horrid smells from up front... what an increase in diameter of the dumptube benefit me more and locate it further down to the bottom of the oil pan to recirculate?
#16
Honda-Tech Member
Join Date: Jan 2007
Location: Oahu, HI
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
Actually, the real reason is due to elevated exhaust pressures after recirculating the WG back into the downpipe.
However, this elevated exhaust pressures is also raising your EGT's and lowering your overall power. That's why wastegate dumped to atmosphere increases power.
Having a wastegate dumped to atmosphere is like having a 3.0" + 1.75" exhaust in terms of exhaust flow capacity (under boost). Recirculating back into the downpipe is similar to downsizing your exhaust, thus, also lowering power and increasing EGT's/exhaust pressures.
However, this elevated exhaust pressures is also raising your EGT's and lowering your overall power. That's why wastegate dumped to atmosphere increases power.
Having a wastegate dumped to atmosphere is like having a 3.0" + 1.75" exhaust in terms of exhaust flow capacity (under boost). Recirculating back into the downpipe is similar to downsizing your exhaust, thus, also lowering power and increasing EGT's/exhaust pressures.
#17
Re: boost creep fix
Yup, learned something too. Exhaust pressure after the turbine slowing it down sounds likely to me.
Might not be be the best solution for you DelSol, due to so much power loss. For me it was worth it. I get a lot of enjoyment spooling 5th gear up to high boost on the freeway and whizzing by with minimum exhaust noise/maximum turbo spool noise.
Might not be be the best solution for you DelSol, due to so much power loss. For me it was worth it. I get a lot of enjoyment spooling 5th gear up to high boost on the freeway and whizzing by with minimum exhaust noise/maximum turbo spool noise.
#18
Honda-Tech Member
Join Date: Jan 2004
Location: Tampa, FL
Posts: 1,251
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
That pic is a comparison between my old setup and my new setup. My old setup was a 38mm which was recirculated into a 2.5 inch downpipe. I did this setup originally because I too was concerned about sound. This setup cannot properly control a 6262. New setup is an open dump 44mm with a 3 inch downpipe. Picked up about 40whp between the two.
#19
Honda-Tech Member
Thread Starter
Re: boost creep fix
If your point was towards the recirculating waste gate, it is void do to the ".5" increase in down pipe size, because that alone could net those kind of power gains depending on the power level. Additionally, that old dump tube is thinner than the new one pictured...
I would be interested to see the power changes someone has experienced by simply adding a recirculating dump tube on the same size exhaust piping that was previously used without causing boost creep and see if the recirculation causes creep...
I am standing by for a full page reply from Tony the Tiger... the guy is a genius
That pic is a comparison between my old setup and my new setup. My old setup was a 38mm which was recirculated into a 2.5 inch downpipe. I did this setup originally because I too was concerned about sound. This setup cannot properly control a 6262. New setup is an open dump 44mm with a 3 inch downpipe. Picked up about 40whp between the two.
I would be interested to see the power changes someone has experienced by simply adding a recirculating dump tube on the same size exhaust piping that was previously used without causing boost creep and see if the recirculation causes creep...
I am standing by for a full page reply from Tony the Tiger... the guy is a genius
That pic is a comparison between my old setup and my new setup. My old setup was a 38mm which was recirculated into a 2.5 inch downpipe. I did this setup originally because I too was concerned about sound. This setup cannot properly control a 6262. New setup is an open dump 44mm with a 3 inch downpipe. Picked up about 40whp between the two.
#21
Honda-Tech Member
Thread Starter
#23
Honda-Tech Member
Join Date: Sep 2006
Location: Mid-Michigan, USA
Posts: 1,235
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
So do you think recirculating the WG into a 3.5" or 4" exhaust would NOT reduce the creep because the pressure in the DP wouldn't be elevated, or at least not elevated as much?
Actually, the real reason is due to elevated exhaust pressures after recirculating the WG back into the downpipe.
However, this elevated exhaust pressures is also raising your EGT's and lowering your overall power. That's why wastegate dumped to atmosphere increases power.
Having a wastegate dumped to atmosphere is like having a 3.0" + 1.75" exhaust in terms of exhaust flow capacity (under boost). Recirculating back into the downpipe is similar to downsizing your exhaust, thus, also lowering power and increasing EGT's/exhaust pressures.
However, this elevated exhaust pressures is also raising your EGT's and lowering your overall power. That's why wastegate dumped to atmosphere increases power.
Having a wastegate dumped to atmosphere is like having a 3.0" + 1.75" exhaust in terms of exhaust flow capacity (under boost). Recirculating back into the downpipe is similar to downsizing your exhaust, thus, also lowering power and increasing EGT's/exhaust pressures.
#24
Honda-Tech Member
Thread Starter
Re: boost creep fix
I have been able to hold 13psi with the setup I posted but I am trying to be able to hold 9psi for 1st and 2nd gears (in hopes of gaining traction down low) and then use boost by gear to turn up the boost for 3, 4, and 5 (well not really 5 lol)
#25
Honda-Tech Member
Join Date: Jan 2004
Location: Tampa, FL
Posts: 1,251
Likes: 0
Received 0 Likes
on
0 Posts
Re: boost creep fix
If your point was towards the recirculating waste gate, it is void do to the ".5" increase in down pipe size, because that alone could net those kind of power gains depending on the power level. Additionally, that old dump tube is thinner than the new one pictured...
I would be interested to see the power changes someone has experienced by simply adding a recirculating dump tube on the same size exhaust piping that was previously used without causing boost creep and see if the recirculation causes creep...
I am standing by for a full page reply from Tony the Tiger... the guy is a genius
I would be interested to see the power changes someone has experienced by simply adding a recirculating dump tube on the same size exhaust piping that was previously used without causing boost creep and see if the recirculation causes creep...
I am standing by for a full page reply from Tony the Tiger... the guy is a genius
Let me be clear - YOU WILL HAVE BOOST CREEP if you recirculate that dump with that big of a turbo, whether is 38 or 44. Either leave it open, or step up to a 60mm.