what if i recirculated a larger dumptube into the exhaust than the norm.... if i did a merge off the 44mm to a 2.5 inch pipe recirculating?

basically i want to run 9psi in 1st and 2nd and recirculate the dumptube.... i think i just need to do a new elbow off my manifold to a 60mm to be able to support that... FML

 

Just use the TiAL 44mm properly, and don't look back.

On a side note, I have had people use SuperTrapp motorcycle mufflers to be able to quiet the sound, elminate a lot of the fumes, and still be open wastegate. A lot of Subie External gate enthusiasts have used this approach.

http://www.supertrapp.com/product_se...rsal/index.asp

 

maybe i am just stubborn but i feel that the 44mm wastegate is not going to be able to control boost at 8-9psi after doing a recirculating dumptube. i am definitely doing the dumptube recirculation because of the smell reduction, noise reduction, and overall quality for a street car... reading a lot of reviews makes be believe that the recirculating dumptube would not help with boost creep but hurt it...

i think the optimal setup for my preferences would be to do the 60mm tial wastegate with large elbow off my ramhorn manifold...

my question is what is the best place to recirculate the dumptube so that i am not see drastic power losses.

ive posted a picture of what im currently working with... notice the 38mm to 44mm bracket

 

Peakboost went out of business and most boost creeps stopped. On 38mm PB manifolds we ended having to redo the wastegate and entry to cure creepage.

 

Really funny... lol!

 

I know I made this thread a long time ago but figured I would atleast update what I was doing. I had the original 38mm flange/pipe cut off my ramhorn and replaced with a 2.75inch schedule 10 elbow with the Vband for a 60mm tial wastegate. The wastegates recirculating pipe is 2.25 inch. Notice the AC condensor fits lol

 

And? Is the creep handled now?

 

oh its not finished yet i was just "updating"... im pretty sure this will hold 7.5 recirculating though... atleast i hope...

7.5 spring in this huge wastegate and that elbow of the ramhorn is like twice the size of the old one...

 

i went from 38 to 44mm and it only marginally solved the boost creep issues. i now see about 1.5 psi creep between 6500 and 8500 rpm. interestingly im also using a peakboost ramhorn.

i think a lot of it has to do with wastegate placement and not just size, though as they say bigger is better.

what are you using for boost control?

 

The use of that phrase is dependent upon turbo size and boost pressure related to the wastegate. But as stated, placement is as important as size of gate, pressure used, and turbo used.

 

It pains me seeing this.... The fact that you have to use a 60mm gate is uncalled for. Get a good manifold and never look back. You'll gain more in good design too. There is a very good reason why Peakboost is where they are now....

 

Recirculating, AC, and PS are all requirements I have for this setup and to maintain a low level of boost up to 9.5k RPMS.... i was not confident the 44mm could do that...

 

Heh. That is interesting. Hell, even a 38mm can do that, depending upon whre it is placed in relation to HOW your dumptube is recirculating. From what you had, it was decent, but could have come in at a better angle to avoid "creep".

 

shodan-would you say that getting an "AC" manifold for a 44mm wastegate recirculating would have been more efficient than running this 60mm wastegate recirculating? its to late now anyway lol

my concern was that if i stayed with the 44mm that it would still have some creep issues because of recirculating... im pretty confident that this setup should do what i want... 7.5psi at 9.5k rpms... maybe its just overkill (not a bad thing)

 

I see your concern and the answer is no. I still think the 44mm would have been fine. Its how you're routing the recirculation that is the key issue. I guess I'm trying to understand using such a large turbo to run at such low pressures out of its efficiency range, then go onto run such an unnecessarily large wastegate. I mean, hopefully, you'll get this with a huge 60mm. If not, look to seriously into finding a smoother transition to recirculate so that those exhaust pressures don't get so damn high.

Just get a smaller turbocharger instead, why do big, for such low pressure?

 

The problem here is the manifold and running such a low boost pressure on that size of a turbo.

I feel like a straight pipe off the collector instead of the bend would be better.

 

Shodan- the turbo is a 6265

Lightning- look how tight the elbow is with the AC condensor there... would not happen with a straight pipe off the collector... remember AC, PS, and recirculating... im considering putting the cruise control and window washers back in to

 

That's just so big to try and run such low pressure. No wonder you think you have to run a 60mm gate; to try and bleed off boost from such a big turbo with a large exhaust wheel for 7.5-9psi of pressure. That makes no sense.. get a smaller turbocharger and stop trying to run these huge things on low pressures. Betcha you'll eliminate a lot of creep that way.

 

Oh the picture lacks the condenser there and it threw me off. mmmmm

 

Shodan- My goal is maintain 7.5psi in 1st gear using boost by gear to optimize the street traction of the car... i could turn it up if i can get traction... the peak power goal is 700whp using e85. This is a street car first

 

I think this will work Kieth. I would make sure that the re-circ is merged REALLY well! You don't really have much room to work with A/C and P/S so all you can do is try at this point. Chris was showing me some of the pics of your new exhaust and it looks pretty cool. Definitely not something you will see on a Honda much! Oh and BTW thanks for the injectors a few months back! Looking to put them to use before 2012!

 

I see where you're coming from a bit better now that you've explained that. With that in mind, I think that merging the collector in an optimal way is the only way you can get that accomplished. Be it 60mm or 44mm gate.

 

With the wastegate dumping to the downpipe the only issue you could have is exhaust backpressure from the housing to the tailpipe, regardless of size. That would affect the wastegate performance.

What is the A/R on the turbo? What's the ratio of emap vs. map, if you have the ability to measure that....

 

I have done a lot of research on this especially reading through the Supra and Evo Forums (those guys are recirculating crazy) I have addressed to my fabricator that a 45 degree merge is not sufficient enough for this and he already knew. I will post pics when he gets to that part...

Reading through the forums it sounds like a properly merged recirculation will actually act like a vacuum and pull the exhaust gasses out the back of the car faster...

Couple questions were asked I didnt answer: Boost controller will be neptune boost by gear and the 6265 is 82ar

 

Is the main problem with the boost creep because you are trying to keep it as low as you can in 1st gear? Unless your talking about slicks at the track you're not going to get traction in 1st at 7psi with street tires.

IMO a little bit of boost creep is good. I spent alot of money on a Hytech manifold with perfect wastegate priority only to learn that I wanted my boost to ramp up with rpm. Now I intentionally ramp up my boost with an ebc to keep my torque flat. In fact I suspect I LOSE power because of my wastegate priority manifold. Boo