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II Phatshaft racing twins question

1394 Views 17 Replies 6 Participants Last post by  crackerscummins, 
crackerscummins
I have been running this kit for the past month and it seems like the big brother turbo just doesnt want to lite...:banghead:

I have all the mods listed in my sig.

I was thinking it could be a wastegate issue but not sure. At the intake horn I will see around 35lbs with 1/2 throttle but nothing from the big bro turbo. I have to have my foot to the floor and rpms around 3.5k just to see any boost out of it. And when at wot i'll see around 20 psi from the big bro turbo(seems kinda low) and yes i know its a low press. turbo but still should see more than that.

Any help would be much appreciated!
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Blizzard06
You need more CP3, you are probably draining your rail, which is hurting spool up. You have 100% over injectors, but only an 85% over CP3.
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golfsnow
Just a guess but I would say that your waste gate is set too tight on the secondary...shouldn't see 35lbs of boost out of your secondary you want that somewhere between 25 and 30...

Also it is a set of race twins for a reason...I don't think it is designed to spool like a set of towing twins.

If you want a ton of good information and talk about setting up twins check out this thread: http://www.cumminsforum.com/forum/3...rts-discussion/547623-twin-guys-get-here.html
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crackerscummins
Yea I know the cp3 is killing me. But I've never seen it drop below 20k at wot. As for the wastegate I was thinking that it might be set to the wrong psi. But I'll have to look into that twins thread.
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crackerscummins
As for the 35lbs of boost from the secondary, I only can read primary boost and overall boost.
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golfsnow
There is a lot of information in that thread for sure. I learned a lot reading it and participating myself. I would loosen the gate on the secondary and see if that helps, assuming it isn't too big of a PIA to get at...
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crackerscummins
thanks for the advice guys! Yea that wastegate arm sucks to get too! But I will say tho when that turbo does light i get a grin from ear to ear!
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golfsnow
You're welcome, throwing some more fuel at it would help too as Blizzard said 20k is pretty much a drained rail with that large of injectors an additional 6k pumps a lot more fuel for sure. That will just give you bigger traction problems...but I bet that thing puts a smile on that can't be wiped off when it hits though...hope you get it figured out.
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D2'd
At WOT you have 20 psi primary and how much total? With your lack of fuel, I'd suspect that this is bang on for primary pressure.
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crackerscummins
Yea total it's around 65 psi but that's only at wot.

Now is It possible to run another cp3 with the dragon fire pump I already have?
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D2'd
Yes you can, and I wouldn't play with your gate before getting your rail pressure sorted. 20 and 65 is a decent balance in load between chargers.
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crackerscummins
Ok cool looks like I'm going to have to start selling Girl Scout cookies to buy a dual pump kit! Haha.
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broketryin
More fuel for sure. That turbo takes a lot of number 2 to get singing, but when she does it's a ride. I'm runnin 65 lpm sticks and see about 40 outta mine.
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crackerscummins
Yea I cant wait to get her running good! Dont get me wrong shes pretty strong now but i know theres alot more power hidden in there...
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3brorce
Dual Pumps FTW!
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crackerscummins
Any suggestions phil? I'be been cruising the forum and reading about duals. Now just gotta find a good company. I saw II has a setup which would be nice since I already have their pump.

By the way funniest thing I've ever seen!!! I was racing a mustang cobra and I blew a boot and the guy slammed on his brakes thinking it was his motor. Roadside fix and some cherry tape limped me to get a new boot.
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3brorce
Yeah, if you can hold out for a bit we will be unveiling our dual pump kit hahaha. If you need it now, ATS makes a nice kit though for sure. II pumps for their kits are backed up for about a month.
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crackerscummins
Of course I can wait! Plus I'd rather buy from y'all than xdp or one of those chain sites! You can definitely count me in for one of your kits!
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