power guesses
#12
dodgezilla is 60mm hx40 compressor wheel with the same bottlenecked hx35 turbine housing. estimated flow of 66lbs/ minute depending in wheel design. It is limited in the HP it can support due to drive pressure.
unmodifed hx35 turbine housing 12cm only gates the front 3 cylinders.
unmodifed hx35 turbine housing 12cm only gates the front 3 cylinders.
---AutoMerged DoublePost---
really depends on the turbine choice
Last edited by 94 12valve; 01-07-2014 at 03:59 PM. Reason: Automerged Doublepost
#14
#17
I got a similar question, any comments would be appreciated! I haven't got a chance to dyno mine yet but would like to get an opinion on how much u think I'm putting down. Got a 98 12v with a 0 plate all the way back. 191 delivery valves, 370 marine injectors, marine pistons, marine cam, 4 inch turbo back, dodgezilla turbo, pushes about 48 psi, and head studs. Any suggestions? Thanks.
Originally Posted by jkidd:
your boost is an indication of extreme drive pressure. You will probably gain 20-30 hp alone by letting the front 3 cylinders wastegate at 32-35psi. Unless you have modified the divided in the turbine housing the rear 3 cylinders will not gate.
your back pressure must be like 2:1 compared to boost.
Suggestions:
1) get a bigger turbo with at least a 68mm turbine. Prices start about $1300
2) if you can't/won't spend money on a turbo upgrade lower boost to 32-35psi, remove the turbo and drill or cut the divider to allow the exhaust to wastegate all 6 cylinders.
--- you might as well have a 2" exhaust as your system is NOT free flowing with that much restriction in your turbo.
Im not really into buying a turbo as of right now, probably more likely in the future. But this whole drive pressure to boost pressure has kind of got me on edge now because i don't wanna screw anything up. So from what I have gathered is to fix this problem i should pull the turbo off and cut the divider out in the manifold that separates the front and back 3 cylinders? Btw forgot to add i have 4k governer springs and 75 ILB valve springs
Originally Posted by jkidd:
your boost is an indication of extreme drive pressure. You will probably gain 20-30 hp alone by letting the front 3 cylinders wastegate at 32-35psi. Unless you have modified the divided in the turbine housing the rear 3 cylinders will not gate.
your back pressure must be like 2:1 compared to boost.
Suggestions:
1) get a bigger turbo with at least a 68mm turbine. Prices start about $1300
2) if you can't/won't spend money on a turbo upgrade lower boost to 32-35psi, remove the turbo and drill or cut the divider to allow the exhaust to wastegate all 6 cylinders.
--- you might as well have a 2" exhaust as your system is NOT free flowing with that much restriction in your turbo.
Im not really into buying a turbo as of right now, probably more likely in the future. But this whole drive pressure to boost pressure has kind of got me on edge now because i don't wanna screw anything up. So from what I have gathered is to fix this problem i should pull the turbo off and cut the divider out in the manifold that separates the front and back 3 cylinders? Btw forgot to add i have 4k governer springs and 75 ILB valve springs
#18
higher rpm will increase drive pressure as you have more air trying to escape the engine.
drive pressures above 1.2:10 bost will start to kill HP. So many people are leaving 20, 30 50hp or more on the table because they refuse to wastegate properly or choose too small of a turbine housing and wheel. A wastegated housing on a s300 can add 25% more flow making a 14cm flow like a 17cm while open.
drive pressures above 1.2:10 bost will start to kill HP. So many people are leaving 20, 30 50hp or more on the table because they refuse to wastegate properly or choose too small of a turbine housing and wheel. A wastegated housing on a s300 can add 25% more flow making a 14cm flow like a 17cm while open.
#19
Im not really into buying a turbo as of right now, probably more likely in the future. But this whole drive pressure to boost pressure has kind of got me on edge now because i don't wanna screw anything up. So from what I have gathered is to fix this problem i should pull the turbo off and cut the divider out in the manifold that separates the front and back 3 cylinders? Btw forgot to add i have 4k governer springs and 75 ILB valve springs
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jkidd (01-08-2014)
#20
Ok that definitely makes sense Jkidd an sounds like i might be one of the guys.. So now from what I understand you don't have to take the turbo off? Just take off the wastgate cover and you can drill a 3/4 to 7/8 through the divider from there? Btw how does a guy go about adjusting the waste gate? Don't know as much about this stuff as I'd like to.. Thanks for helping me out here! Much appreciated!