twin pick poll

[DTanklage]

if you had to tow 22k# 50% of the time and were empty playin the other 50% which turbos would you choose? (22k total, truck and trailer)

'97 dually, 4500 with a splitter and 3850 dub disk. 3.55 gear 31" tires

bottom end is stock for now has 200k on it and i am not taking it apart to upgrade til it takes itself apart. stock cam

head has stock size valves, good springs, max porting w/o removing the plenum. its flat n has .011 protrusion stainless wire. +020 gasket. 220k tensile arp's

injectors are 5x14 +015 lift 280 bar (thanks weston)

215 pump is gonna get swapped out for a single feed 180, maxed on a bench (550cc), 191 dv's, 4k gsk (for when its not towing), fully tuned aneroid. (thanks seth) 0 plate to remove fuel as req. 200+ gph fuel system set @ 40 psi

timing will be between 18° and 26°, what ever works best

max ported t-3 3 pc manifold max ported 13cm² ex housing (1"+ gate passages)

what top turbo would you put in that ss housing?

and what bottom charger would you put under it?

not as concerned with the cost of the turbos as i am with doing it right the first time

think i included all pertinent info but if something is missing plz ask

 

[DTanklage]

Sounds like a little much fuel for pulling a heavy trailer? I would do a 62/S400

Is all the porting really needed ? to me its a waste of time for the little benefit you will see. Just my opinion here....


I would leave the timing no higher than 18*

thanks

 

[DTanklage]

I think the general thought is that it isn't how much power your turbos can keep cool its that you eventually reach the limit of the cooling system around 450hp towing if using all the power. A 62/65/13 over a S475 would keep you cool when playing and tow well but that seems like a lot of fuel for towing.

i understand it is a lot of fuel for towing. 550cc from a 12mm 180 pump is not the same as 550cc from a cds 13mm pump. it is still a lot of fuel thats why i have a fuel plate and respect. just like you have to respect a 200hp 500 pound street bike or it will kill you - i will have to respect this things cooling system or it will kill my motor. thats why they both have a throttle.

so you like the basic 62/75 combo? i like that too, but wonder about when there is no trailer behind it

i should have also stated that i dont care how the thing runs below 1800 rpm. i have the gear vendors in there and never 'lug' the thing

 

[DTanklage]

Run a valet switch on it. That will cut back some of the fuel.

i have moved your guys posts over here where the poll is, hoping the mods will delete the other thread?

i dont think it would fuel enough with the lever all the way back, would it?

besides, this is gonna have a fully tuned aneroid, seth has been working on it, and i am pretty sure full fuel wont happen til 50 or 60 psi

boost (fuel) can be controlled with the throttle, no? or with twins when ya hit a hill do you get 50+ psi with min throttle? can picture 30 or 35 but i dont see it developing max boost with minimal throttle

even if it does that is why i have a plate

dont care about how it runs down low, just want a good compromise so it will haul the mail empty but still be under the chargers at 1900 or so rpm for when i am cruising/towing

 

[mondtster]

i have moved your guys posts over here where the poll is, hoping the mods will delete the other thread?

i dont think it would fuel enough with the lever all the way back, would it?

besides, this is gonna have a fully tuned aneroid, seth has been working on it, and i am pretty sure full fuel wont happen til 50 or 60 psi

I'm planning on trying a unique valet setup (at least I've never heard of anybody trying it yet) that you might want to try too.

Basically what I want to try is to take a pressure relief valve to relieve some (but not all) manifold pressure from the aneroid. That should still allow the aneroid to travel some, but not as much as it would if it could see full manifold pressure.

boost (fuel) can be controlled with the throttle, no? or with twins when ya hit a hill do you get 50+ psi with min throttle? can picture 30 or 35 but i dont see it developing max boost with minimal throttle

even if it does that is why i have a plate

dont care about how it runs down low, just want a good compromise so it will haul the mail empty but still be under the chargers at 1900 or so rpm for when i am cruising/towing

Fuel can be controlled with your foot (which is how I currently do it too), but you don't really want to do that every time you tow do you? Or are you going to set the truck up on the conservative side for towing and just live with it?

I personally wouldn't want to have the truck tuned for towing all the time, so unless you have enough charger to make the kind of horsepower you want to and can keep the temps down while towing I think you're going to either have to adjust things when you go to tow, live with it in a state that you can tow with all the time, or leave it in kill mode and just baby the thing when towing.

 

[zstroken]

I'm planning on trying a unique valet setup (at least I've never heard of anybody trying it yet) that you might want to try too.

Basically what I want to try is to take a pressure relief valve to relieve some (but not all) manifold pressure from the aneroid. That should still allow the aneroid to travel some, but not as much as it would if it could see full manifold pressure.



Fuel can be controlled with your foot (which is how I currently do it too), but you don't really want to do that every time you tow do you? Or are you going to set the truck up on the conservative side for towing and just live with it?

I personally wouldn't want to have the truck tuned for towing all the time, so unless you have enough charger to make the kind of horsepower you want to and can keep the temps down while towing I think you're going to either have to adjust things when you go to tow, live with it in a state that you can tow with all the time, or leave it in kill mode and just baby the thing when towing.

Use a regulator, and put it in the cab.

 

[GRotman]

I voted for the 62/65 over 475, only because there wasn't an option for 62/68.

 

[DTanklage]

opps sorry glenn

it only gives you 10 options

i think i am gonna end up stuck with the 35/40 cuz i now have more in it than the guy i was building it for wants to spend

and i still have that tv-75 so i used up one option throwin those out there

but, i did leave #10 for you - other

guess i could start over (on the turbos, not on the thread) and get one of those from you guys. what do you do? take the stainless housing for the 65 turbine and open it up an 1/8 inch?

i'll shoot you a pm, that is definately an attractive option

thanks

Basically what I want to try is to take a pressure relief valve to relieve some (but not all) manifold pressure from the aneroid.

leave it in kill mode and just baby the thing when towing.

yes, that has been done before and will work great for towing. especially if you put a reg in cab as zstroken suggested

"leave it on kill and ..." lol, thats my modus operandi

 

[mondtster]

Use a regulator, and put it in the cab.

Not a bad idea...

yes, that has been done before and will work great for towing. especially if you put a reg in cab as zstroken suggested

"leave it on kill and ..." lol, thats my modus operandi

Cool, I didn't know anybody had tried it yet. I haven't seen it mentioned before.

LOL, leaving it on kill is the norm for me too. We'll see if the valet switch project ever even gets done.

 

[NickTF]

Something that's been on my mind is if you dump the wastegate exhaust from the secondary into the hot pipe prior to the primary won't you be able to drive a larger primary turbo harder and in turn spool it quicker?

 

[DTanklage]

thought everyone running an external gate did just that?

by design internal gates do the same thing

 

[NickTF]

thought everyone running an external gate did just that?

by design internal gates do the same thing

No, some dump it into atmosphere just like I do with my single. This just seems like a way to drive a larger primary harder than dumping the wastegate exhaust into the atmosphere.

 

[cetanefreek]

I currently run a 64/65/14 over an S475 and it has been GREAT for towing, at least it was when I had a stock head, cam and VP44, if I was to do what you are suggesting I'd go for the 62/71/12 on top.