Twins help

dvst8r

dvst8r

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Feb 16, 2008
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Ok, so I know some of you have tried nearly every combo under the sun, so I come for advice.

I have 1990 VE 12v, 5spd. It has head studs, 60# springs, 4kgsp, moded fuel pin, and turned up to just before run away. Timed to the head. Stock sticks.

It currently has an HX35 12cm, and with the wastegate blocked it will hit 50psi + with the wastgate set for 35psi it will still hit 1600+ in a short pull.

My original plan was to run the hx as is with an external gate over a GT4294, it has a 1.32hot side. Maybe upgrade to a 60mm 6 blade on the HX.

Now an S366 has fallen in my lap it has a divided T4 1.10 (I'm 90% sure on the 1.10) and iirc BD's twins run a s357 over an s366?

So here is what I do with the truck, go 4x4ing, camping, sometimes pull friends race car trailers, make garbage runs, might go look at going to some local pulls this year (not even looking to compete, just to try it out) it is not my DD, just a toy. I am looking to get 500 - 550hp out of it eventually, nothing more or I think I will be into some serious drive train upgrades. I would guess at this point it is a really hot 230hp - 250hp.

So the question is for my goal is the s366 as a primary enough? I'm thinking of running it in a twin setup with the hx-35 and an external gate till I upgrade the sticks, and then grow from there, half the fun for me is just tinkering on this thing, so if I need to fab up a new hot pipe, and downpipe in a couple months so be it.

Cliff notes:

Want: 500 -550hp

Have: 12V VE pump, 5spd, 230 - 250hp, gauges: boost, dp, egt, fuel press.

Twins options:
hx35.12 over S366
hx35.12 with 60mm compressor, over s366
hx35.12 over GT4294
hx35.12 with 60mm compressor, over GT4294

Clear as mud? :bang
 
Ok using this and the handy apple to apple cider conversion of lbs/min to cfm, by dividing lbs/min by 0.069

TurbochargerSizes2.jpg


I have determined that I am going to try the S366 as my primary to start. As the BD tow twins are rated at ~550rwhp which is what I am ultimately after, and they use a 64.7mm primary, according to the chart. If I need more air the GT4294 that I have flows just a touch less then the R700 primary. If I really decide to step it up I can move to my HT60, which would put it right around the R850 primary.

With that being said it looks like an 8 blade 60mm compressor is going to flow almost exactly the same as the 57mm super B used in as the secondary for BD twins.

I realize I have not taken the hotside into account at all here, mostly because I really don't have much in data comparing the two. If some one would be so kinda as to shed some light on the hotside comparability it would be greatly appreciated.

Any comments??
 
The super B S357 has a 14cm dual gated HX40 style hotside, vastly different than an HX35s 12cm small single volute gate 3" outlet hotside. The superior S357 will spool near the same but way outflow the HXs hotside. You can help compensate by using a 1/2" spacer plate @ the manifold but that will hurt spool slightly, you can also port the gate hole to 7/8" and use an outlet cover such as Sources which has a machined relief to help aid exhaust flow through the gate. adding an external gate with a divider will work best though, IIRC E.D. makes such a piece. for your power expectations and spool/towing requirements the 366/1.10 should work well. One thing not mentioned was if the head has been ringed, a single running "up to 50psi" is not the same as twins pushing over 60psi. also you'll need to put a drain for the primary in the pan as 12v dont have a extra provision and draining both turbos into one drain is not recommended, and the IC may not survive such boost levels.$.02
 
Thanks for the reply. I have a tial 44mm external wastegate that I am going to run, I have it already it was off of one of my past turbo cars.

It is stock non ic'd when I come across an ic for a good deal I will put it on, for right now I am just gonna leave it.

The head has not been o-ringed, just studs. As it is just a toy, I will run the hg till it blows then o ring it. I realize a scorching hot 50psi on a small single isn't even close to the same as 60+psi cool (dense), but imho that little single at 50psi boost was over 75psi drive (I do run a drive pressure gauge), and it had made many, many trips to 1600+ degrees. Which is what finally killed this hg. I'm hoping that next time it will be from too much boost.

I was thinking about running a Y and a -10 or -12 drain, but I guess, I will pop the pan off now and go that way. Thanks for the heads up.

I think since I will pull it off the road while I screw around getting the twins fabbed up, I will put a cam in it as well. I have been doing some reading and the stock 1st gen cam seems to be the worst of all, and since it will have small twins to begin with it could use all the ease of breathing it can get.



ANOTHER question: Hot pipes, do people normally make them out of like a sch40 elbow or out of like 16 gauge "muffler pipe" ?
 
dvst8r said:
ANOTHER question: Hot pipes, do people normally make them out of like a sch40 elbow or out of like 16 gauge "muffler pipe" ?
Click to expand...

I have had that passed around a lot too and sched.40 has a .22 wall and Source uses a .11 wall and they do not have burn through or melt down issues. I am not saying go ahead and use cheap "tin" pipe but I also think as long as its a good quality pipe, sched.40 isnt needed for most applications. $.02
 
hy35 with ported wastegate over s366 (0.80 A/R)
SD530730.JPG


quick bracket i threw together
SD530732.JPG


hot pipe (16g mandrel bent 3" pipe)
SD530737.JPG


mock up
SD530739.JPG

SD530740.JPG


primary drain
SD530744.JPG

SD530745.JPG
 
more pics are in the other thread here.....

i dont even have the water/meth running and im sitting around 1200*
 
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