Twin turbo first gen ?'s

S

scuzzytc

Member
Ok I have decided I would like to do twins on my first gen, I would like to get between 450-500 horse out of this setup and still be able to drive it regularly,?'s are what headers to use, what turbos to use, and should I use internal or external wastegates, and what compression should I be running in the engine, I have extensive fabrication skills and have built several large horse cummins engine but have never done a twin setup on a gas engine any help would be appreciated. Thanks
 
scuzzytc said:
Ok I have decided I would like to do twins on my first gen, I would like to get between 450-500 horse out of this setup and still be able to drive it regularly,?'s are what headers to use, what turbos to use, and should I use internal or external wastegates, and what compression should I be running in the engine, I have extensive fabrication skills and have built several large horse cummins engine but have never done a twin setup on a gas engine any help would be appreciated. Thanks
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A lot of people flip the fort motorsport shorty headers and use those. And for twins I would go with a pair of evo turbos or something similar. Compression will be fine at 9.5 and under. And most people I believe run external wastegates.
 
see turbodgumby, see thread below on his twin turbo build.
you might PM him, I think he has a connection on some pre fabbed headers and hot side parts that he is developing for a twin turbo gen 1 kit.

I just got my single MP T-70mm turbo on a 393 running last month, @ only 7psi on my 393 it ran 12.2 on street gen2 tires. that is right out the box , so there is more in the combo, even before I turn boost up.
 
so what should I be shooting for boost wise ? I figured 9:0to 1 compression ratio, maybe 9:5 to 1 at the most, and then wat about a cam and heads.
 
all depends on how much money / how much power and how many rpms you want.

mine is 8.9 comp.
for comparison
a member had, a forged 351, vic jrs, tfs box upper, single precisian turbo 76mm, dynoed at over 600-650 to the tires. He was at around 15-18 psi.
truck ran a best of 11.05 ,new owner with a better stall, and taller rear end gears, it has ran in the upper 10 now that is on SD also.
 
thats good power #'s i'm not really building it for racing its more of my drive it on nice days truck, being in Alaska it will sit in the shop for 6 months at a time, my previous gen 2 had 680 rwhp and was a blast. I am also planning on using a massflow fuel injection setup, does anybody out there have any pics of the exhaust routing for twins.
 
A pair of 55mm to 60mm turbos will make what you are wanting to make. But for your power goals you can do a single unless you are like me and just wanted twins just cause! And I had NO spool issues! I had boost whenever I wanted and just as fast as the BIG KB/Whipple Gen2s!! I beleive Twiceblown351 is fixing to upgrade his twin T04E turbos to bigger ones!!
Here are my pics from my build! and my combo NOW

393stroker
Trickflow CNC205 heads
Cam Motion Custom grind Hydraulic Roller Cam
PI torque converter, Punisher COMP VB
Aeromotive Fuel System
and just now doing a conversion to a FAST:screwy:
2 Master Power Dynamic Flow P-Trim T70s turbos
2 38mm Tial wastegates.
2 Black turbo blankets
25x17x3.5 dual 2.5" in and 3" out Intercooler.
2.5"/3" aluminum coldpipe kit.
1 3/4 primary twin custom made PONYDOWN headers(T4 Flanged)
3" downpipes
RCI 75# Injectors

Twin Turbo Lightning Build pictures by turbodgumby - Photobucket


I will help ya anyways I can or if ya have any questions just LMK:thumbup:
a20a0745.jpg
 
Im running the obx twin turbo headers for my setup, with twin 60-1 masterpower internal wastegated turbos. The headers are cheaply made they tig welded over mig welds to make them look pretty. One flange wasnt square but a large table mounted belt sander squared it up. I also noticed a crack in one of the primaries that had to be welded up. The passenger side turbo gets a little close to the valve cover, so a turbo blanket or heat shield is recommended.

All that being said, for starting out they are not that bad for $175 stainless steel headers, you just get what you pay for. I had custom 2.5" stainless downpipes made and they were realtivly easy to route.

Ive been told that most turbo headers crack at some point, cast or tubular, and these will be no exception. With that being said down the road when that issue comes up ill replace them with better parts.

As far as the turbo setup i couldnt be happier im making 10psi off wastegate boost and it makes boost a lot faster then my old B-trim Vortech @9psi. Im estimating running low 13s to 13 flat. I raced my bosses 370z that is bone stock (he ran a 13.24 the next weekend) and i beat him by 3 car lengths or so, With 3.08 gears!:scared1:. So needless to say im excited to take it to the track.
 
I was looking into the t3/t4 setups turbogumby your setup is awesome I just dont need that much power, lol but if it is built right and I decide to go bigger I can upgrade the turbos later, are you using a bauman controller for the trans ? that is another thing to deal with how is it to setup?, can you still use the factory overdrive on off button, I am trying to keep the interior as close to stock as possible.
 
lucifer do you have any pics of ur setup are you still running A/C I would like to see the difference in header setups if possible
 
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