First off i guess i can be called a beginner... i just ask
that you take into consideration that i am an ASE certified
mechanic of about 5 years so when it comes to cars, i know a
fair share...but when it comes to turboing a 420A, im in the
dark. Ok for starters i read the writeup in the tech
section...found it useful and yet wanting for info. So anyway
im looking to build a custom turbo kit with meager boost goals
(5psi w/7max). My questions are this: i have a turbo off a 98
GST (presuming its the 16G)and im wondering how i can regulate
the boost down to acceptable levels for my needs. The spring
on the wastegate sounds about corny... would i be better off
running an external wastegate on there and just suffer with 2
wastegates? and how/ what is the best way to control boost
creep? next is on the fuel system... is it absolutley
necessary to run that 255lph walboro? thats a huge amount of
fuel,that thing would empty the fuel tank on a DSM 3x over in
an hour almost. wouldnt a 190lph be better suited? and the
Vortech FMU, isnt that vacuum operated? and if so then why
mount it in the back? big thing i see with that is running a
mile of vacuum hose that could potentially be cut or something
one day and leave you with a terrible idle problem...along
with a ugly lean condition... and the fcd? wtf is that? and
finally guages...i know i need a boost guage, but as far as
monitoring a lean condition, would i be better off with a a/f
guage or EGT guage, and would i be smart to run something
close to a Apexi SAFC? thanks for the help.
Talon (no joke its my name)

[div class="dcquote"][i][b]Originally posted by
DSMTalon[/i][/b]
 First off i guess i can be called a beginner... i just ask
that you take into consideration that i am an ASE certified
mechanic of about 5 years so when it comes to cars, i know a
fair share...but when it comes to turboing a 420A, im in the
dark. Ok for starters i read the writeup in the tech
section...found it useful and yet wanting for info. So anyway
im looking to build a custom turbo kit with meager boost goals
(5psi w/7max). My questions are this: i have a turbo off a 98
GST (presuming its the 16G)and im wondering how i can regulate
the boost down to acceptable levels for my needs. The spring
on the wastegate sounds about corny... would i be better off
running an external wastegate on there and just suffer with 2
wastegates? and how/ what is the best way to control boost
creep? next is on the fuel system... is it absolutley
necessary to run that 255lph walboro? thats a huge amount of
fuel,that thing would empty the fuel tank on a DSM 3x over in
an hour almost. wouldnt a 190lph be better suited? and the
Vortech FMU, isnt that vacuum operated? and if so then why
mount it in the back? big thing i see with that is running a
mile of vacuum hose that could potentially be cut or something
one day and leave you with a terrible idle problem...along
with a ugly lean condition... and the fcd? wtf is that? and
finally guages...i know i need a boost guage, but as far as
monitoring a lean condition, would i be better off with a a/f
guage or EGT guage, and would i be smart to run something
close to a Apexi SAFC? thanks for the help. Talon (no joke its
my name)
[/div]

what is the internal wastegate set at on your turbo ?im not
possitive but i dont think its mor than 7 psi . if you have a
internal wastegat dont run a external with it . yes it is
nessacery to run the 255lph or even better the 255hp . if you
search you will find a flow chart and it will show you that
the 190 wont cut it . the 255 flow just about enough to handle
7psi on stock injectors thats around 100psi.the fmu is vacuum
operated .people mount it in the back because thats where the
return line is. would you rather run a rubber fuel hose from
the rear to the front and then back to the tank . its a lot
easier and safer just to run the vac line to the back . an fcd
is a fuel cut defender . that keeps the map sensor from seeing
boost and sending it to the ecu . if the ecu sees boost it
will get confused and cut fuel . there is no need for a safc .
hope that helps but next time try searching more . all the
info you need is on this board .

 well i appreciate the help guys...i would have used the
search button but everything i came up with didnt exactly
answer my questions, as far as the turbo is concerned, i dunno
what the wastegate is set too, all i know is that it came off
a 98 GST w/ slushbox tranny. and its going on a (go ahead and
laugh it up) 96 Talon w/ slushbox tranny. and i am aware that
the turbo is a little small, but for my needs right now it'll
do just fine, since i dont need a huge amount of boost, plus
im told that it will spool pretty quick. i guess that my only
big hesitation about boosting my car is that the engine is
nearing 120K miles and its bone stock, save the exhaust and
intake mods ive done, and i cant afford to have detonation in
this sucker, cuz its my commuter back and forth to college (
ahh the benifits and drawbacks of living in the middle of
nowhere). i guess another question would be what octane of
fuel should i run? i would assume that 92 would be sufficient
to keep detonation down to a minimum, but would i be better
off running 89+octane booster? i dunno... quick other
question...is it possible to run nitrous on a stock block?
like say a Zex kit? like maybe a 50 shot...probably outta
search that one too... 

do a compression check and if its good boost away . i always
put 93 from sunoco in my car but 91+ should be okay

Originally posted by DSMTalon
i have a turbo off a 98 GST (presuming its the 16G)and im wondering how i can regulate the boost down to acceptable levels for my needs.

No, its a T-25 aka T-toosmall. It's a wimpy turbo thats not even worth the trouble of installing. The wastegate is vacuum operated, and stock boost (if you just hook the actuator to the compressor) is about 8psi. There's no need to regulate it.

BTW, these are ALL generic questions. They've been asked a hundred times. Use the search button at the top, right under "2gnt". Also, buy yourself a copy of "Maximum Boost" by Corky Bell. It explains turbosystems very well.

What year is your car? If it's a 95 then you mount the FMU in your engine bay and you also don't need a FCD or anything for the MAP sensor.

If you're deadset on wasting your time installing a T25, then make sure you upgrade your fuel pump to a Walbro 255lph-HP, and get better injectors, like 252-310cc. Detonation comes from lack of fuel most of the time, or irresponsible overboosting.

If you want the NAWZ, you can do that for much cheaper, and get the same power level as a T25, but it's less reliable because generally people don't do any supporting mods (like upgrading injectors) because the box says its safe.

Seriously though, read more before posting again. A lot more.

Originally posted by thedawg
If you're deadset on wasting your time installing a T25, then make sure you upgrade your fuel pump to a Walbro 255lph-HP, and get better injectors, like 252-310cc. Detonation comes from lack of fuel most of the time, or irresponsible overboosting. If you want the NAWZ, you can do that for much cheaper, and get the same power level as a T25, but it's less reliable because generally people don't do any supporting mods (like upgrading injectors) because the box says its safe. Seriously though, read more before posting again. A lot more.

if ur boosting on a stock motor you can probably use stock injectors from what ive read on this site many times they will work fine for like 8 psi
by the way not to steal ur post but while were talking about where u mount the fmu where does everyone mount there sfmu for easy "tuning"

Originally posted by rs_smoked_you
where does everyone mount there sfmu for easy "tuning"

I removed my washer fluid res. and used the esiting holes to fab up a bracket. It's right there easy to adjust. I also just ran a line from my rear washer fluid tank and used that up front :)

before i even bought the car i have i ran a compression
check...i got lucky on my car since i work at a shop, a chick
brought it in for a battery cuz she was selling it and
conviently i had just sold my diesel truck and while it was
there i ran a compression check...flat 140 across the board
with 2psi variations in the 1'st and 3rd cylinder.. so i gave
her a week to sell it then i called her up and picked it up
for 1800 bucks. had 111xxx on it and is a slushbox but since i
was off to college i figured why not. anyway thats why im
gonna throw that T25 on there i know its a crappy turbo but i
picked it up for the low low price of free so i might as well
use it, especially since im on a budget build (tuition sucks)
otherwise i got a couple 8-71 blowers, a turbo off a cummins
diesel, and a turbo off a Iveco Diesel that the inlet is big
enough to swallow a cone filter. I could put that on there but
theres no wastegate and i doubt i could even spool it...that
and i dont think a turbo as big as the head on my car would
fit anywhere convient. as it sits though any of you have any
ideas as to how i could get that wastegate dialed down to like
7 psi or there abouts without the "spring" theory? 
so far you guys are awesome more helpful than i
imagined...ordered a copy of maximum boost but wont be in for
like two weeks..or something. if you guys have any
reccomendations as to where to pick up parts for this install
it would be appreciated. i can find most of the stuff but most
of the prices seem kinda crazy.  

Originally posted by DSMTalon
i ran a compression check...flat 140 across the board with 2psi variations in the 1'st and 3rd cylinder..

What were the conditions of the check? Cold/warm engine? Dry/oiled cylinders?


To tune the boost DOWN, you either need a new wastegate, or to modify the wastegate actuater rod. Basically, you lengthen the rod to open the wastegate more so boost doesn't build higher than you want it to. There's write ups around, but I forget what they're called.


Brian

Originally posted by ForceFed420a

Originally posted by DSMTalon i ran a compression check...flat 140 across the board with 2psi variations in the 1'st and 3rd cylinder..

What were the conditions of the check? Cold/warm engine? Dry/oiled cylinders? To tune the boost DOWN, you either need a new wastegate, or to modify the wastegate actuater rod. Basically, you lengthen the rod to open the wastegate more so boost doesn't build higher than you want it to. There's write ups around, but I forget what they're called. Brian

Compression seems kinda low...my built 8.6:1 longrod gets better compression numbers...either way boost away and have fun...
As far as the wastegate goes, straighten the arm with a vice. Next use the process found on this page http://www.denverspeed.com/wastegates.html now you will have a fast spooling t25 with lowered boost level. If you just extend the arm it will spool pretty slow since the flapper is alway's open a bit...anyway don't get too discouraged by all the bad mouthing that you will get for using a t25. It does pack a punch and when I had mine it was awsome for auto x, anyway have fun and boost away...

Originally posted by RxR_Eclipse

Originally posted by ForceFed420a

Originally posted by DSMTalon i ran a compression check...flat 140 across the board with 2psi variations in the 1'st and 3rd cylinder..

What were the conditions of the check? Cold/warm engine? Dry/oiled cylinders? To tune the boost DOWN, you either need a new wastegate, or to modify the wastegate actuater rod. Basically, you lengthen the rod to open the wastegate more so boost doesn't build higher than you want it to. There's write ups around, but I forget what they're called. Brian

Compression seems kinda low...my built 8.6:1 longrod gets better compression numbers...either way boost away and have fun... As far as the wastegate goes, straighten the arm with a vice. Next use the process found on this page http://www.denverspeed.com/wastegates.html now you will have a fast spooling t25 with lowered boost level. If you just extend the arm it will spool pretty slow since the flapper is alway's open a bit...anyway don't get too discouraged by all the bad mouthing that you will get for using a t25. It does pack a punch and when I had mine it was awsome for auto x, anyway have fun and boost away...

Thanks for the link. That's a great idea, and certainly superior to my idea of just lengthening the rod :)

Brian

the engine was checked dry while being warm..it was run on a
drive of about 30 miles before it got to the shop. the car
came from a nearby town...but as far as low compression
goes...id say the lower the compression the better...at least
for boost...thats the point of lowering the compression right?
all id have to worry about is detonation...speaking thereof...
did any of you guys clean up the intake manifold before you
went turbo, i mean as far as the inside of it to remove any
oil deposits, because unless im mistaken that will cause
detonation right? and if thats the case then what would be the
best solution for your PCV? just put a external filter on it
and vent to atmosphere?( probably what i'd do anyway..)

Originally posted by DSMTalon
did any of you guys clean up the intake manifold before you went turbo, i mean as far as the inside of it to remove any oil deposits, because unless im mistaken that will cause detonation right? and if thats the case then what would be the best solution for your PCV? just put a external filter on it and vent to atmosphere?( probably what i'd do anyway..)

I cleaned my intake when I ported the shit out of it. But my motor was sitting on a stand so it was easy. I think it's a PITA to remove it with the motor in the bay.

And no, I think you need to have a crankcase ventilation valve.

Read this.

http://www.machinerylubrication.com/article_detail.asp?articleid=234&relatedbookgroup=Lubrication2

Originally posted by Blizare

Originally posted by rs_smoked_you where does everyone mount there sfmu for easy "tuning"

I removed my washer fluid res. and used the esiting holes to fab up a bracket. It's right there easy to adjust. I also just ran a line from my rear washer fluid tank and used that up front :)

thanks sounds like what in gonna do then (who needs washer fliud ne way lol)

Originally posted by rs_smoked_you
who needs washer fluid ne way lol

Well I wouldn't go that far. Everyone needs washer fluid.....unless you just don't care if you can see or not :P

lol i live in nevada i rarley use it think of it as weight reduction lol

aight...heres anothre dumb question...how much of my luck
would i be pushing to run 5lbs of boost and a 50 shot of
Nitrous? could i kiss my engine goodbye? wait...nevermind
scratch that dumb post i know the answer to that one....

hmm ok next question, just cuz im worried about running
lean... would i be better off to upgrade the injectors on my
car when i go turbo? and if i do would i need to go w/ a
different pump and FPR? and what # injectors should i look
for.. would 30#'ers work?

You can run around 8psi fine on your stock injectors.. any
higher, and you are risking it.. Buy a new pump and fuel
pressure regulator.. as for the injector size, depends on
where you want to boost.  You'd be fine with 440's (gst
injectors), but 550s would be nice if youre really hi
boosting.. But, you may want to buy an safc to tune it
correctly.  you can have all the parts needed to deliver the
fuel, but if it isnt done properly youre asking for trouble.

cool thanks for the help... i dont plan on going over 7psi
until the engine goes and i can rebuild it for more boost.