15g upgrade checklist?

[Hard AttacK]

I wanted to go single turbo, but nobody would help me do it or tune it....so I'm thinking I want a 15g setup with around 400 reliable awhp on my all stock longblock and heads. That will leave me with more power to be made down the road.

Here's what I know I need.

550 injectors
walbro or supra fuel pump
something to tune with (piggyback?)
Air/fuel gauge
quality boost gauge (my prosport sucks)
new oil feed lines
FMIC
Stage 3 clutch
T case brace
BOV

What else?? I know there's more

Thanks!

[SpdDmnVR4]

A Blow through set up will make it easier to make that kinda of power. And I would add a decent BOV to the list. The stock one does not hold boost well.

BTW I love my DEFI boost guage for something on the cheaper side.

My mod list will be similar to this when im done and I have the same goal as you (reliable 400 AWHP DD):

-Full Turbo Back exhuast
-Gutted Cats
-16T's(in your case 15G's)
-Hard intake pipes(like DEJONs) w/ twin K&N's
-2 Piece Y PIPE with a LS1 MAS
-MAF-T Pro
-SAFC (maybe replace both of these with an Emanage if I get excited)
-MBC(EBC if you can justify the money)
-550cc injectors
-Denso (Supra) fuel Pump
-Aftermarket FPR(stock FPR does not like bigger pumps much)
-Wideband A/F guage
-Greedy Type RS BOV
-DEFI boost guage
-Setrab Oil cooler (power = more wear/tear + hotter oil/engine temps)
-High capacity/high flow Radiator
-Dual Core FMIC
-MBC(EBC if you can justify the money)
-HHH datalogger

I think thats everything. Some of those can be scratched since they are completely necessary, but I want it to be as reliable in rush hour stop and go traffic as it is cruising or doing 1/4 mile pulls

[thor'svr4]

my setup works pretty good and left quite a bit of power on the table. During my first dyno session I made 418 awhp and 408 awtq at 18psi with no knock. The car had more left in it, but since I had 154k on a stock motor that had seen better days ray wanted to call it quits before something went boom. that was all before the rebuild though. i really want to go back asap with the new short block, a safc and upgraded exhaust.

i have the following mods

hot wired 255lph fuel pump
550cc injectors
3sx fuel rail loop
bigger fuel lines
K&N cone filters
Dejon 'blow through' intake pipes
GM LS6 MAF
MAFT
Robbeck 13T turbos (13T's ~ equal to 15G's but it seams like 15G's tend to make a little more peak power on the dyno. plus there easier to install....)
FMIC with full alu piping
MSD wires
3sx radiator
HKS EVC electronic boost controller
turboxs R.F.L. BOV
maximal performance T case brace
new OEM Clutch
new output shaft
rebuilt T case
A/C delete
vacuum delete
AEM wideband O2
solid motor mounts
short throw shifter
3sx ross pistons
3sx rods w/ ARP bolts
new oem forged crank
clevite bearings
B&M oil cooler

ill admit a LOT of that stuff is overkill / pointless. some of the things i don’t think you will need are

3sx fuel rail loop (not sure if its needed but it was cheep and I was doing the fuel system anyways)
bigger fuel lines (mine were rusted / rotted to the point I didn’t trust them)
FMIC with full alu piping (my smic’s were shot)
MSD wires (figured I might as well replace the wires while I replace the plugs)
3sx radiator (didn’t have a rad when I bought the car)
new output shaft (if your 18 spline you might want to consider upgrading but i doubt its needed.)
A/C delete (could be the difference between 380 and 400whp though…)
vacuum delete (dont need to do this but it makes finding vacuum leaks so much easier, plus no egr helps out a little bit)
solid motor mounts (I was bored and wanted to play with a welder…plus my front motor mount hated my 13T)
short throw shifter (I was bored)
3sx ross pistons (spun a bearing)
3sx rods w/ ARP bolts (spun a bearing)
new oem forged crank (spun a bearing)
clevite bearings (spun a bearing)
B&M oil cooler (spun a bearing plus my oem oil cooler was trashed)

most of the stuff above adds almost no hp and is terrible bang for the buck. most of the above mods I did out of necessity due to old worn out parts. BUT i do recommend the T case brace, and while you have the t case and exhaust off you might as well replace the main and rod bearings. i really wish i had because ~2 months after the turbo upgrade i spun a bearing and had to do a full rebuild which took a lot of time and money and ruined the summer. all because i cheeped out on ~$100 bearings... i felt like a moron.

I love having a blow though setup though, its awesome when you pop off an IC pipe and are able to relax and just pull off the next exit and fix it at your leisure. Blow though with maft + safc is prob the easiest route to go for tuning.

hope that helps.

[Hard AttacK]

Awesome!!! Even though I have a new oem clutch in my car I would rather have something with more grip. Thanks for that list! I will keep updating my OP. How hard is it to change out the bearings?? I heard you can't just "pop" new ones on.

[SpdDmnVR4]

I have a south bend stage 2 clutch and IPS lightweight Flywheel. I did 6 runs, hot lapping the car(ran them around 15 mins apart). It had enough grip to spin all four KUHMO EXSTA ASX allseason from the 5k launch. well more of a slight chirp. I can't launch that well and Im afraid to clutch drop

[thor'svr4]

Awesome!!! Even though I have a new oem clutch in my car I would rather have something with more grip. Thanks for that list! I will keep updating my OP. How hard is it to change out the bearings?? I heard you can't just "pop" new ones on.

I’m not exactly sure what you would have to do if you replaced the main and rod bearings but not the crank and rods. i would assume that if you haven’t spun a bearing your crank journals and rod journals would still be within spec and new bearings would simply replace the old ones. I would use a micrometer to measure the journals and then use some plastigauge to double check the tolerances once its reassembled. But if you have been told that you’re not able to simply replace the bearings than that might be true. I would try to find someone with more 3000gt bottom end rebuilding experience for more specific info though. They might even tell you not to bother replacing the bearings and save you some money and work.