Need Advice for Throttle body and Intercooler Piping size

[BOOSTJUNKIEGSX]

I am in the process of building a weekend race car/Daily driver if needed and i am stuck on what would be best for my setup. I do not know what size intercooler piping to go with ( 3" or 2.5 ) nor what throttle body to use ( 1g or 75mm). I want to use a Magnus Intake manifold. Any advice on piping size from experience would be appreciated and same for throttle body.

Concern: I do not want problems with idle and stalling like the 75mm TB claims to give and my goal is to make 450Hp to the wheels.

Here are my mods to help figure out what setup to go with -
- DSM link - 1000cc injectors - 255lph - Aeromotive FPR ect.
- Stage 2 block
- Completely Balanced and Blueprinted
- 4G63 Block - 2.0L Crank
- 85.5mm Bore
- Eagle Forged Rods
- Arias Pistons
- New Front Cover w/ Oil Pump & Gears - Water Pump
- Balance Shaft Elimination Kit / installed
- Prothane Motor Mounts
- Cometic Metal Head Gasket
- ARP Head Studs
- Fidanza Cam Gears & Flywheel
- ACT 2600 TTR built tranny
- 1G Turbo Cams (idle purposes)
- Stage 5 Head - 283.4 CFM on the intake side
- Hot Tanked and Pressure Checked
- Competition valve job + Stage V port and polish work
- New valve stem seals and SS swirl polished Ferrea valves
- New Guides / Crower springs with titanium retainers
- Decked head surface and new exhaust manifold studs
- 5-angle valve job
- Turbonetics RS49T 50 trim with evo III ported manifold
- SBR o2 dump with 40mm tial wastegate
- Apexi gt spec downpipe N1 exhaust
- Fluiding Radiator w/ slim fans

Build being done in a 95 GSX and charcoal canister( with all vacuum lines ), A/C and all unused misc. parts removed.

 

[BlueTurboSpyder]

You should be fine with 2.5 inch intercooler piping and a 1g 60mm throttle body with those mods. If you go with anything larger, you may get into some driveability issues on the street.

 

[CanadianTSi]

2.5" piping and a 1G TB will be fine for 450whp.

Also if you really want 450whp I would pick up a set of cams...

 

[BOOSTJUNKIEGSX]

Yea i was really leaning towards the 2.5 but i really couldn't decide. It just makes everything so much easier and driveability is a big issue. What would the max HP be for the 2.5 because im really trying to make the car reliable and im going to be boosting 25psi and up to 30psi race gas. I dont want 450whp to be my max, id like to have room for more if i need it.

What do you think about a 1g throttle body bored out to a 63mm claiming to flow 65mm airflow?

As far as the cam's, i used them for the issue of idle purposes but i am deffinitely swapping them out to get full potential of this head!

Thanks!

 

[CanadianTSi]

My FP2x's Idle fine at 750. Also if you don't want 450whp to be your max your gonna need alot bigger turbo...

 

[BOOSTJUNKIEGSX]

- Not too Fond of the Turbonetics RS49T.. I talked to darren at FFWD and the 1yr warranty doesnt seem like a bad deal for his regrinds.. We will have to see.. Im just trying to finish up all the odds and ends to get her running so i will be using the Turbonetics that i took off my 97 gsx to break her in.. Then i will be getting the FP 3052

I was looking around and i could only find intercoolers with a 2" or 3" inlet outlet NOT 2.5" - ???

I was going to use 2.5 to the 3" gm MAF then continue the 2.5 to the throttle body.. Do i do 3" all the way and then downgrade smaller to the 1g throttle body ( ?? ) or do 2"intercooler outlet to 2.5 piping - 3" maf and continue 2.5 to the throttle body - Any one tell me the complete route to do because im very confused what steps to take here.