What Turbo for this 420a setup?

So, as most of you know i'm going to be dropping $5-6k into my engine alone...and i'm at the point of piecing together my own turbo kit...

Problem is, I really don't know how much horsepower to expect out of this setup; thus problems picking the right turbo.

Main Engine Mods:
-Forged Internals (including crankshaft); .04 overbored pistons
-Stage 2 Crower Cams
-Custom "Race" Head; 5-angle Valve-Job, Full Porting/Polishing, all new seats, retainers, undercut valves, fully decked
-Adjustable Cam Gears
-MegaSquirt EFI system

That's basically it excluding all of the turbo components and minor shit.

So, anyone have any clues on appoximate WHP, turbo recommendations, or max amount of boost i'll be able to run SAFELY?...and yes, this is going to be a DD :icon16:

With that setup I would run a 16g.

A EVO 16g would be a nice turbo, but I think you could go with something a little bigger like a 50 trim or something. It all depends on what you want for goals and so forth. I think Jake (EclipseRST) was running 27-28psi on his turbo'd 420a. Safely, I would only push 20-22 through it for the DD, then crank the bitch up for the weekend/track runs.

Problem is, I really don't know how much horsepower to expect out of this setup; thus problems picking the right turbo.

The turbo will end up being the deciding factor in how much power you make, so I can see why that would be problematic ;) Everything needs to be built around the turbo, especially the fuel system. If there are limitation in the fuel system design, like a limit to how big you can go on injectors with the megasquirt for example (hypothetical), that may help you put a limit on the largest turbo you can run. Otherwise, it's just up to how much power you want to make and what your lag tolerance is.

Build the engine around the turbo, makes sense lol....

A 50 trim sounds right up my ally, but even talking about it makes my computer lag...how bad are they really? When could I, roughly, expect it to be at full boost (RPMs)?

Honestly though, my power goal is unknown really, I want to push my setup as far as possible with it still being fairly convienient and reliable for a DD.

I would be very happy with 400-450fwhp, is that a realistic goal? Feedback would be nice on this, as i'm curious to get "professional" opinion on that at least...

I would be very happy with 400-450fwhp, is that a realistic goal? Feedback would be nice on this, as i'm curious to get "professional" opinion on that at least...

On a built 420A? I bet it's possible, once you go turbo it should be just as easy to put up numbers like that as it should be atleast as able as a stock 4g63 block to handle the power, and as long as you pick a turbo that can give you that power and the supporting mods you should be good to go.

On a built 420A? I bet it's possible, once you go turbo it should be just as easy to put up numbers like that as it should be atleast as able as a stock 4g63 block to handle the power, and as long as you pick a turbo that can give you that power and the supporting mods you should be good to go.

:1:

Remember 400 hp isnt easy.

I would go with a SBR 50 trim. They are big enough to get like 427 hp (if I read the dyno sheet right, there were two power curves) and make good power at street boost (I wouldnt recommend over 20 on pump gas and a pretty good IC), but small enough to spool. IIRC, full boost comes about 3500 rpms. I am going to get one but not to max out. I would rather run 320-360 hp all the time rather than having to boost the shit out of a smaller turbo for a track weekend and have to be running less power when I am cruising.

If I remember correctly, a 50 trim hits 20-25 psi around 3800 rpm. This was on a TDO6H hotside, so basically a SBR M50 or FP Green. OTher variations may vary slightly. I don't see why any "built" motor wouldn't be able to comfortably handle a 50 trim, but that assumes good tuning (WOT AFRs around 11:1 at all boost levels, reasonbable timing advance, and no knock) and good intercooling. On race gas people with 50 trims have done 475 AWHP with decent consistency, and as much as 500 whp with large hotsides, but thats pretty much a best case scenario.

Perfect, thanks for all the info guys, once again AF knowledge wins again :grinyes:

So now I have a whp goal (~380 street and hopefully ~450 track) , and a pretty great idea of what turbo i'll be getting...

Thanks again!