420A Maximum boost on stock fuel system

[Toms rs-t]

I have a 1999 mitsubishi eclipse rs being fully rebuilt with 8:5.1 pistons aftermarket rods arp head studs.
I already have a msd ignition coil pack, granatelli spark plug wires. Log style manifold with a .63 trim ebay turbo. AEM boost guage. Fully rebuilt tranny. What's the max boost I can run on the stock fuel system? (without a tune with no fuel mods)And how much hp will it be? My goal is around 300-350 hp daily driven. But after I get a fuel system upgrade and a tune. Since the rebuild is costing alot of money I'll have to wait on that a few months.

It was running smooth on 6psi before it seized.The reason why it's being rebuilt is because when I installed my turbo kit I didn't put a oil pressure guage and the return line got slit because I put the metal clamp to tight and i was leaking oil on the highway on the way to work.

 

[BLACK'98DSM]

What's the max boost I can run on the stock fuel system? (without a tune with no fuel mods

I personally wouldn't run any boost without some kind of a tune. And you say you want 300hp w/o changing the fuel system but thats not acheivable with stock injectors. You will at least need to change those. As far as "max boost" I would just go back to the 6 psi (push 8 if you're brave) since you already know that will run smoothly.

Not trying to be discouraging, but you WILL need better injectors and you WILL need a tune to run correctly.

If you plan on a tune try exceeding 10 psi but otherwise face reality.

 

[ThunderChild]

Agree with @BLACK'98DSM , not wise to try and run boost without fuel and tuning capabilities, at the very least you need a wideband to monitor AFRs.

@VelocitàPaola and @dsmcrzy can shed some light on 420a upgrade paths as well.

 

[Toms rs-t]

I personally wouldn't run any boost without some kind of a tune. And you say you want 300hp w/o changing the fuel system but thats not acheivable with stock injectors. You will at least need to change those. As far as "max boost" I would just go back to the 6 psi (push 8 if you're brave) since you already know that will run smoothly.

Not trying to be discouraging, but you WILL need better injectors and you WILL need a tune to run correctly.

If you plan on a tune try exceeding 10 psi but otherwise face reality.

Ok thanks for your input. Do you know what the stock srt4 injectors can handle as far as psi from the turbo?

 

[BLACK'98DSM]

The stock 420a injectors couldn't handle more than 180 whp. If you have other injectors then do your research. I think 375cc or 400cc would be appropriate for your assumed 300-350whp.

 

[Toms rs-t]

The stock 420a injectors couldn't handle more than 180 whp. If you have other injectors then do your research. I think 375cc or 400cc would be appropriate for your assumed 300-350whp.

Thanks for your help man. I appreciate it. After the rebuild it's just gonna stay on 6psi until I can afford to get the fuel pump, injectors, fpr fmu 12-1 ect. The rebuild bill kicked me in the wallet hard . Because the forged pistons rods and arp head studs.

 

[BLACK'98DSM]

One can always complain about prices, but the feeling of knowing you did the job right is unbeatable.
I hope it goes well and keep us updated.

 

[VelocitàPaola]

This is a really vague question and psi is just one part of the equation. I suggest taking a more systematic approach and researching in detail how turbochargers and fuel systems interact before making any further purchases or changes. I think you'll find what you're looking for if you search through these forums. Good luck!