My girlfriend is itching for a few more ponies... I'm aware the 8s spike to 19 and then taper to around 16psi. We bought a mbc, boost guage, and pillar for the car... I come from the DSM world so I'm not positive on safe stock boost for these Evos, I know they have 550 injectors and a larger factory pump than dsms...

Will 20-21 psi to redline be safe? Car is bone stock.

PS: I'm probably the 99,000th person to ask this.

 

If you don't want to take it to a tuner at least have the proper gauges to monitor the AFR and tactrix cable to log knock, and alter ignition timing if you want to turn up the boost. I wouldn't just turn up the boost blindly. That being said my stock Evo 8 peaks around 20 psi.

 

Safe? Don't cut corners. Sure, you can probably turn the boost up a pound or two and be okay since the stock tune is so rich, by why risk it for like 20hp? As the above person said, either get the equipment to tune it yourself (at the absolute bare minimum a wideband in addition to the boost gauage) or bring it to someone that knows how to tune. If you just crank the boost controller without touching anything else, you are most likely going to hit boost cut before anything else.

Not sure when you say stock daily boost, if you are relating it to an untuned Evo or just in general. But there are many people on this forum that run 25+ psi safely on pump gas (stock turbo, not stock exhaust) including myself (over 70k miles now).

Edit: And no, you can't hold 20-21 psi to redline without touching the tune.

 

Installed gauge and MBC tonight car is on 19psi to red line... Feels nice, also removed air box and added new filter turbo spool is louder... A lot louder car seems to have picked up a few ponies. Pretty quick for virtually nothing done!

 

I would get someone to log the car and see how it is doing particularly AFRs and timing and knock. This car has either already been tuned or is running particularly rich.

 

Along with the advice others have suggested above, I would recommend getting a 255 fuel pump. The stock one in the 8's isn't as big as the ones in the 9's.

 

Thanks for the advice... This is probably as far as this car will go for now...it is daily driven over an hour a day.

 

It has more to do with how you drive and how you take care of your car. If you don't want a tune then don't turn your boost up! You are asking for trouble IMO. Especially without an afr gauge. I'm sure many people on here can say it has saved them a time or two. All it takes is a small leak somewhere

 

more boost = more flow = more fuel = needs a tune

 

Any changes to flow through the engine requires a tune for maximum efficiency.

 

The stock ecu is tuned out to 260 load, or about 24psi. before fuel cut. So raising the boost to 21 psi is not going to hurt anything. This is assuming a stock or lightly modded car, ie. exhaust. As long as the recommended fuel is used and there are no serious mechanical issues with the vehicle.

Is it the best tune?... NOT AT ALL, but Mitsu made sure you would not run lean with the afrs dropping into the 9's. Timing is a little wacky too, but nothing that should cause damage.

With that said I am not saying people should raise their boost and not get a tune. You should always tune with the proper tools when searching for more power.

 

I don't know what gauge you have but if your afr is in the 9's your car probable looks like a diesel because you are running so RICH.

 

Car has intake and gutted cat... Started Hitting the fuel cut at only 18psi??

 

Please re-read my post. I'm referring to a stock evo. And to clarify they don't run afrs in the 9's throughout the powerband but just before redline. Point is they run incredibly rich from the factory.

VRP

Try putting the stock intake back on.

 

Changing the inlet tube/intake filter will change the tune more than raising the boost a pound or two. Please stop being dumb and get a 255 and a tune. Done.