Just wondering what the stock turbo on a EVO VIII can be boosted to, but at the same time be totally safe for the car and the turbo? And of course what mods can be added to let the car breath better so it can be boosted at a safe level as well. So im looking for stock and modded EVO VIII safe boost levels.


Thank you for your time for answering my question.

 

Given the right tuning, the turbo will run to about 24psi peak, probably a realistic max of 21-22psi though.. anything over that and its no longer efficient.

reducing the restrictions in the "air pump" everywhere possible will allow you to get air in and out as fast as possible.. Intercooler upgrades, piping, freeflowing exhaust, cams, ECU Tuning (Flash, Piggyback, Standalone).. It depends on what you want to invest in getting the turbo to do what you want before it becomes more cost effective to replace the turbo.

Making big horsepower isn't about making the most boost a turbo can produce.. its the efficiency of the engine, the ability to move a volume of air (Not necessarily at a high pressure, but alot of air) and of course, compressing it into the cylinder without it breaking anything (Excessive cylinder pressure, can lead to detonation, piston failure, stretched head bolts, etc..)

I've seen custom turbo setups run as high as 30psi or more, but the engines have been modified to minimize its failure points, and fuel tuning (and octane levels) to prevent detonation.

To make a long winded answer short, 19.5-20psi through redline, and optimized ECU settings, will provide the most reasonable gains and reliability. Then making modifications around that to get the air in and out of the engine (of course the fuel system too) I've seen higher boost, but I personally would recommend going much higher on pump gas (93 or 94 octane) 91 octane, 18-19psi through redline.

Some will disagree, but its a good guideline.

 

i live in philadelphia, so the highest octane i can get legally is 94. So given i go, Intake, BOV, Fuel pump, turbo back exhaust and manual boost controller, what can i boost my turbo to without the worry of messing my car up?

 

I still wouldn't go higher than 20psi.. I think the 1psi difference isn't going to have a huge effect on things, tuning the ECU specifically for the modifications will have much greater gains. (For what its worth, the BOV really doesn't have any performance gain, the stock Diverter valve seems to begin to leak at over 20psi) and a BOV (A real Vent to Atmosphere blowoff valve) will just lead to drivability issues.

An upgraded fuel pump is a safety measure, but not much of a performance gain until you start needing alot more fuel volume (upgraded fuel injectors, etc)

In all seriousness though, the difference in the modifications you want to make, and what the car currently feels like STOCK, is dramatic.. Just remember that all of those bolt ons will require fuel tuning, so you should reflash your ECU, or go with an aftermarket piggyback to adjust it.. The additional gains are well worth it.

 

so with the mods i listed, where do you think i will be at, HP and 1/4 mile times? and yes i forgot to mention walbro fuel pump, i will be getting that as well

 

oh and the ECU flash

 

I have run 12.42 with Buschur Air Filter, MBC (@19psi), S-AFC, Full 3" Turbo back exhaust WITH a 3" Catalytic converter.. I can't really guess at the horsepower, but you probably can do a little better with a custom reflash as opposed to a road tuned S-AFC

 

ok 12's is fast enough for me. soo ill look into it, thanks