Boost presure 1.0 Bar without increasing pressure.How?ST205

Good afternoon guys,and hello from Georgia.I'm driving ST205.Car is in a good condition.1996 year,and only 94 000 KM.Car is slightly modified and that's the reason of my new thread.I have some questions.

So we have an aftermarket frontal cooler
new exhaus system starting from downpipe and ending as a Fujitsubo cat.exhaust is 3 inches in diameter
Cold Air Intake + HKS filter (you know that green filters,looks like a mushroom : ))) )

So now comes my question.My car is boosting 1.0 BAR in all gears,till 200 + km/h.Boost is 1.0 and i have no boostcontroler instaled.So why the pressure is so high and not 0.7 like other stock cars have?Because of Exhaust?Exhaust is increasing boost presure?


And the second question.What pressure would be safe if i install boostcontroler (electro) and increase pressure?Internals are stock,turbo is stock,clutch and gearbox is stock too.Thanks

photo of my car

Welcome! For a moment I thought you were from Georgia in the U.S

The exhaust is the biggest contributor for the increase in boost, but overall you've made the motor more efficient with the mods you've done. HTH

Thanks for an answer.But what does mean HTH i can't understant,can you explain? Thanks




and what do you think,if i install boostcontroler gonna be maximal Horse powder that i can reach?and how much would be maximal boost in this setup?

Gamarjoba!

gagimarjos : )) kartveli amerikashi GT4it magaria!


so guys,any ideas ?

The mods exhaust mods that are installed create less backpressure which allows the car to boost slightly higher before the wastegate opens. It's completely normal and nothing to worry about.

Not sure about safe boost for a stock ST205 engine, but probably not much more that you're seeing now. Maybe 1.1 bar. 1.2 bar is probably pushing it and also depends on what octane gas you have available.

i'm using 95 octane gas.So you think that buying and installing highly expensive boostcontroler like an apexi around 300$ is just wasting money?instaling controler for only adding 0.1bar ? sound silly?

I'd just install a manual boost controller if you want to experiment.

You might find more info on the ST205 engine on the UK GT-Four forums or maybe searching on mr2oc.com for "gen 3" topics.