Maximum safe BHP for stock 1.5 with turbo

[H3LlIoN]

Originally Posted by TonyHanscomb

Anyone know what power output to expect (or risk) just adding a good turbo to the stock 1.5 Yaris engine?
As far as I can ascertain the boost can just be turned up to produce whatever power one wants, until it self destructs.
It would be good to know how much it can take?

Also is there any inherent weaknesses that can be eliminated to allow higher boosts, such as forged pistons, different crank, special rods?

Also, the turbo won't self destruct, it'll just tear the engine apart. As for higher boost applications, Garm is running 24 psi with the mods previously mentioned, as well as a few others (block bored/sleeved/notced,standalone, fuel pump/rail, P&P'd head, etc.) If you have not already heard, tuning will be an issue at higher levels.

[Parmas]

Originally Posted by TonyHanscomb

Anyone know what power output to expect (or risk) just adding a good turbo to the stock 1.5 Yaris engine?

This question was posted too many times (including myself) and I think the question is too general since a stock 1.5 Yaris engine is made of several parts you need consider. We mainly focus on rods and pistons but they aren't the only issue to consider. You have to note the physicial inside parts of the head, head bolts and fuel delivery. These and more make a turbo project complete and not just a turbo!

As far as I can ascertain the boost can just be turned up to produce whatever power one wants, until it self destructs.
It would be good to know how much it can take?

That depends what turbo are you running. If you take a GT28 with an internal wastegate spring pressure that gives you 9 psi boost, the lowest maximum boost would be this and could be already fatal for you engine especially if not tuned.

Also is there any inherent weaknesses that can be eliminated to allow higher boosts, such as forged pistons, different crank, special rods?

There are much weaknesses that can be eliminated/ or upgraded to allow higher boosts that would be almost every part your engine has which in that case would cost you a fortune! That depends what are your intensions for the car and how much cash are you ready to invest!


This thread made me think...... how about gathering information from turbo or supercharged owners and list in divisions every stock part how much withstanded boost and power?

For example I have a complete stock Head and Crank that is running an efficient 9psi (don't know the exact power & not yet) on a GT28 turbo.

[Yoda]

Sounds like not too bad of an idea...Let me put one up