Maximum safe BHP for stock 1.5 with turbo

[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?

[cali yaris]

there are less than 25 boosted cars here & most are making 125-175hp with stock engines.

yep, that's just about the complete answer right there.

I ran 183 whp for about 9 months on the stock motor, but without a tune. I lost a little compression in one piston, but with a good tune that might not have happened.

[thebarber]

its likely more about the psi you're pushing with the turbo or superchager vs the actual at-wheel hp

i think 9-ish psi would be the max max on our already 10.5:1 compression engines...

[mightyMax95]

Originally Posted by thebarber

its likely more about the psi you're pushing with the turbo or superchager vs the actual at-wheel hp

i think 9-ish psi would be the max max on our already 10.5:1 compression engines...

hate to do this to you :hide: but psi is irrelevant, flow is key here.

little bitty turbo can run high pounds psi and big turbos less pounds psi without blowing. this is coming from a Maxima forum where some guys reliably run 15 pounds of boost while others blow at 10, all on a stock 10:1 cr motor (vq30). the key thing is to use an appropriate size turbo with flow characteristics that will fit the application.

however, by far the most important thing is a good tune.

[cali yaris]

9lbs on with a T28 (what Im using) is not the same as 9lbs with a GT2554R (what Garm is using)........

I think you meant was I WAS using -- currently using a GT28 disco potato.

[Blown_xa]

Originally Posted by cali yaris

I think you meant was I WAS using -- currently using a GT28 disco potato.

haha, i was waiting for that. where did the name disco potato come from? i almost wanna buy it just to say i gotta disco potato under my hood cause it sounds cool.

[eTiMaGo]

thanks for the history lesson on the disco potato, I feel enlightened :D

Some time back I talked to the local TRD distributors about turboing my car, and they explained the reason why the TRD turbo'ed 1NZs are limited to about 140hp is that above this level, the internals are not up to the job. I assume this means the engine will only last 180,000 miles instead of 250,000 (or whatever, just illustrating the difference), since these guys do give a warranty coverage, but that is the most official limitation I have seen/heard.

[cali yaris]

^ +1 good link to bookmark, everyone.

[H3LlIoN]

homemadeturbo.com is another great forum for forced induction specific theory and discussion, free to reg.

[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