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?
:burnrubber:

[Blown_xa]

from my experience, 150whp was the limit (on our dyno). I blew up 4 or 5 stock motors unfortunately (because I was greedy ) before building one. 2 of those were not directly related to power output... I once had my meth nozzle clog so detonation occured , thats why I always recommend a flow rate gauge to customers running wmi. If the car is tuned mbt with meth, and the pump fails or line blows off.... motor go boom even a built one.

150whp is still fun in our small cars for sure, considering 86whp stock! Ive posted videos of track time with 130whp and still passed evos and s2000's . A little hp gain counts for a lot on a car around 2300lbs.

[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]

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. :thumbsup:

[Yoda]

from my experience, 150whp was the limit (on our dyno). I blew up 4 or 5 stock motors unfortunately (because I was greedy ) before building one. 2 of those were not directly related to power output... I once had my meth nozzle clog so detonation occured , thats why I always recommend a flow rate gauge to customers running wmi. If the car is tuned mbt with meth, and the pump fails or line blows off.... motor go boom even a built one.

150whp is still fun in our small cars for sure, considering 86whp stock! Ive posted videos of track time with 130whp and still passed evos and s2000's . A little hp gain counts for a lot on a car around 2300lbs.

Got to agree here. For safety and longevity all the Toyota forums I have seen said the same thing. But I still think if it's tuned really well then 8psi no problem. By tuned really well I mean pro tuned. There was a guy that ran a test(will try to dig up the website later) that showed 5-6psi was safe but when he cranked it up to 8psi engine blew after 6 months of tracking. It also depends on how you drive your car also. How often will you see high rpm?
Street or track use?

[Blown_xa]

Got to agree here. For safety and longevity all the Toyota forums I have seen said the same thing. But I still think if it's tuned really well then 8psi no problem. By tuned really well I mean pro tuned. There was a guy that ran a test(will try to dig up the website later) that showed 5-6psi was safe but when he cranked it up to 8psi engine blew after 6 months of tracking. It also depends on how you drive your car also. How often will you see high rpm?
Street or track use?
I see high rpm often, track it a lot. It's also my DD with 120,000 miles on it.
Yea somebody brought up the point that boost is irrelivent, which is true. As I put the same whp down on my current turbo at 9psi as my Greddy at 20psi.

[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]

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.

[Evangelion335]

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


Can someone explain this to me?

It was my understanding that the # measurement was accurate right untill it passes trough the throttle body.

Flow is an important matter, but only because you can create a bottle-necking effect that will rob you of available o2 into the engine.

The 9lb rating is going to be 9lbs no matter what the size of the turbo is. In the same sense that you can have a gallon of water thats pressurized at 9lbs as well as having an oz of water pressurized at 9lbs. Turbo sizes are relevant to the volume of air intake the engine requires not so much the #s required (this isnt a hard an fast rule).

Smaller turbos are ideal for smaller engines because:
1: A smaller turbo has less mass at the turbine meaning that it will take less force to achieve maximum rotations and therefore less time to achieve desired pressure.
2: Because you engine is smaller (1.5l) the actual internal volume of the cylinder requires less oxygen to reach the desired pressurization.
3: a large turbo and a small turbo running at identical pressures will produce the same horsepower gains. The "power loss" becomes an issue because you have selected a turbo that is limiting your maximum flow rate and spooling time. This can wildly effect torqe curves and produce a torqe curve that will become murder on trackday.

Can someone read that and tell me if ive got the theory right?

[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]

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?
:burnrubber:


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]

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?
:burnrubber:

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