How much Boost is safe on a stock engine.
 

From what I have seen and read 12 psi is completely fine on a stock engine and really if you want anymore power you have to get forged pistons and rods. Can a stock engine handle like 15 psi? If it can how well can it handle it. If you run 8 or 12 psi usually then boost up to 15 sometimes would it hurt?

I ran 18psi on my 1.6L for 2 years and 40k miles. It blew up when I spiked to 25psi...but I have no reason to not believe that it would still be alive today had that not happend. it had 110k on it when the piston just exploded and sent my #3 rod though the oil pan.

What about the 323 GT-X. How much boost did they come with from the factory?

323GTX had 7.9:1 pistons ( hypereutectic cast ) and beefier connecting rods ( ones I currently have in my 1.9L). the 323GTX seems to be able to handle 400whp otr 25psi whatever comes first.

Wait Andy did you run 18 psi on stock internals?

yeah, for 2 years.

wow 18psi on a stock 1.6! that's the highest I've ever heard for a car that actually had miles put on it. what turbo and how much power? what kind of engine management?

Combination of 2 turbos...one was a T3 S60 48/60. The other was a T04E 40 trim .48 stage 3 turbine. I ran the S60 for 1 1/2 years and the 40 trim for 6 months or so. I also ran a Greddy before that @ 15psi. Mind you I bought a lot of race gas to run these pressures...but thats when it was 3.30 at the pump. I ran 12psi 1/2 the time and 18psi the other 1/2 of the time.

This was on the same fuel setup I have now, minus the 330's...I was running 270's from a KA24DE. Engine was perfect until the day it died, still had 170-165-170-170 compression across the board ( 3 days before the engine blew ). If it wasnt for that 25psi spike in 4th gear I think that little 1.6L may still be kicking.

So Andy you think with an Fm II turbo kit I could run 15 Psi pretty easy? On stock internals. If I did I wouldn't do it all the time. Just whenever a mustang wanted to race :cool: haha

yeah hell he runs it with stock ecu a linked car can run 22 psi before the em runs out of head room normally past 15 psi there has been a tendecy for parts to weatr out according to FM but i dunno seems to be more of a maintenance issue.

Very interesting, and tempting. Unfortunately I will run out of injector by about 14-15psi. I'd love to pick up some 650cc's and a 3071R and some WI an see how far I could take the stock 1.6 on pump gas.

18psi, stock ecu, stock engine, 270cc injs...You don't really like to play by the rules, do you?:bowdown:

I ran 15 psi on stock internals with no difficulty. I know I was running 18 psi for a while, but I cant remember which motor I did it on. I think it was the built motor.

you where talking about 323 gtx pistons. Then have those in my car and everything is fine with 18 psi

So did I. :D It was 18 psi on a stock 1.8 with a CA spec FM-II however and put well over 13k miles, until an overrev killed the motor. Ric Stevens was running 24 PSI on a stock 1.6 junkyard motor.

I think a lot has to do with the fueling and tuning.....

so true - many a good engine has been killed well before 18PSI with poor tuning.

..... 12psi here...... muahahaaaaahaahahaaaa Posting dyno scans in a few minutes

where?

Rules are meant to be broken:bigtu:

AS well as records speed limits egos etc.

How much power were you making back then?

On 5psi and running alittle lean i made 127hp at the wheels and the i got 460cc injectors and then i was running 16psi and im pretty sure i was up around 180hp then one of my rods started knocking but the money had like 240xxx on it and a stay 47 hrs of driving on it.

And i have the 1.6

I'm sure the people who posted in this thread from 2006 will appreciate this seemingly random information. Cool story.

he just woke up from a 6 year hibernation don't mind him :giggle:

Lol i was googled how much power the stock motor can handle and found this post and i wasnt paying attention to the dates.

At least you searched ;)

Ya i searched cuz im getting ready to rebuild my turbo motor so i was trying to figure out if i needed to get new rods for what im looking to run for power

well, it's been brought back from the dead, soooo, I got 25psi on a stock 1.8 (1994).
MBSP is the only addition to the bottom end.
Lot of head work though.
t3/t04e hybrid turbo

turbo must spool so slow you never make any good torque :)

/\ this.

as long as you can keep the boost coming on progressively and not within a couple hundred rpm you can run surprisingly high pressures on the stock block.

leatherface was running what, 27psi?

well I've built it according to corky bells formula for a maximum effort system. 3000 rpm is soft for sure but at and beyond 4 k it's monsterous. With the head work and mbsp I have raised the rev limiter to 7500 rpm and there is no boost Droop

Nothing wrong with that.

Its just that most folks on here prefer to get maximum torque under curve which is why brain made that comment.

I took my motor apart today and found that the noise was a piston that was melted due to the injector shorting out and i had the same effect when i was running 16psi, after 4 grand the car turned into and animal lol

hello guys, i changed al metals in my block, polished the head and changed all the seals also the valves, so the engine is completely rebuilt. How many Psi do you think it may hold??

All of it.

"How much boost can it handle" without further details is one of the dumbest questions ever. In order to be able to make any sort of estimation we would need to know all the details. You changed all the metals? What kind of rods? What sort of turbo/manifold/exhaust/etc? Engine management? Who is tuning it?

It is known that, on average, stock rods tend to fail somewhere around 250 wtq assuming good tune and such. if the boost comes on hard and soon it is more likely to break than boost onset softer and later.

good answer.

I recommend you just weld your wastegate shut, that way you won't pussy out.

With the rebuilt motor you can run 23.4568psi. If you accidentally run 24psi, even for a moment the welds on your intake manifold will come apart.

what if he reinforces the welds though? I'm guessing 24.69psi is ENTIRELY possible, though it hasn't been tested by Paul Walker

Well it will come down to if he uses 2 of the big bottles of NOS or not.

Dual NOS bottles should only be used when compound charging, one before each compressor wheel. Bonus - when you're compound charging, you get four times the boost instead of twice the boost!

He'll be fine, so long as he double-clutches. Granny-shifting is what blows welds.

most def

and make sure to scream MONIKAAAAAA

30psi on a GT1241...

Or

4psi on a gt4708.

Stock rods and stock pistons. I replaced all bearings, and the turbo is T25/T28 Turbocharger, stock manifold and Stainless Steel Catback Exhaust System.

You put new bearings in but kept the stock rods?

Banned for trolling.

i didnt replaced rods because my main point wasnt based on Turbo. My engine was suffering of low compression in 3 and 4, so i replaced piston rings and bearings (I have pictures of the complete work).

That sucks for you. Now start reading and let this 7-year old cancer-infested thread die already.

I just threw in some h-beam rods, im sure it will be good for 350hp, which is my final goal.

Should be fine for a street car. For track use you'll need stronger oil pump and other stuff.

isnt the stock 1.6 can handle around 250hp with stock internals??

It not right to ask how many PSi a engine can handle but how much stress it can handle

torque [and clyinder pressure] bends rods.

boost
 

what about no tune. what boost pressure can i run with no tune till i get ecu ?

First post. In a thread that was bumped in 2012 from 2006. 4 years later in 2016.


Must be a helluva hibernation chamber.

None.