is 16psi safe on a otherwise stock engine?

[shif7i7down]

Originally Posted by Dipstik-sportech

Noob with a turbo this should be fun...... Google man it will explain everything.

Everybody's gotta start somewhere.

[Boofneenee]

Originally Posted by shif7i7down

But wouldn't the bottle neck be the throttle body and not the turbo? You would think that a 20g turbo could do 16psi... ehhh. Shows what i know lol
But yeah, i see your point thou...

Guess i didn't have to worry about shit hitting the fan if i can't even boost that high.

learning myself as well. Mike's example of fire house vs faucet is maybe not so much about describing a restriction as it is output. Think of sitting in front of a small fan and a large fan both spinning at the same rpms. The larger fan is going to provide more flow.. right? Their are of course pros and cons to using either turbo size.

In a different discussion, another member gave you an example using straws with different diameter sizing. This is a better example of restriction because air needs to come in and out. While the throttle body may be a "restriction" by your definition, it is still only but a super small part of the piping taking air in and taking air out. 3" exhaust piping is better than 2.5" piping for an FI car. The larger the piping the easier it is for those hot exhaust fumes to exit the car and keep the heat away from the engine which can cause increased cylinder temps, etc.

Engine needs to breath. Combustion needs to happen. The question is how much energy can you get out of it without blowing stuff to pieces.

How is the SBD on your car? you still gitty when you drive? I think its a great buy and if i was more mechanically inept I would do the same!

[DeliciousTuning]

Read This: Compression Ratio - Boost 101

Now with a really high compression ratio and your tuner will need to remove so much timing advance (on pump fuels, 91-93 octane) it over negates the effectiveness of the boost, in turn lowering your overall power output.

If you are running E85 though then there is a major benefit to higher compression and more boost. That is where the fun begins.

Cheers,
William Knose
Delicious Tuning

[Fastbrew]

All boost wears a car down faster. The question is - how do you define "safe"? By its very nature you are going to cut down on the engines life by boosting. I figured 10-12psi of boost out of an AVO getting about 300HP on 92 pump and lasting at least 4 years was "safe".

[DeliciousTuning]

Originally Posted by Fastbrew

All boost wears a car down faster. The question is - how do you define "safe"? By its very nature you are going to cut down on the engines life by boosting. I figured 10-12psi of boost out of an AVO getting about 300HP on 92 pump and lasting at least 4 years was "safe".

Until the details of how the FA20 engine breaks down when pushed to the limits is really well understood I do not think anyone will really ever know. That will take some years to determine and when a couple companies have invested a lot of R&D into understanding those limits.

We have pushed stock Subaru STI engines to 600whp but found even if the smallest thing was off that was the end of the engine almost instantly. How you drive the car, how you maintain the car, how the engine was built from the factory (on a Monday morning or Friday afternoon), etc... will all have an impact especially at higher boost levels on a vehicle never intended for boost.

So to say there is a "safe" number is really unknown. We have had completely stock FR-S cars fail because the cam sensor was aligned incorrectly from the factory, while we have 500+whp stock engines on E85 running strong day in and day out.

Cheers,
William Knose
Delicious Tuning

[Fabron757]

I ran 16 PSI on E85. And my car was a daily. I beat the snot out of it every day. 471hp and 368Tq had no issues or any signs of the motor messing up. Was i sacred the motor might blow? Yes, but after the first oil change i went crazy and never looked back. Its a chance you take. Motors blow on low boost just as well on high boost. A good tune and a good setup will carry a long ways. long as you dont have a lemon motor.

[shif7i7down]

Originally Posted by Boofneenee

learning myself as well. Mike's example of fire house vs faucet is maybe not so much about describing a restriction as it is output. Think of sitting in front of a small fan and a large fan both spinning at the same rpms. The larger fan is going to provide more flow.. right? Their are of course pros and cons to using either turbo size.

In a different discussion, another member gave you an example using straws with different diameter sizing. This is a better example of restriction because air needs to come in and out. While the throttle body may be a "restriction" by your definition, it is still only but a super small part of the piping taking air in and taking air out. 3" exhaust piping is better than 2.5" piping for an FI car. The larger the piping the easier it is for those hot exhaust fumes to exit the car and keep the heat away from the engine which can cause increased cylinder temps, etc.

Engine needs to breath. Combustion needs to happen. The question is how much energy can you get out of it without blowing stuff to pieces.

How is the SBD on your car? you still gitty when you drive? I think its a great buy and if i was more mechanically inept I would do the same!

The sbd kit feel awesome, this being my first turbo car, I'm loving the boost. Btw, the install wasnt hard at all, the last thing i did that was "technical" was install brake pads or i guess installing the phantom sc lol. But i did the turbo kit install by myself and took pictures with my Smartphone Just so i remember how everything goes back together, it took me roughly 12hrs totally.But if i had to do it again i think i can probably do it in half the time from start to finish.

[Fastbrew]

Originally Posted by DeliciousTuning

Until the details of how the FA20 engine breaks down when pushed to the limits is really well understood I do not think anyone will really ever know. That will take some years to determine and when a couple companies have invested a lot of R&D into understanding those limits.

We have pushed stock Subaru STI engines to 600whp but found even if the smallest thing was off that was the end of the engine almost instantly. How you drive the car, how you maintain the car, how the engine was built from the factory (on a Monday morning or Friday afternoon), etc... will all have an impact especially at higher boost levels on a vehicle never intended for boost.

So to say there is a "safe" number is really unknown. We have had completely stock FR-S cars fail because the cam sensor was aligned incorrectly from the factory, while we have 500+whp stock engines on E85 running strong day in and day out.

Cheers,
William Knose
Delicious Tuning

Indeed - the dice are alive.

[shif7i7down]

Just a little background on my car, the reason i want a bit more power is because i recently installed a 3.73 final drive differential from a IS300 and the car feels a bit sluggish compared to the mfactory 4.67 final drive that i had. So i thought that by improving the power i would be able to utilize the taller final drive more effectively. Hence why I'm asking all these "noob" questions.

[spitfire481]

There's no point in pulling the motor to do head studs and head gaskets, but not doing pistons/rods. I ran 20psi on e85 with an avo kit for a while. Then I went with a built motor with a bigger Turbo/kit

[Fabron757]

Originally Posted by shif7i7down

Just a little background on my car, the reason i want a bit more power is because i recently installed a 3.73 final drive differential from a IS300 and the car feels a bit sluggish compared to the mfactory 4.67 final drive that i had. So i thought that by improving the power i would be able to utilize the taller final drive more effectively. Hence why I'm asking all these "noob" questions.

I thought the 3.73 final drive would feel faster since you don't have to shift as fast. So people with a good size turbo reap the benefits. I'm actually looking for the 3.73 final drive.

[shif7i7down]

On the 3.73 2nd gear feels like 3rd, and 3rd feels like 4th, but yes the max wg boost is reached faster on the 3.73 but once Max boost is reached (7psi) acceleration on the 4.67 feels So much faster, only bad part is you have to shift. Into 5th gear at 90mph

[spitfire481]

I can do 137@8000rpm with my 26" rear tires and the 3.73 in 4th. That's with the new setup. With the avo kit the stock 4.10 rear wasn't too bad. I shifted at like 7000rpm with that setup. Boost/power drop was pretty bad up top with that small turbo

[cdrazic93]

ahh I have had that website bookmarked for quite sometime, @DeliciousTuning, good read.

if your okay with following some math, this website will help too; Warning, since the work is done in grey colored font on a black backing, you may want to highlight it to see it.

http://www.enginelogics.com/read-a-t...ompressor-map/