how to make 25 ps1?

[themindfield]

considering you have all the supporting mods and a good tune for a 50 trim. what does the engine need to be done to it, to handle 20-25 psi SAFELY? thank you so much in advance.

 

[1fast97gsx]

bigger injectors, pump, afpr, and some good tuning. ARP headstuds are also recommended.

 

[Turblown]

I don't know much about it... but from what I've read you can safely run up to about 25 psi while using water injection. It might be something worth looking into... with all of the other supporting mods of course.

 

[1fast97gsx]

oh and a good fmic

 

[Squackdiddy]

could the stock rods handle 25 psi? could the stock internals handle 25 psi?

 

[CanadianTSi]

Properly tuned yes and yes

 

[Squackdiddy]

Properly tuned yes and yes

NICE
we are talking about the 50 trim , the internals can handle it?
if so Nice

 

[G_S_X]

25psi... would take water injection and some 118octane , 20psi and w/ water inj maybe youw ont need the race gas then

 

[paul s]

I run 21 psi on my "50"trim everyday(94octane) and had it few times up to around 25 psi and the car keeps on pulling..hehehhee

 

[Squackdiddy]

ok, what the most you can run on pump gas (93-94 octane)?

 

[G_S_X]

I run 21 psi on my "50"trim everyday(94octane) and had it few times up to around 25 psi and the car keeps on pulling..hehehhee

21 psi on 94 octane ... do you have any kind of added injection? do you know what your timing is?

 

[themindfield]

so u guys are telling me that a stock motor can handle 25 psi 50 trim safely and reliably?????

 

[Towlieee]

My friend ran a completly stock except for a hole in the down pipe and boost controller laser.. He pushed 18lbs daily and it creeped to 21 without problems.. although the fuel somtimes shutoff at 21psi..

This was on 91octane......

 

[LandoAWD]

so u guys are telling me that a stock motor can handle 25 psi 50 trim safely and reliably?????

Buy a logger, tune properly, and you should be pretty fine.

 

[GSntncT]

so u guys are telling me that a stock motor can handle 25 psi 50 trim safely and reliably?????

For the most part yes. In addition to what everyone has said, you might as well put a 4-layer headgasket in since you will have to put new headstuds in.

 

[kpt4321]

You really can't define engine limits with a boost level.

A lot of people like to define an engine's limitations in terms of the maximum boost pressure it can sustain, but that's really not the right way to do it.

What happens in most of the cases when these limits are exceeded, is you either blow up bottom end stuff (ringlangs, for example) or you lift the head and/or blow up the head gasket. All of these problems are directly caused by too much pressure during combustion. However, maximum cylinder pressure is NOT determined solely by boost pressure, so we shouldn't use boost pressure to define the limits of a motor.

Another popular way to define the limits of a motor, are with a horsepower limit. While this is closer to being related to the true cause of motor problem, cylinder pressure, it still is not perfect. Horsepower is the net result of cylinder pressure over time, meaning that 300 horsepower at 5000 rpm is NOT the same peak cylinder pressure as 300 horsepower at 9000 rpm. Because of this, you can increase power by increasing top-end breathing capacity, without getting any closer to the limitations of the bottom end.

Cylinder pressure is actually most directly related to torque, because torque comes from the push on the top of the piston. In terms of what we can measure, torque is the most representative of cylinder pressure. Also, rpm is not an influence in the relation between torque and cylinder pressure. In general, if torque goes up, cylinder pressure goes up. (Interesting tidbit: thus, cylinder pressure, motor stress and load, and knock propensity are highest at the torque peak, which is also the VE peak).

In the end, I think that defining a motor's limits in general terms of horsepower, or maximum MASS flow, is the way to go. Torque is a better measurement, but nobody ever has payed much attention to it so switching over would be difficult.

Also, everyone knows that tuning plays a big part in all of this, because the quality of the tune plays a VERY big role in determining not only the maximum cylinder pressure, and also how it happens. Very sharp spikes in pressure can be more harmful to the motor than a nice smooth curve up to the same pressure. Also, knock/detonation is one of the primary killers of motors, because it causes excessive cylinder pressure oscillations.

From http://users.wpi.edu/~ktarry/dsmtech/enginelimits.html

 

[1fast97gsx]

21 psi on 94 octane ... do you have any kind of added injection? do you know what your timing is?

21 psi is very doable on 94 octane. My friend is running 24 psi on 93 octane and had it professionally tuned. The car runs awesome and has no dips in the timing curve.

 

[kpt4321]

25psi... would take water injection and some 118octane , 20psi and w/ water inj maybe youw ont need the race gas then

Not true, lots of people run 23-25 psi on pump gas without water injection.

 

[blackawdturbo]

Kyle's right, lots of fuel and cooling (read BIG FMIC) will allow you to run 25 psi on pump with a 50 trim. I have a somewhat smaller 20g and can do the same right now.

 

[Keaka26]

You really can't define engine limits with a boost level.

A lot of people like to define an engine's limitations in terms of the maximum boost pressure it can sustain, but that's really not the right way to do it.

What happens in most of the cases when these limits are exceeded, is you either blow up bottom end stuff (ringlangs, for example) or you lift the head and/or blow up the head gasket. All of these problems are directly caused by too much pressure during combustion. However, maximum cylinder pressure is NOT determined solely by boost pressure, so we shouldn't use boost pressure to define the limits of a motor.

Another popular way to define the limits of a motor, are with a horsepower limit. While this is closer to being related to the true cause of motor problem, cylinder pressure, it still is not perfect. Horsepower is the net result of cylinder pressure over time, meaning that 300 horsepower at 5000 rpm is NOT the same peak cylinder pressure as 300 horsepower at 9000 rpm. Because of this, you can increase power by increasing top-end breathing capacity, without getting any closer to the limitations of the bottom end.

Cylinder pressure is actually most directly related to torque, because torque comes from the push on the top of the piston. In terms of what we can measure, torque is the most representative of cylinder pressure. Also, rpm is not an influence in the relation between torque and cylinder pressure. In general, if torque goes up, cylinder pressure goes up. (Interesting tidbit: thus, cylinder pressure, motor stress and load, and knock propensity are highest at the torque peak, which is also the VE peak).

In the end, I think that defining a motor's limits in general terms of horsepower, or maximum MASS flow, is the way to go. Torque is a better measurement, but nobody ever has payed much attention to it so switching over would be difficult.

Also, everyone knows that tuning plays a big part in all of this, because the quality of the tune plays a VERY big role in determining not only the maximum cylinder pressure, and also how it happens. Very sharp spikes in pressure can be more harmful to the motor than a nice smooth curve up to the same pressure. Also, knock/detonation is one of the primary killers of motors, because it causes excessive cylinder pressure oscillations.

From http://users.wpi.edu/~ktarry/dsmtech/enginelimits.html

THANK YOU THANK YOU SOOOOO MUCH! Jeezus. I was about to post something very similar, but you beat me to the punch. Although, mine probably wouldnt have been as much of a novel .

You guys are just thinking of things in the wrong way. Shit, I think I heard of buschur making like 700 horses on a stock block before (although, it didnt last all TOO long). A poorly tuned motor can die way before ever reaching 25psi on ANY turbo. Tuning is KEY. Timing advance plays a big role in cylinder pressure as well, in addition to the other things mentioned.

 

[paul s]

I run 21psi on 94 octane and get 18deg of timing top of 3rd(100mph) and 16-17 deg top of 4th(125mph)..Egts are just touching 900c in 4th., the car never seen dyno and is tuned with the help of my butt and some gauges, and the logger ..

 

[GSntncT]

Not true, lots of people run 23-25 psi on pump gas without water injection.

I know I do without water injection