My GT2 vs Peter's 3.8L monster
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It is helpful some what to the Porsche community as to show what these motors are able to do, but when it comes to telling your tuner this... Well it's a whole different story. Me: "I made 30.1psi peak tonight coming back from a friends in 3rd" Justin: "What did I tune your car for again? 27psi peak right?" Me: "Yup... But it was really cool spinning all 4 through when it hit hard into boost!" Justin: "Why do you even tell me things like this?"Originally Posted by Divexxtreme
Chris - That's good information. Thank you.
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Shotcaller - The previous 5.49 in the GT2 and was at 1.7'ish BAR on a 50/50 mix of C16 and 104 octane.
Tonight, I'll run at 1.6 BAR on straight 100.
4.9-5.1 would be very impressive!!Originally Posted by Divexxtreme
Ben - exactly. Shotcaller - The previous 5.49 in the GT2 and was at 1.7'ish BAR on a 50/50 mix of C16 and 104 octane.
Tonight, I'll run at 1.6 BAR on straight 100.
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I know some are running them pretty high. I have been at 1.32 bar on 93 octane for a while with no problems....I have been told and feel it's a pretty good bet - that 1.4 would be no problem for me on stock rods/studs, but I am still a little reluctant to push it.
Originally Posted by John@SpeedTech
What do you guys feel is the limit with stock head studs and stock rods?I know some are running them pretty high. I have been at 1.32 bar on 93 octane for a while with no problems....I have been told and feel it's a pretty good bet - that 1.4 would be no problem for me on stock rods/studs, but I am still a little reluctant to push it.
GRRRRRRRRRRRRRR
It is what the car is tuned for, not the boost pressure. If someone is super aggressive with the tuning then your engine might go kaboom at 1.2 bar. If they are more conservative, then it might last at 2bar....
so to reiterate...
BOOST PRESSURE HAS ABSOLUTELY NO BEARING ON SAFETY(within reason). It is the TUNING
It is impossible to tell you what is safe, and what is not. The tuner of your car is the only one that can answer that question.
Let's think about this for a moment as I have said it before and don't like to repeat myself.... edumacation time
What is your boost pressure? xxpsi (fill this in)
What is your cylinder pressure? xxxxpsi (fill this in)
Do your headstuds clamp the head on, or your pressure hoses?
So will someone please explain to me how boost pressure DIRECTLY affects the headstuds? Let's take an example here.... what is more likely to stretch your studs/blow a headgasket?
18 psi and 30 degrees of ignition advance with 100 RON fuel, ORRRRR
25 psi and 10 degrees of advance with 100 RON fuel?
please, no cheating
Justin
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Don't start.... you give me nightmaresOriginally Posted by Powell
Me: "I made 30.1psi peak tonight coming back from a friends in 3rd" Justin: "What did I tune your car for again? 27psi peak right?" Me: "Yup... But it was really cool spinning all 4 through when it hit hard into boost!" Justin: "Why do you even tell me things like this?"
Justin
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Enjoy !
Justin
Thanks, Justin.Originally Posted by justinn
Congratulations on getting your car back up and running ferociously Scott Enjoy !
Justin
Great post above, by the way.
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Rolando
I don't know WHY you would do that, but let's just say in theory, IF someone did that Originally Posted by rdss
Justinn would that be the 18 psi with 30 degrees of ignition advance ?? but why ??Rolando
Justin
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The 29 psi and 10 degrees of advance would be it's heads intack,ok
you win Originally Posted by rdss
The 22 psi and 30 degrees of advance ignition would be higher,right ?The 29 psi and 10 degrees of advance would be it's heads intack,ok
the 22 psi guy would be frowning
Justin
its cylinder pressure on a given unit of time if there is too much cylinder pressure IE Too much boost and timing mixed is when problems arise.
higher boost needs lower timing, but higher boost generally makes more power then
lower boost with jacked up timing and this is almost always not as safe.
higher boost needs lower timing, but higher boost generally makes more power then
lower boost with jacked up timing and this is almost always not as safe.
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higher boost needs lower timing, but higher boost generally makes more power then
lower boost with jacked up timing and this is almost always not as safe.
OS i got the cylinder presure.If the timing is higher it means its quicker or what ? ThanksOriginally Posted by OS Inspector
its cylinder pressure on a given unit of time if there is too much cylinder pressure IE Too much boost and timing mixed is when problems arise.higher boost needs lower timing, but higher boost generally makes more power then
lower boost with jacked up timing and this is almost always not as safe.
Rolando
Some time ago on another 3d we discussed the exact same topic....and the 3d became very instructive.
Just look at a cylinder pressure vs crack angle curve and that will show how high is cylinder pressure, compared to boost...just google it.
Just look at a cylinder pressure vs crack angle curve and that will show how high is cylinder pressure, compared to boost...just google it.