Ok, need help with turbo info... (boost - compression)

[sparq]

Is there anything out there that says how much boost can be run safely based upon compression ratio? Obviously the stock internals would have to be able to take it -- but say a car had like an 8.5:1 compression ratio -- putting internals aside, is there any way to say like oh it can do 12 psi or 16 psi or whatever before the thing starts to detonate itself to death? Again... dont talk about the internals just yet, im trying to find some information. Anyone that can help I would appreciate it.

Also, I know there is a way to calculate BOOSTED HP off the PSI, but is there a way to then take the NEW HP number and figure out how much torque would be gained? I mean, if I double my HP will my torque also double or how would I go about figuring this out? I mean you guys dont have to give me exact numbers for my application but if you can show me how to do it, and maybe give me an example so I can learn how to do it that would be great! Thanks, hopefully someone can give me some good info!

[drift]

as for boost and compression, it depends on ignition timing, cam timing, and so on.

there's a lot more to it than just static compression. to determine a safe boost pressure in relation to static compression is impossible. with proper tuning, you can run some wild boost levels. but with crappy tuning, you may destroy that same motor with even lesser boost pressures.


as for finding torque from HP, the formula is HP=(Tq x RPM) / 5252

so with that, just plug in the numbers and you'll get your torque value.

[sparq]

Originally posted by drift
as for finding torque from HP, the formula is HP=(Tq x RPM) / 5252

so with that, just plug in the numbers and you'll get your torque value.

Yeah I was just going to come in and edit to say that I found out how to figure out torque. Just for information, on a twin turbo motor like the Supra, how does one figure out how much boost is "really" being made? Actually the Supra is a bad example because doesnt it use a small & large turbo? Well just use something that has two turbos - that both run at the same time, are like... BOTH turbos running at 6psi or are both turbos running at 3psi making 6psi total? I always wondered about that...

[SleeperTeg]

Is the supra sequential turbo? If so, one of the turbos is smaller to get the low end boost and the other is larger to provide higher RPM boost.

If it is just a straight up TT, it is using both all of the time and the should produce the same amount of boost...

[sparq]

Originally posted by SleeperTeg
Is the supra sequential turbo? If so, one of the turbos is smaller to get the low end boost and the other is larger to provide higher RPM boost.

If it is just a straight up TT, it is using both all of the time and the should produce the same amount of boost...

I wasnt sure if it was sequential or a straight dual turbo running them both at the same time.

But my question was like -- most stock turbos push like 6 psi right? So if I have a dual turbo setup... each turbo is only really spinning at 3psi worth of boost right, because what happens to one side happens to the other -- and both sides are added together? See thats where things get confusing -- well because I dont know about it, or if its "6 psi of stock boost" do both the turbos spin at 6 psi ? Someone help me :alien: