AGP Twin Turbo Owners

[Glushenij]

Originally Posted by Unreal

Glush, headers and cam won't do that. If you want to make 900hp now, then just turn the boost up and make 900hp. Headers do nothing, and cam will lower the boost to make same power at lower boost, but who cares. You can make 900rwhp on 16psi or 14psi. Does it matter?

As for the EFRs, of course they are going to be on high dollar builds. No one is paying for a top of the line bling turbo on a budget build. Recently saw a single one make 750rwhp and go mid 9s in a heavy RWD car, and that was just one EFR7670.

Thanks for info Unreal,I was not planing do headers and cam-it was suggested by tuner -I like sound(4K for that) I better prefer save and get build long block to hold big power and then turn boost up! So question what boost level stock block ,heads, head gaskets ....can hold before damage occurs ?

[Unreal]

Depends on gas and luck. A few people have made 1000+ on stock ls3s for a bit on a blower. Others 850-900 for years and a lot of miles. Others come apart at 500hp. It all depends on how much risk you want to take, and making sure you have octane/fuel supply.

[stevieturbo]

Originally Posted by Glushenij

Thanks for info Unreal,I was not planing do headers and cam-it was suggested by tuner -I like sound(4K for that) I better prefer save and get build long block to hold big power and then turn boost up! So question what boost level stock block ,heads, head gaskets ....can hold before damage occurs ?

With some "tuners"...almost none.

With other tuners...lots of boost.

[Glushenij]

Originally Posted by Unreal

Depends on gas and luck. A few people have made 1000+ on stock ls3s for a bit on a blower. Others 850-900 for years and a lot of miles. Others come apart at 500hp. It all depends on how much risk you want to take, and making sure you have octane/fuel supply.

I just got install( 2 month ago) AGP triple flex fuel system with 1400 cc and rails, so I run e85 and still use methanol kit! So I think I'm good on fuel but question how much boost can life heads, blow head gasket?? I want keep engine in safe boost but if it blow o well I get build one

[Unreal]

Totally irrelevant.

0psi of boost, or 50psi. Cylinder pressure lifts heads, not boost. Cylinder pressure is orders of magnitude higher. 20psi can have the same pressure as 5psi. Timing, cam, flow, etc etc etc all affect it.

So to actually answer the question, probably 500-600psi. The intercooler, intake manifold, pipes and rest of the system would rupture before you get boost high enough to damage the headgasket or lift a head.

Figure normal cylinder pressure during typical combustion is 500psi. Add a little too much timing and knock and you can see 750-800psi of cylinder pressure. That is why knocking kills pistons, blows out head gaskets/etc. Starting with 10psi of air or 15psi of air doesn't matter, controlling the combustion properly does.

If a headgasket is limited to say 700psi, you can get there on 5psi of boost or 35psi of boost. It is about preventing the cylinder pressure from spiking and breaking stuff.

[1KillerSS]

Originally Posted by Glushenij

I just got install( 2 month ago) AGP triple flex fuel system with 1400 cc and rails, so I run e85 and still use methanol kit! So I think I'm good on fuel but question how much boost can life heads, blow head gasket?? I want keep engine in safe boost but if it blow o well I get build one

A huge factor here is the tuner, and his quality of tune. Like Nick said, some fail at less than 13psi or 500whp, while others are running 20psi and 1000whp. The contributing factors here are how its driven, how the tune is, and luck.

If it were me, I would turn up the boost, and invest in some forged parts for if, and when it goes south on you. My personal opinion, and preference for a stock block, with upgraded valvetrain is 800whp, but again, there are others past that.

[Ls1408cp]

Originally Posted by blake-b

I am using stock manifolds but non-stock heads. I should know within a couple of months how far I can push the EFR7670s as I'll have more engine than turbo.

Keep us updated I know you are usin a dart block but what ci? Thanks

[fif_gen_powa]

Originally Posted by Unreal

Totally irrelevant.

0psi of boost, or 50psi. Cylinder pressure lifts heads, not boost. Cylinder pressure is orders of magnitude higher. 20psi can have the same pressure as 5psi. Timing, cam, flow, etc etc etc all affect it.

So to actually answer the question, probably 500-600psi. The intercooler, intake manifold, pipes and rest of the system would rupture before you get boost high enough to damage the headgasket or lift a head.

Figure normal cylinder pressure during typical combustion is 500psi. Add a little too much timing and knock and you can see 750-800psi of cylinder pressure. That is why knocking kills pistons, blows out head gaskets/etc. Starting with 10psi of air or 15psi of air doesn't matter, controlling the combustion properly does.

If a headgasket is limited to say 700psi, you can get there on 5psi of boost or 35psi of boost. It is about preventing the cylinder pressure from spiking and breaking stuff.

Very good way of breaking it down. I laugh when people say 20psi will lift the head, like have you ever done a compression test on any car lol 150+psi right there

[Hard Parker]

Any opinions on auto options with this kit?

I know the 6L80 is rated to 650wtq

RPM transmission suggested a built 4L80

Has anyone tried with a 6L90?

[Unreal]

What people are trying to get at is at what power level do pistons/hg/etc start letting go, and equating boost to that power level. Like 12psi makes 800rwhp, and 800rwhp is when stuff starts to go down, so people start claiming don't go over 12psi or you pop pistons. Problem is that can be 5psi or 30psi to get to that power level. You can have a better set of heads, that means boost is 10psi to make 800rwhp, or a bone stock car running 12psi to get there. A good set of heads/big cam/etc could be 5psi. Big intercooler, good turbo setup, etc all effect stuff. This is why people need to not worry about boost, and worry about power level/cylinder pressure.

And that doesn't even take into account timing and knock/etc. You can have one car see 600psi peak pressure running 15psi and 5 degrees of timing and a car seeing 800psi running 5psi and 20 degrees of timing.

If you can prevent any knock, a stock LS3 has proven to take 850-900rwhp all day long. But one bad knock event will spike pressure and spit a piston or head gasket out. Higher power you go, less safety margin you get. Then there is the overall capability curve of the motor. Some may have better ring gaps, less wear, less carbon build up, slightly thicker ring lands, better head gasket seal, and take 1000hp while others may be on the low end of any of that and pop at 700hp. Put a normal curve with the mean around 800 and you could be anywhere on it with a stock ls3.

Application is also huge. A dyno run once a year in 4th gear only isn't the same as a race car that sees 50 pulls a night, or road course work.

While I tout my awesomeness of having a 1200+hp street car with 25k+ miles at 1000+hp, 99% of that is driving back and forth to work, to gym, to home depot, etc. It sees 4-5 events a year, and maybe 3-4 pulls on street a month. Totally different than 25k track miles.

[Unreal]

Kevin has a 6l90 in his car. A few others do too. Several caddies in the 800-900rwhp range with them.

[Hard Parker]

Since I would have to get a diff driveshaft should I be worry with my rear end? Mainly DD and half mile stuff. Maybe a 1/4 here and there


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[Unreal]

That all depends on power level and risk acceptance. Autos are a lot easier on rears.

[Hard Parker]

Lol yeah that's what I thought...shooting for 800whp with 58/62s is the plan


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