# how much hp can I increas before I have to upgrade



## Wyo350z (Jun 22, 2006)

I read the post on increasing hp and the potential for weak pistons and connecting rods in my '03 350Z. Does anyone know about how many hp I can increase before I need to start upgrading these parts? Also, how much boost can I run before I need to think about stronger components? Thanks guys.


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## Spongerider (Nov 18, 2002)

Wyo350z said:


> I read the post on increasing hp and the potential for weak pistons and connecting rods in my '03 350Z. Does anyone know about how many hp I can increase before I need to start upgrading these parts? Also, how much boost can I run before I need to think about stronger components? Thanks guys.


From what I heard the block is good for 500+hp but your injectors are your real weak point. TT Z33 can push 9 psi but that is on the edge with a greddy kit.


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## chimmike (Oct 17, 2002)

psi doesn't matter squat, it's the turbo or turbos you're using.

stock internals can hold 475-500whp. once pistons and rods are upgraded, the stock sleeves can do about 650whp before needing to sleeve the motor.

obviously fuel system upgrades will be in order for any sort of forced induction.


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## Spongerider (Nov 18, 2002)

chimmike said:


> psi doesn't matter squat, it's the turbo or turbos you're using.


Really, please explain? OEM engine, high compression, this should be interesting?


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## chimmike (Oct 17, 2002)

okay, explain to me how running 20psi on a t25 and 20psi on a 60-1 is the same? I could run 20psi on a t25 on the VQ all day long, but 20psi on a 60-1 and you're not going to last.......

compression means very little when you're talking about two very different turbos. That's why nobody says "oh the motor is good for x psi" because it doesn't mean shat....it's the whp that makes the difference. You can't make 500-550whp with a t25 no matter what psi you run.


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## Spongerider (Nov 18, 2002)

chimmike said:


> okay, explain to me how running 20psi on a t25 and 20psi on a 60-1 is the same? I could run 20psi on a t25 on the VQ all day long, but 20psi on a 60-1 and you're not going to last.......
> 
> compression means very little when you're talking about two very different turbos. That's why nobody says "oh the motor is good for x psi" because it doesn't mean shat....it's the whp that makes the difference. You can't make 500-550whp with a t25 no matter what psi you run.


Turbos and compression ratio do work hand and hand. 

*Example,*

_Turbos (T25) being the same on a high compression engine (10.0:1) will not out produce a lower compression engine (8.5:1).

The higher compression engine will detonate before a lower compression engine will.

It is well documented on TwinTurbo.net that you can only run 9psi of boost (on the edge) on a NA engine (High compression) before it blows up while a TT (low compression) can boost 14 psi safely and produce a lot more hp's. _

BTW the compression I used in the example are from a Z32 NA and Z32 TT. 

One more thing chill out chimmike it's a discussion, correct? 

The original poster asked how much hp the engine could take before building it up.


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## chimmike (Oct 17, 2002)

and I specified the whp


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## Spongerider (Nov 18, 2002)

chimmike said:


> and I specified the whp


You don't count! The original poster does. 

BTW, I change my first reply for you. check above?


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## Wyo350z (Jun 22, 2006)

I guess the next question is, how much can my stock exhaust take? I like the way it sounds now, but when I do start upgrading things will my exhaust be a limiting factor?


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## chimmike (Oct 17, 2002)

I personally know a twin turbo G35 coupe with stock exhaust making 440whp.

I'd upgrade the exhaust FOR SURE.......I mean, it's going to sound different with boost anyways....if you like the stock tone that much, get the nismo exhaust like I did.


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## lasthope05 (Nov 20, 2006)

if your serious about power and no bullshit. custom straight pipe exhaust


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## GKovacs (Nov 18, 2006)

I'm pushing 516.3 HP @ rear wheels still on stock block & pistons. I'm running 10 psi boost w/ complete APS twin turbo system.


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## Spongerider (Nov 18, 2002)

GKovacs said:


> I'm pushing 516.3 HP @ rear wheels still on stock block & pistons. I'm running 10 psi boost w/ complete APS twin turbo system.


What size injectors?


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## GKovacs (Nov 18, 2006)

Spongerider said:


> What size injectors?


I have the 880cc injectors APS provides in their Upgrade fuel kit.


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## Spongerider (Nov 18, 2002)

GKovacs said:


> I have the 880cc injectors APS provides in their Upgrade fuel kit.


Thanks!


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