How much power before forged?

[vxrphantom]

What is the level of power an LS3 can run until forged is a necessity rather than option? I appreciate that forged will alway be better as it will give you some buffer to play with and long term is the route I will go but in the mean time could I add a cam or 12psi pulley without fear of the motor melting! Currently dynoed 501rwhp.

Phil

[monkfish1]

vxrphantom said:

What is the level of power an LS3 can run until forged is a necessity rather than option? I appreciate that forged will alway be better as it will give you some buffer to play with and long term is the route I will go but in the mean time could I add a cam or 12psi pulley without fear of the motor melting! Currently dynoed 501rwhp.

Phil

Id say much over 650 flywheel, and sooner or later you will lose a piston. If it helps, when you do break a piston, "usually" there is no bore damage, so it can still be forged afterwards, but theres no guranatees on that

There is no actaul cutoff limit, it is a matter of judgement, and of course good tuning and setup.

[madmunky]

monkfish1 said:

when you do break a piston, "usually" there is no bore damage

[vxrphantom]

monkfish1 said:

vxrphantom said:

What is the level of power an LS3 can run until forged is a necessity rather than option? I appreciate that forged will alway be better as it will give you some buffer to play with and long term is the route I will go but in the mean time could I add a cam or 12psi pulley without fear of the motor melting! Currently dynoed 501rwhp.

Phil

Id say much over 650 flywheel, and sooner or later you will lose a piston. If it helps, when you do break a piston, "usually" there is no bore damage, so it can still be forged afterwards, but theres no guranatees on that

There is no actaul cutoff limit, it is a matter of judgement, and of course good tuning and setup.

Any suggestions to squeese that extra 25bhp(currently 625) from where i am? would running water methanol help protect or not?

Edited by vxrphantom on Wednesday 13th May 09:31

[monkfish1]

vxrphantom said:

monkfish1 said:

vxrphantom said:

What is the level of power an LS3 can run until forged is a necessity rather than option? I appreciate that forged will alway be better as it will give you some buffer to play with and long term is the route I will go but in the mean time could I add a cam or 12psi pulley without fear of the motor melting! Currently dynoed 501rwhp.

Phil

Id say much over 650 flywheel, and sooner or later you will lose a piston. If it helps, when you do break a piston, "usually" there is no bore damage, so it can still be forged afterwards, but theres no guranatees on that

There is no actaul cutoff limit, it is a matter of judgement, and of course good tuning and setup.

Any suggestions to squeese that extra 25bhp(currently 625) from where i am? would running water methanol help protect or not?

Edited by vxrphantom on Wednesday 13th May 09:31

Fitting headers will give some more, but to be sure change the pulley, change the tune and cross your fingers

[ringram]

Yeah Id say it was a risk scale. Moving from stock being most reliable and going downhill from there probably on a geometric scale.

[Trailermasher]

How much would failure rate be reduced by keeping to a low, say 6,500, rpm limit?

Or is power, at any rpm, the main issue?

[monkfish1]

Trailermasher said:

How much would failure rate be reduced by keeping to a low, say 6,500, rpm limit?

Or is power, at any rpm, the main issue?

RPM is not the issue, though 6500rpm is hardly keeping it low when the limiter is @ 6700.

[Trailermasher]

monkfish1 said:

RPM is not the issue, though 6500rpm is hardly keeping it low when the limiter is @ 6700.

It's still low compared to the 8-9,000 RPM high hp race engines, where peak power is @ 7.5k to 8.5k.

Mr. Fish, YHM... err, Y getting M...

[Bonnie and Clyde]

ringram said:

Yeah Id say it was a risk scale. Moving from stock being most reliable and going downhill from there probably on a geometric scale.

Out of interest Rich do you never ever sit back and wonder just what your 7Litre beast could be capable of with a supercharger. I know its a dirty word for you but just think. It could destroy all

[MyM8V8]

Bonnie and Clyde said:

ringram said:

Yeah Id say it was a risk scale. Moving from stock being most reliable and going downhill from there probably on a geometric scale.

Out of interest Rich do you never ever sit back and wonder just what your 7Litre beast could be capable of with a supercharger. I know its a dirty word for you but just think. It could destroy all

Starting with the prop, half shafts, diff...............................

[Bonnie and Clyde]

MyM8V8 said:

Bonnie and Clyde said:

ringram said:

Yeah Id say it was a risk scale. Moving from stock being most reliable and going downhill from there probably on a geometric scale.

Out of interest Rich do you never ever sit back and wonder just what your 7Litre beast could be capable of with a supercharger. I know its a dirty word for you but just think. It could destroy all

Starting with the prop, half shafts, diff...............................

Ok, but what if he changed those too?

[ringram]

MyM8V8 said:

Starting with the prop, half shafts, diff...............................

Exactly. Designed for 500/500 power output.

[Boosted LS1]

Bonnie and Clyde said:

ringram said:

Yeah Id say it was a risk scale. Moving from stock being most reliable and going downhill from there probably on a geometric scale.

Out of interest Rich do you never ever sit back and wonder just what your 7Litre beast could be capable of with a supercharger. I know its a dirty word for you but just think. It could destroy all

I bet he does and then he starts thinking of how high is compression already is along with the cost of belts he'd need to buy. Hmmm, chain drive

[crisisjez]

vxrphantom said:

Any suggestions to squeese that extra 25bhp(currently 625) from where i am? would running water methanol help protect or not?

Edited by vxrphantom on Wednesday 13th May 09:31

STOP.... don`t spend any more money till you try a Turbo Package. (You are nearly at the top of your particular ladder and probably wouldn`t even notice an extra 50HP, which would cost you a huge amount of dosh.)

Did you have a run in Harry`s?

[ringram]

And soon Jez will tell you its all about efficiency and conservation of energy. Increasing efficiency from mechanical, thermal and volumetric sources is all good. Turbo reduces the mechanical losses that the supercharger has as well as using some of the thermal losses wasted otherwise to spin the compressor.

[Bonnie and Clyde]

ringram said:

And soon Jez will tell you its all about efficiency and conservation of energy. Increasing efficiency from mechanical, thermal and volumetric sources is all good. Turbo reduces the mechanical losses that the supercharger has as well as using some of the thermal losses wasted otherwise to spin the compressor.

WTF Rich Cant you ever say anything normally

[anonymous-user]

ringram said:

And soon Jez will tell you its all about efficiency and conservation of energy. Increasing efficiency from mechanical, thermal and volumetric sources is all good. Turbo reduces the mechanical losses that the supercharger has as well as using some of the thermal losses wasted otherwise to spin the compressor.

PD superchargers rock if you want an instant hit the back though. I think it really suits road use and they can be made to make as much power as you'll ever need. Top fuel dragsters use twin screws afterall.

[ringram]

Doesnt make them efficient though! I like my BHP cheap

[paramoreg]

On the basis that GM say not to run more than 550BHP on our std cast alloy pistons and quite a few of us are running well over 600 already, I reckon doing anything more will ultimately end in tears unless at least some forged pistons are thrown in with the next change!

Cheapest option would be 12psi pulley and more belt slip to boot, though not sure if my cut pulley belt would help here... Personally I'd like headers, cam etc to squeeze just a little bit more, as an alternative to a mega spend engine build and twin screw sc, but its just not worth the risk IMO without a piston change.

Edited by paramoreg on Thursday 14th May 19:10