Why does it seem the LS blocks handle less power than the GSR???

[Stopsign32v]

Putting the turbo on somewhat soon and I've noticed that the GSR guys seem to be running 350whp instead of the LS guys' limit of 300whp. Is this because of the LS head not flowing good and making the temps in the motor higher causing detonation on pump gas or what?

I spoke with someone @ http://phearable.net/ and told him I would like to run 330whp on my LS, and asked if he thought that was too risky. He said keep it around 270-280 and only run 330whp if I didn't mind risking my motor and if I planned to run race gas.

 

[mjones73]

Are you talking on a stock or a built motor?

 

[Stopsign32v]

Stock

 

[mjones73]

The main limiting factor would be the strength of the motor, my understanding is the B18C1 can handle more power in stock form without self destructing.

Of course if you want to push either harder you can sleeve it and build it with the proper parts...

 

[Samurai_Blue]

the casting of the block is slightly different, the crank is lighter which sucks for high reving (yes light cranks suck take a physics class) and the head is different

 

[mirrorimg]

You can make the same power on both, its determined by the size of your turbo and the amount of boost you run.

Its going to be easier to make power on the VTEC motor because the head flows better, but both can (relatively) accomplish the same thing.

 

[Stopsign32v]

So far no one has given a good explenation

The main limiting factor would be the strength of the motor, my understanding is the B18C1 can handle more power in stock form without self destructing.

Of course if you want to push either harder you can sleeve it and build it with the proper parts...

I just said the B18C can handle more power...I asked why.

the casting of the block is slightly different, the crank is lighter which sucks for high reving (yes light cranks suck take a physics class) and the head is different

Am I wrong but doesn't the sleve crack and not the block itself? If so block casting has nothing to do with it. The crank is lighter which = good. Nothing at all wrong with a light weight crank. Is the crank forged or cast? That would matter more. Also I don't plan to rev this motor high so what does what you said have to do with the strength of the B18C over the B18B?

You can make the same power on both, its determined by the size of your turbo and the amount of boost you run.

Its going to be easier to make power on the VTEC motor because the head flows better, but both can (relatively) accomplish the same thing.

Yes you can MAKE the same amount of power, but we aren't talking about how much power you can make. I asked why it seems a GSR motor will handle more power before it goes belly up over a LS motor.

 

[mirrorimg]

So far no one has given a good explenation
Yes you can MAKE the same amount of power, but we aren't talking about how much power you can make. I asked why it seems a GSR motor will handle more power before it goes belly up over a LS motor.

I personally wouldnt run in excess of 300whp on stock sleeves. I try not to gamble with my daily driver. What do you mean by "belly up"? I assume that means a cracked sleeve?

The sleeves are the same thickness in both the B18C1 and B18B1. They are also the same design (unlike the B20).

Once you get around 300, anything can happen. Your engine may make 400whp, it may make 500whp before it breaks. It may only get to 275whp before it goes. The cylinder walls are not all the same. Its like with anything, there is not 100% continuity between everything and thats why there are tolerances. Maybe the iron sleeves have a little too much of this mineral, or a not enough of another. Unless you test the sleeves of every motor that broke under boost, and compared each one of them, you wont have an answer.

 

[Stopsign32v]

So has anyone else have any information on why the GSR motor seems to handle power better than the LS motor? I was told "I wouldn't run that on PUMP GAS because the cylinder heads don't flow that well" which led me to believe (and I can't believe I didn't think about it earlier) more restriction = more boost to make the same amount of power. Example..a LS motor might make 340whp @ 18psi where a GSR motor might make 340whp @ 14psi given EVERYTHING is the same from the longblock forward. I'm wondering if the added boost is stressing the motor more because of the access heat being created by the more restriction thus friction. Opinions?

 

[Rich-PMS]

Get a P8R head and some turbo cams. Don't forget arp studs/bolts

 

[DaddyBuiltRacing]

Its not that they "handle" less power, they just make less power...what I mean is you might see a GSR making 340whp vs a LS making 280whp, both bone stock, ect..the reason the GSR makes more power is like you have even stated "the head flows better". In order to make the same power as a GSR you will have to up the boost, most tuners don't feel comfortable turning the boost up on stock motors.

There is no exact science for when a motor is going to let loose, it could be 5psi on a GSR compared to 10psi on a LS, or vice versa. There are too many variables honestly.

The one advantage a gsr has is the fact it has a girdle on it.

BTW lightweight cranks don't always equal success, go weigh a LS and then a type r crank.