What would you think max safe boost is?
Thread Starter
Staging Lane
Joined: Jul 2005
Posts: 83
Likes: 0
What would you think max safe boost is? As title says, what would you think max safe boost is on stock LS2 with 10.9:1 compression.
I’m leaning towards 5 PSI, maybe another 1-2 PSI with methanol.
Mike
I’m leaning towards 5 PSI, maybe another 1-2 PSI with methanol.
Mike
Originally Posted by Skunkworks
As title says, what would you think max safe boost is on stock LS2 with 10.9:1 compression.
I’m leaning towards 5 PSI, maybe another 1-2 PSI with methanol.
Mike
I’m leaning towards 5 PSI, maybe another 1-2 PSI with methanol.
Mike
The Crank is only good for a reliable 550. Others are pushing beyond that, but I would not recommend it. As far as boost, 6psi would be the absolute upper limit with 11.1 compression. Dynamically that would put you somewhere around 18.1 or 19.1.
TECH Apprentice
Joined: Jan 2004
Posts: 305
Likes: 0
Originally Posted by Bryan Wilkinson
The Crank is only good for a reliable 550. Others are pushing beyond that, but I would not recommend it. As far as boost, 6psi would be the absolute upper limit with 11.1 compression. Dynamically that would put you somewhere around 18.1 or 19.1.
Dave
Originally Posted by Bryan Wilkinson
The Crank is only good for a reliable 550. Others are pushing beyond that, but I would not recommend it. As far as boost, 6psi would be the absolute upper limit with 11.1 compression. Dynamically that would put you somewhere around 18.1 or 19.1.
i dont see why people risk it....makes no sense when youre making alot of power.peoples cranks have gone south with STOCK hp,so its probably fine for 500rwhp but if he starts making much more and will need to rebuild anyway why not get a forged crank?
Yea, pretty sure you mean the pistons, right? The cranks seem to be doing pretty well over 550hp. I don't remember seeing any instances where the cranks failed anywhere near the 550hp mark.
Originally Posted by Bryan Wilkinson
The Crank is only good for a reliable 550. Others are pushing beyond that, but I would not recommend it. As far as boost, 6psi would be the absolute upper limit with 11.1 compression. Dynamically that would put you somewhere around 18.1 or 19.1.
Probably because it costs a minimum of $1k to upgrade to a forged steel piece. If you're not trying to make crazy high numbers, I am sure that $1k+ could be put to better use in your car.
Don't recall seeing any instances where the stock cranks failed with stock hp, or even boosted? Are you refering to a spun bearing or what? That's usually the result of poor maintenance (CHANGE YOUR OIL!), over reving, or a poor rebuild.
I guess it depends on what your power goals are. If this guys not trying to change his compression ratio, he's probably going to be more concerned about detonation, lifting his heads or piston failure than stock crank failure.
Don't recall seeing any instances where the stock cranks failed with stock hp, or even boosted? Are you refering to a spun bearing or what? That's usually the result of poor maintenance (CHANGE YOUR OIL!), over reving, or a poor rebuild.
I guess it depends on what your power goals are. If this guys not trying to change his compression ratio, he's probably going to be more concerned about detonation, lifting his heads or piston failure than stock crank failure.
Originally Posted by ddnspider
i dont see why people risk it....makes no sense when youre making alot of power.peoples cranks have gone south with STOCK hp,so its probably fine for 500rwhp but if he starts making much more and will need to rebuild anyway why not get a forged crank?
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Originally Posted by 99Fbody99
I hope you typoed that..Pistons are relaible only to about 550 and rods in LS2 are a bit more. The cranks have been run way over double that without failures.
Dave
Dave
There are people that are making over 550 on the stock crank. But As I said about my setup, 822RWHP on 93 octane, just because I can do it, doesnt make it reliable. For what a high performance engine cost. that should be a piece that is replaced. Harlan, from my understanding is using the stock crank making all of the power he makes, but my understanding he is not running it on a race track, he is taking it to drag strip, nice short little runs. I didnt say you couldnt do it, I am saying that it is not a reliable avenue to take.
I would imagine regardless of who I have pissed off in the past that anyone with any experience at all would agree, that anything over 550 on a blown application the crank should be replaced.
I am not sure of any aftermarket company out there, and in last months GM High Tech where every company listed their builds parts list, not one had the stock crank listed. If I am going to spend at least 10K on a motor, I can afford another 2K for a crank that will hold up. Guarenteed.
thats my thoughts exactly Brian. Thread Starter
Staging Lane
Joined: Jul 2005
Posts: 83
Likes: 0
Originally Posted by ddnspider
with 5psi i hope he can keep a handle on lifting the heads...even with that CR.it would be nice to know what he's actually doing as far as FI.
But I think effective CR of ~15:1 about max without engine grenading. That’s a little over 5 PSI of boost. I thought I would ask the question and see what forum members think.
As far as lifting heads – allot of other things will let loose before that happens on stock LS2.
Mike
Ahh, I was afraid you were going to take a super-defensive position on this. Seems like lately you're always pretty worried about people giving you sh$t about this and that, but I don't think there's anything wrong with putting something like this up for a little healthy discussion...
Let's face it - you definitely make it a point to test the limits of your engine, therefore a forged crank is definitely the choice for you. However the guy that started this post is looking for 5-7psi, not 14-18psi!
I think for his setup, the stock crank will be just fine.
As far as the stock crank goes in general, from what I have read so far, it seems like 550hp is reliable. It seems like people are making more than 550 reliable hp. If you're constantly testing the limits of your engine, than obviously a forged steel crank (or anything for that matter) is going to be better than the stock internals. What you need to decide is whether or not you can better spend that $1k-$2k somewhere else on your car. I think it all depends on what your goals are, but I would not sell your stock crank short at 550hp.
Let's face it - you definitely make it a point to test the limits of your engine, therefore a forged crank is definitely the choice for you. However the guy that started this post is looking for 5-7psi, not 14-18psi!
I think for his setup, the stock crank will be just fine.As far as the stock crank goes in general, from what I have read so far, it seems like 550hp is reliable. It seems like people are making more than 550 reliable hp. If you're constantly testing the limits of your engine, than obviously a forged steel crank (or anything for that matter) is going to be better than the stock internals. What you need to decide is whether or not you can better spend that $1k-$2k somewhere else on your car. I think it all depends on what your goals are, but I would not sell your stock crank short at 550hp.
Originally Posted by Bryan Wilkinson
You know for everything that I was given crap about......
There are people that are making over 550 on the stock crank. But As I said about my setup, 822RWHP on 93 octane, just because I can do it, doesnt make it reliable. For what a high performance engine cost. that should be a piece that is replaced. Harlan, from my understanding is using the stock crank making all of the power he makes, but my understanding he is not running it on a race track, he is taking it to drag strip, nice short little runs. I didnt say you couldnt do it, I am saying that it is not a reliable avenue to take.
I would imagine regardless of who I have pissed off in the past that anyone with any experience at all would agree, that anything over 550 on a blown application the crank should be replaced.
I am not sure of any aftermarket company out there, and in last months GM High Tech where every company listed their builds parts list, not one had the stock crank listed. If I am going to spend at least 10K on a motor, I can afford another 2K for a crank that will hold up. Guarenteed.
There are people that are making over 550 on the stock crank. But As I said about my setup, 822RWHP on 93 octane, just because I can do it, doesnt make it reliable. For what a high performance engine cost. that should be a piece that is replaced. Harlan, from my understanding is using the stock crank making all of the power he makes, but my understanding he is not running it on a race track, he is taking it to drag strip, nice short little runs. I didnt say you couldnt do it, I am saying that it is not a reliable avenue to take.
I would imagine regardless of who I have pissed off in the past that anyone with any experience at all would agree, that anything over 550 on a blown application the crank should be replaced.
I am not sure of any aftermarket company out there, and in last months GM High Tech where every company listed their builds parts list, not one had the stock crank listed. If I am going to spend at least 10K on a motor, I can afford another 2K for a crank that will hold up. Guarenteed.
Originally Posted by KraZy
Keep to asking about a girdle.
Last edited by 01red28; Jul 31, 2005 at 06:51 AM.
Originally Posted by 01red28
I read at EPP that they had a 700 and some RWHP TA running stock crank and block with a girdle system when they forged the bottm end becuse the stock crank was good for over 900RWHP
Originally Posted by FastKat
Ahh, I was afraid you were going to take a super-defensive position on this. Seems like lately you're always pretty worried about people giving you sh$t about this and that, but I don't think there's anything wrong with putting something like this up for a little healthy discussion...
Let's face it - you definitely make it a point to test the limits of your engine, therefore a forged crank is definitely the choice for you. However the guy that started this post is looking for 5-7psi, not 14-18psi! I think for his setup, the stock crank will be just fine.
As far as the stock crank goes in general, from what I have read so far, it seems like 550hp is reliable. It seems like people are making more than 550 reliable hp. If you're constantly testing the limits of your engine, than obviously a forged steel crank (or anything for that matter) is going to be better than the stock internals. What you need to decide is whether or not you can better spend that $1k-$2k somewhere else on your car. I think it all depends on what your goals are, but I would not sell your stock crank short at 550hp.
Let's face it - you definitely make it a point to test the limits of your engine, therefore a forged crank is definitely the choice for you. However the guy that started this post is looking for 5-7psi, not 14-18psi!
I think for his setup, the stock crank will be just fine.As far as the stock crank goes in general, from what I have read so far, it seems like 550hp is reliable. It seems like people are making more than 550 reliable hp. If you're constantly testing the limits of your engine, than obviously a forged steel crank (or anything for that matter) is going to be better than the stock internals. What you need to decide is whether or not you can better spend that $1k-$2k somewhere else on your car. I think it all depends on what your goals are, but I would not sell your stock crank short at 550hp.