power that kills a block with a blower

[Torinalth]

here is a quandery. ok, so the magic number seems to float around 400-450. here is a question. i'm going to go a lil theorhetical here to make my point and hopefully make it easy to find an answer.

ok, so lets just say you have a stock engine, you add a kenne bell, and with a nice tune (safe mind you) you net 410 HP (remember this is more theorhetical numbers). lets add their cold air kit, and full exhaust and you are at 450. heads and mild cams and now to 500.

will this be more of a ticking time bomb then when you started at 410? my thoughts would be no. reason is that you are not adding any more force to the engine, you are removing restrictions, and letting the engine be more efficient. i may be wrong, hence the question. but since this gets tossed around a lot i figured i'd ask and get a final answer.

with the addition of a blower and more forced airyou have more stress, that i can understand. you upp the boost from 6 to 9 to 12 and each step increases pressure, thus increasing stress. by adding a full intake you would be allowing more air to move, not forcing more. same with going full exhaust, allowing more air to escape without intervention. ported heads, again less restriction. cams: this one i am kinda on the fence about. cams do in part allow more air thus less restriction, however, by the cam dynamics for making more power then stock its shutting down the air flow at times that could possibly be more strssful to the engine.

so, for those of the massive knowledge on motors, what is the vote?

Torinalth

 

[DropTopPony]

Chris at Kauffmans is running around with like 550rwhp on his stock block. Its alot to do with the tune and how you drive it. I wouldn't line up at every stop light and romp on it if i had a stock shortblock and 8psi or more....cause it won't last forever.

 

[Torinalth]

exactly... but what ARE the limiting factors? is it the total power? power created by boost? these are the hard facts i am looking for. as i suspect a lot of others have thought about it before.

Torinalth

 

[Pennywise2]

Detonation is what will kill your engine.

 

[40oz]

well, if you remove the restrictions in the blower intake, aren't you making it easier for the blower to push more air into your engine? And wouldn't that result in more air in each combustion chamber, making more power?

And if you open up the exhaust, you aren't taking a load off the engine. You are allowing exhaust gasses to escape the combustion chamber more easily, meaning there is less exhaust in the combustion chamber at the end of the intake stroke, resulting in better combustion and more power.

Things like electric water pumps and underdrive pulleys reduce parasitic losses, but opening up the intake and exhaust do more.

But, as has been stated here and elsewhere over and over and over, the tune will make or break your engine when you start pushing what it can handle.

 

[jstreet0204]

here is a quandery. ok, so the magic number seems to float around 400-450. here is a question. i'm going to go a lil theorhetical here to make my point and hopefully make it easy to find an answer.

ok, so lets just say you have a stock engine, you add a kenne bell, and with a nice tune (safe mind you) you net 410 HP (remember this is more theorhetical numbers). lets add their cold air kit, and full exhaust and you are at 450. heads and mild cams and now to 500.

will this be more of a ticking time bomb then when you started at 410? my thoughts would be no. reason is that you are not adding any more force to the engine, you are removing restrictions, and letting the engine be more efficient. i may be wrong, hence the question. but since this gets tossed around a lot i figured i'd ask and get a final answer.

with the addition of a blower and more forced airyou have more stress, that i can understand. you upp the boost from 6 to 9 to 12 and each step increases pressure, thus increasing stress. by adding a full intake you would be allowing more air to move, not forcing more. same with going full exhaust, allowing more air to escape without intervention. ported heads, again less restriction. cams: this one i am kinda on the fence about. cams do in part allow more air thus less restriction, however, by the cam dynamics for making more power then stock its shutting down the air flow at times that could possibly be more strssful to the engine.

so, for those of the massive knowledge on motors, what is the vote?

Torinalth

It is nice to see someone actually use some reasoning on this board instead of regirgitating information they've read on here. There are a few things that kill the stock bottom end. Cylinder pressure, detonation, and inertia loading (high rpm). Cylinder pressure is determined by how much air gets into the cylinder before the valve closes, so it doesn't matter how it got there (boost or decreased restriction). Detonation is the most common cause on a supercharged engine, and the more power you make, the more prone the engine is to detonation. Reducing restrictions in the intake track will increase cylinder pressure. That increased cylinder pressure is only slightly harder on the motor, but the chance for detonation increases, and the detonation becomes more severe with the increased cylinder pressure. The reason people use this "magic number" is because there come a point where you are going to stop making power on a conservative tune. To get those big hp numbers the tune needs to be a little leaner and have a little more timing, which are also going to icrease the risk for detonation. While the EEC is very adaptible, it can't adapt to everything, and eventually you'll get some bad gas, a clogged fuel filter, or the wind will blow the wrong way, and you'll get a bit of detonation. With the difference in cylinder pressure, the detonation on a 375hp engine, is not going to do near the damage as a 450hp engine when that detonation occurs.

 

[back_in_black]

I think my past experience answers the question. I had Dave Guy at Kauffnman's, (who also tuned Chris' car), do my tune with kb, conservative tune, 10 lb pulley, all kb options, blew up my motor first run at the track, the rods did not hold up, I was at 390 rwhp through an auto, so I don't think you can always say it is in the tune, Dave is an excellent tuner and I still go back to him, but some motors don't hold up.

 

[Torinalth]

It is nice to see someone actually use some reasoning on this board instead of regirgitating information they've read on here. There are a few things that kill the stock bottom end. Cylinder pressure, detonation, and inertia loading (high rpm). Cylinder pressure is determined by how much air gets into the cylinder before the valve closes, so it doesn't matter how it got there (boost or decreased restriction). Detonation is the most common cause on a supercharged engine, and the more power you make, the more prone the engine is to detonation. Reducing restrictions in the intake track will increase cylinder pressure. That increased cylinder pressure is only slightly harder on the motor, but the chance for detonation increases, and the detonation becomes more severe with the increased cylinder pressure. The reason people use this "magic number" is because there come a point where you are going to stop making power on a conservative tune. To get those big hp numbers the tune needs to be a little leaner and have a little more timing, which are also going to icrease the risk for detonation. While the EEC is very adaptible, it can't adapt to everything, and eventually you'll get some bad gas, a clogged fuel filter, or the wind will blow the wrong way, and you'll get a bit of detonation. With the difference in cylinder pressure, the detonation on a 375hp engine, is not going to do near the damage as a 450hp engine when that detonation occurs.

there we go, that was the kind of rundown i was looking for to either prove me right or wrong. I always knew detonation was thhe main kicker, but assuming no detonation chance (again, magic) why would an engine blow?

i see now that no detonation is near impossible, but even with it being out of the equasion i see i was wrong, and more air is allowed to be pulled in, thus forced in by the blower, and more stress. the better exhaust pulls out more burnt up fuel and air to be expelled, making the new air less tainted thus giving a better ignition.... more stress.

thats good to know, and finally have a full blown explantion of why the 400-450 number is still valid regardless of if its blower driven, or NA driven....

hmmm, maybe another can of worms... but what about an NA engine.... to 450 hp.... same results? no more force due to no blower....all the air is pulled in, not pushed in... engine theory... inda enjoying this.

Torinalth

 

[jstreet0204]

there we go, that was the kind of rundown i was looking for to either prove me right or wrong. I always knew detonation was thhe main kicker, but assuming no detonation chance (again, magic) why would an engine blow?

At some point cylinder pressure would be too much, but you are much more likely to get detonation before that happens, because of the heat associated with that pressure.

hmmm, maybe another can of worms... but what about an NA engine.... to 450 hp.... same results? no more force due to no blower....all the air is pulled in, not pushed in... engine theory... inda enjoying this.

Torinalth

N/A engines will be less prone to detonation to to less cylinder pressure, and less heat, BUT in order to make the same hp as a forced induction motor of the same displaement, you'd almost always have to spin it faster. This puts much more stress on the rods and crank due to the inertia loading. A 12% increase in rpm increases loads by 50%

 

[Torinalth]

good point... i should have thought more about that. i really should have been able to ration that one out.

also nice to see a local NC guy posting. pic kinda looks like BCB.

Torinalth

 

[jstreet0204]

good point... i should have thought more about that. i really should have been able to ration that one out.

also nice to see a local NC guy posting. pic kinda looks like BCB.

Torinalth

What is BCB?

 

[Torinalth]

brunswich county beach

T

 

[dew22]

I think my past experience answers the question. I had Dave Guy at Kauffnman's, (who also tuned Chris' car), do my tune with kb, conservative tune, 10 lb pulley, all kb options, blew up my motor first run at the track, the rods did not hold up, I was at 390 rwhp through an auto,

What octane were you running?

 

[jstreet0204]

brunswich county beach

T

Ok, I got ya. No that was at Pensacola Beach FL. That is where I am originally from I moved up here in 99 for work.

 

[hotmustang331]

Well one thing I find odd is that modularpowerhouse has never lost an engine that they have tuned....they tune ALOT of stock shortblock GTs to 400-420RWHP with 0 issues....alot of guys have been running like that for years. I think its all in the tune....I only trust MPH.
All these other guys like murrillomotorsports in texas, and kauffnmans like above, seem to loose motors, and never make good power.

I will be making another trip to MPH here pretty soon Its worth the drive....

 

[jstreet0204]

Well one thing I find odd is that modularpowerhouse has never lost an engine that they have tuned....they tune ALOT of stock shortblock GTs to 400-420RWHP with 0 issues....alot of guys have been running like that for years. I think its all in the tune....I only trust MPH.
All these other guys like murrillomotorsports in texas, and kauffnmans like above, seem to loose motors, and never make good power.

I will be making another trip to MPH here pretty soon Its worth the drive....

The best tuners can't tune around a mechanical failure which can and do happen. If you ever have an injector stick or a fuel pump go while you are under boost there is a good chance the motor is going to blow, and the safest tune in the world isn't going to save it.

 

[back_in_black]

What octane were you running?

93
I would venture to say that all tuners have had an engine blow, you just tend to here about the high hp engines they tune more. Myself along with a lot of other people have a lot of faith in Dave at Kauffman's, I think my engine failure was due to a mechanical issue or gas not the tune.

 

[dew22]

93
venture to say that all tuners have had an engine blow, you just tend to here about the high hp engines they tune more. Myself along with a lot of other people have a lot of faith in Dave at Kauffman's, I think my engine failure was due to a mechanical issue or gas not the tune.

Thanks,

I asked because I have a 10lb pulley on the way.

 

[hotmustang331]

The best tuners can't tune around a mechanical failure which can and do happen. If you ever have an injector stick or a fuel pump go while you are under boost there is a good chance the motor is going to blow, and the safest tune in the world isn't going to save it.

I understand that, but thats VERY VERY rare. Its just odd that none of the cars Tim has tuned have let go (due to mechanical or whatever...and if so I dont know about it) , yet I know people personally and have heard of people online that have been tuned by these other guys and loose their motors in a matter of months or less . Some go a LONG time, but just seems like their failure rate is much higher for some reason...and in reality I guess you cant know if its the tune (not safe enough for 100* weather maybe) or if its purely mechanical.

Just my take on it....but ill stick with MPH . If my car lets go after the TTs, I have 4K in the bank under the name "car pay off/forged motor...whichever comes first"