Question for the experts...can you get a KB to produce 600rwhp SAFELY on 92/93 octane
- Thread starter Hunter6
- Start date
Yes.
15+psi, a real good tune (JDM), and full exhaust will get you there.
15+psi, a real good tune (JDM), and full exhaust will get you there.
I'm no expert, but a word of caution...there have been reports of a few KB-blown motors that failed.
I think those were all pushing 19-21+ pounds of boost, and some of them were going for more while running on the edge as far as a/f goes. 15 pounds should be a no-brainer. Hell, the Heaton drivers are running almost that high with no issues.
As I said, it was just a word of caution. But just for the record, Coleman was only running 17 psi (according to his sig). Not sure what RaceRat was running. Also, I don't think there are any Eatons pushing 600 rwhp.
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There have been non-kb blown motors that have failed as well. Its all in the tune.
There have been STOCK motors that have failed...
I meant the Eatons are running close to 15 pounds of boost.. obviously nowhere near the efficiency of a KB, but the engines are still holding on.
Like Shadowgray03 said, it's all in the tune. I'd run 11s for a/f just to be safe.
Like Shadowgray03 said, it's all in the tune. I'd run 11s for a/f just to be safe.
There are WAY to many variables that go into a making a motor hold up to high horsepower to try and pinpoint what is safe. Are we talking weekend racer, daily driver, cool cruiser? Although our cars are pretty stout, there is not a known "safe" limit. At 15 PSI you are creeping on 600rwhp on a KB, not enough facts exist to prove what makes the car able to stand up to that power level consistently. We don't know if it is the fuel systems limit, or the wrist pins, or oiling...you get the point. Plenty of people are having success stories, and a few have had issues. The issues are much more publicized than the success stories. If you want to have 600ponies under the hood-you run the chance of breaking something. It is just the nature of the beast.
I agree that there are many variables. My question is really about OCTANE. Whether or not it is inherently unsafe to take a KB to 600rwhp on 92/93 octane.
Better put...Can 92/93 octane SAFELY support 600rwhp when using a KB?
IMHO 600 is about the limit for 92-94 octane pump gas. Most of the engine builder's I know of will set a limit based upon compression ratio or HP/liter. The max HP/liter running pump gas being in the 120-140HP/liter range. The biggest problem with pump gas lies in the fact that it just doesn't have the slow burn characteristics of race gas. You can ramp up the horsepower and tune out the detonation with more fuel and less timing, but the burn characteristics of the lower octane fuel will induce more stress on the motor. So the question is how long do you want your motor to last? I wouldn't push anymore than 600 without resorting to racing gasoline or adding toluene, xylene, or some other octane booster.
I agree its definantely in the tune !! But also most important regardless of who tunes... The motor needs Fuel Pressure (Chip Tune) & Volume (Pumps or BAP) to sustain it with the increased
boost. No matter how good the tune if you don't have volume holding that pressure the A/F is going to lean and do that enough times. You get a broke Motor !!
Jon L
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I dont care how safe the tune is; I always run 101 octane on my kb.
Coleman's and Racerat's issues had little to do with their KB blowers, unless you consider a loose vacuum hose and a failing fuel pressure sensor Kenne Brown's fault.
And the one man that actually did his research before posting:beer:
Yep, I second that!
Well put!!
There was two seperate issues at hand, neither was a direct result of a faulty KB. Both were very "flukey" things that happened to two people that both happened to have KB's.
FYI...My car was tuned by the same person that tuned racerat's car, so it definately was not the tune that caused racerat's delima.
I have a KB(15#'s), I run 93 and have absolutely no problems whatsoever!! IMO, the real problem with the KB's is not the octane, (yes, you have to have a higher octane), but having enough fuel pressure to support the engine at the big end, is the real sticking point. I will be installing the focus pump to help insure that the car doesn't run lean.
:beer:
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Settle down guys. I wasn't blaming KB. The issue, as I see it, is what is a safe HP level for these engines. My response was merely a warning that if you increase the power by 50%, you're going to be putting a lot more stress on the internals, and possibly more than they were designed to withstand. As SVT4J said, there are more issues than just the tune. Would I consider a hose coming off to be KB's fault? Of course not! But as I recall, there was speculation that that hose came off because of the higher boost levels. So if that was the case, there's one of those "other variables" one needs to concern themselves with. Do you see the point? I wasn't flaming KB, so try not to take offense. Sorry if it was taken that way.
Ok..I'm going to step in here since my car is mentioned.
Mine and colemans cars were set up differently and the failures have no similarities except two KB cars in Texas trashed motors in the same week.
We don't know the exact cause of my problems. It may have been the FRPS or it may have been the gas.
The only real damage to mine is the pistons...two of them melted badly and the other 6 are scorched.
The car fell on it's face between the 3-4 shift. No knocking, no pinging, no drivability issues whatsoever.
My take on the original question, about 600rwhp on pump gas...I honestly think the motor is on borrowed time at that power level. Too many variables and if just one thing falls out of sync..boom!
What happens if you get a tank of lower octane gas than is advertised? It happens more than you want to know!
What if the temps drop drastically like ours did that night and you make more HP because of better air thereby requiring more octane?
What if the two above instances happen on the same day?
If you want to play, be prepared to pay. Our motors are NOT bulletproof!
The forged pistons are bottom of the barrel compared to others forged ones. The fuel system has it's limits.
Just look at the other problems that vary from car to car...in stock form. The tick, the vibration...different in cars built only days apart.
Sorry for rambling...just some stuff to think about.
Mine and colemans cars were set up differently and the failures have no similarities except two KB cars in Texas trashed motors in the same week.
We don't know the exact cause of my problems. It may have been the FRPS or it may have been the gas.
The only real damage to mine is the pistons...two of them melted badly and the other 6 are scorched.
The car fell on it's face between the 3-4 shift. No knocking, no pinging, no drivability issues whatsoever.
My take on the original question, about 600rwhp on pump gas...I honestly think the motor is on borrowed time at that power level. Too many variables and if just one thing falls out of sync..boom!
What happens if you get a tank of lower octane gas than is advertised? It happens more than you want to know!
What if the temps drop drastically like ours did that night and you make more HP because of better air thereby requiring more octane?
What if the two above instances happen on the same day?
If you want to play, be prepared to pay. Our motors are NOT bulletproof!
The forged pistons are bottom of the barrel compared to others forged ones. The fuel system has it's limits.
Just look at the other problems that vary from car to car...in stock form. The tick, the vibration...different in cars built only days apart.
Sorry for rambling...just some stuff to think about.
There you have it.
And actually, I don't think they ever did pin point the issue with coleman's car, either. I know there were lots of things speculated. Coleman wondered about the missing hose, and there was also thoughts about stretched/broken rods, oiling problems, fuel problems, et al. (I think his thread might be of record length!)
And actually, I don't think they ever did pin point the issue with coleman's car, either. I know there were lots of things speculated. Coleman wondered about the missing hose, and there was also thoughts about stretched/broken rods, oiling problems, fuel problems, et al. (I think his thread might be of record length!)
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