max boost on forged internals
max boost on forged internals
i searched and couldnt find anything. what kinda boost/hp can i safely run on a KA with a rebuilt/stronger bottom end? i know the tuning has alot to do with it, but what limitations am i gunna run into on the KA after the internals are stronger?
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You can stuff as much boost as a turbo will support on a properly built bottom end. All forged goodies with new bearings will be good for 30 psi easy assuming the parts and block are in good shape. The hard part as you already said will be tuning the fuel and ignition side of things. Type of fuel will also have to be considered, as you approach 30 psi and above your going to run into your octanes limit to resist preignition/knock.
WD
WD
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^^^ on an engine that came NA If the engine came with a factory turbo, you can practically double the boost with basic tuning.
But with a NA engine, running 15 psi on 91 octane…Even with good tuning, one hole in the fuel map, and you have yourself a firework show, I say too risky.
Back to my original statement a reliable engine is better then a blown engine.
But with a NA engine, running 15 psi on 91 octane…Even with good tuning, one hole in the fuel map, and you have yourself a firework show, I say too risky.
Back to my original statement a reliable engine is better then a blown engine.
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9.5/1 CR isn't all that high. Its only .5 higher then the RB25's. Using a knock sensor and a wideband O2 sensor, I'd say you can easily run 15 psi. NA maps are easily made up for by proportionally adding fuel to the boost curve. An engine that runs efficiently in NA form will run like a raped ape on boost. I'm not saying crank up the CR. I'm simply stating that the 9.5/1 KA will do well under boost.
WD
WD
Checkered-Member wrote:Ah ok I forgot to consider race gas in to the equation
15 PIS on 9.5; possible with 110 octane
Try 93 pump gas. (Yeah, he was talking about me). 350rwhp at 15psi on stock bottom end KA with pump gas. No special tuning either...just JWT plug and play. Please quit spreading your speculative information when there is hard evidence to the contrary, Checkered.
I don't really see forged internals giving people a whole lot of reliability...just more liability. The same things that keep a stock engine running keep a built engine running...and the same things that blow a stock engine blow a built engine. Difference is...if you blow a stock engine, you swap another one in for a few hundred bucks and 12hours of work...if you blow a built engine, you max out the credit cards again.
Dennis
I have run 18psi with 8.2:1 forged pistons for along time and have had no problems. From what I hear, the stock pistons are have extremely weak ring lands and won't handle much boost at all. Fuel map tuning is extremely critical if you use the stock pistons and too much of a good thing will grenade the engine.
yeah the way I see it (correct me if I'm wrong) is if you want a little leeway in your mapping, use a built bottom end. At least then if you slip just a little bit the parts should be able to hold up. Stock parts - much cheaper, that's true, but if you slip up somehow or if something goes wrong that you cant control, it's all over and you're rebuilding your motor again.
Do you really think it's not "worth" it to go built, Dennis?
Do you really think it's not "worth" it to go built, Dennis?
Besides...put a stock piston up against a forged one (I just compared my Ross forgies to a stock piston) and you'll feel better just looking at it, there's really no comparison 
I think the stock pistons can hold up, I just dont like them very much, and after seeing the rod that came out of the engine that was in my car when I got it...I dont like the rods either! Ugly things.
I think the stock pistons can hold up, I just dont like them very much, and after seeing the rod that came out of the engine that was in my car when I got it...I dont like the rods either! Ugly things.The rods are somewhat suspect at high HP levels. They are ugly but I had mine polished and shot peened and then put in ARP hardware. The machine shop says that is what they do to the Nasport rods and they haven't had any problems. I just sent my computer to Wolf for the 740 cc Nismo injector upgrade which should get into the 450-500 HP range so it might be time for some Crower or Carillo rods. I agree with you, that the forged pistons are way better looking. The shine like chrome. It's ashame to hide them inside an engine.
This is true...it's like night and day between forged and stock, if I had a good digital camera I'd post a picture just so everyone could see how pretty they are. I'm sure the stock rods are sturdy...its just that I have an uneasy feeling after seeing the pieces of the broken one literally bent in half, it was crazy stuff, I still dont know how Syntax360 managed to blow the motor that well.
Quote »Do you really think it's not "worth" it to go built, Dennis?[/quote]
Absolutely. You just have more to loose. Engines don't blow up because you just run too much boost on a daily basis...they blow up because something screws up, and it is just as easy to blow up a built motor as it is a stock motor. It wouldn't give me any piece of mind...it'd make me more scared because if I did blow up the motor, I'd be out thousands of dollars. If I blow up my motor now, I have a spare that cost a few hundred dollars.
I've just seen too many people blow up "bulletproof motors" and max out all their credit cards...and here I am with a reliable stock-bottom-end KA turbo making just as much power with half as much invested and half as much to loose.
Absolutely. You just have more to loose. Engines don't blow up because you just run too much boost on a daily basis...they blow up because something screws up, and it is just as easy to blow up a built motor as it is a stock motor. It wouldn't give me any piece of mind...it'd make me more scared because if I did blow up the motor, I'd be out thousands of dollars. If I blow up my motor now, I have a spare that cost a few hundred dollars.
I've just seen too many people blow up "bulletproof motors" and max out all their credit cards...and here I am with a reliable stock-bottom-end KA turbo making just as much power with half as much invested and half as much to loose.
"Bulletproof" is a realitive term. You are right, you have more to lose blowing up an expensive motor but an expensive motor is less likely to blow up if you throw crazy abuse at it. All motors have a threshold which beyond they will break. Expensive correctly built motors have a higher threshold than an unmodified motor. Motors can blow up because of too much boost. Boost creates heat and heat is the enemy. You have to mach higher levels of boost with differnt ignition systems and timing as well as modified fuel maps and higher octane fuel not to mention forged pistons that can handle the additional heat and upgraded internal parts to handle the additional stress that is put upon them. If you are running small amounts of boost, then the stock engine can probably handle it. Try putting moderate amount of boost in a stock engine without the requisite upgrading and watch the ring lands blow out. Piece of mind is having an engine that you know can handle what you are dishing at it. It all depends on what you want out of your engine.
Quote »"Bulletproof" is a realitive term. You are right, you have more to lose blowing up an expensive motor but an expensive motor is less likely to blow up if you throw crazy abuse at it. [/quote]Yes, it is...but how much? With a factory engine, you have factory reliability. With a built engine, you have machine shop reliability which is at least a little less reliable than Nissan. If you spend 10 times as much for a 10% increase in reliability, is it worth it? In my opinion, no...and I think you get less of an increase in reliability than that.
Quote »All motors have a threshold which beyond they will break. Expensive correctly built motors have a higher threshold than an unmodified motor.[/quote]Exactly...but it is hard to get a correctly built motor built as well as the factory...also, the threshold is not that much higher.
Quote »Motors can blow up because of too much boost. Boost creates heat and heat is the enemy. [/quote]Sure, that is correct...but how many KAs do you know that lived a normal life and eventually blew up because of boost. I don't think I have ever heard of one in 5 years with the community and 4 years turboing KAs. They all blow up because of overboosting or running an inadequate fuel system or timing or breaking something and running out of oil or something like that. The engine that is closest to running a normal life and eventually blowing up (of the blown engines I know of) was a built motor.
Quote »You have to mach higher levels of boost with differnt ignition systems and timing as well as modified fuel maps and higher octane fuel not to mention forged pistons that can handle the additional heat and upgraded internal parts to handle the additional stress that is put upon them.[/quote]See, this is where you and I disagree. The stock pistons, rods, crank, etc. have been proven, so why do you thin it is necessary to upgrade them? Besides, EGTs don't change much with increased boost as long as timing and fuel are good...and it doesn't really matter since EGTs and in-cylinder temps are way higher than the melting point of aluminum anyways.
Quote »If you are running small amounts of boost, then the stock engine can probably handle it. Try putting moderate amount of boost in a stock engine without the requisite upgrading and watch the ring lands blow out. [/quote]Well, duh. Built motor or not, it isn't going to run 15psi with stock injectors and stock ignition maps. But stock pistons
Quote »Piece of mind is having an engine that you know can handle what you are dishing at it. It all depends on what you want out of your engine.[/quote]
Exactly, and for me...built engines can't handle anything you can throw at them, they give little extra protection over stock engines at a huge price penalty. It all depends on what you want out of your pocketbook. Personally, I'd like to spend less for more.
But we have a difference of opinion, and I am fine with that. But when it is all said and done, I have my piece of mind and money in my wallet.
Quote »All motors have a threshold which beyond they will break. Expensive correctly built motors have a higher threshold than an unmodified motor.[/quote]Exactly...but it is hard to get a correctly built motor built as well as the factory...also, the threshold is not that much higher.
Quote »Motors can blow up because of too much boost. Boost creates heat and heat is the enemy. [/quote]Sure, that is correct...but how many KAs do you know that lived a normal life and eventually blew up because of boost. I don't think I have ever heard of one in 5 years with the community and 4 years turboing KAs. They all blow up because of overboosting or running an inadequate fuel system or timing or breaking something and running out of oil or something like that. The engine that is closest to running a normal life and eventually blowing up (of the blown engines I know of) was a built motor.
Quote »You have to mach higher levels of boost with differnt ignition systems and timing as well as modified fuel maps and higher octane fuel not to mention forged pistons that can handle the additional heat and upgraded internal parts to handle the additional stress that is put upon them.[/quote]See, this is where you and I disagree. The stock pistons, rods, crank, etc. have been proven, so why do you thin it is necessary to upgrade them? Besides, EGTs don't change much with increased boost as long as timing and fuel are good...and it doesn't really matter since EGTs and in-cylinder temps are way higher than the melting point of aluminum anyways.
Quote »If you are running small amounts of boost, then the stock engine can probably handle it. Try putting moderate amount of boost in a stock engine without the requisite upgrading and watch the ring lands blow out. [/quote]Well, duh. Built motor or not, it isn't going to run 15psi with stock injectors and stock ignition maps. But stock pistons
Quote »Piece of mind is having an engine that you know can handle what you are dishing at it. It all depends on what you want out of your engine.[/quote]
Exactly, and for me...built engines can't handle anything you can throw at them, they give little extra protection over stock engines at a huge price penalty. It all depends on what you want out of your pocketbook. Personally, I'd like to spend less for more.
But we have a difference of opinion, and I am fine with that. But when it is all said and done, I have my piece of mind and money in my wallet.
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WDRacing
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I don't think the 240 comunity will be at ease with boosting on stock internals until someone builds a 400hp terror. I'm probably going to try when I get home simply cause taking a motor right to the edge is crazy fun. Not to mention, like you already said Dan, round 2 is only a couple hundred bucks away. Give me 6 hours and I can have the blown engine out and the new one installed. So assuming I can tune a 400 hp stocker, I'd have a more powerful car then 80% of the guys spending all that extra cash on forged internals.
Don't think I can do it?? Your talking to the guy who boosted a stock RB20DET all the way to 28 psi with no ECU changes and stock injectors.
WD
Don't think I can do it?? Your talking to the guy who boosted a stock RB20DET all the way to 28 psi with no ECU changes and stock injectors.
WD
WDRacing wrote:I don't think the 240 comunity will be at ease with boosting on stock internals until someone builds a 400hp terror. I'm probably going to try when I get home simply cause taking a motor right to the edge is crazy fun. Not to mention, like you already said Dan, round 2 is only a couple hundred bucks away. Give me 6 hours and I can have the blown engine out and the new one installed. So assuming I can tune a 400 hp stocker, I'd have a more powerful car then 80% of the guys spending all that extra cash on forged internals.
Don't think I can do it?? Your talking to the guy who boosted a stock RB20DET all the way to 28 psi with no ECU changes and stock injectors.
WD
You my friend, are a hero among cowards......
I was just about to tell everyone your car runs reliably...but apparently you found the thread too.d240t2 wrote:Try 93 pump gas. (Yeah, he was talking about me). 350rwhp at 15psi on stock bottom end KA with pump gas. No special tuning either...just JWT plug and play. Please quit spreading your speculative information when there is hard evidence to the contrary, Checkered.
I don't really see forged internals giving people a whole lot of reliability...just more liability. The same things that keep a stock engine running keep a built engine running...and the same things that blow a stock engine blow a built engine. Difference is...if you blow a stock engine, you swap another one in for a few hundred bucks and 12hours of work...if you blow a built engine, you max out the credit cards again.
Dennis
400whp KA stock bottom end isn't farfetched at all. I think I could do it with just the addition of a .82A/R turbine housing and an equal length manifold, as well as a little tuning. I made 350rwhp with a RevHard manifold and JWT plug and play ECU...that is hardly optimized. I think 400whp could be done on a stock KA on pump gas, but I know for sure that tuning, .82 housing, equal length manifold, and race gas would net 400hp easy.
I just don't have any cash right now (as a college student, about to graduate and probably continue to be a slightly less poor graduate student). I have the .82 housing...and if I can ever get Jason to build an equal length manifold...then I just need to do some tuning.
Dennis
I just don't have any cash right now (as a college student, about to graduate and probably continue to be a slightly less poor graduate student). I have the .82 housing...and if I can ever get Jason to build an equal length manifold...then I just need to do some tuning.
Dennis