Murf SuperShark - Supercharged US-Spec 1981 completed - fun way to spend a weekend.
#166
Originally Posted by Hacker-Pschorr
The blower I have is maxed out right now. Z is trying to talk me into a 20psi setup.
I don't know why so many people automatically think cast pistons are such a weak point. At 2.1 horsepower per cubic inch, the Ecotec 2.0 liter turbo engine is the highest specific output engine that GM has ever offered. Stock specs are 260hp at only 5300 RPM, with a stock 20psi of boost, and a 9.2:1 compression ratio. A number of changes were made to the 2.4 liter Ecotec engine when the turbo was added, including reducing the stroke, and reducing the bore to give an increase in cylinder strength. It uses cast pistons.
Chrysler's 2.4 liter turbo engine is rated at 300hp with a 6,500 RPM redline. When they added the turbo, they also made a number of changes to the original naturally aspirated engine that they started with, but it also uses cast pistons.
If forged pistons alone were the complete solution, you wouldn't see so many broken forged pistons. Those sure don't seem to be too hard to find though. If anyone's got forged pistons and is sure that they're failure proof, I'm very sure I could show you otherwise if you'd let me try to see if I could break them.
Kevin,
If you aren't running lean due to the inability of the fuel pump that you have to deliver sufficient fuel at an adequate pressure, the Boost-a- Pump won't do anything for you. If you are running lean due to the inability of the fuel pump you have to deliver sufficient fuel at an adequate pressure, get a bigger/stronger fuel pump.
The only time you'd need to upgrade your ignition system would be if it wasn't up to the task of firing the spark plugs, and you were getting missfiring as a result. If it's in good condition, your stock ignition system is more than capable of working just fine under any boost and power level you're ever going to get to, unless you significantly modify both your engine and method of boost. You'll max out that supercharger before you max out that stock ignition system if it's in good condition.
#167
Rocket Pilot
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Z , thanks for clarifying and your advice. There are alot of misconceptions, I think, about our cars.
Erik, I am running a bosch copper plug one range colder.
Erik, I am running a bosch copper plug one range colder.
#169
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Originally Posted by toofast928
Hacker awesome numbers!
Tony
Tony
X2
as for those 2.4L Chrysler Turbos, Watch out for those PT Cruisers ,some of the tweeked ones can seriously haul *** and will leave a stock S4 behind.
Z....
You going to SITM?
#170
Rainman
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The PT Turbo and the Ecotec use cast pistons, but don't you think that casting techniques have changed in the last 20-30 years? The new pistons were designed to make up for shortcomings previous ones did. Although the 928 pistons are strong enough for alot of boost, turning it up to Ecotec levels would mak you shoot a rod out the oilpan (or other catastrophic failure)
#172
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Hmm
Originally Posted by Aj928
If a boosted car, say a 928s4, is in the 10 range/intercooled, has proper fuel flow, timing, air-fuel mix (JDS SharkTuned), uses 96 octane and is well maintained...how many miles do think it will be before engine failure begins ?
#173
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With all $tuff we do to our 928's...the price of mixing race fuel with premium unleaded is not so bad and does lower the chance of detonation. However, my 928 is not a daily gas-guzzling driver.
Sounds like 8psi w/intercooler is the max set up on a stock 32V motor.
Sounds like 8psi w/intercooler is the max set up on a stock 32V motor.
#174
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Originally Posted by Aj928
Sounds like 8psi w/intercooler is the max set up on a stock 32V motor.
Even though he is running a lower compression ratio for extra boost. His pistons have less material than a stock piston would.
#175
Originally Posted by Aj928
With all $tuff we do to our 928's...the price of mixing race fuel with premium unleaded is not so bad and does lower the chance of detonation. However, my 928 is not a daily gas-guzzling driver.
Sounds like 8psi w/intercooler is the max set up on a stock 32V motor.
Sounds like 8psi w/intercooler is the max set up on a stock 32V motor.
*With proper fueling* while there is more "heat" in the combustion process, and more power being taken by bearings and clutches and synchros, there is no reason that the 928 engine can take 50% more then that safely. Now letting the 530rwhp that 12psi should do in an S4 hit your clutch from 5k rpm is a separate matter.
#176
Originally Posted by Aj928
If a boosted car, say a 928s4, is in the 10 range/intercooled, has proper fuel flow, timing, air-fuel mix (JDS SharkTuned), uses 96 octane and is well maintained...how many miles do think it will be before engine failure begins ?
Originally Posted by Tony
Z....
You going to SITM?
You going to SITM?
Originally Posted by Aj928
Sounds like 8psi w/intercooler is the max set up on a stock 32V motor.
This is not intended as a slam towards anyone, as I've heard a lot of similar statements to some that have been made here for years, but it might get some people to think about a few things. Lets say that someone had a fireplace in their house that exploded because they modified it, and all the windows blew out. Everyone pretty much agrees that getting your windows blown out by an explosion is no fun. Some people might have the opinion that the windows were too weak, and that the homeowner needed stronger plexiglass windows to make them strong enough to withstand the explosion. Some might have the opinion that newer windows, like those used in newer houses, might not have broken, because glass is made differently than it was back when the original windows were made. Of course if the windows were made strong enough to survive the explosion, the walls or ceiling would have blown out instead, but hey, the windows wouldn't have. I may be in the minority here, but it seems to me that knowing how the fireplace works, and taking the proper steps to keep it from exploding in the first place might have been a reasonable solution.
So Erik, when is the 400+rwhp attempt?
#177
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Originally Posted by Z
So Erik, when is the 400+rwhp attempt?
So now the fun begins - EuroS cams, intake.......who knows.
Actually - my #1 priority with the 81 is finding out why the heat doesn't work.
#178
Originally Posted by Hacker-Pschorr
Actually - my #1 priority with the 81 is finding out why the heat doesn't work.
#179
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Well, both ends of that red vacuum line are not going anywhere. So that means the valve is open.......still no heat.
Something else is stuck - time to pull the center console.
Something else is stuck - time to pull the center console.
#180
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Originally Posted by Hacker-Pschorr
- time to pull the center console.