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4.6 guys come in.
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Wichers123
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My built 4.6 with big cams was fun and had more potential but the 5.4 is the way to go. I don't really like to rev the shit out of the motor to make power. Yeah it's tight as **** but hey whatever. I run the 4.6 eddy with adapters and it actually helps by adding runner length and moving injectors up actually give the fuel better swirl time. It's very tame just driving around slam on the pedal it puts you into the seat with ease.
[MENTION=10623]330CubeGt[/MENTION]
^ thats him! Great guy!
Yeah, Frank's a good dude
Mustang Mark
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the most cost effective build would. Be pi heads on a non pi block 10.5:1 or so compression ration and a vortech with ~10psi of boost. With a free breathing exhaust that should net you somewhere in the 400-450rwhp range. Most people go by the old way of thinking that you need low compression to run boost, but its quite the opposite if you have a good tuner. My car is a 3vv so it breathes better and I can rev it higher andd still make power but its almost 10:1 compression and I'm running around psi, but my car has the added benefit of knock sensors so the tuner can really crank up the timing without worrying about pinging. 6k rpm is a pretty good shift point for a stock pi 2V. The stock rods are about as thick as a toothbrush and are made of powdered metal... Not very strong, 430-450rwhp is considered safe for these motors, but the blocks are good for 800+rwhp.
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Nuttinbutcrumbs
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Is that 430-450 safe estimate on a stock bottom end or after forged internals? According to Google the stock compression ratio for a non "pi" motor is 9.3:1 and the pi is 9.7:1, would you say that's accurate? We're you running 10.5:1 before the blower or is that after? How much psi are you running again?
Don't Sext and Drive.
I've always heard for a boosted npi 2v, its better to have pi cams and intake but npi head to keep compression low. I thought we were avoiding putting pi heads on an npi block because the bump in compression was bad? (for a boosted application)
Not bad at all. 10.5:1 is fine for boost. Think about it this way, the Mach 1's come stock at 10:1 and people boost those all day long.
Yea...what this guy said and youll be running 2v heads at that. You will have a bigger advantage! 2v swirl, no quench pad, tiny exhaust valve...these are good attributes for boosted applications
Mustang Mark
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430-450 on stock bottom end, after forging the sky is the limit. I'm at 9.8:1 or so, easy enough to round up to 10:1. Higher compression does nothing more than raise cylinder pressure, which is the same thing you are doing when adding boost. With higher compression it won't be such a dog when out of boost, and it will make more power with less boost. You will just have to make sure a reputable tuner tunes your car. I'm currently running about 9 psi on the stock high mileage bottom end which is ~10:1. When I rebuild the motor with forged internals I will be going at least 10.5:1. There are a lot of people that go 11:1 on the 3Vs, but that will be 93 octane minimum, and make crazy power on E-85.
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Nuttinbutcrumbs
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I bet for the average joe running 8-10 pounds the extra compression wouldn't be enough to cause catastrophic failure as long as the a/f ratio is good.
Lemme pick your brain. My 95 has the stock 9:1 comp ratio n/a. With 8 lbs of boost what would it be?
Also so you're saying that a 97 GT can handle more psi than a '99? If that's the case then why not go w more psi vs spending money on cams and intake for the npi owner? Say a guy had a 97 w a stock motor and he added 12# of boost. And say there's another guy who had a 97 and he did a cam and intake swap and added 8 lbs. I kinda think it'd come out as a wash at best if they were to race. But if I were a betting man I'm placing my money on the guy making 12#'s if all else were equal as far as suspension and tires etc.
Don't Sext and Drive.
Your 95 also has a 4" bore and cast iron heads.....thats all I have to say
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Nuttinbutcrumbs
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Why is that all you have to say? So a stock topend npi motor can't handle 12#'s of boost and wouldn't make as much power or more as a pi motor making 8#'s all else being equal?
Don't Sext and Drive.
Npi and pi produce the smae hp when forced. This has been proven over many times. The heads are only a gate way into the cylinders. Only so much can pass through valve hole and both heads have the same size hole.
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Nuttinbutcrumbs
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Got ya, I didn't realize the valves were the same.
So I guess the best bang for the buck npi guy looking to make 300-350 whp is the a Vortech kit vs doing a pi swap.
Don't Sext and Drive.
A n/a streetable modular 2v 4.6l can produce 350rwhp,...not a daily driver. The daily driver can easily do 320rwhp.
The best bang is to do a pi swap on top of a npi shortblock. Most dyno at 260-280 depending on accessorie mods.
The best bang is to do a pi swap on top of a npi shortblock. Most dyno at 260-280 depending on accessorie mods.
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Nuttinbutcrumbs
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Ballpark figure spent to make that 280 hp? New parts, used? Trip to a machine shop?
Don't Sext and Drive.
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Nuttinbutcrumbs
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Is that 280 estimate w long tubes? What injectors are most running in that range? 30's?
Don't Sext and Drive.
Don't Sext and Drive.
Stock 19lbs. Stock running npi shortblock, stock running pi h/c/I. No machine shop. Long tubes help.
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