A good limit would be 6500 IMO.
I have a brand new 1 piece crank gear I could sell you if want to ditch the crappy 2 piece crank gear setup .Yep. On Nick's website the head/cam combo is highlighted as part of a 300 RWHP combo but he and I are both expecting closer to the 280-290 I mentioned above. That's mainly due to the T-bird's auto trans and IRS, plus I'm choosing the stage 2P cams over the stage 2.5 which is a sacrifice of about 5 RWHP for a wider torque curve. Daily driver, after all.
My parts list looks like this so far:
190 lph fuel pump
Braincoating ported/ceramic coated manifolds
Modular Head Shop stage 2 PI heads (Romeo)
Modular Head Shop stage 2P cams
EEC dyno tuning by Don Lasota
3500 stall 10" DirtyDog converter
2004 GT 4R70W built by DirtyDog
And of course all the supporting stuff to go with it all. New timing chains and guides, stamped trigger wheel, rebuild/clean the injectors, new front and rear main seals, etc.
Not only that, better atomized fuel increases HP and fuel economy, hence D.I. in newer vehicles with necessary ultra-high fuel pressures. Partly the reason I'm gonna set up my fuel system to push ~70psi.Well, the only problems is the older styles will hurt mileage a little and increase wear on the engine because raw fuel rinses the oil from the sides of the cylinders faster than well atomized fuel.
I've been told that I can use the datasheet for Ford Racing 39#/hr injectors for my Cobra 39#ers. It has the multipliers for all the injector data for up to 60psi, so I'll just extrapolate it for another 10psi. If that doesn't work, I'll simply stick with 60psi. Not only that, I'm gonna time the injector delay table to inject all the fuel right when the intake port velocity is greatest, at any given load/rpm. At 8k, I think the intake port peaks at machAre you going to use a model for the flow, or are you going to measure it?
I used ethanol to do a flow measurement in #/hr/duty cycle; it's fairly non-linear in spots... even at stock pressure.
That will be interesting, gm, for sure!
BTW, are the orange 19# injectors the type III?
your best bet for a good price on injectors is used. From a mustang owner or MMR. I know MMR has a bad rap for some of their products, but they shelve a lot of brand new take-offs from cars they work on and sell them at really good prices. The rebuild KIT is only $20 and you can flush them out yourself if you wanna clean them via this youtube videoInteresting. I'll just bide my time and wait for a good set to turn up here on the forums. :thumbsup:
Any news on that crank gear GM?
you've seen other 4.6 MN12s with NPI heads/PI cams/PI intake tuned put down 230 rwhp?Nice torque numbers. Your horsepower numbers look a little low tho any idea why?
Edit: maybe not with 18% drive train loss that puts you right at 260 at the fly wheel. I just kinda expected you to be up around the 220 or 230 area.. Like others I've seen
Just remember that more flow is not the same as increasing engine displacement, which would vertically raise both the Torque and HP curves. More flow means everything is shifted up on the RPM band, and depending on things like bottom end, intake, converter stall, gearing, etc, more flow might not be beneficial to you if you can't tap into it way up on the tach which is where the improvement is gonna be.:zdunno: It is what it is - I'm still content with the 45-50 HP I've gained with the minor mods I've done. I haven't done a thing to the throttle body, plenum or exhaust manifolds and I'm sure Don didn't go crazy with the tune either since it was mail order. He'll be dyno tuning it when I do the head swap however. I'm now starting to wonder about the heads - Nick has some ugly ducklings available and I can get the stage 3 heads right now for less than the stage 2s... Hm...
Maybe he was able to get stage 3 performance without touching the swirl dam now? I wouldn't doubt he's better at porting heads now than he was a year ago, as he now offers Stage 4 heads. I think its better because you lose 1cc of volume with the laid back swirl dam. My stage3s checked in right at 40.5cc's at the local machine shop.Well, finally started the teardown on the engine this afternoon... all I can say is it's a good thing I'm replacing the plugs and wires. The ones coming off explain a great deal about the strange behaviors of the car lately... lol.
Anyway, while I was examining the heads a little closer this afternoon I took a good look at them and compared them to the photos of the stage 3 heads I see on Nick's website (and elsewhere). I'm now almost certain I have stage 2 heads and NOT stage 3 heads like I was told. All the stage 3 heads I've seen have the air dam between the intake valve and spark plug hole ground back. Mine are untouched. I asked for a confirmation from MHS on the matter, but they never replied to my inquiry.
Oh well, no big deal - I got what I paid for. I'm just a little irritated about their saying to me that I got upgraded when in fact I didn't. But life goes on. Depending on a great multitude of factors, I hope to have it reassembled and begin tuning by Christmas.
just remember the more compression you give it, the more cam you have to give it to keep dynamic compression in check, otherwise you're driving right into ping-city and you can't leave without changing cams. Always look into that relationship.I have thought about an aluminum block to get some weight off the nose. If I ever picked one up I'd build something with even an higher CR (closer to 11.5, maybe 12:1) with notched pistons alongside a bottom end to support 7000 RPM shifts. The rest of the drivetrain is capable, it's the bottom end and intake that's holding me back now. I'd like to stay N/A though.