How to get to 400+ NA??

[PDXStangDude]

Okay, call me stupid but I would like to get the 4.6 3v to 400+ HP without a SC. I have seen some kits that change out the internals and add a cobra crankshaft, bored out to 304cid IIRC, and I think that is it. I have know idea what that would get me to but it just seems like it would be cool to get these powerplants to 400+ NA. I would add LT's and a catted H-pipe to the list, Alum Driveshaft, and I think that is about it.

Any thoughts from the rest of 2005+ stangers?

 

[MBDiagMan]

At 304 cubic inches you are talking about 1.314 HP per cubic inch. There is only one way to do that, and that would be to cam it, port it and open up the intake and exhaust tract such that you can raise the torque peak to a higher RPM. Since the torque peak is already at a relatively high RPM, you will have your work cut out for you.

If this were an old time push rod engine with limited flow, you would have lots of room for improvement, but in stock form, these engines are already making about 1.07 HP per cubic inch.

SOOoooo.... it is doable, but my question is, how long will you expect this engine to last?

 

[CBus 06 GT]

Are you talking 400 at the motor or 400 at the wheel? 400 at the motor should be easy with new rotating assembly, ported/polished heads and new cams and valve springs and still be totally reliable on 92 octane. 400 at the wheel would be a little more difficult, but I knew a guy who had a 96 Cobra who saw 425+ at the wheel with p and p'd heads, cams, 13:1 pistons and race gas. 400HP at the motor would be the same specific output as the newer 350Zs (300HP out of 3.5L)

 

[bigcat]

you will need all the bolt-ons including cams and P&P heads.

 

[orange 07]

Getting 400 crank hp is'nt that hard with the 3 valve
check out brenspeed's web site and check out the comp cam
install, the car has exhaust,cai,bbk throttle body, pulleys,comp
cams stage 3 cams and a tune of corse. the car made 347 rwhp
and using 15% drivetrain loss thats just over 400 crank hp
Pretty easy if you ask me. Also livernous motorsports got about
the same # with using their ported heads and stock cams.
I bet ported heads with comp cams and all the common bolt ons
450 reliable crank hp is realistic.

 

[TheMaster]

I think it could be done with stock rotating assembly, Just ported heads, cams, longtubes, intake, and a good tune. I'm planning on doing this over the next 3 years so I'll see.

 

[JTGrant]

I think it could be done with stock rotating assembly, Just ported heads, cams, longtubes, intake, and a good tune. I'm planning on doing this over the next 3 years so I'll see.

I'm on the same plan to make great power all motor. I do love Forced Induction, but for the most part NA is more reliable with stock rotating assembly.

 

[mustangdaren]

It's going to take more than ported heads and cams. Thats going to take compression and cubes.

 

["car"azy]

my car makes 357hp na and yes thats cams, p&p heads, valves, and forged bottom end. champion racing did the heads, boss 330 put it all together. we built it for nitrous to

 

[modular81]

Stock internals will be just fine, all you will need is full bolt-ons and a decent cam. This will put you between 345-350 rwhp which is right at 400-410 crank hp using 15% drivetrain loss. Add heads to the mix another 30 rwhp is possible, but now the injectors may need to be increased to the larger 39lb once you approach 375-380 rwhp range.

 

[billfisher]

347 rwhp IS 400 fwhp. stage3 cams have made that much with bolt ons and cams already. add porting and bigger custom cams and it will at least approach that kind of HP.

 

[Mr_Q]

Yup, was just going to say. The guys over at Brenspeed have done just that. 347rwhp with no PnP.

http://www.brenspeed.com/tech/compcams.html

 

[thump_rrr]

I got 308rwhp on a mustang dyno with no head work, no cams, no cmrc deletes, never been dyno tuned.
350-360 rwhp should be doable with cams, P&P and cmrc deletes.

If you want 400rwhp then you need to go 5.4L + stroker.