Ok so next step

[Mustang dog]

On another thread I started, I know what path I want to take, "S/C vs turbo". For my application.
So, today I start looking at forged rotating assembles,as my car is sitting around the 90k mile mark, and I plan on rebuilding my stock engine with forged internals, with plans for a centri to top it off.

Then I start seeing options for stroker kits..Crap, so , now something else to consider because it would make sense to do it while the block is out.

But the more I read the more negatives I start to see about excessive cost and minimal hp improvements with or without boost. So I'm thinking to stay 4.6l and add forged internals, upgrade the springs and guides, etc.

Is this the way to go or should I look into stroking? While I'm at the build.


I have no experience with these motors at all, let alone a stroker, (only with a friends bow tie 383 stroker which was a beast btw) so if you can suggest some good reading, I'll go that route as well. I did a search on site but didn't see much come up on this site but on other sites I did.

Car is 07 GT manual, looking at 400rwhp goal,is no real racing street or otherwise. except some good spirited driving once in a while. Summer driven only.

 

[Department Of Boost]

What is your HP goal?

What kind of fuel?

Why centri vs PD?

 

[stkjock]

@400 whp, IMHO, no need for a built motor

 

[702GT]

On another thread I started, I know what path I want to take, "S/C vs turbo". For my application.
So, today I start looking at forged rotating assembles,as my car is sitting around the 90k mile mark, and I plan on rebuilding my stock engine with forged internals, with plans for a centri to top it off.

Then I start seeing options for stroker kits..Crap, so , now something else to consider because it would make sense to do it while the block is out.

But the more I read the more negatives I start to see about excessive cost and minimal hp improvements with or without boost. So I'm thinking to stay 4.6l and add forged internals, upgrade the springs and guides, etc.

Is this the way to go or should I look into stroking? While I'm at the build.


I have no experience with these motors at all, let alone a stroker, (only with a friends bow tie 383 stroker which was a beast btw) so if you can suggest some good reading, I'll go that route as well. I did a search on site but didn't see much come up on this site but on other sites I did.

Car is 07 GT manual, looking at 400rwhp goal,is no real racing street or otherwise. except some good spirited driving once in a while. Summer driven only.

Search BruceH's posts on motor builds, lots of real world experience there. The important information to take from them is a square motor vs non-square. A 4.6 for example is a square motor, meaning stroke vs bore. Increasing stroke alone adds CID, but at a cost. Budget is almost always the primary concern. I'm a big fan of BruceH's car, as everything he ever did to the car was on his dime LOL. And we got to see what worked, and what didn't, and how different parts affected power curve, gains, and losses. His work with the FRPP Intake Manifold for example, really put to bed the fact that it's a virtually useless upgrade without a blower/turbo huffing into it, or a major displacement increase. Even then, you needed a proper cam to work with all of that. My biggest favorite, was when he had the blower on his Big Bore build. It was coyote-worthy as far as how effortlessly it made power per PSI, for a 3v.

As a fan of centri power, a centri is probably the safest power adder you can go with, as power is linear and comes on, generally, less harsh than a turbo or PD. My stock motor has been through nitrous, 6,000rpm track launches on slicks, and now a D1SC wastegated to 7psi with a 4.00 pulley. On E85 it makes the most power and feels very confident at my power levels, with a max of 22 degrees spark. I know I could push more boost on E85 safely, but I learned from this forum not to be (too) greedy.

I agree with stkjock, there's really no need to build the motor for 400whp. As stated above, I make the power in my sig all day long (depending which fuel I'm inclined to run) and have been for 2 years, never had a sign of the motor getting tired. I keep my tunes safe, I don't over-rev the engine, as there isn't a need to with stock cams and my wastegate setup. I shift at 5800 rpm if I'm doing a full run-out. I make a good deal of torque between 3,000-4,000rpm. And I hang doors or pull a little vs stock GT500's.

Had a guy at cars & coffee accuse me of being lazy, even. Said if he had done a modified GT, he wouldn't have half-assed it. Told him to get off his ass and go buy a pulley and a tune for his GT500, and maybe then he could pull on me.

If you do decide to build a motor with the intent of starting at 400whp and working up to a higher goal, I still think the 4.6 bore x stroke is a great platform to keep, unless you have a crazy itch to go north of 700whp. Forged 4.6 3v will play in 500-600whp all day long with the proper blower and supporting mods. Keeping the motor square will give you the best power curve too. If you're not greedy, and 400whp is what you want, keep running your stock motor. If it's giving you signs of being tired (eating oil, smokey exhaust, unusual ticks/knocks/clacks) do a budget build. Coyote rods and a deal on decent pistons will put you right back in the game without breaking the bank.

 

[slackinoff]

90k is nothing for these engines. I wouldn't hesitate to boost your engine using any power adder..... Unless there is something standing out wrong with your engine, run it!

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[JUSTA3V]

I'm glad I stroked mine while I was forging it. Hasn't wimpered since 2009. And I've thrown lots at it.

 

[Mustang dog]

So my goals are over 400 hp, I don't know what over 400hp feels like, I know what 300hp+ feels like, and it's not really enough. I like the Centri for s/c for two reasons, it's linear,and I already cut a hole in my hood for my shaker, and I really like my shaker,(I know,I know it's a thing for me).

I would love to pick up a Centri tomorrow and install it but I am concerned about the mileage on the car and if I will do damage to it. Yes it runs perfect no strange noises no oil usage, I don't take it past 6k very often.

If i can get away with a paxton s/c with a new clutch, and throw out bearing as is with my current mileage I'll be happy for the next year or so..


Man... what a rabbit hole....
Thanks for the responses, and the time you all took to go into detail for my benefit . This is a great site with great members

 

[46addict]

The rabbit hole gets deeper once you go past a certain power level, and then you reach the point of diminishing returns because you have to upgrade entire systems and not just individual parts here and there. I would consider 400whp through a centrifugal blower gentle and if you're like me you will want more. So if the budget is there for internal upgrades I would do them, along with fuel system upgrades and a clutch so you can run the boost setting of your choice and not worry about breaking something. Of course you can still break upgraded parts but they will withstand more abuse than stock stuff.

 

[2003cobra22]

The rabbit hole gets deeper once you go past a certain power level, and then you reach the point of diminishing returns because you have to upgrade entire systems and not just individual parts here and there. I would consider 400whp through a centrifugal blower gentle and if you're like me you will want more. So if the budget is there for internal upgrades I would do them, along with fuel system upgrades and a clutch so you can run the boost setting of your choice and not worry about breaking something. Of course you can still break upgraded parts but they will withstand more abuse than stock stuff.

This, you might think 400whp will be more than enough but it won't take long to start wanting more and more. In the past I made the mistake of upgrading parts to meet my current hp goal but not thinking ahead to maybe have something that has reasonable room to grow with. 400whp is good with a stock bottom end, driveline, and basic fuel upgrades, then 450-500 chancing it and maxing out the supporting mods for that level.
After that internals are needed and everything else that entails while it's apart (fasteners, bearings, oil pump, valve train, etc). Then driveline needs upgrades, the clutch, trans input shaft with more spline count, maybe go with (T56 mag or 6060) instead, refresh the carrier or maybe go with something else (TrueTrac, Torsen, etc), axles. Then the Fuel system, stay returnless or go return style, upgrade injectors and rails, are you gonna be running E85 or just pump. Then even with all the right supporting mods maybe now you've maxed out the efficiency of your original head unit and that needs to be upgraded. It can quickly become a slippery slope but planning a head can help ease the pain.
Everything is subjective to how the car is driven and taken care of but a centri is probably the best for total longevity, reliability and ease of maintenance, as said power is linear to RPMs so normal driving never sees much load. With that said centri's are more fun with stalled autos IMHO, PD blowers are my favorite instant power and torque, most of my driving is around town so can't beat the power on demand with a manual, that being said they aren't the best with gas mileage and all thing being equal are the hardest on a bottom end. Turbos will definitely be best for the most power and that top end whip in a turbo car is second to none, from my experience they are more involved maintaince which can be fine if you turn your own wrenches but if not then can run up the cost. All in all theres no right way and hindsight can be a bitch. Hope this helps good luck

 

[slackinoff]

Don't worry about 90k miles. Slap that centri on and tune for 400hp. You will be just fine.

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