blown gt40p or N/A 347?

[final5-0]

OEM 5.0 302 cubic inch short block combos that still have the factory pan
gasket seal have put 335 SAE rwhp to the rollers give or take a few.

True ... you don't see them every day ... but they are out there

GT Jake who used to hang here did ... IIRC ... 332rwhp with those conditions

I know for a fact ... that tune was not as good as it could have been

You did see where I said in going for an amount of performance that is beyond
the typical h/c/i combo like in the first sentence of this post ... One would most
likely start to give up SOME drivability for that additional performance.

I don't wanna mislead anybody here ... as I have NOT done such a thing
but
Based upon what I have done

I do think I could take a 94-95 Stang to that level and still obtain a sticker for
legal public road use

Heck ... No doubt in my mind
I could do a good bit better
but
Low end would suffer a good bit and drivability as well ... to the point of .......
You might not be able to sticker it
and
To me ... You're then getting more radical than I want for a Street Car that
would be built with those conditions in place.

Grady

 

[Pokageek]

Yep. I am with you on that one man. These are great threads for learning.

 

[Cwalk]

i think with a high compression 347, an aftermarket head(p/p), matching intake manifold, and mild cam. i don't see why you can't hit the 400hp mark with a 347. at least 11.5:1 maybe even 12:1. you should be able to hit the 400hp mark. with the right block/fuel pressure. the cam doesn't have to be so aggressive you can't enjoy the car on the street.

 

[95five-oh]

Thanks guys for the good info. After reading the replies and doing some more research I think i'm leaning towards the 347 over the blown gt40p 5.0. That being said, I do want around 360ish at the wheels while still having good driveability. The car will be used primarily for street cruising but i will take it to the track occasionally. It is currently my DD but by the time i plan to finish it will no longer be driven daily. Basically I want to soundly beat stock to mildly-modded LS1 f-bodies and hang with stockish c5 vettes, if that gives you guys a better idea of what level of performance I want. What combo could i run to achieve this goal? I was thinking afr 185's, performer rpm 2 and a custom cam with supporting hardware...would that be sufficient with about an 11:1 CR or would I need to go more aggressive on the heads and intake? Also, with the extra power of that stroker, would gears be a good choice or would my stock 3.08's be fine with the newfound grunt? Thanks again

 

[Black95GTS]

Thanks guys for the good info. After reading the replies and doing some more research I think i'm leaning towards the 347 over the blown gt40p 5.0. That being said, I do want around 360ish at the wheels while still having good driveability. The car will be used primarily for street cruising but i will take it to the track occasionally. It is currently my DD but by the time i plan to finish it will no longer be driven daily. Basically I want to soundly beat stock to mildly-modded LS1 f-bodies and hang with stockish c5 vettes, if that gives you guys a better idea of what level of performance I want. What combo could i run to achieve this goal? I was thinking afr 185's, performer rpm 2 and a custom cam with supporting hardware...would that be sufficient with about an 11:1 CR or would I need to go more aggressive on the heads and intake? Also, with the extra power of that stroker, would gears be a good choice or would my stock 3.08's be fine with the newfound grunt? Thanks again

Yeah, that will be sufficient. I'd recommend a minimum of 4.10 gearing and perhaps a Holley intake instead of the RPM 2. You'll definately hang with those cars and your HP goal is certainly obtainable. Ed C specializes in these packages. Watch your hood clearances though.

Gearbanger, I admit after re-reading that I did sound douche-baggy. But I think my point remains that with today's technology, you can tune a car to be lame as hell until 2500 then come on like a freight train. If we were talking about a carb I would agree with you 100 percent but IMO people are just starting to fully exploit fuel injection on street/strip cars.

For example, my car loafs around with a fairly lean A/F ratio and moderate spark until 3K when I add about 20 degrees and fatten it up to 12 to 1. And I did this in my driveway. If you have the ability for higher flowing components, more displacement, and a solid tune, NA beats a smaller engine under forced induction.

Adam

 

[Pokageek]

Maybe you guys can enlighten me? I though anything over 10.5:1 CR and you need MORE than 93 octane..? Thanks in advance.

 

[Pokageek]

Anyone? ttt

 

[Gearbanger 101]

Maybe you guys can enlighten me? I though anything over 10.5:1 CR and you need MORE than 93 octane..? Thanks in advance.

No, not necessarily. When tuning the car, you can cut timing and spark out of the top end to keep detonation (pre-ignition) under control. GM has been doing it for years.

 

[Pokageek]

Thanks gearbanger. But that leads me to another question. If you are raising compression and lowering timing..doesn't that defeat itself? Is there a point of maximum return? How is it achieved? I think I remember seeing some audi's with 12:1 co,mpression ratios...for example...how is there a benefit if you are killing it with timing?

 

[Gearbanger 101]

You can pick up a good chunk of off idle and low/mid range torque with added compression while pulling out timing up top and still measurably increase performance. Even pulling just a little timing out up top on a higher compression engine to starve off detonation, might still provide equal performance to a stock 9:1 engine with added timing up top....all while increasing horsepower and torque at all other load levels.

Check out some of the modular guys (for comparison) after doing the PI head swap on the NPI cars. The compression ratio jumps from around 9:1 up to 10.4:1 and after straitening everything out with a hand held tuner their torque levels across the board and under the curve increase substantially over that of a '99-'04 PI car..

Ford has kept C/R’s low to start with most of their models just so their owners have the choice of running 87-octane all the time. But from a performance and drivability aspect, higher compression is the way to go……unless you’re running forced induction. In which case conservative static compression levels help keep combustion temperatures at bay when the pressure is on. But that’s a whole other conversation.

 

[Grn92LX]

Maybe you guys can enlighten me? I though anything over 10.5:1 CR and you need MORE than 93 octane..? Thanks in advance.

11.045:1 PUMP gas STREET car here FULL timing

 

[5spd GT]

I’m almost insulted by your “shady info” comment. Just because an opinion differs from your own, doesn’t mean it’s “shady” or incorrect. Perhaps you just need to open your mind up to different perspective than your own and come to grips with the reality that just because you hadn’t though of it, doesn’t mean it isn’t correct.

That applies to more than one in here...

As for the PI swap, I'm getting the parts together right now

I see that constant 347 example (yellow sn-95) posted everywhere, and that is typically the only one. I doubt many in here know how much time/effort/dollars was spent to acheive that. The cam was ground to perfection and the ramp rates are probably less desirable for spring life. I hate that example, but to some that is 'all they got.'

Be careful of what a 'street car' is to some, it is much easier to have a unstreetable 'street car' when you have another car. That is the case with many and myself, suddenly I want to go more extreme with my fox because I have another car to fall back on and not have to worry about dealing with the little quirks day in and day out.

A typical 'streetable' 347 in my opinion does not get anywhere close to what the yellow sn-95 did...because his car is not typical. There is NO need to build up ones hopes. That is why you see threads constantly about how they are dissapointed at the dyno making 360rwhp no their 347, because 'such and such' made 450rwhp.

I also see degrading comments towards how that X parts and X car should go this X fast or X rwhp, when there are several differences between cars and their owners.

A custom cam does not mean that it is ground to 'go fast', a custom cam is tailored to the buyer from the seller. It could be just for 'sound' (as some muscle car folks like to install in their restored hot rods) or it could be ground for 'pure power' like the NHRA guys like to have.

Way to much bias....

Just watch out for it and make your best judgement and get the goals that you can afford and want.

Don't let anyone tell you that your car is slow because you got X part instead of Y part - Maybe that is all you can afford or want to spend.

To much 'shunning' parts just because it isn't what gets them from point A to point B faster...

 

[final5-0]

That applies to more than one in here...

As for the PI swap, I'm getting the parts together right now

I see that constant 347 example (yellow sn-95) posted everywhere, and that is typically the only one. I doubt many in here know how much time/effort/dollars was spent to acheive that. The cam was ground to perfection and the ramp rates are probably less desirable for spring life. I hate that example, but to some that is 'all they got.'

Be careful of what a 'street car' is to some, it is much easier to have a unstreetable 'street car' when you have another car. That is the case with many and myself, suddenly I want to go more extreme with my fox because I have another car to fall back on and not have to worry about dealing with the little quirks day in and day out.

A typical 'streetable' 347 in my opinion does not get anywhere close to what the yellow sn-95 did...because his car is not typical. There is NO need to build up ones hopes. That is why you see threads constantly about how they are dissapointed at the dyno making 360rwhp no their 347, because 'such and such' made 450rwhp.

I also see degrading comments towards how that X parts and X car should go this X fast or X rwhp, when there are several differences between cars and their owners.

A custom cam does not mean that it is ground to 'go fast', a custom cam is tailored to the buyer from the seller. It could be just for 'sound' (as some muscle car folks like to install in their restored hot rods) or it could be ground for 'pure power' like the NHRA guys like to have.

Way to much bias....

Just watch out for it and make your best judgement and get the goals that you can afford and want.

Don't let anyone tell you that your car is slow because you got X part instead of Y part - Maybe that is all you can afford or want to spend.

To much 'shunning' parts just because it isn't what gets them from point A to point B faster...

I like a lot of what you said here

It easy to get mislead or unintentionally mislead somebody else on these forums

Some of the time ...
What I know and what I have in my mind at the time I try to explain stuff ...
well ..........
It don't always make the entire trip down to my fingertips

I'm like most others .........
I want the results you see from those "exceptional" combos you spoke about
but
I expect I'm gonna get those results with "average" results funds

Grady

 

[5spd GT]

I'm like most others .........
I want the results you see from those "exceptional" combos you spoke about
but
I expect I'm gonna get those results with "average" results funds

Grady

I know exactly what your saying

 

[95five-oh]

How much more expensive is it in the long run to build a combo off of a 351w instead of a 302? By that i mean a fully done out 347 stroker with good H/C/I etc. vs a 408 with the same mods? I know the larger engine has to be more expensive to do right, but how much more power would it produce than the 347 and would the added cost be worth it?

 

[final5-0]

How much more expensive is it in the long run to build a combo off of a 351w instead of a 302? By that i mean a fully done out 347 stroker with good H/C/I etc. vs a 408 with the same mods? I know the larger engine has to be more expensive to do right, but how much more power would it produce than the 347 and would the added cost be worth it?

Well Tim

I guess if you follow the 1 hp for 1 ci thing ....
you should get about 50 more hp with the Windsor

To build a stroked Windsor short block is not gonna be all that more costly
than a 5.0 short block it would seem to me

They ask more for suitable heads for Windsor Strokers ... do they not

You got to have different parts to stuff a Windsor in our cars so that would
be a bit more outlay of cash

A tune on either Stroker would be needed so that is no different

You can find a big ole thread on this very subject we talked about before
and I wanna say it was about 3 to 5 weeks ago

I don't know ... those are just a few things that quickly came to mind

Grady

 

[Mustangless]

If it does not cost too much, I would build a 351 based engine, like a 408, 418

here you go
http://www.coasthigh.com/Assemblies/Ford/ford_427w.htm

 

[chaos254]

If it was me I would do the gt40ps and a supercharger. A 347 would be nice but your probably gonna make 350-375 rwhp. Gt40ps with a supercharger will make 400+ rwhp. It really depends on what you want. Personally if Im going to spend all that money.. I'm going to want the best bang for the buck.