Cobra intake on GT

joemomma

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I'm working on a budget, so I picked up a non-EGR Exploder upper/lower from eBay. I don't have a cam or heads yet, but the intake and gaskets are on a shelf in the garage. I really don't want to do it twice, so I'm waiting until I at least get a cam before I tear into it. Ideally, I'd score some heads and do it once.
 
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r1ch999999

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I don't think cams are worth a whole lot on daily drivers, once you have basic aspiration handled with heads/manifold/etc. Seems like the majority of people buy them because they want a novelty idle sound - I can't understand that motivation at all, but you'll already have a fat torque curve with the stock cam. A racing cam is a lot of work and money for a power band you'll barely use if you're not just in pursuit of dyno numbers or competitive racing.

I have the MM strut bar on my 94, it fits fine past the Cobra manifold. The clearance around the oil dipstick could be better but it's OK too. My 96 V6 did not come with a strut bar, but my old GT bar bolts right in so.. score! Though I have to admit there's not like any consistent stretch of road or specific place I drive over where I can point to it and say THERE, THERE IS WHERE IT MAKES A DIFFERENCE.. it kinda hasn't made a difference. Both my cars are coupes.
It's not a daily driver, I've had a few recommendations for a E303 cam, but I haven't looked into it. I'm a middle aged dude who likes cars but really knows jack about engines.

I heard that the 97+ explorer 5.0 had gt40p heads that are supposed to be superior to the e7, or whatever the 5.0 HO has, but I don't know for sure. If the Explorer intake and heads are better, why wouldn't I spend $1000 on the entire engine and swap over the parts? Might as well do a cam at the same time, right?
 

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You can put whatever in wherever.

I think the relevent part of that is that "A Mod" is not a fungible value, every change you make has specific characteristics and they interact with each other, they have different costs and produce different outcomes.

If what you want is a dookie-load of power, get on https://www.clevelandpap.com/ and order you a GT350 on a pallet. But that's money.

When money starts being a factor it becomes more advisable to know the outcome you want first and then work backwards on what the most cost effective group of parts will get you that outcome. "Mo Powah" is probably not specific enough to make any important decisions, that just goes back to buying a GT350 engine on a pallet. How much powah? How do you want it delivered? What else is important to you other than just a dyno number? How cheap are you trying to keep this?

This website has a really handy calculator for working out this type of build https://fastgood.cheap/
 
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r1ch999999

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You can put whatever in wherever.

I think the relevent part of that is that "A Mod" is not a fungible value, every change you make has specific characteristics and they interact with each other, they have different costs and produce different outcomes.

If what you want is a dookie-load of power, get on https://www.clevelandpap.com/ and order you a GT350 on a pallet. But that's money.

When money starts being a factor it becomes more advisable to know the outcome you want first and then work backwards on what the most cost effective group of parts will get you that outcome. "Mo Powah" is probably not specific enough to make any important decisions, that just goes back to buying a GT350 engine on a pallet. How much powah? How do you want it delivered? What else is important to you other than just a dyno number? How cheap are you trying to keep this?

This website has a really handy calculator for working out this type of build https://fastgood.cheap/
Ok, that all makes sense.

I'd like the car to be a bit faster, honestly I could probably just swap out to 3.73 or 4.10s and be done, but I'd like to fiddle a bit. Since I have a budget of $1,500-$2,000, I figured cam, intake, and heads was a decent place to start. What I don't want to do is pick one of those things that requires more extensive work to install. For instance, I believe I'd have to swap out the springs if I did those things, maybe the throttle body too. Those don't seem expensive so I'm not too worried about it. If I picked up an explorer engine just for the intake and heads, and then discovered I also had to get headers, that might not be for me.

Am I making sense?
 

shovel

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Changing the intake manifold to any of the performance options moves your tuning peak up a little because the runners are larger diameter and slightly shorter internally, which raises their tuning peak even if the heads are unchanged. They also have a more equal distribution of flow (see chart I posted earlier in this thread, along with evidence of this effect at the exhaust collector) . That's a good accompaniment with the gears you intend to install since you'll also be occupying/accessing that higher RPM continually.

An alternative is send your HO manifold off to one of the established porting services, well this part seems to light some people off into tribal controversy so I'm going to preface by saying I don't know or care about which porting service is better or worse or whose uncle's cousin's cat's girlfriend supposedly got burned by one of them on craigslist or... whatever.

All I can say on that is that "A well known porting service" quoted another forum member $350 last year to "stage 2" port a HO manifold and they claim it outflows a GT40 manifold. Personal opinion I think that's plausible and $350 if that's still the going rate, doesn't sound too bad since they also clean and refinish it to look like new and you know everything is going to fit and work perfectly since it's your own existing manifold.

As you've noticed there are a million ways to build these engines and that means there are a million opinions about how to do it "right" and everyone is certain they alone got it right.. you know how it goes.

Some of the GT40 heads have the spark plugs at a different angle and they don't all work with normal Mustang headers for that reason. You'll want to put a little study into that before deciding on some junkyard heads.

Controversially you can increase power and smoothness a little bit without removing heads by installing high ratio roller rockers & damped springs on your existing E7's. At peak RPM a high ratio rocker on a stock cam on E7 heads (specifically) will only flow 3% more at any given aperture but at less than peak RPM it's considerably more and it's a difference you'll feel. You can bundle this with replacing your valve stem seals which - if they're original - absolutely do need to be replaced.

Controversially you can shift your power band up by retarding your cam timing while performing the maintenance job of replacing your timing chain assembly which typically starts getting a little sloppy after ~150-200k miles depending on maintenance practices. Performance timing assemblies will often have multiple keyways on the crank sprocket so you can pick your advance or retard from stock. 2 degrees of retard on the cam will move your torque peak up several hundred RPM.

Those sorts of things can scratch your tinkering itch, provide you with a whole lot more than a placebo and get some necessary maintenance jobs out of the way without having to remove the heads and without having to pull the lifters and camshaft, both of which are sort of annoying jobs. It also avoids the considerable expense of performance heads, head gasket sets, performance camshaft, etc.
 
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badass98svt

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Ok, that all makes sense.

I'd like the car to be a bit faster, honestly I could probably just swap out to 3.73 or 4.10s and be done, but I'd like to fiddle a bit. Since I have a budget of $1,500-$2,000, I figured cam, intake, and heads was a decent place to start.

If you are doing gears, budget $600-$1000 on the parts and labor depending on how deep you dig.
 
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r1ch999999

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Changing the intake manifold to any of the performance options moves your tuning peak up a little because the runners are larger diameter and slightly shorter internally, which raises their tuning peak even if the heads are unchanged. They also have a more equal distribution of flow (see chart I posted earlier in this thread, along with evidence of this effect at the exhaust collector) . That's a good accompaniment with the gears you intend to install since you'll also be occupying/accessing that higher RPM continually.

An alternative is send your HO manifold off to one of the established porting services, well this part seems to light some people off into tribal controversy so I'm going to preface by saying I don't know or care about which porting service is better or worse or whose uncle's cousin's cat's girlfriend supposedly got burned by one of them on craigslist or... whatever.

All I can say on that is that "A well known porting service" quoted another forum member $350 last year to "stage 2" port a HO manifold and they claim it outflows a GT40 manifold. Personal opinion I think that's plausible and $350 if that's still the going rate, doesn't sound too bad since they also clean and refinish it to look like new and you know everything is going to fit and work perfectly since it's your own existing manifold.

As you've noticed there are a million ways to build these engines and that means there are a million opinions about how to do it "right" and everyone is certain they alone got it right.. you know how it goes.

Some of the GT40 heads have the spark plugs at a different angle and they don't all work with normal Mustang headers for that reason. You'll want to put a little study into that before deciding on some junkyard heads.

Controversially you can increase power and smoothness a little bit without removing heads by installing high ratio roller rockers & damped springs on your existing E7's. At peak RPM a high ratio rocker on a stock cam on E7 heads (specifically) will only flow 3% more at any given aperture but at less than peak RPM it's considerably more and it's a difference you'll feel. You can bundle this with replacing your valve stem seals which - if they're original - absolutely do need to be replaced.

Controversially you can shift your power band up by retarding your cam timing while performing the maintenance job of replacing your timing chain assembly which typically starts getting a little sloppy after ~150-200k miles depending on maintenance practices. Performance timing assemblies will often have multiple keyways on the crank sprocket so you can pick your advance or retard from stock. 2 degrees of retard on the cam will move your torque peak up several hundred RPM.

Those sorts of things can scratch your tinkering itch, provide you with a whole lot more than a placebo and get some necessary maintenance jobs out of the way without having to remove the heads and without having to pull the lifters and camshaft, both of which are sort of annoying jobs. It also avoids the considerable expense of performance heads, head gasket sets, performance camshaft, etc.
I never considered porting the stock intake that would make things easier, especially with my desire to keep the STB on the convertible. I'll have to look into a place to do that.

I really appreciate the engagement here, my plans are already shifting based off of what people are saying.

I wonder how this plan would work: New gears, ported stock intake, rockers and springs, and retarded timing. Luckily I have under 90k on this engine, so not much is worn out from use, maybe from sitting. I know a few things have been replaced before I bought it, and it sat for years in a rich mans garage.

Like I said, I'm just looking to wake it up a little bit, I'm not trying to win any races, I just want a little more fun out of my weekend cruiser.

Thanks again everyone for the comments.
 

ttocs

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I think to get the stock intake to flow as well as the gt40 or the aftermarkets either takes an extrude hone or some cutting/welding if I am not mistaken? It isn't like they just take a little out of the throat/bottom.
 

Musturd

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I never considered porting the stock intake that would make things easier, especially with my desire to keep the STB on the convertible. I'll have to look into a place to do that.

I really appreciate the engagement here, my plans are already shifting based off of what people are saying.

I wonder how this plan would work: New gears, ported stock intake, rockers and springs, and retarded timing. Luckily I have under 90k on this engine, so not much is worn out from use, maybe from sitting. I know a few things have been replaced before I bought it, and it sat for years in a rich mans garage.

Like I said, I'm just looking to wake it up a little bit, I'm not trying to win any races, I just want a little more fun out of my weekend cruiser.

Thanks again everyone for the comments.
Throw some subframe connectors in it and a k member brace and you won’t miss the strut tower bar
 

joemomma

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If you're on a budget, start with gears. That may surprise you enough that you decide you don't need/want anything else.

Like you, I'm a middle-aged old fart and on a budget. I'm not trying to win the Indy 500, but I don't want to get gapped by a minivan between stoplights either. "Performance/HP" is kind of a big can of worms - once you open the lid, there's a lot in there. The old saying "how fast can you afford to go" really rings true on the 302 pushrod motors. As far as picking up an Explorer block for the heads and intake, keep in mind that you'll likely want to have the heads reworked, or at the very minimum cleaned up and new springs installed at a machine shop. That specialized labor gets expensive quickly. Then, if they are GT40p (4 bar) heads, you have the sparkplug/header issues to contend with. The GT40 (3 bar) do not have these problems, but are harder to find. I've been shopping GT40 heads for a little while, and people are asking $400 or better for them pulled straight from the junkyard. You're going to have at least that much more in getting them worked. At that point, you're about halfway to a set of nice aluminum heads.

My car is stock engine with 4.10 gears and full exhaust. It's a fun driver, but isn't winning me any races even with the gears. Plus, it's done at 5k RPM. I'd like to get a decent set of heads and a cam to go with the Explorer intake. That would really wake it up, plus it would make power through the RPM range without falling on it's face at 5k.
 

shovel

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I think to get the stock intake to flow as well as the gt40 or the aftermarkets either takes an extrude hone or some cutting/welding if I am not mistaken? It isn't like they just take a little out of the throat/bottom.

The specialist porting services that I'm most familiar with hone out the full length and build extra material onto the areas they cut through & for max effort jobs they cut the plenum off with a bandsaw and work from that end, and then grind it down to resemble stock before repainting it.

You're right that just getting the parts you can see from the bottom would barely do a thing both for volume and for charge timing.

I don't want to speak as if I'm an expert on porting services specifically, I have not used such a service. But I have done a lot of reading and watching - which unfortunately exposed me to the weird culture war stuff going on between a few such services and why I'm not mentioning names in this thread. I am going to be sending my V6 manifold to one of those services and I have already been in contact with them about it, they'll be doing the full cut-and-shorten job and I'll share my results of course but that's still a few months off.
 

badass98svt

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.

I wonder how this plan would work: New gears, ported stock intake, rockers and springs, and retarded timing. Luckily I have under 90k on this engine, so not much is worn out from use, maybe from sitting. I know a few things have been replaced before I bought it, and it sat for years in a rich mans garage.

Like I said, I'm just looking to wake it up a little bit, I'm not trying to win any races, I just want a little more fun out of my weekend cruiser.

Thanks again everyone for the comments.


I'd just get the gears/diff taken care of. Then go from there. The gears make a HUGE when changing from stock. Just dont fear the gear, you'll regret it if you dont go steep enough.

From there I'd drive it, and contemplate on my next move.

How much HP/TQ would you want as goal in the LONG run?
 

ttocs

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The specialist porting services that I'm most familiar with hone out the full length and build extra material onto the areas they cut through & for max effort jobs they cut the plenum off with a bandsaw and work from that end, and then grind it down to resemble stock before repainting it.

You're right that just getting the parts you can see from the bottom would barely do a thing both for volume and for charge timing.

I don't want to speak as if I'm an expert on porting services specifically, I have not used such a service. But I have done a lot of reading and watching - which unfortunately exposed me to the weird culture war stuff going on between a few such services and why I'm not mentioning names in this thread. I am going to be sending my V6 manifold to one of those services and I have already been in contact with them about it, they'll be doing the full cut-and-shorten job and I'll share my results of course but that's still a few months off.
I am not a porting expert either, just curious what you are thinking your bill will be? We had a guy here that had a nice stock GT intake that had been extrude honed and you could see how much had been removed from it but he had a hard time moving it for the money that was into it.

I thought the trickflow intakes were just under $700?
 

shovel

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I am not a porting expert either, just curious what you are thinking your bill will be? We had a guy here that had a nice stock GT intake that had been extrude honed and you could see how much had been removed from it but he had a hard time moving it for the money that was into it.
I thought the trickflow intakes were just under $700?

I have to assume I'll be north of $400, maybe more for max effort on my V6 manifold. To be clear I don't actually think going max effort is necessary for OP's engine if he's keeping the E7 heads there's a point of diminishing returns and the 80/20 rule plays heavy here - the first 20% of work provides 80% of the benefit.

This is unrelated to OP's question but to address the first questions most people will ask on my own V6 project -

* Nobody makes an aftermarket single port V6 manifold and there are no alternate OEM manifolds for the single port heads, which means modifying the stock one is the only option (I am aware of Morana but that's way off the rails from this conversation)

* Yes I know I could split port swap. I could Coyote swap too. I could just drive my GT or buy newer GT or even a base model ecoboost and be faster. That's not the goal of the V6 project I'm working on.
 
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r1ch999999

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I'd just get the gears/diff taken care of. Then go from there. The gears make a HUGE when changing from stock. Just dont fear the gear, you'll regret it if you dont go steep enough.

From there I'd drive it, and contemplate on my next move.

How much HP/TQ would you want as goal in the LONG run?
I'm not sure, 250ish probably. I don't want it to break, but I'd like a bit more than it has.
 

shovel

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In my travels through the internet I've seen a few E7 head/NA builds plausibly get close to 300hp with receipts, that seems to be the upper limit for E7's but I'd bet 250+ is real easy with the parts already discussed here.
 

95opal

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An intake alone isnt going to do anything.
Slap in a set of 3.73 and a short shifter.
Those 2 mods alone will put a smile on your face and will wake the car up. Also a set if subframe connectors if the budget allows.
Those 3 things should be the first mods on the list. If you feel you need more HP after that then youll need a game plan and bigger budget.
 

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