Fox T-Bird/Cougar Forums

Hey guys,

I picked up a nice 5.0/AOD combo from 50RACER last weekend. He's a cool dude and very helpful!

I am planning my transplant around the "Mid Output" 5.0 mod from coolcats.net. The upgrade parts I have acquired thus far that I plan to swap onto the motor are:

Rebuilt GT40P heads

Foxbody Mustang 5.0 Headers

My plan is to use a 87-93 HO upper intake plenum and 60mm throttle body/EGR spacer. I was browsing CL and found someone selling an explorer upper and lower intakes for a very reasonable price. My questions is, am I going to run into a problem with too much airflow for the amount of fuel I'm dumping in with the stock computer/injectors? If so, should I stick with the HO intake/TB and call it a day? I'm not trying to get major horsepower out of this car, just making it a little more fun to drive without spending too much money.

Thanks!

I've run several "mid output" setups over the years utilizing stock injectors and stock ECU. Most using the speed density injection as found on the 88-earlier 5.0 Birds and all the 5.0 Mk7s. The stock injectors, if in good operating condition will suffice for your parts list.

With the exception of the in-tank fuel pumps, Ford has traditionally designed their fuel systems with a fairly wide margin of additional capability. Putting another 35-50 HP thru it is well within the fuel system and the ECU's abilities to compensate for it with the caveat that you should make a Walbro 190 or 255lph pump a part of your upgrades.

So more fuel supply from an aftermarket pump would be good enough to allow me to run the GT40 intakes no problem? Are there any other mods you recommend for this mid output setup?

If you're going to have the car completely apart to redo the heads you might as well do the camshaft while you're at it

Its not so much that its supplying any extra fuel at the motor at a given time, as it is ensuring that the pump is delivering an adequate supply of fuel(and at pressure) to the injectors, all 8, all the time. On a stock 150 horse Tbird V8, even with some age on it, the wimpy stock pump will probably keep up. The motor is essentially dead at anything above 4800 rpm as far as power making goes, anyhow. Once you do an HO swap, and then improve on that, with ported heads, explorer/cobra intakes, exhaust, etc, the stock pump should not be expected or relied on to bring the fuel to the party. The stock injectors may be perfectly capable of doing the job but if the pump cant put the required amount of fuel (and at pressure) up to them, its not the injector's fault.

I'd suggest bolt down 1.7 ratio roller rockers if youre using any of the Explorer/GT40 or stock E7 HO heads. Leave the stock HO cam in it, install a good roller timing chain set if the stock one one hasnt been replaced yet.

 Common 1 5/8" shorty headers and bolt on 2.5" H pipe are sufficient for most 302's not using power adders. If you are going to use a small dose of nitrous later on, full length headers would then be worth considering instead of shortys.

Plan on needed AOD transmission upgrades or a T5 5 speed swap if you are going to go much further with power upgrades, or plan to run it hard at the track very often.

If you're gonna do heads and intake, and have the time/ability, I'd throw in an HO cam. Those heads will need something other than the stock springs, and if you're going to replace the cam, new timing set and oil pump.

I did basically the same thing, except I started with a low mileage HO engine. E cam, P heads with trick flow springs, Cobra intake, BBK shorties, Exploder 65mm TB and the usual stuff. Runs great. I also slapped in a Walbro 255 pound/hour fuel pump. Probably a little overkill for the current stuff, but if I decide to throw a blower on later or even nitrous, I'm sorta in good shape.

I'm running 24# injectors, but in your case, unless you go with a cam more than HO specs, the 19's will suffice. Is your engine the SO from a Tbird? Reason I ask, the SO engines had pistons that did NOT have valve reliefs. If you put a higher lift cam in (an HO will not cause issues), you will likely run into some PtV issues (piston to valve). As mentioned, an HO cam will work with stock SO piston however.

You can build or buy nice AOD trans that will handle HO power levels, the stocker probably will be ok if it's been taken care of, good fluid, etc. If you're gonna beat on it (why not, right?) it won't last.

If you can or haven't already, 3.73 gears will make an AOD car pull pretty good, 4.10s would be better.

I've been thinking myself about an AODE and a standalone for my Mustang. Take more power than a T5. I've already broken 3 of 'em. With Nitto tires though, it ain't hard to..

I understand that while I have the motor out of the car it would be relatively easy to do a cam swap. The reason I am trying to avoid it is because at that point I need to start worrying about whether or not my trans is strong enough and I would need to deal with swapping out the stock springs on my heads. The idea behind this project is to use the parts I have and take my SO motor to “mid output” levels. I have no intentions of drag racing or even driving very fast. I’d just like a little more get up and go. The current plan is:

Swap stock  upper and lower intakes for GT40 units

Swap throttle body and EGR spacer for 60mm HO units

Swap E6 heads for rebuilt GT40P heads

Swap stock fuel pump for higher capacity Walbro unit

Swap cast iron exhaust manifolds for HO headers


Anything else I should be considering?

The combo you have laid out absolutely will not run correctly with the stock speed density Tbird computer.  With all of the modifications you are planning you are so close to going 100% with a better than stock Ho set up. When I first started my conversion I ran the same combo that you were describing with the only difference being a speed density HO camshaft with the HO speed density computer.  Back then people nearly gave this stuff away,  you might be lucky enough to find these two additional items for nearly free. You won’t need to change the valve springs on the GT 40 P heads but a lot of people recommend it.

I'm not sure if I have any more HO cams, but if I find one, it's yours for shipping cost..?

You may as well, then grab yourself an SD1 or equivalent speed density EEC and you're good to go with the above stuff. It's actually well worth it. With an HO cam though, I would recommend upgrading the valve springs on the P heads. The explorer cam didn't have the lift that the HO units do, and those P springs on the wimpy side.

(as an aside, my '98 Explorer runs outta steam before 5 grand...my Mustang...does not LOL)

Ok, firstly, reading comprehension owned me when I read the OP. Apologies. I thought you had bought an HO motor and were improving that, so my bad for replying without reading more carefully.

Anyhow, the P heads have a different spark plug angle that will cause contact between the stock HO headers and the plug wire boots. I've heard where people have used a combination of a special shorter spark plug and plug wires with 90 degree boots to keep them from melting against the headers and to fascilitate spark plug removal that doesnt require unbolting the header to get a socket on the plug.

Ford racing makes the P specific shorty headers and people report that some of the aftermarket long tube headers have better clearance for the GT40 P head spark plug angle. You will want to get that sorted out to save hassle later.

Truthfully, I'm not of the opinion that making head and intake improvements is worthwhile if its going to eventually be piped thru stock HO headers. The stock HO heads and intake do not run out of lung until around 5200rpm on a basically stock 302. The Explorer intake only starts to offer a significant comparative advantage past this area of engine speed. Which happens to be the same rpm area where the stock HO headers become more restrictive. Adding additional airflow/fuel to create more power and thus, creating, by effect, more exhaust is not going to make the stock headers any better at what they are doing. My guess would be disappointing or very marginal gains over what a regular HO swap would bring. Just my $.02.

I skimmed over the stock header part.  The opening of them is smaller than the actual exhaust port on the gt40p head.  Decent headers can be had on ebay for $60-$70. 

To the OP again, you ask about to much air for the stock computer and injectors.  Its absolutely too much and will run lean.  Even with the upgrades stated on a speed density computer you are still going to want an adjustable fuel pressure regulator and bump up the pressure to compensate for what the computer wont be able too.

Speed density doesn't like change in volumetric efficiency without tuning that table. More information on that here

http://support.moates.net/theory-speed-density/

Also if your AOD is in decent condition what you're planning to run on it should be ok when you go to adjust your TV Cable just pull it slightly tighter you will have a little longer and harder shifts but it keeps the pressure up. I've run the stock AOD in mine with countless 150 shots of nitrous and lately 10 psi plus nitrous. I'm sure it will give up the ghost someday but not today and it's held on for over a year still shifting great.

I agree with others on the cam swap while you’re into it that far. If the Explorer intake is within your budget I say get that also. An Explorer TB can be converted to work as well I think? Check your local Craigslist and the Mustang forums. You may find what you need there. Good luck and keep us posted
I like the sound of the Ford B cam but I don’t think the SO pistons will allow it and it would require switching to MAF. Although a member on here is running 1 currently.

No worries about the misinterpretations. I appreciate all of the insight. I think most folks opt for doing a full HO setup when they are in the position I am in, and I understand that it's not a huge stretch to take my build in that direction. As CougarSE and ThunderbirdSport302 mentioned, all I would need is a speed density EEC and an HO cam. My reservations about going this route are:

A) I'm hesitant about sticking in a used camshaft. If I opt for a new one I imagine I'll be spending at least $150 on a stock spec roller cam.

B) I'd still have to go out and get new roller rockers and pushrods regardless of whether I go used or new on the cam. Add another $150 and time to the budget?

So, I'm not ruling it completely out but you can see where my reservations are. CougarSE, you mentioned that the stock computer couldn't handle these mods. Which mods do you think are taking it over the edge and what do you think could be scaled back to make it work?

To address A), if it helps put your mind at ease, I've taken the exact same HO cam that I pulled out of my 88 GT probably around a hundred years ago and installed it another 4 motors, that all eventually evolved over time from mid output to high output to super??high output when they got HCI and stroker internals. So yeah that poor HO cam got around, alot. The factory HO cams, in addition to being good performers, are very durable and rarely are damaged unless there is a failure of the oiling system or an equally rare failure of the stock roller lifters. It just doesnt happen often at all.

For B), the standard output 5.0 has the gray 14lb/hr injectors and the standard output ECU is running the car on an assumed injector flowrate of 14lb/hr.  So all of its fuel calc's will be off if an injector with a diff flowrate is installed. Same goes for the Mustang or Mk7 speed density ECU, you're pretty much locked into using the 19lb/hr injector with it.

To put it bluntly, the explorer heads and intake are a waste of time to install if the standard output cam, injectors and ECU are utilized. If the budget or labor are getting in the way of swapping these items and adding a good fuel pump, its better to wait until they can be sourced and added to the build.

Vintage is exactly right.

I have some pink top bosch injectors and a speed density HO computer laying around somewhere I'd be willing to part with if you needed them. Maybe a speed density HO camshaft too just PM me.

My buddy has what he thinks is an early 90's cobra roller cam he says he'll just give to me. I'll hit you up about the computer and injectors, Outsidedog. You guys have convinced me to take the build farther since I already have a lot of the parts. I was also able to get an explorer GT40 upper and lower, along with new fuel rails for $45 yesterday. They are very clean and recently painted as well. I think I got a killer deal. Any suggestions on which rockers and pushrods to buy?

I meant roller lifters, not rockers

As with the HO cam, the factory Ford roller lifters are completely fine to utilize in used condition assuming they came from a clean, non gunked up engine. Ford designed these for a very long service life. I've tore down well maintained HO motors with over a quarter million miles on the factory roller lifters. Looked nearly new and still functioned perfectly fine. Oil changes every 3K miles is the reason.

 Like anything else new or used that goes into your engine, they should be clean, closely inspected. I do this with brand new oil pumps, roller rockers, gaskets, everything. I have rejected new, out of the plastic, parts before because of defects.

You did great scoring the explorer intake for under 50. Go out and find some of the regular 3 bar GT40s for under $100 so you can use regular headers and you might even make OutsideDog cry!  :shakeass:

I do envy a nice budget build haha and I'll help out however I can. (I sent you a message CowboyKiller) You don't need thousands of dollars  to have a solid fast everyday driver just a little patience and a place to take stuff apart.

Used HO cams are usually good to go assuming the engine wasn't oil starved (mine weren't).

I'll look for it in a bit, let me know if you want it, like I said, if it's here, you can have 'er for the stamps ;)

Anything you do to increase airflow, basically every performance mod.  The old HO speed density systems could make good power and were tunable but had no provisions to adapt like the MAF cars did.  The combination of heads and intake are your worst offenders but the most desirable for performance.  Adding the Cobra cam is a great Idea, even with stock 1.6 rockers it has a greater profile than a stock HO cam.  At this point you need to run a MAF system or HO speed density with the fuel pressure turned up or call an SCT shop and tell them what you have and get an HO computer tuned.  When I say fuel pressure turned up I mean running the 19lb injectors too.  This is pretty much the setup I had on my car at first and it ran incredible.

Stock computer on sd can compensate up to 10% for general wear and tear. We have e10 which takes up 7% for fuel correction, so you really only have 3% to compensate as far as fuel goes.

I like e10, I bump the timing up to like 14 or 16° and get a bit of the power back.

I'd like to pick your guys brains about this cam I just picked up from my buddy. It's definitely a Mustang cam because it's got ZE engraved between the the distributor gear and the first lobe. The only other marking it has is on the last cam bearing journal (flat side). There is an etching that says "20:52" and underneath it says "02/16/94". I assume these are time and date stamps. Being that I can't find any other markings on this cam, how can I tell if it's a Cobra or HO cam, and does it matter? I was able to find these specs to compare the two but can't tell how different these cams are from one another:

91-95 GT:
Lift: .278 intake, .278 exhaust
Duration: 276 intake, 266 exhaust
Overlap: 39 degrees, 19.51 factor
Lobe Center: 116 intake, 115 exhaust

93-95 Cobra:
Lift: .282 intake, .282 exhaust
Duration: 270 intake, 270 exhaust
Overlap: 33.5 degrees, 15.24 factor
Lobe Center: 115 intake, 121.5 exhaust

Another question: The cam has been sitting for awhile and has accumulated some surface rust. If I were to use this cam would it be recommended to clean in up in my blast cabinet using walnut shell?

Thanks!

While I would like to see something to confirm any kind of adaptive strategy for speed density the combo he is describing is way beyond 10% a stock HO EEC e7 headed 302.

93-95 Cobra cam and 86-95 HO cam are so close that a SD HO computer won't care which one you use.

As the story goes, during the devlopment phase of the Cobra engine program, the Ford engineers were looking to restore some of the torque lost compartively to the regular HO engine due to the higher flow capacity Gt40 heads and manifold being used.

If you compare the numbers, it bears this out. The lift at the lobe is pretty much the same, although the Cobra is multiplying this lobe lift by 1.7 rockers instead of the standard HO 1.6 rocker. This gives it an effective valve lift around .479" as compared to the HO's 444".  The additional valve lift helps flow only as much as the valve/port/chamber allows for. Since the Gt40 has a slightly larger as-cast intake port and a 1.84" intake valve vs the 1.78" intake valve, it is better suited to benefit from the additional airflow across the valve, from the added lift.

The 1.7 rocker ratio has the added benefit of speeding up the movement of the valve. Effectively, it is a way of adding a more aggressive ramp on the lobe of the cam without actually putting the aggressiveness where the roller lifters feel it. Overly cautious concerns about valvetrain noise if you ask me, but noone from Ford asked me, so there you are. The valvespring do feel some additional strain from the added rate and lift of the 1.7 rocker ratio but it is easily handled by aftermarket springs. If you look at the factory Cobra heads, they employ a different valvespring with an inner damper spring that the HO heads do not.

Next, duration. Duration on the Cobra cam has been shortened on the intake side and extended on the exhaust side. Why? Again, to better suit the flow characteristics of the cross sectionally larger Cobra intake and heads. The Ford engineers were aware that adding the larger Gt40 parts was changing the negative pressure wave in the intake tract. The cam revision is their attempt to retune a wave that worked with the larger ports and plenum and maintain velocity across the valve. On the exhaust side, since additonal airflow and fuel would create more power and more exhaust gasses, the duration of the exhaust was lengthened keeping the exhaust valve open slightly longer to ensure sufficient time for the piston to push enough exhaust past the valve that it wouldnt remain in the cylinder and spoil the next incoming intake charge on the subsequent combustion event.

The cam overlap was shortened also. This is the brief time where both the intake and exhaust valves are open, or overlapping. The intake on its way to opening, the exhaust on its way to closing. This crossflow effect helps draw some of the intake charge into the cylinder due to the vacuum effect of exhaust scavenging. Basically, working in concert with the pressure drop of the piston, on its way down, creating a pressure drop in the cylinder that ordinary atmospheric pressure immediately attempts to fill or equalize, which brings the air and fuel in past the open intake valve. There is a downside to excessive overlap, and it can cost power due to some lost intake charge, compression, etc. Shortening duration on either intake or exhaust lobes also shortens overlap.

Not sure if this will be of any help..

Edit, apparently I'm missing the chart that would be "page 1"....
I saved this from somebody here, maybe Paul posted it many many moons ago?

Fellas, speed density uses fixed lookup tables for its timing and fuel strategy for a given set of conditions including load,rpm,manifold pressure, etc. Its stuck on picking a strategy from the lookup tables,  based on comparing the info it is seeing from the various engine sensors, it then selects its strategy. Operating under either closed loop or open loop, it cannot "adapt" or choose something outside of what is contained within the preprogrammed lookup tables it has to work with. Thats it.

That said, the speed density system is plenty capable of running the engine in a very wide range of conditions and climates which is a testament to the strength of its programming and design. It was state of the art in the eighties and still an effective means of engine management today. Yes, it has limitations and once reached, a change to the mass air system is absolutely the right move.

But for what the OP has repeatedly given for expectations and intended use of the vehicle, speed density will cover his needs and budget. Handily.

All that's moot anyway if he wants a cam that's above an HO or '94/'95 Cobra. The cam itself won't give a rat's ass whether it's speed density or mass air, long as it's HO or Cobra. BUT...if he wants to run higher flow injectors (over 19#) he WILL need to go mass air or else have a chip burnt for his EEC, and that means an SD1. I don't think the Mark 7 EECs had provisions for a tuner chip, unless they open them up and directly solder them to the board (i don't know).

And you're right, there's a hell of a lot of fast-assed cars running SD setups. For a country boy hundreds of miles from a tuner shop, I simply got what I needed and made mine mass air, probably came out money ahead, but the logistics was the deciding factor. When I did the build, money and time wasn't an issue.

Yep, thats true. The thing to keep in mind however is that if you look at the flow numbers for unmodified Gt40 heads is that they pretty much level off at a little over .400" valve lift. It hardly improves from .400 to .500 and lifting the valve even past that becomes really pointless. So with the stock cam having roughly .444 valve lift using the stock 1.6 rocker ratio, its right where the flow starts leveling off.

Honestly, I've always ported my own heads and intakes including more Ho and Gt40 heads then I care to recall way before I even considered swapping from an Ho cam to aftermarket. The low hanging fruit on the 5.0 are the cylinder heads and intake. Per dollar or per hour of labor, that is where the most impressive improvements to the entire powerband are to be had. The other benefit not often talked about is the reduced pumping losses and better fuel mileage that is attained with the improved efficiency.

Ironically, this also allows more of the fuel to be redirected towards increased engine power instead of being wasted overcoming engine pumping losses, with the increase being better the higher the engine speed is.

The stacking effect of gathering all these improvements together can result in an engine with the stock Ho cam that quite easily outpowers the engine with unported heads but with a performance cam. Not just at one rpm point but everywhere on the curve and by an embarrassingly noticeable amount when on the street or track.

Wouldn't let me add pictures in the PM so here's what I'll be sending you these are the injectors and computer I ran before I switched over to MAF. Also I had a Jet chip for this computer I'll send with it not sure it did anything performance wise but I have no use for it.

Thanks again for the hookup, Outsidedog!

Another questions for you guys regarding this swap. Do you guys generally leave the EGR system stock when doing this swap? If not, what do you need to change to keep things running smooth? I don't believe emissions will be an issue since I've had this car registered and inspected before and they gave me an emissions exempt sticker. If it helps to keep the system stock I will do that though.

When I did the swap from S.O. to H.O. I used a 70 mm bbk throttle body with egr spacer and left the egr on it and plugged in, actually passed emissions pretty easily too. Just retarded the timing and aired up the rear tires to 60 lbs.

Speaking of throttle bodies, I've been thinking a lot about which units to use here and I'd like to get ya'lls thoughts.

A) Since I'm upgrading to a GT40 intake I'm imagining I have around a 70mm opening to work with. That said, if I take advantage of the opening size is it worth spending the money on an aftermarket throttle body/EGR spacer? I'm sure that acquire a stock explorer combo would be cheap but it looks like getting the linkage right and having to re-route the air intake tube due to the different orientation of this setup might be a pain in the ass.

B) I could stick with a stock 87'-93' HO throttle body and EGR spacer for cost and simplicity sake. I've read that they bolt right up to the GT40 upper. Is this true and will I be sacrificing anything by using a stock 60mm size.

I guess the general theme of my question is, for my build what throttle opening size is ideal? 60mm, 65, or 70mm?

There is no appreciable power gains to be had by anything larger than a 87-93 Mustang 60mm throttle body and Egr spacer at your engine's level of airflow.

There is a place for larger throttle bodies but it simply isnt on near stock engines. Multiple independent dyno and track tests over the years have borne that out. Save your money for better, more effective mods and improvements.

Just as an FYI, the explorer upper intakes that I have measured have a stock throttle body opening of 67-68mm. Ditto for the Cobra uppers that I have measured. The additional size is fine for use with a stock HO 60mm throttle body and Egr spacer.

Vendors sell lots of throttle bodys for the same reason they sell a lot of cold air kits, its easy to bolt on and the customer convinces himself during the subsequent test drive that he realized a sizable power gain because he paid a couple hundred for it. Wouldve been better off throwin the $200 in a jar and putting some more with it each week or month to buy some good heads/intake and/or port work to same.

Sounds good to me! That's less money I have to spend, so I like it. I'll start searching around for a good deal on a stock HO throttle body and spacer now!

After you get it running what are your plans with it? Daily driver ? Any power adders or racing in it's future? Sorry if you already answered I didn't read back through the posts

If you're adding GT40 heads and a HO cam to a stock 86-88 short block be sure to check piston to valve clearance. Better to know if you need to cut some piston valve reliefs than finding out when you bend all the valves the first time you rotate the engine over :hick:.

I'll def check PTV clearance once I start tearing into this thing. My intentions for this car are for it to be a fair weather driver. I like how comfortable it is for long trips so I'll probably try to get some of that in too.

Right on man looks like you're well on your way, a stock 60mm mustang throttle body will be perfect. and let us know about the piston to valve clearance with that setup just so I know because I'm curious. I assume it will be fine but never done it.

It should def always be checked but I've done it years ago with an 86 GT. It had the flat top piston with no valve reliefs or dish. Using the stock 86 GT cam and Gt40 heads off a 93-5 Cobra. It ran surprisingly strong for a fairly basic bolt-on car using a ported HO lower and extrude honed upper intake. I still have that upper intake, come to think of it, haha.

Cowboy, you might want to shop around the cost of having a quick cleanup port job on the lower intake. Someone local and experienced should be able to pickup some torque and horsepower from the midrange rpm's to wherever your shiftpoint is at. Money well spent for a budget build. The intake is already off the car, there is no better to time to get it done then now.

What does this porting job typically cost?

You need to get ahold of Tom Moss and have him port it.  He ported my lower Cobra intake and it was like night and day on the dyno.  I believe his email is mosstpsa"at"sbcglobal.net (put the "at" in there in lieu of the symbol) and this should direct you to their website (took a minute to load up).

http://tmossporting.0catch.com/

I had heard Tom Moss turned that business over to his son, not sure. He is good at what he does though.  Anyhow, if you go that route, there is the cost of shipping the intake both ways, plus the cost of the porting, which I imagine is somewhere around $150 or so by itself.

What I would do, unless you live in the middle of Nowhere, Nebraska.. is check around at your local machine shops, cylinder head shops, speed shops if you have any in your town or the local dragstrip if you don't.

 Usually one or two locals names will keep coming up as the guy who knows his . Get his number or webpage and dont be afraid to ask questions and see some of his work.

 A good port guy will usually stay busy, dont be surprised or discouraged if the there is a 2 or 3 week backlog. Quality work takes time.

The advantage here is, if you find someone good thats local, you can get the intake done and for your intended use of the car, get some basic tricks done on the heads. Nothing crazy, just basic bowl/valve seat/chamber work and light transitioning into the ports is it. For mild street engines, the basic porting tricks is where probably 75% of the potential power gains are to be had.  If you can get that, without paying shipping, plus the added benefit of the head work, you'll have lifted both the engine's power and fuel efficiency levels. Thats what its all about.

Need an HO TB and EGR? I'm yo' guy..lol.

So Tom has turned the "business" over to his son but is still doing quality checks and has been doing this for a couple years now.  All I can say is the proof in the work and quality is in the shear number of intakes they have done over the years and the work he did on mine was outstanding and picked up on the dyno.  Do a Google search on Tom and you will find hundreds of satisfied customers.  Just didn't what them to get any kind of a bad rep here being that his son had taken the business over as evidently the quality translated.

ThunderbirdSport302, I ended up picking up a BBK 65mm TB and EGR spacer combo for a decent deal. Thank you for letting me know though.

No worries dude :)