Need some help (Upgrades on me 93 GT)

[Ray@VSK]

Hey guys just got me another Mustang (4th one now) and need help figuring out what everything I should or will need to do, I already got Ram Air, Pulleys, DriveShaft, Shifter, 3:55's & 2.5 Off Road with Flows, I have yet to start doing everything else yet do to some concerns I had possibly running into problems, I got a new Polished Cobra intake, Aluminum GT40 Y303 Heads, May 1/58 Headers & 24# Injectors & was going to leave the stock cam because of the extra work & $ involved in doing so is this a bad idea or should I change the cam as well, I meen from my research cams are very inexpensive but have such little performance gain & require alot of other things to be changed, I was going to be reusing my stock Rocker Arms (1.6 I do beleive they are) & Stock Pushrods, is this ok ? I meen can I use these rockers & pushrods on these heads considering I'm not changing the cam ? another thing, stock mass air flow & stock throttle body, these do I need to change, I was thinking za 65 mm throttlebody, what's stock 60 ? last thing I have offroad hpipes on her right now with flowmasters but with yearly emmisions tests here I was wondering would it be best to drop some catbacks in there, if so what is not only a good performing but best sounding set ?

My Car

 

[samuraichamploo]

460 swap.

 

[Ray@VSK]

Seriously, any help would be greatly appreciated

 

[Gearbanger 101]

Wow…lotsa questions.

Lets see…if you’re going to tear it down to add heads and intake, you may as well install a new cam. True that a cam change with little or no mods isn’t worth a lot of power, but you’ve got enough breathing mods to justify a new bumpstick. A valve spring change would be a good idea, but If the Y303 heads were complete, then I’d imagine that the springs that came with them will suffice for most street grinds.
I suggest the use one of the CompCams Xtreme series dual pattern cams over that of the old Ford “Alphabet” cams. Any of the CompCams will be better suited to your needs and will outperform the Ford cams at every RPM. You could re-use the old rockers, but I’d suggest an upgrade to a set of more accurate 1.6 roller rockers if money permits. The stock pushrods should be OK as well, but again if you’ve got the extra money, you could always upgrade there as well.

Now, you don’t need no necessarily change the T/B and MAF, but your engines full potential won’t be realized unless you do. I’d suggest a 65mm T/B and 76mm MAF would provide ample gains and still allow you to retain all drivability and low-end torque.

The exhaust issue I’m afraid isn’t really just cut and dry. You’ll get a dozen opinions on what kind of exhaust you should be running and all of them will probably be equally as good. Adding in some cats to your existing H-pipe would be the least expensive rout. Bassani just came out with a new compact high flow design, but Magnaflow also makes a nice set that’s more competitively priced.

 

[Ray@VSK]

I'm looking for the best bang for the buck, Heads are the biggest bottleneck in the Mustangs so I got a set of like new, never fired GT40 Y303's from ford racing (Take Offs) for only $750 with valves & springs, then a new polished cobra upper & lower intake off ebay for $400, I wanted dual scoop hood for looks & figured for only $175 more I could get the Ram air kit for it aswell, I also got a set of mac shorty headers & some 24# injectors, I'm not trying to make a race car but make a really good everyday mustang, everything else I listed was already done when I got it but I have no catylac converters right now so I figured I would just take off the off roads & flows & throw on some catbacks so I can pass emissions, if I get a cam will I need to get different pushrods or rocker arms or anything else, I know rocker arms don't do much when it comes to performance & would like to just reuse the stock ones that are on it now to save some $ & get a 65mm throttlebody & maybe a better mass airflow what's your suggestion there ?

btw does anyone know what stock throttle & mass air sizes are in mm ?

 

[Gearbanger 101]

Just to clear something up for you. A Cat-Back isn't a type of catalectic converter; it's everything from the mid-pipe (H-pipe in your case) back. It consists of the flow tubes, mufflers and usually tailpipes. The most inexpensive way of doing it would be to add converters to your current H-pipe like the ones I suggested in my earlier reply. The Catback and Flowmasters have nothing to do with emissions control.

You do not need to get different pushrods or rocker arms in order to change the camshaft, but doing so will net you slightly better gains and durability...but again, it's not mandatory. Aftermarket roller rockers, though do gain you a little performance in the sense that they're considerably more accurate than the stock stamped steel arms (which can vary in ratio), which will make the most use out of a cam change and their roller fulcrum and tip reduce valve train wear and friction, allowing the engine to rev out more evenly during acceleration. But this can always be done at a later date.

Pretty much any 65mm throttle body would be a good start (although Mac should be avoided due to poor quality) with Accufab likely being the best and most expensive of the bunch. They'll all produce about the same amount of horsepower, so buy based on quality, not performance. The stock unit is 60mm (actually around 59-59.5mm). I'd go with either a C&L or PRO-M 73-76mm MAF calibrated to your injectors. You'll probably best realize the T/B and MAF gains when installed together, so it would be best if you saved up until you could afford both of them.

Anything else you’d like to know?

 

[Ray@VSK]

The Catback and Flowmasters have nothing to do with emissions control.

Anything else you’d like to know?

I thought cats were mandatory do to emmisions am I wrong here, if so I already got a great exhaust just thought I had to have catylac converters or catbacks or something since my stock catylac converters have been removed, am I mistaken or just missunderstanding you ?

Last one, so I'm clear, I can just bolt & go right, I meen everything I listed is compatible with each other & don't require additional work or anything then right ?

Thanks alot man you've been beyond helpful

 

[Gearbanger 101]

True, you need catalectic converters to pass emissions, but catalectic converters and a Cat-back are two totally separate parts of the exhaust. Catalectic converters are located on your mid-pipes (that’s the part of the exhaust that bots to the header and ends near where your drive shaft meets the rear end) as seen here…..

A Cat-back is the section that bolts on after your mid-pipes, and consist mainly of mufflers (in your case Flowmasters) and tailpipes, as seen here….

Does that clear it up a bit?

As for the rest of the parts, yes they’re all compatible with one and other, but never is anything just bolt on and go. There are always little gremlins and such that tend to rear their ugly head when you start a project this big. But just ask questions as you go….it makes things a lot easier. A good rule of thumb is to take your projected cost of your mods and add another half to it before the project is finished, just to leave room for the little inconsistencies. You may come off lucky and not need to worry about it, but it’s better to be prepared in advance, than to run out of money mod project and have it sit until you’ve accumulated more.

 

[Ray@VSK]

But I thought Cat Backs were performance replacements for catylac converters, meening if you remove your catylac converters & install catbacks you'll not need catylac converters no more thus the difference between catbacks & mufflers guess not, Thanks again.

 

[5spd GT]

But I thought Cat Backs & Mufflers were 2 different things, same in theory but I thought Cat Backs were performance replacements for catylac converters, meening if you remove your catylac converters & install catbacks you'll not need catylac converters thus the difference between catbacks & mufflers & still be ok on emissions ?

The mufflers are on the cat-back system...alls a cat-back is...is two pipes coming from your h-pipe (bolts up to h-pipe) and leads to two mufflers (one on each side) and then the pipes goes over the axle and out the back...

You can buy mufflers seperatly and weld into your cat-back in replace of the mufflers already on your cat-back to get a different sound...

A cat-back is like an extended version of a muffler...

If you go under your car you will see the complete exhaust system broken up into 3 areas...the first one is your manifolds (also called headers) that are bolted against your heads in the engine compartment...

Next you have the h-pipe (stock has catalytic convertors on it) which bolts up to the bottom of those manifolds...hard to see...

And thirdly at the end of that h-pipe (towards middle back of car)...there are 4 bolts that bolt the h-pipe up to the actual catback which is that pipes that run to the back of the car with mufflers right before the rearend...

The mufflers on the cat-back do not prevent "smog" getting out to pollute the air...they are just their to quite the whole system down...alls you got to do is unbolt the mufflers and you will see how loud the car gets without that cat-back on there...

An offroad h-pipe is the "performance replacement" for your catalytic convertors...because it cancels the convertors out...they are no longer on your car...and have less restriction for exhaust flow which make it the "performance replacement"...

 

[Gearbanger 101]

But I thought Cat Backs were performance replacements for catylac converters, meening if you remove your catylac converters & install catbacks you'll not need catylac converters no more thus the difference between catbacks & mufflers guess not, Thanks again.

Nope....the term "Cat-Back" signifies the exhaust system from the catalectic section of the exhaust system, back to the rear of the car...hence the name.

Catalectic converters control emissions, where as mufflers (located within most cat-backs) control sound. Two different entities! You can buy a performance Cat-Back exhaust, but they’re only a power/sound-altering item, they do nothing for emissions.

 

[Ray@VSK]

Ooh now I see, guess I was misinformed, thanks for clearing that up for me

 

[5spd GT]

Ooh now I see, guess I was misinformed, thanks for clearing that up for me

Yep...you already have mufflers...no need for more

 

[Ray@VSK]

btw check out this deal I found http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=6654

GT40 Aluminum Y303 Heads for $385.00, I got some & was a bit weary about what I might get but upon receival I opened em up & they were brand new heads with valves & springs just swirl marks from being bolted on a block but never started