Started tearing the rustang down today, going to borrow my brothers cherry picker and pull the engine next weekend. Planning on switching it to a carb setup. Figured while I have it apart this winter I would swap the heads as well since that would yield the biggest power increases. Figure I will pick the heads first; intake, carb, and cam to match.

Really trying not to spend more than $1k on the pair. Thus far I am considering:
Trickflow - $1200, obviously top end of the budget but very good heads
Edlebrock Performer - $1000 or so, good all around from what I understand
Ford Floo Tech - $700 or so, not sure of the quality
ProComp - crap brand but very cheap, have seen a couple good writeups, couple bad ones
GT40P - could heavily port them and they would still be the cheapest, dont like the spark plug angle issue.

This really could be an endless list, so much info out there it seems to be a nightmare to narrow it down. Planning on talking with my machinist this week to see what he might recommend. Anyone have any experience?

[Edited on October 11, 2009 at 8:25 PM. Reason : ...]

10/11/2009 8:24:35 PM

edlebrock is the only way to go IMO. Ive never had the slightest of trouble out of any of their products.

[Edited on October 11, 2009 at 8:28 PM. Reason : lol]

10/11/2009 8:28:15 PM

GT40P

K.I.C.S (CHEAP)

10/11/2009 9:45:31 PM

Your mom.

10/12/2009 1:27:18 AM

Quote :

"Planning on switching it to a carb setup."

why? i've never understood why people do this, other than they don't understand f.i. and refuse to learn.

10/12/2009 8:08:38 AM

^ I'll second

[Edited on October 12, 2009 at 8:12 AM. Reason : at least on the factory provided engine]

10/12/2009 8:12:16 AM

as an admitted mechanical noob...what's the advantage of a carburetor over a fuel-injection setup? isn't fuel injection more efficient and more powerful? i guess a carb is simpler and cheaper...

10/12/2009 8:14:38 AM

Quote :

"i guess a carb is simpler and cheaper..."

years ago, sure. not really the case anymore, though.

10/12/2009 8:26:08 AM

Anybody who switches from fuel injection to carb oughta have their balls cut off. Pussies.

10/12/2009 9:02:30 AM

does a fuel injection system take up more space and add considerable weight? why do lower-end motorcycles still come with carbs if they're no more expensive?

10/12/2009 10:08:14 AM

Quote :

"Anybody who switches from fuel injection to carb oughta have their balls cut off. Pussies."

switching to the carb to simplify things and in this case it is cheaper. this car is a speed density car, does not have mass air. in other words a PITA to tune. likely cost me another $500 to change it to mass air and I still have to pay someone a couple hundred bucks to tune it each time i change something significant.

figure cost to stay with efi
tb = 200
intake = 500
mass air conversion = 500
tune = 200, more each time i significantly alter something, and not willing to learn this myself. too easy to demolish an engine with a small screw up.
= $1400


cost to go carb
carb = 250, my machinist even has one he might give me a deal or trade on, so this might be $0
intake = 200
mechanical fuel pump = 50
fuel line = 100
initial tune = 150
misc linkages and brackets = 100
= $600 - $850

doesnt take a fucking genious to do the math, youll need to get off your high horses and either offer your advice on the initial question or keep your damn opinions to yourselves. cant ever ask a question in here without getting bashed, its ridiculous.

[Edited on October 12, 2009 at 12:53 PM. Reason : ...]

10/12/2009 12:52:33 PM

Quote :

"this car is a speed density car, does not have mass air. in other words a PITA to tune."

Is there available and affordable software for DIY speed density tuning, without resorting to piggybacks? I tried some google searches and had no luck. If they have Hondata style software for it I'd be willing to help you tune it. For speed density I've done turbo Hondas and cammed (equivalent) twin turbo turbo rotaries. n/a engines are a walk in the park. Maybe you just need a ROM burner. I've been meaning to pick one up.

the biggest problem with going carb is the shitty gas mileage and driveability, not to mention the lack of precise timing control. And cammed engines drive and idle a lot better if you know what to do with the timing and how to adjust the IACV.

10/12/2009 1:24:42 PM

most of what I have seen are like SCT's and do a piggy back style. I appreciate the offer, I live in Hickory unfortunately. The other catch is the dyno time to really tune it. I do expect driveability to suffer quite a bit but then again this car is only the road to the drags and back. Even considering trailering it.

10/12/2009 1:32:43 PM

I agree with arghx.

If there is anything for mustangs comparable to any of the Honda software (even the free stuff) its a walk in the park. I'm sure they have a few large hills in hickory you can use for a "dyno".

10/12/2009 1:45:43 PM

So I downloaded the TwEECer software for reprogramming Ford ECU's http://www.tweecer.com/ . It seems to have a lot of capabilities once you get the software set up right. I loaded up the stock calibration for the DA1 speed density computer:


one of the main 3D spark timing tables


2D idle timing map


Volumetric efficiency table for speed density fuel calculations


cooling fan control tables. Damn, I didn't realize these things were programmed to run so hot. A lot of OEM cooling fans come on at low speed at 95 C (203 F) from the factory.

The package without realtime tuning is something like $350 and the one with realtime tuning (presumably has an onboard ROM emulator) is $550. That's not bad at all, and it can log analog inputs (wideband). So you'd need another $250-300 for that. I'm not sure why you'd need a different intake manifold or TB, is that for the MAF conversion? Figure $900 for everything if did DIY tuning. I will say though, most of the information out there is for the A9P MAF ecu, the table names are a little different on this ECU. If you didn't have anyone to help you it could be pretty tough on a cammed engine.

[Edited on October 12, 2009 at 4:29 PM. Reason : when I built my car I thought I'd hardly drive it. I ended up trying to make it really streetable]

10/12/2009 4:26:11 PM

^thanks for all the research. Ive read through a good bit of your buildup thread, you obviously know what your doing. Reason for replacing the manifold is performance not for the conversion. The stocker is choked down pretty good. Your comment about the cammed engine is one I hear quite a bit. Quite a few mustang only sites will tell you straight forward that SD on a cammed engine is a nightmare.

As far as driveability I have already made it nearly unstreetable, mickey thompson ets, a spool, and a gutted interior will do that to ya. wipers dont work and the headlights are a joke too lol.


Also quick update from my machinist. Hes really pushing me to let him do all the work, not something i plan on doing. But he is pushing just doing a race port on the stocker heads. Claims a guaranteed 400hp. Not sure I believe that when I have seen so much info to the contrary. Also claims the the forged pistons that year are a piece of crap up until 89 or so. Recommended a full rebuild regardless of who did the work.

10/12/2009 4:59:41 PM

[50pager]

Quote :

"Quite a few mustang only sites will tell you straight forward that SD on a cammed engine is a nightmare."

Now I only know what I can see in the software, but it seems that few people have bothered to do a lot of testing and research on the speed density ECU tables given the lack of detailed information about it. The lack of information seems to be an inherent problem at least on naturally aspirated builds. Besides normal variations in the weather, on any cammed motor the biggest driveability problem stems from the weaker vacuum signal. On a speed density system, less vacuum is determined to be more engine load. The cam reduces the vacuum signal resulting in a lot more fuel being dumped in. From the factory my Rx-7 typically does about 18 inches of mercury at a 750 rpm idle. With the aggressive street porting/"camming" I have going on, at that rpm I get maybe 8 inches, and so I prefer to idle at 850 or so where I can pull 12 inches. So the low vacuum is the root of the rich idle problem on cammed speed density engines.

The idle can also surge depending on how the throttlebody and IACV are configured. The normal procedure on an engine with that IACV design (duty controlled plunger valve) is to first unplug the IACV. The idle will drop, and the engine may even cut off. You would adjust the idle manually by turning a bypass air screw on the throttlebody so that the engine idles perhaps 100-200rpm lower than you would like it to. You may even have to adjust the throttle plate opening angle with the stop screw on the throttlebody. Then you may have to add IACV duty cyle to stabilize idle, and there is a scaling (transfer) function for this in the speed density ECU. But what's really tricky is the IACV control logic on deceleration. Just reading through some of the instructions for this EEC/5.0 tuning software I can see that a cammed engine can confuse the IACV circuit on deceleration, resulting in stalls or surges without some tuning. The speed density IACV control tables are actually a lot simpler than the MAF based ones.

The next major tuning issue you run into on a cammed engine may be bucking during part throttle. The increased overlap between intake and exhaust stroke necessitates increased ignition timing advance under idle and low load. At idle my Rx-7 runs at -5 degrees BTDC (5 ATDC), but with the additional overlap it needs at least 15 more degrees of advance (10 degrees BTDC minimum) for stability. Examine some stock Honda VTEC timing maps and you can see their use of additional timing advance even during lower rpm/load conditions.

On turbo cars, the whole MAF vs MAP deal is debated to death by people who read too many forum posts. IMO it is kind of like trading one set of problems for the other. Each sensor has to be scaled ,you need a new MAP sensor that can read boost or a MAF that can read more grams/sec. That scaling presents its own unique set of problems for either system. Right now I can't figure out if they let you edit the MAP sensor calibration table in the DA1 ECU. MAP sensor calibrations may initially seem straightforward enough. More voltage = more pressure, a mostly linear 0-5v function.

On some speed density systems it can get tricky though as barometric pressure changes, either for altitude or natural fluctuations in ambient conditions. OEM computers adjust the MAP reading to compensate for changes in barometric pressure usually by having a barometric pressure sensor built into the ECU itself. I have never seen an aftermarket standalone do this--not AEM, not Haltech, not Apex'i, nobody. So you can have some problems if you change altitudes. On turbo setups it can get really frustrating when your ECU reads one pressure reading, your boost gauge reads another, and your electronic boost controller reads another. So which do you believe?

MAFs can be a bitch if you have changed the intake system. Flapper and hotwire type air sensor outputs have exponential functions so that they will be more precise under low load, emissions controlled driving.



But that can be a pretty big pain in the ass when you are trying to adjust your scaling for WOT. The design of the MAF housing and other aspects of the intake systems can cause a lot of problems. All the ECU's fuel calculations assume that the MAF is reading accurately and precisely. When you start modifying a car there are problems with both MAF and MAP systems. The OEM's don't have these issues because all their parts work together and they have enough information to calculate everything out properly. When you're working on something you put together in your garage you end up having to do a lot of "guess and check" and "good enough" tuning.

[/50pager]

[Edited on October 12, 2009 at 8:01 PM. Reason : .]

10/12/2009 7:51:12 PM

BBC + lots of spray


nuff said.

10/12/2009 8:11:39 PM

leaks and burns to much oil^

10/12/2009 10:01:57 PM

you could try to find a set of GT40 3 bar heads, no funky spark plug issues. I run them and they are impressive over E7's with some 1.7 roller rockers.

10/13/2009 2:33:19 AM

^thats one I am def considering.

10/13/2009 6:17:24 AM

Mas air conversion is not $500 it is a $50 harness then you jsut need a junkyard ECM and a mass air. When I used to work on Mustangs, people would saiy they were switching to carb, the conversation ended. Unless they were building a track only car with 400+cubic inches then maybe...

And edelbrock, not the highest power but the lack of hassles is worth it. Brodix if you can afford it.

GT40Ps are not bad for a stock head but need alot of work before they are as good as any aftermarket head, plus you woudl still needs bigger valves, plus better springs and such.

10/13/2009 6:54:47 AM

^and different headers correct?

Figured a good set of performers are good for 45hp? GT40's maybe 20?

10/13/2009 12:30:56 PM

hmmm all this money into this thing now. i think i would have just bought a done up one. but if ur having fun wasting money on what's been done 10000000's of times already...totally go for it.

10/13/2009 1:59:53 PM

message_topic.aspx?topic=520621

10/13/2009 2:30:32 PM

^ouch

^^and yes not a cheap hobby as most of you in here know. small price to pay for my sanity.

10/13/2009 5:49:48 PM

Eh. Don't worry about it RyaNCSU1... As long as you don't wreck it into a tree, people won't give you too much hell for it.

10/13/2009 6:53:14 PM

have you tried craigslist, might get some head off there??????

10/13/2009 7:47:26 PM

Quote :

"doesnt take a fucking genious to do the math, youll need to get off your high horses and either offer your advice on the initial question or keep your damn opinions to yourselves. cant ever ask a question in here without getting bashed, its ridiculous."

you know, i would think someone running slower times than a dodge caravan might would be a little more open minded to the good advice being given here. then again, i'm no "genious" so wtf do i know. i'm sure this is another worthwhile mod to get out of the 10's and maybe trap somewhere faster than the speed limit. you've got it figured out, we'll just keep our mouths shut from now on, lol.

10/13/2009 9:43:51 PM

fuckin 10's

10/13/2009 10:01:19 PM

where can you get a decent 5.0 intake, even carb, for $200???? I kept my shit fi, but I paid $300 even for a used gt-40 manifold, which is by no means that great of an intake compared to a holley or an edelbrock.

10/14/2009 12:05:13 AM

Carbs suck stay efi.... get decent efi manifold.

10/14/2009 12:23:07 AM

there is a bunch of good FI stuff on CL and HPJ right now. if you are gonna go with GT40 heads. just spray the piss out of it.

10/14/2009 12:34:35 AM

your mom gives the best head

10/14/2009 12:39:38 AM

^^ god i hate spray...

effing cheating..

10/14/2009 12:45:24 AM

naw its only cheating when you dont tell. other than that its fun to feel your car pull harder

[Edited on October 14, 2009 at 12:50 AM. Reason : lol]

10/14/2009 12:49:07 AM

i keep reading FI as forced induction

10/14/2009 12:54:35 AM

EFI

10/14/2009 1:14:25 AM

trick flow top end /thread

10/14/2009 2:38:31 PM

Anyone know for sure if heads with 2.02" intake valves and 1.60" exhaust valves fit a stock 87 sbf bottom end? Worried about valve to piston clearance. Figure cam lift at about .520.

10/16/2009 4:05:16 PM

see if you cant find desktop dyno or something

10/16/2009 4:12:58 PM

ive had those numbers before on a stock bottom end out of an 89. youre fine

10/16/2009 6:36:44 PM

^thanks, figure i will check the clearance just to be sure when i put it together, just didnt want to be stuck with heads i cant use.

10/16/2009 9:17:22 PM

if you want to REALLY be sure. put some clay on a cylinder and turn the crank by hand with the heads not bolted down

10/17/2009 2:01:09 AM

or not be a trailer park ass nigger and use a dial indicator or a depth micrometer like someone who builds real engines

10/19/2009 9:13:50 AM