Question on 94-95 Mods

[dads95gt]

My son Steve-O is up at Wyotech taking the Chassis Fab & Hi Performance Engine elective. He would like to do a H-C-I swap such as Trick Flow or similar on the 95GT. After all I have read in MM&FF or 5.0 Mustang about the computer issues on the 94-95's I am not convinced. What issues will we have if I agree to do this? What else is necessary besides the H-C-I package? The GT currently has a CAI, BBK H pipe w/cats and Flowmaster American Thunder cat back. Steve has run a 14.07 with drag radials(stock gears). Any input would be appreciated.

[Killercanary]

I'm running out the door now but I'll type a book for you later LOL! It is true that the 94-95 EEC is a little finicky, but its nothing to shy away from. I'll be home after 5pm and will tell you more then.

[yeahloh95]

do it just get a cam with a 114 centerline and you should be ok then plan on a tune to dial it in

[Killercanary]

My son Steve-O is up at Wyotech taking the Chassis Fab & Hi Performance Engine elective. He would like to do a H-C-I swap such as Trick Flow or similar on the 95GT. After all I have read in MM&FF or 5.0 Mustang about the computer issues on the 94-95's I am not convinced. What issues will we have if I agree to do this? What else is necessary besides the H-C-I package? The GT currently has a CAI, BBK H pipe w/cats and Flowmaster American Thunder cat back. Steve has run a 14.07 with drag radials(stock gears). Any input would be appreciated.

The most common issue that comes from a buildup such as this is that the EEC doesn't like a cam swap. The 94-95 EEC differed from the fox body's A9L in that it is a load based setup. The A9L was more of an RPM based one. The 94-95 EEC uses mostly the mass air voltage signal (an a few other things like TPS, vehicle speed sensor, etc) to determine how much load the car is seeing. Think of load as the amount of starin the engine is seeing. Example- driving on a flat road at a steady speed have very little load compared to driving up a mountain. The engine has to work harder to accelerate and even maintain speed. During the steady cruise on a flat road the EEC will see that the throttle is barely open (TPS voltage will be low), there isn't a lot of air flow coming in through the MAF as shown by the voltage, and the vehicle speed is constant. The EEC will then use the lower values of load in the spark and fuel tables to determine how much of each it needs. Now when climbing a steep hill the throttle may be wide open, but the EEC will see that the air coming into the engine isn't increasing as fast as it should if it had no load, it will also see that the vehicle speed isn't increasing very fast given a wide open throttle. This is HIGH load. The computer will takes the readings from these sensors and determine how much load this is and then look at that cell in its fuel and spark tables to determine how much of each it should use.

Now that you have an understanding of this, let me explain why these EEC's are touchy. There are two things here to concider. First is that when you do a HCI setup you will also be changing injectors. The way that this is usually done is by buying a "calibrated" MAF. All a calibrated mass air sensor is one that alters the voltage from what the stock sensor would send for the same airflow. It does this to "trick" the EEC into thinking that less air is entering the egine than there really is. The EEC then shortens up the pulsewidth (or time that the injector is open) so that less fuel is delivered. Since you will be running larger than stock injectors at this point, they will still flow more fuel than the stockers did. Its all a balancing act in terms of getting this right, but IMO Professional Mass Air systems have the best track record. C&L does this by using sampling tubes that either speed up or slow the amount of air that passes over the MAF wires. I do NOT like this method as there are a number of other things that can effect this like MAF clocking, bends in the tubing before the MAF can lead to high and low velocity areas inside of the MAF, etc. Anyway... The reason this can have a negative effect on the 94-95's is because the EEC is using that voltage to determine load, if you trick it and send a different voltage to shorten the pulse width, you also decrease the load that the EEC thinks its actually seeing. Now don't worry too much about this as there are thousands of guys running like this (I am) without troubles. You would think that the larger injector you have the more problems you would see with this, but lots of guys are running 42's without a problem.

The second problem is with the cam. There is a LOT of speculation on this. Most will tell you to stick with a cam that has an LSA at or higher than stock, but I don't like this way of thinking. These types of cams are good for power adders, but they are not the best at producing NA horsepower. I run a 110* LSA in my car. It gave me fits when I first installed it. Typically the car will develop the "surge and die syndrome" where it hunts for an idle and eventually stalls because it can't find one. The more overlap you have the worse the problem seems to be. This may be due to decreased vacuum, reverb (exhaust gases backing up into the intake at low RPM), etc. The way i fixed mine was to bump the idle speed to 850-900rpms and cut some puslewidth back at idle. My method of thinking is this, don't sell your combo short by picking a "safe" cam. Make up you mind to get the cam that will make the most power for the given combo and just plan on needing to tune around it.

For tuning options you can get a custom burnt chip, or get soemthing like a PMS, twEECer, EEC Tuner, etc and tune it yourself. You will find that a lot of 94-95 owners choose this route because a lot of tuners are not familiar with the 94-95 EEC's. What ever you do, do not get talked into getting the PIH that alows you to convert to a A9L. The A9l was good in its day, but its slower and not as sofisticated as the 94-95's EEC. Plus, the PIH will run you at least $600 and in the end all you'll have is a stock A9L in your car.

[Killercanary]

As for what else is necessary with a HCI... here's some of what you'll need or should change.

-roller rockers
-timing chain
-fuel pump
-MAF
-injectors
-possibly a fuel pressure regulator
-some sort of tuning devise
-head gaskets
-intake gasket
-timing cover gasket
-thermostat and gasket
-headers and gaskets (I'd also do locking header bolts)
-head bolts or studs
-new rear gear ratio to match the combo

As for which HCI combo is right for you, it will all depend on how much power you want, how the car is driven (daily or weekend street/strip terror), what RPM range you want and how high you want to shift it, will this be going on the stock bottom end, etc.

I REALLY like AFR165's for stock short block applications. they work great out of the box, they provide great flow AND velocity which is great in a street car, and they allow for some decent cam choices without too much piston to valve clearance issues.

[yeahloh95]

yeah what he said

[dads95gt]

Thanks for all the info. I was thinking of a kit like the Trick Flow Street Heat. From what I have seen or read Holley, Edelbrock and Ford all have kits also. The Trick Flow seems to be the most complete though. They are all about the same price. It seems that in addition to the kit I would need lifters, MAF, injectors, fuel pump, headers and a tuner at a minimum. I don't know enough to mix and match components. A kit seems the safest way to go unless we start out with heads and slowly build it up. Something to think about. Thanks

[Steve-0]

Ok so I took a look at the kit and the things from your list that it doesnt come with are as follows: Fuel pump, MAF, injectors,fuel pressure regulator(maybe), tuning device of some sort,t-stat and gasket,headers, and maybe gears. What do you recommend as far as fuel pump and injectors go? Also what about a bigger tb? My dad, if he goes for it, is leaning towards the trick flow street engine package. Comes with most of the things needed and is relatively cheap. Thanks for all the help so far.

Also, you got a link to a MAF that I can look at that would work?

[cam303]

Pure stock has a harness and a computer that he got for the 94 he used to have to convert a 94-95 to an a9l computer. If you are interested in it I am sure he would be willing to sell it. I think it was made by pro-m.

[Killercanary]

Ok so I took a look at the kit and the things from your list that it doesnt come with are as follows: Fuel pump, MAF, injectors,fuel pressure regulator(maybe), tuning device of some sort,t-stat and gasket,headers, and maybe gears. What do you recommend as far as fuel pump and injectors go? Also what about a bigger tb? My dad, if he goes for it, is leaning towards the trick flow street engine package. Comes with most of the things needed and is relatively cheap. Thanks for all the help so far.

Also, you got a link to a MAF that I can look at that would work?

Fuel pump- I'd get a Walbro GSS340 high volume 255lph. Its a little over kill for a basic HCI package, but it'll allow you to grow. For injectors, 24's are perfect for the typical 302 with a simple HCI setup, but they will not allow you to grow. I run 24's because when I built my old combo I never thought I'd do any more with the car. Now that I'm going to be running a stroker I will be coming up short on the injectors. The one benefit of running 24's is that you run that at a high fuel pressure than the 30's, which promotes greater fuel atomization and usually that means power. Honestly, I haven't seen much of a difference in power from combos with 24's versus 30's.

Throttle body- Get which ever size matches the intake he chooses. I chose a 65mm FMS throttle body because it was fine size wise for my combo and it is the best quality TB you can buy. It also comes with new sensors.

Dollar for dollar the TF kit is very hard to beat. Just make absolutely sure you know how to setup the valvetrain geometry correctly or you WILL have valve guide wear issues with TF heads.

Here is the MAF I'd run: The 80mm unit.
http://www.massairsystems.com/

Cam303 is refering to the PIH I mentioned above.

[Steve-0]

Ok, well we decided what we are going to do with the car. My dad ordered headers already and is only waiting to decide what cam to go with. We arent sure what to pick, as we are afraid of clearance issues with the pistons. So far we are going with a trick flow street heat intake, Im going to port the heads in school as much as I can. I will be flow benching them before and after. There are way too many cams out for us to make a decision on, so what are everyones recommendations? And do you think 24lb injectors would be enough? And you think we need a pump too? And I think a 80mm MAF might be a little bit big for this combo as well, but thats just a guess. Thanks for any help you can give me.

[RUSH2112]

Ok, well we decided what we are going to do with the car. My dad ordered headers already and is only waiting to decide what cam to go with. We arent sure what to pick, as we are afraid of clearance issues with the pistons. So far we are going with a trick flow street heat intake, Im going to port the heads in school as much as I can. I will be flow benching them before and after. There are way too many cams out for us to make a decision on, so what are everyones recommendations? And do you think 24lb injectors would be enough? And you think we need a pump too? And I think a 80mm MAF might be a little bit big for this combo as well, but thats just a guess. Thanks for any help you can give me.

I am going through the same choices right now. There are alot of good people on here with excellent knowledge and first hand experience with many different specific parts and general applications. I don't have much advice and cannot speak from experience but for what it's worth, this is what I have heard several dozen times:

1) Choose your cam wisely. There are hundereds of them out there and picking the right cam is important. Depending on what you want to do with your car, a custom cam (while a little more expensive) might be an option over to the 'off-the-shelf' brands.

2) 24# injectors will be more than adequate for your setup. Unless you intend on cramming more air into the engine (turbo, supercharger), then they'll be just fine.

3) As far as the fuel pump, I would go as big as possible. When my stock pump kicked the bucket a few months ago, I opted for a 255lph BBK (Walbro) pump. It is definitely too much for my current measly setup, but allows for room of growth for bigger and better things. For the price difference of a 190 or 255 fuel pump, go with the 255lph.

I hope this helps and is accurate (i've been known to talk complete ignorance when it comes to cars, but I am learning and try to listen well )

Finally, most importantly, take your time and plan out a budget with a top spending $$ amount. If you have a limitless $$$ amount, then you'll never get done with the project. Good luck and hope everything turns out well.

[Stangman701]

Ok, well we decided what we are going to do with the car. My dad ordered headers already and is only waiting to decide what cam to go with. We arent sure what to pick, as we are afraid of clearance issues with the pistons. So far we are going with a trick flow street heat intake, Im going to port the heads in school as much as I can. I will be flow benching them before and after. There are way too many cams out for us to make a decision on, so what are everyones recommendations? And do you think 24lb injectors would be enough? And you think we need a pump too? And I think a 80mm MAF might be a little bit big for this combo as well, but thats just a guess. Thanks for any help you can give me.

I got a set of stock heads you guys can have if you want to practice the porting a little first

[Steve-0]

I am going through the same choices right now. There are alot of good people on here with excellent knowledge and first hand experience with many different specific parts and general applications. I don't have much advice and cannot speak from experience but for what it's worth, this is what I have heard several dozen times:

1) Choose your cam wisely. There are hundereds of them out there and picking the right cam is important. Depending on what you want to do with your car, a custom cam (while a little more expensive) might be an option over to the 'off-the-shelf' brands.

2) 24# injectors will be more than adequate for your setup. Unless you intend on cramming more air into the engine (turbo, supercharger), then they'll be just fine.

3) As far as the fuel pump, I would go as big as possible. When my stock pump kicked the bucket a few months ago, I opted for a 255lph BBK (Walbro) pump. It is definitely too much for my current measly setup, but allows for room of growth for bigger and better things. For the price difference of a 190 or 255 fuel pump, go with the 255lph.

I hope this helps and is accurate (i've been known to talk complete ignorance when it comes to cars, but I am learning and try to listen well )

Finally, most importantly, take your time and plan out a budget with a top spending $$ amount. If you have a limitless $$$ amount, then you'll never get done with the project. Good luck and hope everything turns out well.

Hey thanks for information, the more opinions we can get the better.

I got a set of stock heads you guys can have if you want to practice the porting a little first

I could probably take em, but I should be alright. Im probably gonna end up port matching them, smoothing out all the burrs it has, then maybe do a 3 or 5 angle valve job on the valves. Also probably going to replace the stock springs out for some stiffer ones. The port work should get the heads close to some of the lesser aluminum ones flow wise. Weight is a whole other story, but youll have that. In the end I should be able to shave a few pounds off each head, but thats about it. Guess the flow bench and dyno will be the judge in the end.

[Killercanary]

Ok, well we decided what we are going to do with the car. My dad ordered headers already and is only waiting to decide what cam to go with. We arent sure what to pick, as we are afraid of clearance issues with the pistons. So far we are going with a trick flow street heat intake, Im going to port the heads in school as much as I can. I will be flow benching them before and after. There are way too many cams out for us to make a decision on, so what are everyones recommendations? And do you think 24lb injectors would be enough? And you think we need a pump too? And I think a 80mm MAF might be a little bit big for this combo as well, but thats just a guess. Thanks for any help you can give me.

Honestly, if you are going to use the stock heads (even ported) I'd leave the cam alone. The 94-95's can be a bit temperamental with cam swaps and I really don't see the possibility of loss of drive-ability being made up for by any sizable amount of HP. I could be wrong, but I wouldn't waste my time and/or money on a cam swap with stock heads, ESPECIALLY if you don't want to budget in some sort of tuning devise for the EEC.

I also wouldn't waste time or money on porting the stock heads, but that's your call. If you are set on doing your own check out this link as it could be VERY useful to you:
http://www.cmc.net/~xero/Mousesporting.html

Most of us have thought about this when we had stock stuff on our cars, but in the end the pay-off just doesn't seem worth the time, trouble, and money (head gaskets and bolts) IMO. I also do not like the trick flow street heat intakes. They just don't seem to put up the numbers that others do. For a stock headed car my pick is always the edelbrock performer intake. It will also allow you to grow a little as you can always swap on a RPM I or typhoon upper onto it later which has shorter runners which help promote higher RPM breathing. Its an old design, but it still is one of the best in its class.

24lb injectors will be good for your planned combo, but you could probably get away with the stockers since I doubt you'll make more than 240-250rwhp MAX. As for the MAF, its one item I feel you can never go too big on. It can act as a restriction down the road if and when you step up the combo to better parts. Our stock MAF are larger than the fox body's inside diameter, so they flow a bit more. As for the fuel pump, that's a hard one to answer. You may get away with the stocker, (they flow a little more than the older fox's) but for the price you may as well upgrade the 10+yr old stocker.

I hope that helps.

[yeahloh95]

i agree the most power is to be had with an intake and throttle body along with headers. i liked my car with cobra intake and stock long block ,it ran really well "around 14.1 in the 1/4" with no drivablity problems.

[Steve-0]

i agree the most power is to be had with an intake and throttle body along with headers. i liked my car with cobra intake and stock long block ,it ran really well "around 14.1 in the 1/4" with no drivablity problems.

The car already runs faster than that with intake and exhaust.... so I dunno whats going on. Guess it will be my dads final decision based on all of this what we are going to do.

[Killercanary]

Your dad's car with stock untouched heads, an edelbrock intake, a homemade CAI, ASP aluminum underdrive pulleys, 3.73/4.10 gears, sticky tires, and full exhaust should be EASILY capable of sub 13.5's at over 101mph with a good driver. I went 13.83 at 98.55mph with the above mods in my then nealry 3800lb 'vert. I've seen two guys run in the 12's with very similar setups in 94-95 GTS coupes but they drove them like they stole them and had drag suspension and slicks.

[Stangman701]

The car already runs faster than that with intake and exhaust.... so I dunno whats going on. Guess it will be my dads final decision based on all of this what we are going to do.

C'mon Steve, talk him into getting some better heads . AFR 185's, new pistons and a big ole cam. Give that bad boy some lope

[Killercanary]

I like Ray's idea even better!!!