[racinrc14]

Hey guys,

I've been lurking around and doing a lot of reading, but I need advice. I have a '90 GT Convertible that I just recently acquired from a friend. This is my first fox body 5.0. I have worked on cars, and in fact, I am a machinist/welder for the USAF. The car has a 347 bottom end with a completely stock top end. I mean stock. injectors, intake, cam, heads, etc.. The car was an automatic and has had a 5-speed installed (still has the AOD computer). I really want to make this car a nice daily driver, but I'm not convinced that I posess the know-how to buy the correct equipment and tune the car (EEC) myself. The car currently runs, but not what I would call good. It seems to "fall off" above idle under load. It does buck a little also when lugged at low RPM. Things I am planning on doing to the car between now and summer: Cam, exhaust. Im probably going to leave the heads alone, but I'm not sure. My question is this, would I be better off having a chip burned after I get the parts on the car and all back together since once that's done, I will probably never change anything else on the car, or should I invest in the tuning hardware and software to tune it myself? I am not a computer programmer, nor do I wish to be, and I find the idea of getting into the computer and tweaking numbers to be very intimidating. We also only have one professional tuner here in town, that I know of, and he primarily does hot rods and race cars, so I'm pretty sure I can't afford him. Thanks for taking the time to read this, and I appreciate any help or insight you all might have.

-Tommy

[decipha]

Tommy, welcome to the forum

if the top end is still stock including the MAF then the stock tune should run it as good as stock being the only change is an additional 45 cubic inches which is nothing

the MAF and the injectors is what controls your fueling so you should be fine there

it sounds like the hegos are faulty/bad, how old are they? do you have a check engine light?

the heads are the most restrictive component on a stock 302 much less a 347, the heads should be the first thing changed in any hot rodder's 5.0 even if all else stays stock

if tuning is not in your interest then your best bet is to just get a tune from someone, as i stated though, being that its still stock it should run like stock, so figure out your mechanical/electrical issues first

as long as nothing changes significantly in the future all those future mods can be written into a tune that you can still utilize now, i'd highly recommend it, the fox tunes are crap from the factory

theres quite a few members here that can get you situated, anyone with "professional tuner / shop owner" in their avatar, or if you want i can send you something, i do mail order tunes all the time

btw, i recommend changing your thread title to be a little more descriptive before the "police" come along and say something, theres a thread in the newbie section that has some good pointers for thread titles, maybe something along the lines of "stock 5.0 tune" would be a good title?

[cgrey8]

As decipha pointed out, your choice of title suggests you haven't read the getting started thread at the top of every forum on this site. Here's the link to that thread:
How to get started and Best Practices

...The car has a 347 bottom end with a completely stock top end. I mean stock. injectors, intake, cam, heads, etc...

I'm amazed someone would've spent the money on a 347 stroker and gone back together with 100% stock long block components. Obviously it happens. I'm just curious how someone comes to decisions like that. Regardless, that's a nice starting point to begin a build. But stock injectors and MAF are not a good idea if mods are in the plans.

...The car was an automatic and has had a 5-speed installed (still has the AOD computer). I really want to make this car a nice daily driver,...

There are idle strategy differences between manual and automatic transmission tunes. Usually you notice it more running a manual trans tune on an automatic than the other way around.

What's the catch-code on the computer? Put that into your user profile signature so it shows up below all your posts.

...I'm not convinced that I posess the know-how to buy the correct equipment and tune the car (EEC) myself...

Regardless of whether you have the know-how or not, the good news is you know that and can learn everything you need IF you have the time, budget, and desire to do so. Read over that link I posted above. Between it and the other threads it references, you'll begin learning what it is you don't know, what you need to know, and how to begin your education into DIY tuning if you decide that's the best route for you.

.....The car currently runs, but not what I would call good. It seems to "fall off" above idle under load. It does buck a little also when lugged at low RPM...

This would be a new discussion you would want to post here if you decide to make the leap into DIY tuning. Without the equipment to tune and datalog, all we can offer are opinions and anecdotal information.

...Things I am planning on doing to the car between now and summer: Cam, exhaust. Im probably going to leave the heads alone, but I'm not sure...

Do you already know what it is you will be buying? Or are you also looking for advice there too? In order to know what will serve you best for a cam, we would need to know what your intentions are for the vehicle and what you are willing to sacrifice.

To give you an idea, a mild cam will give you more off-idle torque, solid low RPM idle, and decent responsiveness. But you sacrifice top-end HP. If you care more about optimizing performance, then you may sacrifice things like fuel economy, stock-stable RPMs, and low RPM torque.

Add to this, will you be upgrading the valve train with a stronger (and higher lift) spring package and Roller Rockers? If not, this will severely limit your cam options and thus the resulting performance.

Are you wanting to run regular gasoline or is it acceptable to run premium only? Without knowledge about what kind of pistons, deck clearance, or head gasket thickness your engine was built with, it's impossible to be sure exactly what the compression is. But it sounds like it might be a little on the high side...or it just means the spark table needs to be calmed down in the detonation areas. But a more aggressive cam can actually help here to get the Dynamic Compression Ratio (DCR) lower.

I'm sure none of these things are surprising, but if they haven't been considered, they are all things you should think about before selecting a cam.

But I agree with decipha, the first thing to go should be the heads. Cam and exhaust will help, but not like ditching the stock heads. Ditching the heads will also give you a chance to do some measurements of what you are dealing with inside such as the piston type & deck clearance of the pistons. Those are VERY valuable pieces of info when making an INFORMED decision on heads and cam.

Again, it all just depends on what your intentions and expectations for the car are.

...would I be better off having a chip burned after I get the parts on the car and all back together since once that's done, I will probably never change anything else on the car, or should I invest in the tuning hardware and software to tune it myself? I am not a computer programmer, nor do I wish to be, and I find the idea of getting into the computer and tweaking numbers to be very intimidating. We also only have one professional tuner here in town, that I know of, and he primarily does hot rods and race cars, so I'm pretty sure I can't afford him...

Only you can answer this question. But after you read through the attached link above and the recommended associated links, you should have enough info to make that determination.

[racinrc14]

Thanks Decipha. Changed as requested.

I don't have a MIL, but to be honest, I'm not sure that the PE might not have 'disabled' it. I will look into that next time I'm with the car. The car had sat for a considerable amount of time and now that I think about it, the problem could definitley be the O2's and even old stale gas. I will definitely be a little more 'thorough' before my next attempt at diagnosis.

The thought of modifying profiles in the EEC terrifies me. I have no rationale for this, except that me and computers (of any kind) don't hang. So I will likely just buy a tune that gets me close and call it good. I appreciate your input, and I will be calling/emailing you soon. Thanks,

-Tommy

[EDS50]

Thanks Decipha. Changed as requested.

I don't have a MIL, but to be honest, I'm not sure that the PE might not have 'disabled' it. I will look into that next time I'm with the car. The car had sat for a considerable amount of time and now that I think about it, the problem could definitley be the O2's and even old stale gas. I will definitely be a little more 'thorough' before my next attempt at diagnosis.

The thought of modifying profiles in the EEC terrifies me. I have no rationale for this, except that me and computers (of any kind) don't hang. So I will likely just buy a tune that gets me close and call it good. I appreciate your input, and I will be calling/emailing you soon. Thanks,

-Tommy

Someone may have pulled the bulb for the mil.

[Stengun]

Howdy Tommy,

I'm new at all this tuning stuff and it can be a little overwhelming at times.

I'm also an "Ol' School" engine guy and before you do any tuning you need to do the basics first like a major tune up especially since you just got the car and it sit for a while.

You need to replace the plugs, dist cap and rotor, plug wires, clean the TB and put fresh premium gas ( ethanol free ) in the tank and go from there.

Plus you can go to Autozone and they can pull all the trouble codes for free.

Paul

[racinrc14]

Thanks Paul. I have done exactly as you suggested and the car actually runs just as Decipha has suggested it would; like a stock 5.0. Pretty good now actually.

Decipha, I have a few questions for you, expect a PM shortly...