rdw401

I was just wondering if a tune is required or helpful if I am just adding a new pair of GTAs to my GT? Next I am going with the x-pipe. No CAI yet.

Will the GTAs alone add hp, without at tune? Does the Shelby-H or GT have a special tune? If they do, would some Ford dealers be willng to load it on if I get the same exhaust and CAI?

blkstang06

GTA's add HP! ...Mine didn't. The Tune question is a good one! I would assume its the standard Ford Racing tune that comes with the performance pack!!....

Doug@C&L

Yeah, there is a tune for it but not until you add a CAI.....

theedge67

Just adding the GTA's will not gain you any measurable HP, the stock exhaust flows very well as it is.

m05fastbackGT

Agreed, not even a straight flow through design such as the FRPP/Stingers have been determined to produce more than up to 5HP over stock, if even that ? let alone going with the GTA's which are still considered as a chambered muffler.. So If your expecting to gain anything over the stock muffler other than sound and perhaps shave a couple of lbs. in weight ? Your more than likely going to end up pretty disapointed..

metroplex

The CAI kit by itself will add horsepower/torque because it gets rid of the restrictive MAF and upper airbox housing. The extra power/torque comes from the typical CAI tune that switches to different timing values optimized for 91-93 octane gas. I bet if Ford used something like the Saleen air intake box for all stock GTs, the GT would be making around 315-320 fwhp stock: larger MAF and low restriction airbox lid.

theedge67

If Ford did everything it could to make HP in the GT, there would be no aftermarket. I, along with many others, enjoy the fact that I can easily and inexpensively add HP to my car in my garage with my own hands. If the only thing I could to do make more HP was a $6000 supercharger, that would take some of the fun out of the car IMO. Even though I have not yet added anything performance-wise, dreaming about it keeps me happy (not to mention coming back to this wonderful website!!)

metroplex

I would prefer Ford attempt to make reliable horsepower out of the production vehicles. I'll most likely keep the Stang stock for at least 5 years or until the warranty runs out. I've been down the path of aftermarket mods and I'll just let everyone else do the beta testing.

m05fastbackGT

You seem to be forgetting some very important factors..One, the stock airbox that's used on both the Saleen and Shelby GT500 have to be larger in order to allow more airflow to enter the intake manifold due to forced induction from running it's factory supercharger..However on a naturally aspirated stock Mustang GT ? you might see up to 280 and maybe 285 Max hp. with a tune if your lucky but if you think your going to come even close to 315-320 HP just because you now have a larger stock airbox ? not only is that unrealistically impossible but insane..Not even the largest aftermarket cold air intakes are capable of producing 315-320 HP by themselves with a computer reflash You also seem to forget the stock air lid is still considered an air restriction because airflow is still not aimed directly towards the air filter itself thanks to the very same flat design as the stock GT.. So where you come up with this unrealistic claim of the stock airbox lid as being low restricted ? is way beyond my comprehension and let's also not forget the inlet tube is still also considered an air restriction as well being it also has the same curved bends and the very same ridges inside the tube as the stock Mustang GT which again reduces airflow from reaching the intake manifold..Therefore I'm sorry to have to say this but If I were you ? I'd think twice before placing such a bet

YaoNYC

i think metroplex was referring to 315-320hp flywheel???

metroplex

The Saleen uses the stock airbox bottom, but swaps out the airbox lid and inlet tube. The stock airbox lid has a very small MAF housing and the stock air intake transfer function is more suitable for a 200 fwhp Crown Vic than a 300 fwhp Mustang GT.

The stock air inlet tube is NOT a restriction. The ridges do not have a significant effect on restriction contrary to what some hack aftermarket vendor tries to tell you. A respected CAI vendor once told me not to worry about retuning becaue the adaptive fuel system would compensate for the change in the air transfer function.

The restrictions in the stock intake system are the airbox lid (needs to be raised more), the MAF housing tube, and the MAF itself.

metroplex

Correct. I've seen some dyno figures of around 285 rwhp with a CAI and tune, so that puts the fwhp at around 330-334 fwhp. The paper panel filter is not a restriction, and Saleen only modifies the airbox lid, MAF housing, and MAF for their supercharger intake. The GT500 paper panel filter has comparable dimensions to the GT paper panel filter, and again the airbox lid is raised, has a larger MAF housing, and a different MAF with an air transfer function resolution suited for a supercharged application (it would still work with a naturally aspirated engine though!).

LBJay

The Roush and Saleen kits both use the stock air box




Saleen only ups the size of the MAF tube with their 475HP Boost Upgrade Kit.

metroplex

Thanks for the clarification LBJay! So it seems the stock airbox + paper panel filter has even greater potential than I originally believed!

theedge67

Well it has the ABILITY to flow a lot of air I'm sure, if you put a sufficiently large vacuum behind it! The key here is being able to flow a lot of air with ease. A panel filter will flow air, but a conical filter (k&n style) will flow it easier.

m05fastbackGT

Fine, I may agree with you if the airbox lid is designed to improve airflow.. However ? when it comes to the stock air inlet tube ? not only do I disagree but the hundreds and perhaps even thousands of other forum members who use aftermarket intakes will also disagree as well and of course Ford is going to tell you their stock airbox and inlet tubes for either the Shelby GT500 and the Saleen are not airflow restrictive ? being that Ford doesn't want their customers modifying their vehicles to begin with for warranty purposes..As for the 315-320 HP range you mentioned ? sure I can go along with that, providing you're referring from at the crank and not rear wheel HP But on the other hand ? an aftermarket intake will provide even more and the FRPP cold air intake is no longer considered as aftermarket, I can provide you with a Ford dealership who both installs them and includes them as part of the factory warranty

metroplex

So do you have a few thousand dyno graphs showing the supposed 8-10+ hp gains from JUST swapping the air inlet tubes? The ribs on the stock air inlet tube are designed to make the tube a bit more rigid, and to reduce NVH. The stock airbox LID and the stock MAF are, IMHO, restrictive for a N/A application.

m05fastbackGT

Who said anything about 8-10 Hp gains from just swapping air inlet tubes Metroplex ? so don't even attempt to put words in my mouth, I clearly stated the ribs and bends on the stock tube reduce airflow from reaching the intake manifold and that those who use aftermarket intakes as well as myself don't share in your opinion and yes tuners such as Doug and Brenspeed's dyno testing do confirm this in the higher RPM band or don't you remember the test results I sent you comparing the C&L intake with the STEEDA ? in which his results clearly confirm
The steeda worked great but fell short above 5,000 rpm’s, most likely due to the lack of aftermarket inlet pipe.
Now I suppose that in your opinion Brenspeed is also full of it right ? As I previously mentioned before, I personally don't know exactly how much more HP an aftermarket inlet tube provides ? but even a 2-5 HP increase is a major improvement over stock in which I'll say once again..MORE AIR = MORE POWER And once again Metroplex ? Saleen designed the stock airbox exclusively for Supercharged applications and not for Naturally Aspirated ones..Therefore there would be very little to be gained if anything at all if you were to replace the Mustang's stock airbox with Saleen's..What I recommend is this ? why don't you contact Saleen and ask for their opinion at least this way, you'll know for sure one way or the other...

metroplex

Please do add some more question marks. I'm not sure you used enough. The stock air inlet tube is not a restriction. The stock airbox lid and stock MAF/housing ARE restrictions. The Saleen upgraded airbox lid and MAF looks to be an excellent design. The resolution of the air transfer function may be suited for supercharged applications (same way as the 90mm Lightning MAF is to a naturally aspirated Mustang) or it may not. However, you incorrectly said, "Therefore there would be very little to be gained if anything at all if you were to replace the Mustang's stock airbox with Saleen's.." The Saleen unit uses a revised airbox lid and larger MAF housing.

On the 4.6 2V Panthers, going to a revised airbox lid with a larger MAF housing can yield a 15-20 fwhp gain over the stock airbox. Raising the roof of the airbox lid increases the volume of that plenum which can effectively increase the amount of airflow going into the engine. On the other hand, the ribs on the stock air inlet tube are not restrictions regardless of how many question marks you use.

metroplex

..

I read that report, and it was pure speculation that it was from the lack of an aftermarket inlet pipe. I've tried straighter and larger diameter inlet pipes on 4.6 2V V8s without any change in power output. The MAF sensor is upstream of the air inlet tube, so unless you stick a hydrocarbon filter in the tube right next and downstream of the MAF, it won't affect the air transfer function. Most people buy into the aftermarket inlet tubes because they look cooler and should provide smoother flow. Been there, done that... it's all a marketing gimmick unless your engine has serious air requirements.

#1 reason to market a CAI kit with a conical air filter with a shiny inlet tube: It sells faster than an "ugly" zytel nylon airbox using a boring paper panel filter and ribbed rubber inlet tube.