kingyboy

i just bought this car a few months ago i dont know much about the for modulars i dont know what all is done to it either but of the things i do know its been driven rough, it has bbk cold air intake, and long tube headers and a fuel chip with three settings that just makes it run stock lean or leaner. and it has what i was told 4:10 gears in it. i swapped the speedo gear and fixxed it a little bit was told a 23 tooth gear would correct the speedometer and i did a little bit... instalead of 30 mph off im now 15. i dont like the the top end it gets up and moves but quick to top out 115mph at 4700 rpm... 5th gear... i want to loose the 4:10's and put somthjng else in there so at 45 mph im not at 2100 rpm in 5th im not worried about lossing the acclrtion its a sohc cam but was looking to do a swap to dohc and blow it eventualy also its got cat delet and my muffler on the pass side rides against the drive shaft was going to put glass packs on it and do side pipes if anyone can help me out with ideas on what to do i would prefer to start with the gears its killing my gas milage...

kingyboy

also i was wonderj g if anyone has hear of a kit to convert a turbo to a centrifugal type supercharger... i have a brand new turbo thats too small to use for both left and right banks... i think its a .50 ar t03/04e flange i dont have it here due to me being in the military i left it in a storage unit at my last station


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SXGT

welcome! have have you done the basic tune ups for a new car purchase?

air filter
oil change
fuel filter change
spark plugs
sea foam cleaning on TB / fuel system cleaner


It sounds like you would be happier with 3.73 gears or maybe even 3.55 gears. Either option are much better than stock gears for that car but arent as hardcore as 4.10s

I suggest you get rid of the chip. Get a a good tuner. Instead of a DOHC swap, what most people do is a swap the heads and intake from the 99-04 GT. there is a chance this car already has that done. I can tell by looking at your intake.


also


POST PICS! we want to see your ride.

kingyboy

i have done all the tune up maint. i switched to full synthetic oil. and everything else is new for the fuel... i was look at some 3.55 gears for it but i dont want to buy a set and have the 4.10 sitting around i was hoping to find someone willing to trade i found one guy but he did not have what he said he did...whags the diff between the 99-04 cobras compared to the stock gt?


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kingyboy

sorry I know how that last part sounds... lol... what I was trying to ask about the gt and cobras is whats the differnce in the heads... originally I thought the cobras had the dohc 4v or do they have a sohc 3v. or would it be better if I just got a spare 2v and port and polish. im trying to gain a moderate hp range while also keeping as much stock parts... I heard the 4.6 bottom ends can only do a max hp of 400 hp before they peak out... by the time im done I would like to be around 380 hp with a supercharger with light mods


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SXGT

99-01 cobra has DOHC and upgraded ECU and upgraded cat back. the 03 - 04 is IRS, Eaton Super Charger at ...8psi ?? and forged internals. The 05 GT was the first 3 valve and has about 305hp.

the Mach 1 is DOHC too and about ~305 horsepower.

99-04 GT = 260 hp
99-01 Cobra = 300hp but 320hp if factory recall with ECU and catback
Mach 1 = ~305hp
03-04 Cobra = 390 HP


EDIT:

kingyboy

I beleave it has the stock intake on it I will get pics as soon as I can... I know its the sohc 16v 4.6l but im a little confussed as to our previous posts. I just want to clearify... I was wanting to do a dohc swap but in the one you sent I thought you said to forget that and swap for the 99-04 cobras... but those are dohc arent they or did I miss read the post? but aside from that, if I did keep the originals and port and polish and upgraded the valve springs and cam to ones more agressive what would be a recomendation for that as far as the valvesprings and cam to meet my goals? also the chip is not really as much as a chip as it seems... its tired in the the fcm and just changes the setting I figured if I go to blow it I could keep it and flash the setting to accomidate the supercharger... I was looking at a itsx programmer by sct that is bluetooth and for android phones but I have a blue tooth scanner and was also wondering if you know I could use the blooth scanner obd-ii and the programmer app?


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JC316

All Cobra's from 96+ are DOHC, but there are different versions of it. The 96-98 Cobra and the 93-98 Lincoln Mark VIII use the "B" head, which makes 305hp/300ftlbs of torque. The problem with these engines is that the intake ports are HUGE, which means that you have no port velocity, thus below 3500RPM, you have next to no power. The B head actually has two individual intake ports for the intake valves. Ford uses an Intake Manifold Runner Control, or IMRC to shut off one of the intake valves below 3500 to increase port velocity. Unfortunately, they don't work all that well, they have a tendency to get gummed up and stick. Most people choose to get a shorter rear end gear and delete them.

The real advantage to this engine is that it's cheap. You can get a Mark VIII engine and swap it for around $500 if you do your own labor.

The 99-01 Cobra is also DOHC, but it's the "C" head, it allegedly makes 320HP/300ftlbs, but is more like 305. This was a much better design and beats the B head engines in every way, from idle all the way up. Much more torque and power below 3500RPM. The Mach 1 also uses this engine, but with more compression, while they claim 305HP, it's a touch higher, more like the 320 that the Cobra is supposed to have.

The 03-04 cobra has C heads, but all forged internals from the factory and an Eaton M112 supercharger on top. Underrated at 390HP/390ftlbs.

Now the 99-04 GT is a SOHC 16V engine, but it has the Performance Improved, or PI heads. These engines make 260HP/300ftlbs of torque, but when used on an NPI block, it bumps compression and gives you about 270HP. This swap is common because it can be done for around $300 and gives you a significant HP increase. You also don't have to remove the engine to do this swap and requires no modifications.

Since you are looking for top end, I would go with a Mark VIII engine and keep the 4.10's

kingyboy

thanks for the input... its very helpfull...


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JC316

No problem. In answer to your internals question, the stock internals are good to around 400RWP, more if tuned properly. The blocks and crankshafts are incredibly strong, it's the rods and pistons that are weak.

Let me give you an idea on the power levels. My driving is terrible in all of these videos, but it gives you an idea.



96 GT. Bone stock. 0-60 roughly 7 seconds.

96 GT with Mark VIII engine. Bone stock otherwise, exhaust, 3.27 gears, everything. 0-60 is roughly 6 seconds.


98 GT. PI Swap, 3.73 Gears, LT headers, UDP's, CAI, ORH pipe with flowmasters. 0-60 roughly 6 seconds.


97 Cobra. ORH, flowmasters. 0-60 roughly 5.5 seconds with a very soft launch and slow 1-2 shift.