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Discussion Starter #1
I have an untouched 98 cobra and was wondering about a few mods. I want to change gears but I dont want to lose too much driveability as it is my daily driver. So would 3.73's or 4.10's be better? Also with changing gears is there any other things that should be changed to the car to cope with the gears? I have also heard of a programer that can adjust timing, adjust the computer to deal with gear and tire & wheel changes. I can't remember the name of the company that makes them and was wondering if anyone knew? Would it be better to get a chip than the programer or vice versa or could I use both? I also wanted to know if anyone know if an x-pipe put out more horses than an h-pipe or is it the other way around? Any other ideas for mods would be nice. Thanks.
 

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I'd get 4.10s in the Cobra. The DOHC loves to rev high, and the 4.10s get the engine into it's sweet spot nice and quick. If you change gears, you will need an Abbott E.R.A. (electronic radio adapter), It will correct your speedometer for any gear and tire/wheel changes.

I would stay AWAY from any sort of computer chip. The only computer chip I would ever consider would be a dyno-tuned & custom-burnt Autologic chip. But you wouldn't need one of those unless you do some serious mods (power adders, etc).

As for exhaust, I would get an off-road H pipe with a Flowmaster American Thunder catback. The H and X give you the same amount of power.
The H pipe and Flowmaster combo has the traditional "Mustang" sound, whereas the X pipe sounds like a raspy, tin can in my opinion. :barf:
 

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The 4.10s are an excellent choice. I have 3.73's in my '96 cobra and have found that it is just right with my supercharger. However, if I didn't have the vortech, I'd want more gear. I agree that you should avoid a computer chip until you have some serious mods. But, you will have to get the ERA in order to have your speedo correct.

Next, for exhaust, I too would recommend an offroad or high-flow catted H-pipe w/ flowmasters (or stick to your current cat-back and see how it sounds with the new H). I have sound clips and videos of my exhuast sound on my website (see sig). I have an H-pipe and 3-chamber flowmasters. I am really happy with the sound, but understand that it will be LOUD. With the offroad H, People will look up to see who that is ANYWHERE YOU GO. If you don't want this kind of attention, then go for a high-flow catted H pipe & the exhuast of your choice (I like flowmaster 3 or 2 chambers - give that "muscle car" sound when paired with an H pipe).

Next, consider some lowering springs. I have some before & after pics of my '96 cobra. This, too can be an expensive proposition, as ideally you want to replace the springs, shocks/struts, and get caster/camper plates to help with the alignment. This is more of an appearance mod, so do this if you want, but it won't help you run any better.

Have fun!
 

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Discussion Starter #4
Does anyone think a different/bigger mass air would help out at all? Can you use an aftermarket maf with cold air induction? I've heard that with like c&l it will screw up the readings. thanks for the input
 

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With 3.73's you won't need the ERA, just a 21 tooth speedo gear. 3.73's are a decent gear, but I can tell where a lower gear would be nice for drag racing. However, if you don't plan on running around on Drag Radials all the time, the lack of traction with any gear above 3.73's would get frustrating. I have some traction problems with my 3.73's on 265/40/17 street tires. If I had 4.10's or 4.30's it would be nothing but smoke in 1st and all of 2nd gear too.

The o/r H-pipe sounds good with some flowmasters. I used to have this same setup on my car until I went with Longtubes. The sound of the Magnaflows is alright, but nothing like the sound of flowmasters. If you are interested in an O/R h-pipe, I have my "old" o/r H-pipe(BBK) that has about 3k miles on it fot $125 shipped to your door. I bought it about 1 yr ago and I only drive the car about 4-5 months out of the year.

If interested email me at [email protected]

The O/R h made a definite difference in the mid/top end RPMs.

Steeda pulleys are also a nice addition in power. They free up between 5rwhp and 9rwhp across the entire RPM band. Each car/dyno facility seems to show slightly different numbers. The pulleys and H-pipe are proven power gainers though.

Good luck.

EDIT: Fixed my typo on the speedo gearing.
 

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blue88mustang said:
With 3.73's you won't need the ERA, just a 23 tooth speedo gear.
The correct speedo gear for 3.73's in a Cobra is 21 teeth (red).
 

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DO not use a speedo gear.

First, your speedo will not be completely on. It will still be a good bit off, enough to get you a ticket...as in my case :(


Second, speedo gears have been known to shred.


No matter what gears you do, get a speedcal.
 

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Good grief, of course he can use a speedo gear with 3.73s (DLF is correct -- 21-tooth is the one to get). Your speedo will read a few percent high - maybe 3 or 4 mph. And the gear won't "shred" -- that has been a problem with 23-tooth gears (which aren't even a Ford product) but the 21-tooth will be fine. Good luck!

Edit: forgot to mention that the 21-tooth gear/3.73 combo works for Cobras, not GTs. Their tranny setups are a bit different.
 

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cool, I didn't know the 21 tooth was any different. Sorry.


anyways, dude, even so, the speedcal is the right way to go. Especially if you ever change gears again or tire size, you can just set it to those specs. That's just my opinion though.
 

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Discussion Starter #10
I'm thinking about a tri-ax shifter anyone have any experience with them? Oh if I had 3.73's where would my rpm's be at oh say...65 mph in 4th gear? 4.10's at the same? If anyone knows it would be much appreciated.
 

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Actually the 21 tooth gear is pretty accurate. Its a Ford part and won't disintegrate like the 23 tooth part will (as it is a chrysler part) and the size is a little off and it will slowly start to loose some of the teeth. The 21 tooth gear is accurate because it was used in the Ranger 8.8" with the 3.73 gear option. My 98 Cobra with 3.73's, Bassani Xpipe with cats, UltraFlo mufflers, and a k&n on stock BFG's ran a 13.2 @105.8 mph, bumping against the rev limiter in 3rd gear crossing the traps. This was with a 2.17 60 ft. time. If you want to go higher (numerically) than 3.73's the next step up should be at least a 4.30 gear to get more use of 4th. With 4.10's you just get into 4th, the car gets in the cam and you just cross the traps. With 4.30's or 4.56's you get to use a lot of 4th gear. However, that being said, as one of the previous posts states you will need some sort of D/R as 1st and 2nd gear will go up in smoke. Dave.
 

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My recommendations, in order:

1. 4.10 gear, I use 23 tooth speedo gear, have had it for 2 years, 24000 miles. No probs. Reads about 5% high. Saves tickets. I get 25mpg. No traction probs with my 315x35x17s in back

2. Off road pipe, H or X... I've tried both, liked H better.

3. And then all other stuff. In my experience, all the noticeable gain came from the first two mods. You can do others. That's what's so neat about these cars. But, IMHO, the return you get in gains for anything else (other than power adders) is insignificant.

I didn't exactly stop after the first two, though, and I doubt you will either. Once you start to mod, you can't stop.

Later,
CW
 

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Like CW said.......
 

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I would do the following:

1. 4.30 gears-just right for the street and the strip. For quick
acceleration and responsiveness the 3.73's are a joke.
Also, 4.10's won't get the DOHC into its powerband quick
enough and will not pull like the 4.30's.

2. Drag radials.

3. BBK off road h-pipe. Keep the stock mufflers and tailpipes.

4. ASP pullies with built-in balancer.

5. A good short throw shifter.
 
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