Discussion in 'SVT Tech Forum' started by markt1968, Dec 16, 2003.
LOL. You said a stock 03 Cobra. Got me a little confused for a second there
... As well as them having 03 Cobra heads with bigger exhaust ports...
...i read before that they were 5.4dohc navigator heads. does anybody know for sure (not that it matters, i'm just curious).
FR500 cams are a bolt on (sort of haha) and provide a nice TQ improvement throughout the entire RPM range...
I know where to get a good price on them too...
OOPS!!! I meant 03 Mach1 not 03 Cobra...heh heh...fixed...
well, the Mach1, Marauder, 03 Cobra, and Aviator all use the same 4v heads...
How do you know they hurt the torque up top? Do you have pulls with no other changes except headers that show this? If it did hurt torque up top, it would have also hurt HP.
Mach 1 also has different heads, a different intake, a bit more compression, different EEC tune, and likely a few other minor things.
Much easier question to answer:
Full Exhaust (probably best mod)
Custom Chip (probably second best - if done on a dyno by a competent tuner)
There are no "bolt-ons" that are going to help low rpm power and hurt high rpm power - at least not of any significance.
Bob just invented a new word everybody!
where do u get those cams at
None of my bolt-ons thus far have sacrificed power at any rpm. The C&L MAF is the only mod I've installed that hasn't boosted performance over the entire range (it increased power up to 6000 RPMS, where it broke even with the stock MAF). My biggest gain has been the MAC prochamber, followed by the MAF and underdrive pullies.
Don't forget folks the Mach's also have a higher C/R as compared to the 96-98's and the 99-01 Cobras. Thats helping that TQ and hp bump. It's not just the cams or the heads or the revised intake on the Mach. It's got some major differences.
Bob, thanks for the info.
Ahh, yep, very true...
The Mach 1 cams are the same as the Nav. 5.4. I found them at www.fordpartsnetwork.com. The intake was changed a little to fit the shaker. I just found out about the compression ratio difference (9.85 Cobra and 10.1 Mach 1). The Mach 1 also comes with an iron crank instead of a steel like the Cobra. The exhaust manifolds are portmatched to the heads too.
As for my headers, I got them from JDM for $750 but you don't have too lift the engine or drop the k-member to put them in. I know the engine gets better torque readings stock from postings here on Stangnet. I attribute my lower flatter readings to the headers.
Also checkout www.karkraft.com in the modular area for engine parts. They have a good selection of parts too.
I thought the Mach1 with a manual tranny had the Cobra's forged steel crank and the autos had the iron one?
[/QUOTE]I know where to get a good price on them too...