View Full Version : need opinions!

12-28-2006, 06:43 AM
I have startd to modify my '04 Mystic Cobra Conv. ......

my mods are:

~ JLT cold air intake

~ BBK Twin 65mm throttle body

~ DiabloSport Tuner

I'm not quite sure that I like the tuner.... may go with SCT Live Wire....

I like the other two, and I have noticed that to keep my Cobra running well I have to have the idle at leat 900 rpms to feel comfortable to drive....

I like the JLT, big differece with it right after installing it....

I noticed wheel hop occurred after the JLT and need to get this taken care of but am on a low budget.. still have stock wheels(stupid me).

I need some opinions on where to go from here.... thinking about a cat-back but don't know which one or what setup to get...

Any othert opinions are welcome for moding my car....

Looking to get at least 500hp out of it.....i know i need a dyno/tune... there is a place about half hour from my house (FCCT, FCCT.net) to get it done, when should i do this???

Remeber low budget right now but that will change in a while... just need to know the right path that i need to be on....

thank you all and i hope all went well over the holidays


12-28-2006, 08:48 AM
Cat-back = $400-$650 (I have Bassani)
Mid pipe = O/R or catted $250-$450 (Bassani O/R)
Pulley = $130 (Billetflow 2.76) http://billetflow.com/supercharger_pulleys.htm
Plugs = $45-$80 gapped .035 only if you get the pulley
All of that plus what you have (-TB) got me around 477rwhp

12-28-2006, 11:19 AM
:cool: If you still have the stock pipes, then most aftermarket kits for the 99-04 would work fine. It will boil down to sound quality and fit/finnish. The better kits are made from Stainless steel in various grades (typically 304 or 409 ). Bassani, Borla, SLP are some good choices. In my opinion, the welded kits (non-modular) would be a better choice but the modular kits do have some advantage in that you can swap the muffler sections. Typical pipe diameters are 2.5" and the mandrel bending/shaping is used. Note: the bulk of the factory exhaust is made from 409 stainless steel or similar grade. The tips on the factory exhaust are probably made from 304 or 316 stainless steel since that grage of stainless is non-magnetic (magnet will not stick to it).

I do not believe your wheels would cause the wheel hop issue but the tires may have some role in that. Unfortunately I did not have a chance to wear out a set of the Factory tires since I traded wheels the day after I took the car. Typical tire will increase in rubber hardness as it wears down. Some tires do not exhibit this but most do. Others may point out that the bushings are to blame. This is true since they are made of rubber as well. Perhaps the bushings are a contributing factor but in my opinion it is the lack of tire grip to the road surface that is the main cause of the hop. Typically the result is severe loading on the differential.

Tires I have used on my 04 that did not exhibit issues with hop unless the streets were cold and wet (Bridgestone Firehawk Wide Oval mounted on 10th anniv wheels) (Toyo Proxes T1-S and T1-R mounted on 18x10 BBS wheels). I have noticed that the traction in the Bridgestones has decreased to some degree after 10k miles of driving (more sit and spin characteristics). The Toyo's have more silicone content in the rubber and usually keep their softness all the way down to baldness (T1-S), the T1-R is a better tire than the T1-S. Many may swear they cannot overcome wheel hop unless they are running drag radials on the rear end. There may be some truth to that since the tire compound is different and consistent. If you plan on replacing your tires, avoid the M+S rated tire since the compound is generally harder. If you have to use your vehicle in the winter, it would be best to locate some 99/01 wheels and mount some high performance snow tires on them. The rubber compound is similar to that of a drag radial but designed to be sticky at low temperatures (note that snow tires are speed limited)