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Dave B.
06-27-2005, 05:13 PM
since I had the 410's put in any speed about say 85 MPH I start hearing a woorble and the mirror vibrates, my mech at True Performance in Sarasota says the near 600 crank HP Im pumping out has most likley either twisted the shaft a little, or ovaled out some hole fittings where steel meets aluminum,

One guy suggested I have a steel shaft made to handle the torque, anyone else had or done any of this kind of stuff?

blk04cobra1
06-28-2005, 09:29 AM
Ive heard of pullied Cobra's breaking/twisting their halfshafts due to hard launches...so, it could possible...I wouldnt think the 410's did it...i would just have them inspected to make sure they are fine...it could also be something with your suspension...

Davesnake
06-28-2005, 12:52 PM
[QUOTE=blk04cobra1]...I wouldnt think the 410's did it...QUOTE]

On the contrary....the 410's are exactly why he has a vibration now.

The vibration you are experiencing is caused by changing the driveshaft RPM @ 85mph with the 410's. Therefore moving the driveshafts critical speed lower in MPH. When you go up in RPM your driveshaft begins to whip, at the shafts critical speed the bending of the shaft gives you lateral runout and vibration. I dought you have twisted your shaft ends so soon after installing the 410's. Aluminum has a lower tortional spring rate than steel so I would not go that route. Carbon fiber's spring rate is less than aluminum an about half that of steel, it's also much better at harmonic dampening and lateral stiffness. A friend of mine an I are working on developing carbon shafts for the 99-04 Cobras. There are a few companies in the game right now but the prices will take your breath away.

My suggestion go back to 355's which will move the vibration higher in the RPM's or your going to have to live with it for now.

my 2 cents
Dave

blk04cobra1
06-28-2005, 04:17 PM
that makes sense...didnt think about rotating the shaft like that...good info :thumbsup:

InfamousSVT
06-28-2005, 08:34 PM
http://www.need-4-speed.com/pst.htm


Here's a link to the PST Driveshafts - CarbonFiber.................price:eek:

Dave B.
06-28-2005, 08:38 PM
UH,,,Well,,,,I had the drive shaft taken out and new heavier duty u-joints put in and the shaft re-balanced, turns out when your pushing 600 shaft HP the aluminum shaft is not strong enough, the other problem is the dissimilar metals in the u-joints,

sholution<<<<< I have to have a steel drive shaft made when it starts to do it again, then ill never have to worry about it again

Davesnake
06-28-2005, 09:03 PM
UH,,,Well,,,,I had the drive shaft taken out and new heavier duty u-joints put in and the shaft re-balanced, turns out when your pushing 600 shaft HP the aluminum shaft is not strong enough, the other problem is the dissimilar metals in the u-joints,

sholution<<<<< I have to have a steel drive shaft made when it starts to do it again, then ill never have to worry about it again

Good luck

Dave B.
06-28-2005, 09:09 PM
man that PST carbon fiber shaft is SWEEEET!!!,,,,,think ill do that instead, anyone else have one on??

RF Cobra
06-28-2005, 09:39 PM
http://www.need-4-speed.com/pst.htm


Here's a link to the PST Driveshafts - CarbonFiber.................price:eek:

As much as you've done to that car that should be like spare change. ;)

Dave B.
06-28-2005, 10:05 PM
Well,,,,,,,,,,,,,,,,,,,,,ya!

Dave B.
06-28-2005, 10:15 PM
heres what I got so far,,,,just a few things man,

2.80 pulley
all idlers
accufab single blade,
Mac cold air
a Predator
Magnaflow cat and X pipe
410 gears
Gordsford heat exchanger
Pro short shifter
really neat push to start button
compressor over ride
18X9's front 18X10.5's rear
lowered 1.5
Cobra "R" hood and wing

now it looks like im going to have to spend another $850 for a drive shaft,,
this keeps up the wifes going to divorce me and she'll end up with the car, would'nt that be some Sh&%

InfamousSVT
06-28-2005, 11:47 PM
now it looks like im going to have to spend another $850 for a drive shaft,,
this keeps up the wifes going to divorce me and she'll end up with the car, would'nt that be some Sh&%

:lol: :lol: Can't be that bad:rolleyes: :D

Dave B.
06-29-2005, 12:23 AM
yea yea yea,,,,,,,I know,,,,,,,,,,,,,guess I deserve that one, its just that every single time I add a part or make a mod,
I go to wifey and tell her " THATS IT,,,,IM DONE SPENDING MONEY ON THE CAR,,,,NO MORE DEAR,,,,,,,HA! HA!"

then she goes,,,,"yea yea yea iv heard that one before"

Then I come up with some other trick HP part, and eat crow for the next two weeks, I had her convinced that I was done after the 410's but then I get on the interstate with the mother of all vibrations,
just today spent another $322 for an oil change (Royal Purple of corse) plus the drive shaft was way out of balance and the end caps on the drive shaft when they took it apart just fell out or off what ever, the guy put in heavy duty u-joints but it wont last,,,,,,,,,,,$850,,,,,,,here I come!! :bounce: :bounce: :bounce: :bounce: :bounce:

InfamousSVT
06-29-2005, 12:28 AM
How do you like that Royal Purple? That's what I've been running in mine since the 2nd oil change and love it, besides the price of it:D

When I purchased my car, I told myself that I wouldn't do anything to it but the exhaust.........look at me know:nope: :banghead:
With one mod comes the other................Well I got the Kenne Bell, but I need a new clutch cause the stock one cant handle it, oh yeah and then theres the rear end........the list just gets longer and longer:D :rotf:

Dave B.
06-29-2005, 01:33 AM
Royal Purple is just that,,,Royal
any of these guys who have Lambos,ferraris, or any of the true exotics all run Royal purple from what I understand, as far as the mods go, you know, 99% of everyone on this board are not the type of people who can leave anything performance oriented stock,

Im 48 years old, every thing iv owned since I was 18 Iv done some mods to,
I had 3 high performance 19 foot speed boats that went over 100MPH
one of the three almost killed me in late 1984

the worst was only a few years ago, its was 1998 Suzuki TL1000R V-twin sport bike, I had almost $45,000 in the thing from when I bought it to the year 2001 when I had my second life threatening crash where it was totaled, not my fault of course.

I tried to not go nuts on this car but its got sort of out of hand, the good thing is I have not made it unreliable by taking the engine apart, doing heads, porting blowers,ect,ect, I really need to stop. :D :D :D

Dave B.
06-29-2005, 01:59 AM
Shoot I forgot compleatly about the 1995 Yamaha Wave Raider 1100 that I put 44 carbs on, lightweight flywheel, high compression head, ported it, had the crank welded so as not to twist the crank when jumping waves, It started at about 110 HP,

I think I got it up to about 140 HP, I was having a 55 gallon drum of VP C-12 that was about $5.50 a gallon(in 1997) delivered to my house and was running that stuff in it, dam I got hugh torque outta that thing with the VP fuel, that stuff must be $12.00 a gallon now, anyone know what some of the exotic fuels are going for now days??