4.10's installed in my Cobra, very dissapointed. What's wrong here?

[Craig Mack]

Finally got 4.10's installed in my '97 Slowbra today. Also got the rear end cleaned out with new bearing packs.

So far, the only thing I notice is the car revvs a little faster, and that the revvs sit a little higher at cruising. Acceleration feels practically the same. Made me very p!ssed at first...but then I started thinking..

Could this be my clutch? I had a SPEC stage I clutch put in about 3000 miles ago. It has always let off a burning smell when I ride the clutch into first (2600rpm~) (getting over speed bumps, etc). The stupid thing has been nothing but trouble. A finger(s) on the pressure plate rub(s) against the throwout bearing, probably becuase of an installation error on AAMCO's part, although they have denied it of course. This causes mad clutch pedal vibration, along with a grinding noise at idle that goes in and out. Could my clutch be slipping during acceleration? Engagement is eerily smooth into first, and I can't even squeek my tires into second gear anymore. Car feels slower and slower.

I think it's my clutch becuase 1 out of 4 times when I mash the throttle the car will take off hard. The other times it feels slow and mooshy, like my puny clutch is hanging on for dear life. Could it be my brand new clutch slipping? Or do 4.10's feel the same as 3.27s? SOTP feeling hasn't changed at all, which leads me to believe its the clutch slipping or something, becuase I was expecting a big improvement. I can't really get on it TOO hard, since there is a 200 mile break in period, but i'm a little down right now on my purchase.

Thanks in advanced for the replies.

 

[hognutz]

yeah It should feel way diffenert. first gear should be way shorter and second should pull more like first used to. If you clutch is slipping you should feel or smell it though. try coming off the clutch hard in a taller gear at speed. see if it bogs or slips.

 

[KaPPaBaLL]

Specs and their share of problems. I don't see why the gears would do that. Might be your clutch.

 

[Craig Mack]

yeah It should feel way diffenert. first gear should be way shorter and second should pull more like first used to. If you clutch is slipping you should feel or smell it though. try coming off the clutch hard in a taller gear at speed. see if it bogs or slips.

I know, I was expecting exactly that. I'll take another test drive tonite after traffic dies down.

A slightly warn flywheel will bog when you let off the gas hard too, so it could just mean my flywheel is normally uneven. But, if I am cruising at say 3000rpm in 2nd, and mash the gas, and it kinda wimpers up to redline one time, and takes off strong at others, and sometimes will have spurts of power in and out of rpm as they climb, isnt that another sign of a dying clutch?

What really gets me is the fact that 9 times out of 10 I can't even get a squeek outta the tires on a 1-2 shift. The clutch looked really thin before it went in, I don't know if it has been up to the task of handling the power. Hopefully SPEC would credit me with $270 (lightened PP option as well) to put towards a better clutch. I hear they are supposed to be one of the best companies, they were nice on the phone at least.

 

[BullittStangV8]

i doubt they will refund you. i dont know the company personally, but most major companys wont. especially and wear items like clutches. they could say, "you burned it yourself ridding the clutch too much..." i hope they do though. sounds like you have a clutch problem to me..
Mike

 

[ZIPP0]

Well, when I got my 4.10's, I could feel it sure, but it wasn't as great as I expected.

I don't believe in what 'hognutz' says "yeah It should feel way diffenert"...

But that's just me

 

[menasci]

Hmmm....
When I first got my 4.10's I thought the same thing.
They didn't feel like others have described
(ie. HOLY ***** WOW WOW!!!)
I mean it is definatly better, but not like that.

This could be due to a clutch?
I don't see how.
I too have trouble chirping my tires.
However, I do have a brand new set of Nitto 555ER's.
I think people have just been overexagerating their gains with the gears.

 

[03-s281]

My car will roast second all the way thru the power band and throw
the car sideways when I hit third. (with 3.55s)
So I would say its your clutch.

 

[menasci]

My car will roast second all the way thru the power band and throw
the car sideways when I hit third. (with 3.55s)
So I would say its your clutch.

How could a worn clutch do this?

I feel a pretty big difference with my 4.10's but
I'm not throwing my rear-end around and putting the car sideways.
What am I missing here?

 

[Craig Mack]

*Update*

I took the car out tonite. I can feel a nice difference in 5th gear on the highway. At 70mph cruising, I am at 2600rpm. I credit that to the 295/35/18 tires in the rear and the slightly offset speedo. 5th gear pull is improved.

I got to row through the gears pretty good, and second gear is a bit quicker, the main thing is that the rpm just wind out significantly faster. I havent gotten to do an extensive test, as I want to get to the break in mark before I romp on it too hard.

I think too, that people are just talking up gears too much. It probably will shave ~.2-.3 of my 1/4th. First gear is still definately useable, but noticably shorter.

The clutch kinda goes in and out. Sometimes it will grab, sometimes it wont. When it does grab, the pull is faster, but not "OMG it feels like 60hp!"...its more like ~25-35hp. I havent gotten to do a REAL test, like downshifting, back to back runs, etc yet. That's when the real test will come.

So far, i'm happy with the gears, and I hope I can explore them more as the break in period comes. But, thus far it's not the miracle mod I expected.

 

[ZIPP0]

Agreed.

I remember the first few days I got the 4.10's, I was kicking myself for not getting 4.30's.

People on stangnet act like 4.10's are INSANE. Sure they are nice improvment over stock, but not that insane....

I do feel an increase though as my tires fade, now when I floor it I get no traction in first ...

 

[GinoGT]

It has always let off a burning smell when I ride the clutch into first (2600rpm~) (getting over speed bumps, etc).

Wait a second......so you let the clutch out while revving at 2600rpms to get the car going?!

I hope I misunderstood that. If not, then I wouldn't be surprised if your clutch is dying.

 

[medik13]

Should of gotten 4.30's

 

[03-s281]

How could a worn clutch do this?

I feel a pretty big difference with my 4.10's but
I'm not throwing my rear-end around and putting the car sideways.
What am I missing here?

What I was saying is If I want to I can(from 20mph) roast 2nd all the way threw and catch a fat 3rd (enough to throw the car sideways)
I'm not talkin normal driving. He said he couldnt even get it to
bark 2nd. (In a 97 cobra with 4.10s )
Sounds like a clutch issue to me.

 

[PEA]

*Update*

I took the car out tonite. I can feel a nice difference in 5th gear on the highway. At 70mph cruising, I am at 2600rpm. I credit that to the 295/35/18 tires in the rear and the slightly offset speedo. 5th gear pull is improved.

I got to row through the gears pretty good, and second gear is a bit quicker, the main thing is that the rpm just wind out significantly faster. I havent gotten to do an extensive test, as I want to get to the break in mark before I romp on it too hard.

I think too, that people are just talking up gears too much. It probably will shave ~.2-.3 of my 1/4th. First gear is still definately useable, but noticably shorter.

The clutch kinda goes in and out. Sometimes it will grab, sometimes it wont. When it does grab, the pull is faster, but not "OMG it feels like 60hp!"...its more like ~25-35hp. I havent gotten to do a REAL test, like downshifting, back to back runs, etc yet. That's when the real test will come.

So far, i'm happy with the gears, and I hope I can explore them more as the break in period comes. But, thus far it's not the miracle mod I expected.

hey craig first problem you have is beliving what you hear
second a n/a 97 cobra with those tires will have a hard time barking those tires,,very big,psi in tires matters
third if it was your clutch it would slip like madd
and ,did you get your flywheel resurfaced??
ajustable cable?

so my best answer is the driver
ps might be your limited slip?
but it sounds like its you ,,sorry but learn how to drive lol

 

[kj99]

It's got to be the clutch if you can't bark the tires in 2nd

I've got a non PI 98 GT, and it will get sideways in 2nd and chirp 3rd AND 4th gears. Your cobra should be burnning thru 2nd and barking 3rd and 4th EASY...

 

[01BlkGT]

If your clutch is going out (which it sounds like it is), then you wont feel the full potential of the gears b/c there is still a percentage of power that is being wasted b/c of the slipping clutch. When I first got the 3.90's in my 2v it, there was a significant difference between those and 3.27's, so you should be feeling the same thing. Replace your clutch, make sure your flywheel is still in good condition and you should notice a considerable difference in how the car drives all-around.

 

[Craig Mack]

http://forums.stangnet.com/showthread.php?t=417455