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Post by Buddyg - Forum Founder on May 21, 2014 8:55:01 GMT -5
So going through the gears 1st - 4th the cars rips along nicely. When I shift into 5th it feels like I shifted into 8th gear or something. The pull just stops and is very sluggish?
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jcam
New Member
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Post by jcam on May 22, 2014 7:39:50 GMT -5
So going through the gears 1st - 4th the cars rips along nicely. When I shift into 5th it feels like I shifted into 8th gear or something. The pull just stops and is very sluggish? When I was researching Cobras to buy, I discovered most Cobra's had the five speed to include an overdrive gear for the highway. I am sure the fifth gear ratio is different from car to car, but I would not think the word sluggish is how I would describe mine. I was having a sluggish feeling with my Cobra when I brought it from NM to NC. Below 2k rpms, it felt like it was struggling. The claimed double pumper 750 carb was actually only a single pumper. After installing a 750 double pumper, the below 2k rpm struggle was gone. BTW, congrates on having a place to rip through 4th gear and looking for more. I cannot get through third gear before having to back off. I did get a chance to take another soccer Dad for a ride last night while our boys were having tryouts. We jumped on the highway for an exit to exit run. My Cobra did not disappoint as for the first time (for me) the tires barked hard as she went into third gear. I Love this car! |
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Post by Buddyg - Forum Founder on May 22, 2014 7:52:37 GMT -5
Yeah it was beautiful here yesterday and I drove mine to my Golf league. Took an older friend for a drive and he had a grin from ear to ear. Then driving
home last night I said the exact same thing
I LOVE THIS CAR!
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Post by spf2932 on Jun 3, 2014 10:42:29 GMT -5
I had the same experience.
Have a strong 427 paired with a TKO 600 with the .64 overdrive fifth gear. Fifth gear was great for cruising at 80 MPH, but sucked at everything else. Felt like I hit a wall after winding it out in fourth and then hitting fifth. At least a thousand rpm drop.
Solution? Swapped out the trans for a Gordon Levy super alloy T-5 with his .80 fifth gear. Now, I can cruise comfortably at 2500 rpm at 70 mph and still accellerate smoothly from 60 mph without having to constantly row back and forth between fourth and fifth when traffic on the freeway slows.
Should have done this years ago.
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Post by Buddyg - Forum Founder on Jun 3, 2014 23:23:27 GMT -5
Sounds exactly like my issue. I love my car but 100 ponies and this gear change would make it much better!
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Post by mudhenk27 on Jun 4, 2014 7:40:01 GMT -5
My 427 Hi-Tech has a Jag 3.73 rear and a TKO600 with .64 fifth gear. I find the ratios nicely spaced and I like it. I think I use fifth around 55mph.
Bill
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jcam
New Member
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Post by jcam on Jun 4, 2014 12:08:18 GMT -5
My 427 Hi-Tech has a Jag 3.73 rear and a TKO600 with .64 fifth gear. I find the ratios nicely spaced and I like it. I think I use fifth around 55mph. Bill I think the 3.73 rear end might be the difference. I have the 3.73 as well and do not have an issue with fifth gear. Buddy - do you know what the rear end gearing is in your Cobra? |
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Post by spf2932 on Jun 5, 2014 10:13:25 GMT -5
You're correct about that rear end ratio. Most of the newer cars have a 3.46 rear end.
Even so, there is a thousand rpm drop between fourth and fifth with the .64 fifth gear.
With my .80 fifth gear, shifting from fourth to fifth feels normal. And my mileage actually increased now that my motor is running more efficiently.
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Post by Buddyg - Forum Founder on Jun 6, 2014 9:46:56 GMT -5
My spec sheet says 3.73
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Post by spf2932 on Jun 6, 2014 10:21:15 GMT -5
It's still a huge rpm drop from fourth to fifth no matter what your rear end ratio is.
If you want to be able to shift from fourth to fifth and keep the engine in its power band, you'll need to change the ratio.
Gordon Levy can make you a super Alloy T-5 with whatever fifth gear you want. With your 3.73 rear end, a .75 fifth might work better. I decided on the .80 after driving with a .64 for five years. Couldn't be happier!
Go to one of those rpm/speed/gear ratio calculators and work backward to find the combo that suits your engine and driving style.
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Post by mudhenk27 on Jun 6, 2014 10:45:07 GMT -5
Wow, you guys must have some wide-open spaces to drive if you are concerned with keeping it in the power band through 5th gear...I get into big-ticket territory in third :-)
Bill
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Post by Buddyg - Forum Founder on Jun 6, 2014 18:56:09 GMT -5
Midwest baby!
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Post by spf2932 on Jun 6, 2014 20:13:35 GMT -5
If you want to effectively use all 5 gears, you will have to replace the trans with a more friendly fifth gear.
Freeways in so. California can go from 80 mph to 50 mph in the blink of an eye. I got tired of shifting back and forth between fourth and fifth. Now I have a .80 fifth gear and can leave it in fifth if traffic slows down and still accelerate smoothly when traffic lets up.
But that's so cal. Your local May be different.
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