True Trac

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Luke

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Anyone running a Tru Trac in a 9in looking at 3.5 gears on a mild clevo,not racing just waking up a stocker. all feedback appreciated.

 
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I run one in mine. Fun at the stop light and for getting onto the freeway, not so much fun on the freeway. At 65mph I am pushing 3200 RPM, 75MPH at am at 3600RPM. There is no 'passing gear' since dropping to 2nd at 65mph would put me at 4600. However, I can just 'get on it' and since I am in a good torque spot it speed up pretty quick. (c6 transmission)

 

Luke

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I run one in mine. Fun at the stop light and for getting onto the freeway, not so much fun on the freeway. At 65mph I am pushing 3200 RPM, 75MPH at am at 3600RPM. There is no 'passing gear' since dropping to 2nd at 65mph would put me at 4600. However, I can just 'get on it' and since I am in a good torque spot it speed up pretty quick. (c6 transmission)
Do you think 3.25 would be a better choice for a similar combo. What size tyres are you using mine are pretty tall 275/60 15s

 
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cazsper

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1968 Coupe: 393w, TKO-600, Maier Racing springs, Global West suspension, Currie 9in with forged axles, 3.50 gears, Trutrac, Baer brakes front/rear
1973 Mach-1: 351c 4V, C-6, 3.73:1 gears and a long "To Do" list..
I have a TrueTrac in a 9 inch with 3:50 gears behind my 393w (into '68 coupe). I love it. If you're asking about the TrueTrac, it's much nicer and smoother than the Auburn I had in the original 8 inch. The TrueTrac is smooth, quiet, nice in corners (windy roads going to the beach). It handles 475 hp getting on the freeway. As for gears, I have a 5-speed TKO-600 so RPMs on the freeway aren't an issue.

 

Luke

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I have a TrueTrac in a 9 inch with 3:50 gears behind my 393w (into '68 coupe). I love it. If you're asking about the TrueTrac, it's much nicer and smoother than the Auburn I had in the original 8 inch. The TrueTrac is smooth, quiet, nice in corners (windy roads going to the beach). It handles 475 hp getting on the freeway. As for gears, I have a 5-speed TKO-600 so RPMs on the freeway aren't an issue.
Thanks yes I am asking specifically about the true trac so you have been most helpful. Where did you get yours? And how much if that's not a rude question

 

CZ-75

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Your tires are pretty tall, approx. 28".

Assuming your top gear is 1:1 (3 speed automatic), you should see RPMs right around 3,000 at 70MPH.

A well tuned engine should be fine at those RPMs even on long hauls. Hell... My old boat had a Ford 302 in it, and I would cruise for 20-30 minutes at a time at 4,100 RPMs. And when I sold the boat after abusing it for 14 years, the engine was still running like a clock..

Your fuel economy will suffer, though.

 

phagan63

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I don't have the True Trac in mine but I'm definitely considering a change. Presently I have a Detroit Locker in the 8" and 3.08 gears. No doubt, in a straight line the car really moves out. That is until I get up to about 70-75 mph. By then, because it has a C4, the motor is screaming and I can actually watch the needle on my fuel gauge move. Not by the mile, but by the yard ! (Maybe a little exaggeration, but just a little). I really don't care for all the little "noises" it makes during normal driving either. I can't help but feel as though any minute I'm going to see parts rolling in the street in my rear view mirror. I'm told by people with more experience than myself that these noises and related little "bumps" and "clunks" are normal but I find it a little unsettling. Sometimes I think I'd prefer going back to the stock configuration. After all, I'm not interested in racing the car. I just want to be able to leisurely tool around town with the top down, and/or take that run down I-95 to visit the old man, on a regular basis :)

 
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Anyone know how to 'test' one? I had mine rebuilt years and years ago. With the axle off the ground both tires spin in the same direction.

I get good traction off the line, when I do a 'corner burnout' I can't tell if one or both tires are spining.

 

Luke

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Anyone know how to 'test' one? I had mine rebuilt years and years ago. With the axle off the ground both tires spin in the same direction.

I get good traction off the line, when I do a 'corner burnout' I can't tell if one or both tires are spining.
Easy drive back past the corner and see if both wheel have laid rubber Lol.

 

cazsper

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1968 Coupe: 393w, TKO-600, Maier Racing springs, Global West suspension, Currie 9in with forged axles, 3.50 gears, Trutrac, Baer brakes front/rear
1973 Mach-1: 351c 4V, C-6, 3.73:1 gears and a long "To Do" list..
I have a TrueTrac in a 9 inch with 3:50 gears behind my 393w (into '68 coupe). I love it. If you're asking about the TrueTrac, it's much nicer and smoother than the Auburn I had in the original 8 inch. The TrueTrac is smooth, quiet, nice in corners (windy roads going to the beach). It handles 475 hp getting on the freeway. As for gears, I have a 5-speed TKO-600 so RPMs on the freeway aren't an issue.
Thanks yes I am asking specifically about the true trac so you have been most helpful. Where did you get yours? And how much if that's not a rude question
Not a rude question at all. I got mine from Summit. A TrueTrac for a ford 9 inch with 31-spline axles. I believe it was about $500. I had a Torsen in my '95 GT and I believe it was about the same price.



I don't have the True Trac in mine but I'm definitely considering a change. Presently I have a Detroit Locker in the 8" and 3.08 gears. No doubt, in a straight line the car really moves out. That is until I get up to about 70-75 mph. By then, because it has a C4, the motor is screaming and I can actually watch the needle on my fuel gauge move. Not by the mile, but by the yard ! (Maybe a little exaggeration, but just a little). I really don't care for all the little "noises" it makes during normal driving either. I can't help but feel as though any minute I'm going to see parts rolling in the street in my rear view mirror. I'm told by people with more experience than myself that these noises and related little "bumps" and "clunks" are normal but I find it a little unsettling. Sometimes I think I'd prefer going back to the stock configuration. After all, I'm not interested in racing the car. I just want to be able to leisurely tool around town with the top down, and/or take that run down I-95 to visit the old man, on a regular basis :)
My did use to have a '77 ford F-150 he used for truck pulls. It had a 9 inch with a Detroit Locker. I remember it being pretty noisy in the turns. The Truetrac is very quiet. You'll never hear anything. I'm not sure how the locker is in the turns on the mustang but the TrueTrac is very smooth as well.

Mike

 
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CZ-75

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If you don't fishtail when you burn out while turning, it's a pretty good indicator that only one wheel is spinning

 
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I run one in mine. Fun at the stop light and for getting onto the freeway, not so much fun on the freeway. At 65mph I am pushing 3200 RPM, 75MPH at am at 3600RPM. There is no 'passing gear' since dropping to 2nd at 65mph would put me at 4600. However, I can just 'get on it' and since I am in a good torque spot it speed up pretty quick. (c6 transmission)
Wille

You'll be on the road before me and I am curious how you like the GV when its done.

-jbojo

3.25 is a good rear end however if I remember correctly I was turning 3000 rpms at around 65 with F70's-14's, MPG's wasn't very good either.

 
Joined
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'73 mustang convt.
I run one in mine. Fun at the stop light and for getting onto the freeway, not so much fun on the freeway. At 65mph I am pushing 3200 RPM, 75MPH at am at 3600RPM. There is no 'passing gear' since dropping to 2nd at 65mph would put me at 4600. However, I can just 'get on it' and since I am in a good torque spot it speed up pretty quick. (c6 transmission)
Wille

You'll be on the road before me and I am curious how you like the GV when its done.

-jbojo

3.25 is a good rear end however if I remember correctly I was turning 3000 rpms at around 65 with F70's-14's, MPG's wasn't very good either.
I will post up a thread when I am done. I got the driveshaft back today. I may take it for a test run on the weekend but it will be without the tach/fuel/speedo since I have them out.

cz-75, would I still fish tail with traction bars and a rear sway? My guess is the clutches are worn out. But pointed straight and getting on it I get really good traction. Even when it breaks loose going into 2nd it stays pretty straight.

 

cazsper

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1968 Coupe: 393w, TKO-600, Maier Racing springs, Global West suspension, Currie 9in with forged axles, 3.50 gears, Trutrac, Baer brakes front/rear
1973 Mach-1: 351c 4V, C-6, 3.73:1 gears and a long "To Do" list..
I don't fishtail at all I'm my '68. That setup is: 393w making about 450-475 hp, TKO-600 9in rear with 3.50:1 (Truetrac), 600# coil springs, 165# leaf springs, Global West upper/lower CA's Total Control strut rods and subframe connectors. 1 1/8" front/3/4" rear swaybar.

Mine doesn't fishtail at all.

 
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