High HP Vettes with ZF6?
Thread Starter
Safety Car
Joined: Jul 1999
Posts: 3,946
Likes: 63
From: Marianna FL
High HP Vettes with ZF6?
What has been your experience with high HP vettes and the ZF6? ZFdoc says the ZF may or may not handle 700 HP, but his blueprinted and upgraded unit definitely would. I don't plan to drag race regularly and when I do, I won't be trying to hit 1.50 sixty ft times and will use the clutch on all shifts. What is everyone elses experience with this HP level and the ZF6?
Drifting
Joined: Dec 2006
Posts: 1,480
Likes: 35
From: Duck, NC
over 200 passes
I have over 200 strip passes on my 95 with the entire drive line stock with the exception of a centerforce clutch and stock 95 Z28 flywheel (much lighter than a vettes) On drag radials it will produce consistant 1.8 60' with out beating on the car and it will run consistant 10.90's at 132+mph and its the original zf unit.
Thread Starter
Safety Car
Joined: Jul 1999
Posts: 3,946
Likes: 63
From: Marianna FL
Well these are certainly positive results. 
Every now and then my current ZF won't shift into third when running hard through the gears, so I priced a rebuild/upgrade from ZFdoc and he suggested buying a new one and upgrading instead of rebuilding.
Every now and then my current ZF won't shift into third when running hard through the gears, so I priced a rebuild/upgrade from ZFdoc and he suggested buying a new one and upgrading instead of rebuilding.
Instructor
Joined: Oct 2004
Posts: 247
Likes: 0
From: Montanja Noord Aruba
If your car is producing 700hp and you're not planning to drag race, I think it will definately hold.(ruling bad luck out)
I have 651rwhp and 790lbs/tq trough the stock '95 blue tag with a 4-link 9". Amazingly it held with a 1.42 60ft. In 2003 I rebuild it my self(the synchros that is), so I think you're safe.
I have 651rwhp and 790lbs/tq trough the stock '95 blue tag with a 4-link 9". Amazingly it held with a 1.42 60ft. In 2003 I rebuild it my self(the synchros that is), so I think you're safe.
Racer
Joined: Nov 2002
Posts: 427
Likes: 0
From: Stillwater OK, Fun City USA
If your car is producing 700hp and you're not planning to drag race, I think it will definately hold.(ruling bad luck out)
I have 651rwhp and 790lbs/tq trough the stock '95 blue tag with a 4-link 9". Amazingly it held with a 1.42 60ft. In 2003 I rebuild it my self(the synchros that is), so I think you're safe.
I have 651rwhp and 790lbs/tq trough the stock '95 blue tag with a 4-link 9". Amazingly it held with a 1.42 60ft. In 2003 I rebuild it my self(the synchros that is), so I think you're safe.
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
McLeod twin disk units will hold up to that level (and considerably more) without an issue. My McLeod is still going strong (knock on wood).
I am still running the IRS, but have nowhere near the 60' times that Dr. Juice has listed above.
Aaron
I am still running the IRS, but have nowhere near the 60' times that Dr. Juice has listed above.
Aaron
Pro
Joined: Dec 2002
Posts: 704
Likes: 16
From: Dallas Texas
I run ZF with 315 drag radials and McLeod twin disk w/o any problems...tires tend to break loose before breaking any driveline parts. However, I don't launch my car very hard and I always shift using the clutch.
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Team Owner
Joined: Jul 2002
Posts: 37,063
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From: This city NEVER sleeps! Frank's back yard!
One word of wisdom -you'll note that everyone with big power above noted that they use the clutch on every shift - this isn't a coincidence. The ZF's synchros do NOT like to be shifted shallow (clutch pedal not all the way to the floor on shifting) and they HATE power shifting. With a hurst shifter, and some practice you can shift really fast anyway - and the ZF can take the power.
Instructor
Joined: Oct 2004
Posts: 247
Likes: 0
From: Montanja Noord Aruba
It's a Spec 3+. I launch around 5500rpm and shift 6000rpm and the tires are 26x12x16 M&H drag slicks @10.5psi. I do shift with the clutch...
I think these transmissions are a master piece for a stock equipment. I didn't think my gearbox will survive all the nitrous I'm launching with. Well it took the abuse and I think it could handle alot more(even for a street aplication). But now I'm switching to a powerglide.....
I think these transmissions are a master piece for a stock equipment. I didn't think my gearbox will survive all the nitrous I'm launching with. Well it took the abuse and I think it could handle alot more(even for a street aplication). But now I'm switching to a powerglide.....
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
I am just thankful that when it did fail, it did not take my foot or other body parts. It completely cut the bellhousing off the back of the motor, narrowly missed the main wiring harness and the FAST harness, and sliced the passenger header collector off the header (except about 3/4") and took out the front sleeve on the input shaft of the trans.
SPEC replaced the complete unit (which I sold, in the plastic) and now I run a McLeod twin w/ Al flywheel and have had good luck. I also shift with the clutch. No speed shifting on the ZF.
Aaron
Last edited by AKS Racing; May 11, 2007 at 01:39 PM.
Instructor
Joined: Oct 2004
Posts: 247
Likes: 0
From: Montanja Noord Aruba
You don't want to wait until the SPEC comes apart? I thought I was the odd one when my SPEC come apart during a pass. But... upon posting on here, I found multiple people had it come apart as well, and they all seem to fail when going from 2nd to 3rd gear.
I am just thankful that when it did fail, it did not take my foot or other body parts. It completely cut the bellhousing off the back of the motor, narrowly missed the main wiring harness and the FAST harness, and sliced the passenger header collector off the header (except about 3/4") and took out the front sleeve on the input shaft of the trans.
SPEC replaced the complete unit (ehich I sold, in the plastic) and I run a McLeod and have had good luck. I also shift with the clutch. No speed shifting on the ZF.
Aaron
I am just thankful that when it did fail, it did not take my foot or other body parts. It completely cut the bellhousing off the back of the motor, narrowly missed the main wiring harness and the FAST harness, and sliced the passenger header collector off the header (except about 3/4") and took out the front sleeve on the input shaft of the trans.
SPEC replaced the complete unit (ehich I sold, in the plastic) and I run a McLeod and have had good luck. I also shift with the clutch. No speed shifting on the ZF.
Aaron
Wow
.....That's scary...I never heard about that. Well, I'm glad I've heard about it now. Now I won't have to worry anymore.
ps. Sorry for the thread hijack.
Last edited by dr.juice; May 11, 2007 at 01:21 PM.