ZF vs ZFQ differences?

[middy]

Hello,
Exactly what are differences between them two? The info I got so far are as follows, but still need to know the remaining (in red):

ZF
Supplied by: RBT
Manufactured by: ?
Made in: ?
Shaft centres: 79mm
Crown wheel diameter: ?
Bevel or Hypoid: ?
Hypoid offset: ?
Shift forks on input or pinion shaft: ?
Direct shifting mechanism (shift finger a la Hewland), yes or no: ?
Dog-leg 1st gear: Yes
Reliability issues: ?
Recommended max. engine torque: ?
Are non-syncromesh gears available: ?
Clutch fork or concentric slave cylinder: ?
Weight: 70kg
Price: ?

ZFQ
Supplied by: Quaife
Manufactured by: Quaife
Made in: England
Shaft centres: 85mm (same as G50, so can Porsche gears be used?)
Crown wheel diameter: ?
Bevel or Hypoid: Hypoid
Hypoid offset: ?
Shift forks on input or pinion shaft: ?
Direct shifting mechanism (shift finger a la Hewland), yes or no: ?
Dog-leg 1st gear: Yes
Reliability issues: ?
Recommended max. engine torque: ?
Are non-syncromesh gears available: Porsche Cup?
Weight: 65kg
Price: ?

[Jac Mac]

If you go into the 'ZFQ thread on the manufacturers Forum, Post #94 has a dimensioned PDF file drawing, from the dimensions given you can scale these out to work out the Ring Gear dia, Hypoid offset, etc, IIRC RBT have drawings of the RBT/ZF trans also which will enable you to do this.
From memory the ZFQ Ring Gear is just under 8" dia, but I would have to re-check the dwgs to be sure...shifter forks are all on pinion shaft.
Initial torque rating given was 550 ft lb & max of 600HP @ 7000, but again I think this might have been lifted slightly since

[middy]

Thanks for the link to the dwg on page 94. Yes, you're right that the crown wheel is just under 8". The offset is 16mm... again the same as a non-turbo G50.

I have also just seen the RBT dwg but it doesn't show the crown wheel or offset. Where is RBT made?

[DaveM]

The RBT box is manufactured by High Performance Gear in Texas. It has to be ordered thru RBT in the Los Angeles area, CA. RBT is owned by Lloyd Butfoy, the son of Roy Butfoy who acquired the rights from ZF.

[Jac Mac]

Originally Posted by croc

Thanks for the link to the dwg on page 94. Yes, you're right that the crown wheel is just under 8". The offset is 16mm... again the same as a non-turbo G50.

I have also just seen the RBT dwg but it doesn't show the crown wheel or offset. Where is RBT made?

No offset on the RBT/ZF, spiral bevel.....Rinion & Ring Gear are at same height, so the 79mm dimension is the distance the Ring & Pinion is input below(GT40) or above ( Pantera etc) input shaft--- that is why/how the RBT/ZF can simply have the Ring Gear swapped from side to side for either application... The ZFQ would require a Mirror imaged Ring & Pinion to enable fitment to a Pantera in the original location without lowering the motor.... not sure if ZFQ/Quaife have actually made this setup yet, you would have to contact Chris Melia

[middy]

Originally Posted by jac mac

The ZFQ would require a Mirror imaged Ring & Pinion to enable fitment to a Pantera

As a point of interest, a mirror imaged R+P would mean teeth angled in opposite way and I think there is no such thing because the engine is still rotating in the same direction. I think you're talking about a slightly different teeth angle due to 32mm difference in hypoid offset.

Anyway, the ZFQ is obviously G50-based but why the smaller one, not the bigger one (G50.50)? The latter has the same shaft centres (85mm) but a larger crown wheel with 10mm hypoid offset.

Additionally, if it were me, I would have instructed Quaife to put the shift forks on the input shaft and also to provide a provision for a Hewland shift finger in the same location.

[Jac Mac]

Originally Posted by croc

As a point of interest, a mirror imaged R+P would mean teeth angled in opposite way and I think there is no such thing because the engine is still rotating in the same direction. I think you're talking about a slightly different teeth angle due to 32mm difference in hypoid offset.There are several things that happen with that, the pinion in the GT40 setup tends to push itself out of mesh from the Ring Gear under power, where a Pantera application would tend to pull itself into mesh., at the same time the GT40 pinion tends to pull toward the input while the Pantera trys to force them apart

Anyway, the ZFQ is obviously G50-based but why the smaller one, not the bigger one (G50.50)? The latter has the same shaft centres (85mm) but a larger crown wheel with 10mm hypoid offset.I cant answer that, try your luck with Chris/Quaife might have been to keep the overall package as close to the ZF as possible, an increase in ring gear dia changes all sizes very quickly.

Additionally, if it were me, I would have instructed Quaife to put the shift forks on the input shaft and also to provide a provision for a Hewland shift finger in the same location.

Im sure that feature was discussed in the ZFQ manufacturers forum

At the end of the day it sounds like your trying to make it into something else, so do you not want either of them..

[middy]

Originally Posted by jac mac

There are several things that happen with that, the pinion in the GT40 setup tends to push itself out of mesh from the Ring Gear under power, where a Pantera application would tend to pull itself into mesh., at the same time the GT40 pinion tends to pull toward the input while the Pantera trys to force them apart

I wasn't talking about using the existing R+P, I meant a custom one designed and manufactured by a reputable company, but anyway thanks for the insight.

[middy]

Originally Posted by SwiftDB4

The RBT box is manufactured by High Performance Gear in Texas. It has to be ordered thru RBT in the Los Angeles area, CA. RBT is owned by Lloyd Butfoy, the son of Roy Butfoy who acquired the rights from ZF.

Thanks. Anyone know the diameter of the RBT crown wheel? I have seen the dwg but it doesn't show the dimension.

[wanni]

ZF is well working for about 40 years. All the rest shall be proved.

[Alan Watkins]

Originally Posted by FOX1

ZF is well working for about 40 years. All the rest shall be proved.

Yeah we heard you the first five times Wanni. I think some ZF gearboxes also have broken when forced to swallow 500+ lb-ft of torque. Is there a new point here, or is this just a continuation of the jeering we saw on Chris Melia's original thread?

[Russ Noble]

Originally Posted by awatkins

Yeah we heard you the first five times Wanni. What's your point?

I should have thought Wanni's point was obvious, maybe it got lost in the translation, The ZF is well proven, the new kids on the block are not.

Funny, I was just thinking the other day how much really good tech Wanni had left for us on this forum. Much, much better than the drivel that seems to dominate this forum now. It was just a pity that he had a knack of rubbing some people up the wrong way. Still, for me, the tech that he has offered and no doubt still can, way overides any slightly grating personality traits.

Cheers.

[Russ Noble]

Alan,

You changed your post after I posted my reply. Which appears to me to be a little disingenuous The entirety of your original post is shown in my first reply.

I am no fan of the ZF, but unless you know the reasons for failure, age and state of the trans etc, as well as all the other variables, comparisons are somewhat irrelevant. As Wanni said, the ZF has been around for 40 years. One would expect some failures in that time, for a whole variety of different reasons. We know it's weaknesses. The point is we don't know how any of the new trans are going to hold up over the coming years.

At this point let me put a plug in for the good old well proven and cheap (relatively) 930! LOL

[Tom]

Russ - amen.

[Kelly]

Originally Posted by Russ Noble

At this point let me put a plug in for the good old well proven and cheap (relatively) 930! LOL

And dont forget light! I've never really understood the ZF bashing. My experience is all with -2’s but I’ve always been quite impressed with the ZF. I don’t think the remarks about breakage above 500 ft-lbs are at all representative. There are all kinds of examples to the contrary. Those boxes have been subjected to many forms of abuse and stood the test of time. Have there been failures? Of course but if the standard is "never fails" then nothing is good enough.

Given the ZF is a 5-speed synch’d box with LSD, and I can pick it up off the floor with bell housing, and set it on my work bench, I think that is a fairly impressive venerable piece of 40+ year old engineering. Try doing that with a Ricardo. Or, compare it to a Munci or Borg Warner tranny combined with rear differential of the same era.

I’d also add that the issue is not totally unrelated to driving skill. There seems to be a correlation between drivers that break drive train, can’t keep a set of tires on cars, nor finish a race. If you want to do 6krpm clutch dumps with big sticky tires and drag race, why do so with a 2400 lb mid engine road car?
My 2 cents.
K

[Jim Rosenthal]

ZF 5DS25 transaxles were first used in GT40s, for endurance racing. AFAIK, the other applications were worked in as vehicle manufacturers asked for them- deTomaso, Maserati, BMW, etc. I don't know what else they came in. At the time they were fitted to GT40s, I think they were brand new on the market, and running changes were made in them based on advice that ZF got from the GT40 teams running them.

When you consider that these first went on the drawing board in about 1964, and had periodic updates since that time, I think their record is enviable. I don't know that anyone's compiled a list of the endurance races won by cars with ZF 5DS25 transaxles, but I'll bet it is impressive. They are pretty tough. Of course, those races were run by cars driven by very skilled drivers who knew how to keep the equipment together for 12-24 hours. 6000 rpm clutch dumps would not be the order of the day, would they?

[Alan Watkins]

Originally Posted by Russ Noble

I should have thought Wanni's point was obvious, maybe it got lost in the translation, The ZF is well proven, the new kids on the block are not.

"What's your point?" doesn't mean "please tell me literally what you just said but in slightly different words." It means "what was your objective in saying that?"

In this case what he said is obvious to the point of being a tautology. So when an illustrious transmission designer says something that would be obvious to a school child, I think "what's your point" is a fair question.

As for editing posts being disingenuous, it was quite the opposite; I simply realized a few seconds later that by adding to my question it would make my intent more obvious. I don't see how that's a problem, a violation of forum rules or poor communication. If it was awkward for you due to minute timing issues, I'm sorry, but I don't think that deserves an accusation of being insincere.

[Alan B]

One big difference ZF is in production ZFQ is out of production.

[wanni]

correct, but upgradings are available.
remember that the 6 speed zf is successfuly working on the Saleen S7 biturbo.