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ZF 8HP Conversion?


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The ZF 8HP is getting lots of praise for it's fast shifts, cost, robustness etc. 

A stand alone control unit for one is around 1.5k AUD - http://htg-tuning.com/

8HP-70 through that supplier is 2.4k, and I'd think you could source one cheaper locally (the 70 and 75 variants are used in 3 Series and 5 Series BMW respectively) The models relate to torque ratings but are apparently under rated (fine for my SR, maybe not for your big boy RB setups).

The supplier states the box will fit the s chassis tunnel "needs a little hammerwork to fit into the tunnel, although not extensive, easily doable". 

Given what a Z32 or CD009 conversion will cost, I wonder if this would be a better choice? 

Faster shifts, no mishifts, flappy paddles, ultimately smoother and faster power delivery, it can skip shift, etc.

I would love to one day do WTAC clubsprint and I'm not sure if an auto swap like that is allowed, the rules are unclear (I've emailed them for clarification).

That aside though, I wonder what that would be like - Looks ok in action here? 



 

Edited by ActionDan
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That would be pretty cool in my opinion. Certainly it appears to be very well rated in road car formats. 


One interesting note, is the A90 Supra only uses the 8HP51 (rated to 500nm). I would have expected these to be a higher spec especially given the target market of tuners. 

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Anything is possible if you throw the required time & money at it, particularly for race car, not road car.

The only big questions will be;

  • Adaption to the engine. Bellhousing will be the least of it. Getting from the crank/fly to the gearbox will likely require 100% custom shit.
  • How much data exchange the TCU will want with the ECU. Will it demand torque management/reduction for shifts, etc? Will you need to fit sensors somewhere that you don't have now? Is your existing ECU even able to talk to the TCU?
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As above

 

the auto boxes that currently last with decent power all use torque management on up shifts. I would imagine without that the lifespan will go down the drain, and make you sad.

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As I understand it, the GCU from HGT does all of that though as mentioned I would expect it would want input from the ECU. 

ECU for my car has not been selected yet, but almost certainly Halaltech as that's my tuners preference. 

They had a Video of one in a Mazda3 so they're already being put in non optioned cars. 

As for mating to the engine, yes bellhousing/adapter plate, no different than me using Z32 or CD009 (but I get there's off the shelf solutions for those options and tailshaft etc).

 

Edited by ActionDan
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4 minutes ago, ActionDan said:

yes bellhousing/adapter plate, no different than me using Z32 or CD009

Well.....not quite. Torque converter, right? So, flex plate of some sort, choose a torque converter that will do the job and that is suited to the box's input shaft and pump drive, etc. So, quite a lot of fiddling there that is very different to using Nissan manual boxes.

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14 minutes ago, ActionDan said:

Would you not stick with the torque convertor the box comes with? I guess that depends on what flex plate options exist. 

I'd suggest that that would be your first choice. There may or may not be more than 1 TC available for the box, as there is more than one engine application. Choosing among these might come down to best match with torque characteristic of the engine, or it might come down to physical size limitations on the max flex plate diameter that you'll have to work with (which might not be an issue at all - just floating possibilities).

3 minutes ago, ActionDan said:

am I stupid in thinking that an Auto could be faster/smoother than the manual options I was looking at?

Not stupid, no. A fast shifting paddle controlled auto is very likely to be substantially faster around a track, even with the same number of gears and same ratios. With 8 closer spaced gears you're likely to have a better choice of gear coming out of every corner than you would in the 5 or 6 speeders. Maybe only slightly better, but still better. How good it all ends up being will come down to how user friendly it is, how snappy the shifts are, etc, which will likely be 100% specific to your implementation. You don't want to be waiting for a full second after flipping an up or down shift for it to happen.

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1 hour ago, ActionDan said:

Good thinking. 

I know there are drive  by wire setups for SR so that shouldn't be "crazy".

DBW piss easy to do, just find a TB(bosch 60-84mm, New mustang is 83mm or LS), get a flange made and welded to manifold, Use a z33/v35 accel pedal as it bolts up and wire to ecu (12v, Gnd, 5v, sensor gnd and 2 Position outputs). I have found it heaps better to tune idle too and allows traction/launch control :27_sunglasses:

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Even without DBW (which is easy enough and very sexual) you still could use ignition/fuel cut strategies and transient timing decay controls on up/down shifts.

Of course nothing beats proper torque management through timing, throttle position.

ZF box conversion makes my balls tickle, when shift times of 200ms are possible.. why not?

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21 minutes ago, Dose Pipe Sutututu said:

Even without DBW (which is easy enough and very sexual) you still could use ignition/fuel cut strategies and transient timing decay controls on up/down shifts.

Of course nothing beats proper torque management through timing, throttle position.

ZF box conversion makes my balls tickle, when shift times of 200ms are possible.. why not?

gearbox upgrade time for the r33???

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42 minutes ago, robbo_rb180 said:

DBW piss easy to do

 

31 minutes ago, Dose Pipe Sutututu said:

you still could use ignition/fuel cut strategies and transient timing decay controls on up/down shifts

 

Yes.....my point was around the throttle blipping on downshift. Can only achieve that wit DBW and it's not just a case of checking a box that says "blip the throttle on downshifts". There's some tuning needs to be done to get it right across the different downshifts (singles and doubles from all gears down except first) and across different vehicle speeds (because it's not always the same size rev blip even for the same gear if you're looking to be able to do it at all possible speeds for that gear.

Wasn't saying it's impossible or hard. Just work.

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16 minutes ago, robbo_rb180 said:

gearbox upgrade time for the r33???

Yeah, I've looked into it already, involved the following:

  • Sell R33 to some crazy person who wants to build a R33 but realises it's just better value to buy mine
  • Buy a BMW F30 340i w/ Factory LSD (has B58 motor)
  • Haha 2
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