Zanardi Rack and Pinion

[nsx2tall]

Can anyone provide me with copies of the service manual for the manual steering rack on a Zanardi? Does one exist or should I try using the '91 manual rack schematic (which isn't the same I don't think)? How similar is it to the '96 EPS?

Randy

 

[nsx2tall]

Bump
Somebody must have either an answer or an opinion?

My search has yielded the opinion that the Zanardi rack is identical to EPS ('95-'05) but without all the electrical mumbo jumbo. Also, the '91 manual rack can't be swapped into a '95+ without custom bushings. Anybody willing to provide me with the '95+ power steering section of the service manual?

 

[drew]

Opinion: The 95 EPS is probably the same/similar as the 91 EPS for automatics.

Page 17-63.

Drew

 

[D'Ecosse]

Opinion: The 95 EPS is probably the same/similar as the 91 EPS for automatics.

Page 17-63.

Drew

It is - same part number for all auto 91-96 & MT 95-96
53601-SL0-A00

The one in zanardi is same for all 97- 02 (coupes, zanardi, T's - both auto & manual transmissions) - that is a -A01 suffix - although it also lists a -A02 suffix for same years and additionally 03 & 04. Not sure what the difference between -A01 & -A02 is. They are delineated in the parts identifier by an "s" and "z" designator (but nothing to do with Zanardi as both as listed as applicable for zanardi)

The -A03 suffix part is pecific to 2004/05 models. I suspect they are somewhat all interchangeable but can't guarantee that.

 

[nsx2tall]

It is - same part number for all auto 91-96 & MT 95-96
53601-SL0-A00

The one in zanardi is same for all 97- 02 (coupes, zanardi, T's - both auto & manual transmissions) - that is a -A01 suffix

So the Zanardi manual steering rack is really just a power rack without the EPS unit? Does it still have the internal EPS assist motor and gear? I thought the weight reduction came from deleting these-- certainly you wouldn't get -32 lbs from just the EPS unit. Does this imply that you'd have to put an EPS rack on a Zanardi if ever the stock rack needed replacing?

 

[D'Ecosse]

Does this imply that you'd have to put an EPS rack on a Zanardi if ever the stock rack needed replacing?

Whatever is inside a Zanardi rack is also inside an EPS rack since the part numbers are the same.
Way more complex than the 91-94 maual transmission coupes!
(a conversion to that system would most certainly save a lot of weight)

 

[Dinan M3]

The '99 had variable ratio steering, except that the auto transmission versions had fixed ratio steering. Might the variable ratio stuff be the cause of the added complexity vis-a-vis the earlier models?

 

[nsx2tall]

Whatever is inside a Zanardi rack is also inside an EPS rack since the part numbers are the same.

I hope to be able to definitively show this one way or another. More details to follow.

[Details]

Attached is the Zanardi Rack. It is pretty much as different from any NSX EPS system as you can get. It's about as simple as you could make a rack and pinion. My suspicions were confirmed. I wonder if this can still be purchased as an OEM part?

 

[AJKS]

I hope to be able to definitively show this one way or another. More details to follow.

[Details]

Attached is the Zanardi Rack. It is pretty much as different from any NSX EPS system as you can get. It's about as simple as you could make a rack and pinion. My suspicions were confirmed. I wonder if this can still be purchased as an OEM part?

Do you have a Zanardi Rack yet? If so are you going to try an install on your EPS NSX T? I would love to get rid of my EPS in my 2002. If it works let me know ASAP.

 

[D'Ecosse]

Here is the parts break-out for the manual rack

 

[D'Ecosse]

Here's the zanardi breakout - note that it is same part number for the other models (although as I mentioned earlier there is also a second number for both - I really don't know what the difference between the 'S' & 'Z' designations is)

 

[nsxtasy]

Nice rack!

 

[WingZ]

Do you have a Zanardi Rack yet? If so are you going to try an install on your EPS NSX T? I would love to get rid of my EPS in my 2002. If it works let me know ASAP.

Anyone know what happened with this and if this mod is possible?

 

[nsx2tall]

Works fine. No extra parts or modifications needed. Consider removing the EPS bulb if you don't want the light on all the time.

 

[WingZ]

Works fine. No extra parts or modifications needed. Consider removing the EPS bulb if you don't want the light on all the time.

Wow so then with this it's then possible to do the NSX-R limited slip which can't be done with the power steering

 

[Larry Bastanza]

Wow so then with this it's then possible to do the NSX-R limited slip which can't be done with the power steering

Yes that is correct.

Also you can backdate the EPS to the pre-1997 version and keep the PS if you like, for a LOT more money. (I have successfully installed the 4.23 in a 1995-96 w/EPS with no issue. The 1997+ EPS is different.

I spoke with Uehara san over the summer, and unfortunately, the combo of 1997+ EPS and the 4.23 ring gear is a no-go, with no fix available.

 

[WingZ]

Yes that is correct.

Also you can backdate the EPS to the pre-1997 version and keep the PS if you like, for a LOT more money. (I have successfully installed the 4.23 in a 1995-96 w/EPS with no issue. The 1997+ EPS is different.

I spoke with Uehara san over the summer, and unfortunately, the combo of 1997+ EPS and the 4.23 ring gear is a no-go, with no fix available.

Larry you are the MAN! But now is the 4.23 ring gear the same as the LSD or is that just the short gearing? Please excuse my ignorance but I thought the 4.23 was basically just short gears

I can't find the part any longer but I thought that Dali or SOS use to also sell the 02+ NSX-R LSD

Lastly seems like the Zanardi rack is $5k wouldn't I have a better chance finding a used rack off a 95-96 for less or is their more cost to the rack for those years? Thanks!

 

[Larry Bastanza]

OK, the "short gears" are revised 2nd ,3rd, and 4th for the 5 Speed. You already have the short gears in your 6 speed. (not exact but close enough)

Your "ring rear", commonly known as the "dif", in the stock NSX is a 4.06 ratio(5 or 6 speed), the "R" ring gear is the 4.23.

Additionally they change the rear end "break-away" torque from about 60 ft. lbs. to just over 100 ft. lbs. (that is the change in the "limited slip").

If you wanted to use the 4.23, you will also need to backdate the differential to a 1991-94 dif. 1995+ differentials are different and are not compatible with the 4.23 gear. (the ring gear mounts to the dif)

So you will need:

1. 4.23 ring gear
2. 1991-94 dif
3. Special shims to increase the preload + "R" Stopper plate
4. Manual steering rack or backdated EPS(BTW, this requires the ENTIRE system, not just the rack if you want to stay with EPS)

HTH,
LarryB

 

[ffffanman]

Where does this guy get all this stuff.
I really thought Larry had it in books and stuff and looked it up as he went along, but he spewed this kind of stuff out for 30 minutes while driving my car at break neck speeds through a slalom course they call a road in back woods Oregon!
You the man, Man.
Trev

 

[WingZ]

OK, the "short gears" are revised 2nd ,3rd, and 4th for the 5 Speed. You already have the short gears in your 6 speed. (not exact but close enough)

Your "ring rear", commonly known as the "dif", in the stock NSX is a 4.06 ratio(5 or 6 speed), the "R" ring gear is the 4.23.

Additionally they change the rear end "break-away" torque from about 60 ft. lbs. to just over 100 ft. lbs. (that is the change in the "limited slip").

If you wanted to use the 4.23, you will also need to backdate the differential to a 1991-94 dif. 1995+ differentials are different and are not compatible with the 4.23 gear. (the ring gear mounts to the dif)

So you will need:

1. 4.23 ring gear
2. 1991-94 dif
3. Special shims to increase the preload + "R" Stopper plate
4. Manual steering rack or backdated EPS(BTW, this requires the ENTIRE system, not just the rack if you want to stay with EPS)

HTH,
LarryB

Mmm methinks this be not so simple:biggrin:

Well I'd always wondered why I've never seen a 97+ with this mod.

Thanks again Larry

P.S Where would I get the special shims? I guess Honda went the cheap for them route in using the old 91-94 diffs. I'm starting to wonder know if it's better/cheaper to turn a 93-94 into a 02+ NSX-R since headers/exhaust will basically make up the power difference and then just add the six speed.

Oh yeah and do you know off the top of your head what the OEM seats weigh? I've seen from 44-80 lbs and would like not to have to take mine out to be certain:biggrin:

Where does this guy get all this stuff.
I really thought Larry had it in books and stuff and looked it up as he went along, but he spewed this kind of stuff out for 30 minutes while driving my car at break neck speeds through a slalom course they call a road in back woods Oregon!
You the man, Man.
Trev

No kidding plus he mentioned Uhera and called him san w/o missing a beat ...blew me away! NSX sensei:wink:

 

[nsx2tall]

...

Lastly seems like the Zanardi rack is $5k wouldn't I have a better chance finding a used rack off a 95-96 for less or is their more cost to the rack for those years? Thanks!

Some clarification.

There is no "Zanardi" rack. I just happen to have the manual rack from a Zanardi, but 91-94 manual racks are equivalent. Purchasing the manual rack (even new) should be less than $1k (I think). The EPS racks are the ones that run north of $5k.

 

[WingZ]

Some clarification.

There is no "Zanardi" rack. I just happen to have the manual rack from a Zanardi, but 91-94 manual racks are equivalent. Purchasing the manual rack (even new) should be less than $1k (I think). The EPS racks are the ones that run north of $5k.

Hey Tall

Post #11 shows the Zanardi part number and I was just going off the one of the discount dealer prices from the web. Where'd you get your rack from?

 

[nsx2tall]

From a salvage yard in New Jersey. erzcar.com if I recall the name correctly.

I see your point about the power steering from the parts list, though I thought the Zanardi's all have manual steering racks (weight savings). Perhaps mine was actually a 91-94.