Jump to content
HybridZ

RB25 + R32 GTR rear


Guest redm0nster

Recommended Posts

Guest redm0nster

Hi Guys,

 

I'm just about to start on my project... (finally!). Car is in the shop, halfcut RB25DET transferred from my garage.

 

My mechanic and I have decided to also include the rear segment of the RB into my project. He figures that the existing unit wont be able to handle the increased in hp, something I had already known btw. By including the rear portion, I will also benefit from the LSD. All in all, it'll be a skyline with a z body... hahaha... Anyway, my question or should I say problem...

 

Can I fit the rear of a R32GTR to fit nicely with my RB25DET and propeller shaft (with minor mods)? Reason for this, I can only find a R32GTR complete rear (with suspensions and brakes systems, got a super deal on this). I do realise that the GTRS come with 4 wheel steering and for the back steering, a motor actually moves the tires. Can this part be locked? somehow? Can I do this?

 

What do you guys think? Hoping for the best... otherwise its a few more months of hunting!

 

Best - Rizal

Link to comment
Share on other sites

hello, yes you can swap it into your z. it takes a good amount of cutting and bracing and the rear steering your talking about does need to be locked. it is a special bar that you get that eliminates it but im not sure where you can get it. i believe s13 subframe is same as r32 so do a search for 240sx subframe. i believe the rear mounting points mount 2.5 inches behind the original bar that holds up your mustache bar. (not the same width as your old mustache mounts its like 45 inches apart or something) so you have to weld a strong bar between the rear subframe to get it mounted correctly. then the boxes need to be cut out (you know, the little ones in your trunk?) so the forward link can have clearance and the front portion of the subframe, mounts into the front part of the original subframe. you need to cut the front leg of the forward original subframe and weld in a sleeve so this area can be tightened without smashing the original subframe. definately needs to be braced so area does not flex wehn doing all this cutting and welding. (what im working on right now ill keep u updated) Maichor did this and has a few pics but some arent showing up anymore. just measure a lot and you should be ok. im doing this right now so i will post up pics when i can, and if possible try and help you. i got a S13 subframe with CLSD from japan. good luck!

paul

Link to comment
Share on other sites

hi Rizal,

 

I'm Kevin from malaysia and i have a 280zx with a rb25det... you dont need a R32 gtr rear when a cefiro/s13 rear is the same... no difference and the diff they are suing is the same short nose r200 vlsd. yes it will fit butt there will be portions of the undercarriage that needs to be cut and rewelded. not too big a job but need a skilled and knowledgable mech to do this. most importantly the mounting points have to be solid if not you will be messing a perfectly adequate rear axel that could have taken the power of a supped rb26dett!!!!!!!!

 

kevin kong :)

Link to comment
Share on other sites

The R200 in the GT-R and the Cefiro/S13's are not the same. The GT-R diff is substantially beefier with larger ring gear bolts and larger stub shafts. Additionally, the GT-R front differential mount lugs are different. Although in the same position, they are made with a bushing abd have a cross member that runs across the bottom side where the Cefiro and S13 are just two bolts that go straight up. The case length is different, as well. I think what you are asking is if it's sort of a bolt-in job? The answer is no. One advantage to the Silvia member is that you can get it without the Hicas mount and just toe control rods, stock.

Link to comment
Share on other sites

Guest redm0nster

Guys,

 

Thanks for the response... and I am particulary glad to hear from Kev from Malaysia (Where you at?)

 

Anyway, looking at it... I just want to do a good and through job. Money is not really and issue but ability is. I hear the Cefiro arguement and also the GTR32. What would be ideal?

 

Should I do the cefiro as Kevin has suggested or R32 it? I have to admit, at RM800 (USD200+) for the full **** + grooved discs brakes, its a steal.

 

I'll post pics!

 

Best,

 

Rizal

Link to comment
Share on other sites

I do realise that the GTRS come with 4 wheel steering and for the back steering, a motor actually moves the tires. Can this part be locked? somehow? Can I do this?

 

Its called HICAS. Some Nissans used hydraulics running off the power steering pump, and some used electrical actuators to move the rear wheels. I know specifcally the 90-93 300zx TT's used hydraulic, and the 94+ TT's used electrical actuators. You can eliminate HICAS completely by installing a HICAS elimination or locking kit.

 

For example, HICAS bypass kit for Z32 http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=300ZX-HICAS

Link to comment
Share on other sites

Guest redm0nster

that's it... could not remember it as I'm a Z fan whille my mate who told me about is has over 600bhp at the wheels with his R33GTR.

 

Thanks for the information.

 

Best,

 

Rizal

Link to comment
Share on other sites

The R32 GTR diff is the way to go, it is a clutch type LSD compared to the rest of the GTS's and ceferos etc which are all Viscous.

 

I am using a GTR diff in my 240z, not putting in the whole subframe (just too much work for little gain) putting in the diff alone is reasonably simple in comparison.

Link to comment
Share on other sites

  • 3 months later...
Guest redm0nster

Hi Guys,

 

I have a problem!

 

My '79 280zx has been in the garage for the past 3 months. RB25DET Engine is in. GTR Driveshaft and transmission is in. Front brakes is now dressed in 4-pot calipers. completely replaced all the electrics. In short, its almost done. 2 months tops!

 

Now back to the my problem. The handbrake. The 280ZX brake system, handbrakes are connected to the main calipers while in modern nissan brake systems, the handbrakes is activated by a seperate mechanicsm that is built into the disc like drum brakes. Here is where my problem lies. I am trying to upgrade from the old system to the modern but in the modern system, it is activated via this separate mechanism which is not available in my '79 280zx. Phew.... Now if you got that... I need help!

 

How do I fix this problem? Has anyone come across this before? Or is there another solution that I should consider? Thanks in advance.

 

Best,

 

Riz

Link to comment
Share on other sites

I have just bought a mechanical R200 LSD inner that came out of a JDM Skyline BNR32 GTR (12mm bolts).

 

I have mated this up with a R200 out of a UK 300zx single turbo with 3.36 gears (12mm bolts). I am doing a GTR conversion and so need this lower ratio.

 

So far so good - but right now im stuck on stub axles.

 

Please can anyone point me to a way of finding/adapting a stub axle to mate with the larger GTR inner splines as my searches so far have not come up with anything specific?

 

Thanks

Link to comment
Share on other sites

If you are putting a gtr diff in and still going to use the stock stubs then you are waisting your time. try to figure out a way to modify the strut housing itself or fab up a strut to accept the gtr axle as a whole. i was going this route but failed with z31 stubs. i decided to go solid rearend to ensure i fixed any of my issues. just something to consider. search thru JAMIE T posts and look at his idea for a strut. Best idea i have seen to date to keep the IRS but have soemthing that was strong enough to handle Hi HP motors at the track

Link to comment
Share on other sites

Thanks Stony,

 

I am trying to get my car on the road before summer ends here and need a quick fix - just a stub that will fit to get the diff hooked up to the half shafts.

 

So it looks like I may end up slamming in a standard diff whilst I sort out some suitable GTR half shafts and mod them to fit.... unless there are any other suggestions?

 

Cheers

 

Andy

Link to comment
Share on other sites

JAMIE T is working on a set of struts that are going to be perfect for this kind of rearend buildup. I almost wish i would have gone teh same route with mine instead of all out drag car. there are tons of 9 sec gtrs out there and if you got the diff in teh car with a set of custom lenghth gtr axles that would fit in the Z i think it would be indestructable.

Link to comment
Share on other sites

Hi Stony,

 

With that level of encouragement (use of the word indestructable) I am gonna have to give it 100%.

 

I am off to collect my second GTR engine (old oil in water problems) next week and will also try to pick up a set of GTR half shafts so that I can start figuring out what needs to be done.

 

Thanks

Link to comment
Share on other sites

I have just bought a mechanical R200 LSD inner that came out of a JDM Skyline BNR32 GTR (12mm bolts).

 

I have mated this up with a R200 out of a UK 300zx single turbo with 3.36 gears (12mm bolts). I am doing a GTR conversion and so need this lower ratio.

 

So far so good - but right now im stuck on stub axles.

 

Please can anyone point me to a way of finding/adapting a stub axle to mate with the larger GTR inner splines as my searches so far have not come up with anything specific?

 

if you are doing all this to a 300zx, all you need it 300z twin turbo parts, they are compatible with the skyline parts. GTR axles/diff/hubs/brakes = 300zx TT axles/diff/hubs/brakes

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...