Ben D

no need for someone to design a 40 spline part if you are running a Z31T rear end, Ross at Moidern Motorsports www.modern-motorsports.com has already got the design, and they have been tried and tested.

Don't any of the S12 owners in the world have RSX gazelles they are doing up ? It would be a real shame to junk the crank - you guys just can't find them over there.

Hi guys, I still have one good FJ20 ET crankshaft in the USA being copied at Crower, and since I no longer need it, and Crower are finished with it, I want to see it go to a good home. It will be first in best dressed. E-mail me at ben@digsfish.com with your offer and your address and I'll get it sent to you and we can work out how you'll pay me later. I will not let Crower destroy the crank, they are too rare , surely someones needs a spare FJ20 crank over there in the US of A ? Ben D

Radial ball bearings have pretty consistent decription numbers for them as used by manufacturers such as NSK, Nachii etc. A 6007 series bearing has the right dimensions (62 mm OD, 35 mm ID), load and speed ratings to accomodate the part produced by Ross, however if there is enough interest in the part I think he will end up developing and marketing a complete kit including bearing and seal as well as companion flange and of course the stub axle itself. Over to you Ross and Modern Motorsports !

PS, There will be nothing metalurgically wrong with the 27 spline MM stubs that broke - they just have limits like all other parts, and the design of the neck down means they will always break at the end of the spline as the spline itself acts as a serration whenever an axle is necked down like that. The part simply breaks at the weakest point and there is nothing you can do about it except either A. cease the brutish launch behaviour or B. go to a stronger part. Personally, I always like to go to the strongest part available.....

Hi guys, I read this one with much interest. Welcome to the world of heavy duty stub axles. I worked on this with Ross at Modern Motorsports over a year back now after consistently breaking numerous stub axles in my little 4 cylinder S12 gazelle, which while only 2 litres, was running into the 9s at over 147 mph. The S12 gazelle RSX uses OEM R200 CLSD with suspension/crossmember which is identical to Z31 T 300 ZX. What I learned with this car is as follows: 1. stock 27 spline Z31 stub axles are good for a few 10 second passes before failure using a manual gearbox. With an auto I expect they'd last a lot longer. 2. make the 27 spline piece out of good material (4340, 300M, 2767 tool steel) and they will get you into the mid nines at 1.4 to 60 ft before they break with a manual box. Expect 8 to 10 passes out of them if you 60 ft into the high 1.30s. 3. the only solution is to increase the axle cross sectional area, which is possible by running a bigger bearing OD on the inner bearing to remove the neck down in the stock Z31 stub. 4. Ross at Modern motorsports has developed these for the Z31 stub axle and it is a 40 spline unit with matching companion flange which fits into Z31s if you use an inner bearing with a 35 mm ID (OD remains 62 mm) and the appropriate oil seal. 5. The part description for the inner bearing is 6007, the new oil seal to suit the companion flange is a 48 mm ID, 62 mm OD, haven't got the part numnber on me at the moment. Ross has manufactured these and I have tested the prototypes and can report they are good to at least 1.33 sec 60 foots and 9.12 &154 mph in my little 4 banger beast. In fact, its possible to hang the wheels in the air a fair ways with these parts. They should get you guys well into the 8's I would think. I attach pics of the pieces- the big stub is on the left. I also attach pics of what they can do for your car.

PS when the halfshaft broke, the car still drove down and back on the LSD (which is shimmed pretty tight), and since it broke where it did, the CV boot held it in alignment so it damaged nothing. Lucky I suppose.

I've broken one half shaft, I'm using a Z31T IRS with stock Z31 T shafts with a manual gearbox, and if the halfshafts break, they break on the launch. However if you can preload the driveline a little, they seem to hang in there, its the inertia shock of the clutch dump which does it. Furtunately you're doing 0 mph when it happens. They break at the root of the outer CV spline car in my experience, but I have only broken 1 so far, and this set I have in there now has done 25 x 9 sec runs and a best of 9.12 with 1.33 to 60 ft, so they are impressive for stock pieces. I've said to myself if I break another one, it is time to go to either a GTR style half shaft and CV (bigger splines), and/or get a set made from 300M. With both bigger CVs and the 300M shaft, I would say mid 8's would be attainable and reliable with my combo (would need more power then)....

shes certainly doing a great job for Canada. World class. Maybe we should change the name of this thread to something more appropriate ???

1983-85 S12 RSX Gazelle/silvia and 1983-85 DR30 RS turbo and DR30 RSX (intercooled - late model "iron mask") I have FJ20ET in my 510 too, nice swap, but the engine makes it a little nose heavy, and its a tight fit around the steering box for Left hand drive cars. I reckon if you bought a DR30 or S12 RSX, keep the whole car and you won't be disappointed, as they already have R200 LSDs, 5 speed, big 4 wheel disc brakes etc. and aren't too much heaver than a 510.

I ran the car on the street with the GT35R and a tight turbine housing (0.82), I found it spooled about as well as an old T3/4 hybrid I had on a previous car, so I reckon they are definitely streetable . They don't pull like a bigblock from 2000 rpm (they are only 2 litres after all), but from 3500 on you have to hold on. So compared to other cars with similar performance, the GT35R is definitely on the small side. It would boogie with a 88-94 mm compressor on it I'd reckon......... All the FJ20s are twin cam 16 valve, they are simply so old that Nissan was not using the D suffix for their motors back then in the early 80's. Today, nissan would call the turbo variant as FJ20DET. But the comparison between FJ and L is correct, they were both around at the same time., though the L was a late 60's design and the FJ a late 70's early 80's design.

Thanks for the support Guys. It does show what can be done with the Z31T rear end. For those who asked, I'll give it a wheel alignment (looks like the toe /camber moved a bit after that second launch) and will tighten up the LSD a bit more then back for the nationals and jamboree. On a prepped track we should be able to get the power down in the higher gears and we'll see what she will do then. Still running the small street turbo and mild cams, though I'm not sure what I'd do with the extra power anyway if we upgraded either again. Yes, the FJ is a great old motor - they appear to have the edge over SR20 and are at least equal to 4G63 mitsubishi in some areas. I'm running stock block, crank, inlet manifold etc., so they are great packages out of the factory. Pity they stopped making them 20 years ago...... Ben

some videos thanks to the blokes at Gunnamotorsports at http://www.gunnamotorsport.com/vids/willowbank-update/GUNNA-Gazelle-190706.wmv and http://www.gunnamotorsport.com/vids/willowbank-update/GUNNA-N13-190706.wmv

Just thought I'd let you blokes know that I got my S12 gazelle down to a test n tune the other night here in Australia and we put down a 9.12 @ 153.4 mph. Specs on the car include factory fitted 2 litre 4 cyl FJ20 ET engine, little street cams and turbo (garrett GT35R), 5 speed manual out of a R33 GTS-T and stock R200 LSD and Z31 T half shafts. The good bits are the Link G2 ECU and the modern motorsports Z31 stub axle upgrade. All glass etc. still in the car and 2600 lb weight. The air was good so the second pass of the night we turned it up to see if there was an 8 in it, but got into a wheelstand situation and had to get out of it and back on for a 9.7 at 151. Then the last pass of the evening the track went away and we could'nt get the power down. Updated the timeslips section - I guess it might get up the noses of the 6 cyl and V8 guys to have the little 4 cylinder up there, but hey its a factory car with a factory fitted engine , factory fitted Z31 equivalent rear end, factory driveline configuration with the manual stick shift, so I guess its OK to post it here ? Ben