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Spitfire 1500 Rear end conversion questions

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geeteesix Avatar
geeteesix martin diederen
kerkrade, limburg, Netherlands   NLD
I am fully agree, a carrier made of better material would be a solution.
25 years ago i did research the problems of breaking axles all the time of the lockheed axle off the triumph TR2. a better material was the solution. The only problem where the costs of one pair of axles (500 Dollars). nevertheless I did(had to) order 10 pairs of them and sold the others without any profit which was not easy for that price. Otherwise all those who drive this axles had no problems anymore.
It needs a lot of time and energy to develop new parts and does not work for a small number of clients so I think it is easier to take a quaife and modify some parts in case of a GT6 diff.

martin

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Gt6s Avatar
Gt6s Laurence Cochrane
Newtownards, UK   GBR
1972 Triumph GT6 MkIII "2600 EFI"
1973 Triumph GT6 MkIII "2500"
1976 Triumph Spitfire "Sixfire 2500"
In reply to # 858895 by geeteesix
How many horse power has your car and how many mles you did already have experience with the quaife diff now?
Thanks in forward for you reaction in this
martin

Martin My car has never been on a rolling road but at a guess she would be knocking on the door of 200 Bear in mind she is reved to 7000 very regularly, powerband is 4000 to 7000, but due to the EFI she has a lot of grunt everywhere but really comes on strong at four. 0-60 time has been recorded on a race technology performance meter at 4.7 seconds, verified on same run by ECU's data logging. In od top she is begging for another cog @ shift light (shift light on @ 5800 = 140 mph) I had her once on the hard cut limiter 7000 rpm in od top(what's that vibration ?). When I got home I measured the tyres and worked out the gearing, taller than stock tyres and the taller 28% overdrive. These calculations worked out @ 24 mph per 1000 rpm. 7000 rpm = 168 mph.
Never tried that one again not on 130 rated tyres, New ones for next year are rated at 160.

The quaife diff has been nothing but a sucess on the 3.63 crownwheel and pinion it has stuck a lot of abuse several years of very silly road use, autotests, and trackdays. Note, I could break an anvil. Car will be campained in sprints and hillclimbs this coming season and I do'nt forsee any issues with it.

Laurence



Edited 4 time(s). Last edit at 2012-12-30 05:14 PM by Gt6s.

geeteesix Avatar
geeteesix martin diederen
kerkrade, limburg, Netherlands   NLD
Laurence, thank you very much for you fast reply,
In my case it is a 2ltr engine, j-type overdrive, 11.8:1 compression stage 5 cam, exhaust 6-2-1, 3 weber instead of stromberghs.Tyre size 175-70-13(iknow nothing for racing but comfotable on street)is about 10% overdrive towards the originals(155x60).Fully tested and total 158 Hp @ 6400rpm. Power range 3500-7000rpm.Accelerating 6.8 seconds at 100km/h.top speed 225km/h which you cannot drivewithout spoiler because over 210 the front of the car is being lifted. Maybe interesting for people my fuel consuption is 1 ltr more as original at 100km (10-11 ltr). For years agoo we did win a six hour race at the nuernburg-ring with a tr3 agains a tr4 with much more power but a very high fuel consumption.
Specially on carbs I offen see tuned cars wich where very wasting with fuel which is not necessary.
So with your experience I will go for a quaife diff modification.
The only i am worrying about, the choice between 3.27 or 3.63 crown an pinion where many people say the 3.27 is too weak which i do not realy understand here because by damaging the pinion mostly we speak about old and tired diffs out of measurements.
With the 3.63 the accelleration would increase but at traveling more noisy.

martin

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Gt6s Avatar
Gt6s Laurence Cochrane
Newtownards, UK   GBR
1972 Triumph GT6 MkIII "2600 EFI"
1973 Triumph GT6 MkIII "2500"
1976 Triumph Spitfire "Sixfire 2500"
Martin even with me using a 2.5 overbored to 2.6 on modified Lucas PI 46mm throttle bodies and a wild cam, with the engine management driven even half sanely she is not much harder on fuel than a stock Gt6
3.27 with overdrive runs @ 25 mph per 1000 rpm If you up your rear tyre size to 185/70/13 or rolling equivelent (I run 205/50/15) and up the OD to a 28% J type from a 2500S or late PI this gives 24 mph per 1000 rpm.
With a 3.27 the pinion spliting is caused because the pinion gear is not solid the inside of the pinnion has a deep grove in it to reduce the weight, efectively it is shaped like a mushroom or even an umberella, so in my opinion it is not just old pinions but a weakness in the overstressed poorly designed pinion.
Also it appears that the Quaife needs modified to fit the 3.27 crown wheel a 3.63 goes straight on.

Laurence

geeteesix Avatar
geeteesix martin diederen
kerkrade, limburg, Netherlands   NLD
dear laurence,

The quaife with a 3.63 is fitted in my GT6 since 3 week and I have to report, only succes till now.
The operation was peace of a cake.
Because off the 3.63 ratio more torque on the street, cornering is much more better specially in the rain there is much more control because of the quaife in it.
My 3.27 diff lives in the spit where the 3.63 comes from, he is happy and i am happy so again a succes without money.
The quaife was about 800 Euro and new seals/bearings about 200 Euro.
Time wil learn if the crown en pinion like the 160 horse power, in my opinion yes.

steveJM steven mathews
Sandringham, VIC, Australia   AUS
Has anyone managed to find a supplier of the R160 rear adaptor plate, under bracket, top bracket, axles conversion etc....
please update post with contacts,...

OR
Else post interest in a group order from Australia. Greg Tunstall has made for him self in the past and will consider a group order if the numbers are there..


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Gt6s Avatar
Gt6s Laurence Cochrane
Newtownards, UK   GBR
1972 Triumph GT6 MkIII "2600 EFI"
1973 Triumph GT6 MkIII "2500"
1976 Triumph Spitfire "Sixfire 2500"
In reply to # 852729 by claytoncnc Peter

I have an R160 in my spit. This one is from a Datsun 1600 (510) with the flanges. The later R180, and Subaru R160 have a single bolt fixing of shaft to axle, so the axle arrangement will change.

I welded some lugs to the back of the diff that coincide with the spit through bolt, and fabricated a front mount from some rectangular section to bolt onto the R160. Adapter flanges were fabricated for the axle, and a Datsun flange was attached to the spit prop shaft. The conversion has been in the car for 30 years, with no trouble.

I cut my spit axles and put a rotoflex in, made a bearing carrier to support the hub, and added a lower wishbone.

Are they Kirky seats you have in your car? I am just contemplating something similar.

I see from those photos you have re manufactured the (Infamous) SAH Shite a turn suspension

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Sparrow010 Avatar
Sparrow010 Andrew Gaskin
Feilding, Feilding, New Zealand   NZL
1971 Triumph Spitfire MkIV "Spitie"
1974 Triumph Stag "Staggy"
COMPOENTS FOR R160 ADAPTER KIT ARE STILL AVAILABLE

Have done some digging and seems that this conversion kit for the R 160 diff can still be made :-)

Am waiting to hear back about current prices from the manufacturers of the casting, front and top plates and a machine shop.
Wondering if any interest from others in purchasing this kit so could pool together for a production run?

Spread the word
Would look at getting this done in a couple of months time
Cheers
Andy G
4AGE SPITIE

tightapex Avatar
tightapex Greg Bailey
Gilroy, California, USA   USA
Tempting. I believe I've got a bad diff bearing in my '74, so the converting to an R160 might be worthwhile.

In reply to # 1470792 by Sparrow010 COMPOENTS FOR R160 ADAPTER KIT ARE STILL AVAILABLE

Have done some digging and seems that this conversion kit for the R 160 diff can still be made :-)

Am waiting to hear back about current prices from the manufacturers of the casting, front and top plates and a machine shop.
Wondering if any interest from others in purchasing this kit so could pool together for a production run?

Spread the word
Would look at getting this done in a couple of months time
Cheers
Andy G
4AGE SPITIE

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Sparrow010 Avatar
Sparrow010 Andrew Gaskin
Feilding, Feilding, New Zealand   NZL
1971 Triumph Spitfire MkIV "Spitie"
1974 Triumph Stag "Staggy"
Things looking good for getting this fitting kit done

casting is available

Have found the machinists who has specs and jig for the work need on raw casting

Talking to a fabrication shop that has previously made the front mount plate and the road spring mount bracket.

This kit would suit any R160 diff Dasun or Subaru

Have expressions of intrest for 3 sets so far

final cost TBC.

Trzforme Don P
Omaha, NE, USA   USA
I would be interested in just the front mount for the R160. Thanks ,Don

clshore Carter Shore
Beverly Hills, Florida, USA   USA
In reply to # 1471484 by Trzforme I would be interested in just the front mount for the R160. Thanks ,Don

It's just a piece of flat steel, cut out and then creased.
The dimensions have been published online.
You can DIY, or have any local shop make it in a day or so.
The hard bit is the rear plate casting, and having it machined.

Sparrow010 Avatar
Sparrow010 Andrew Gaskin
Feilding, Feilding, New Zealand   NZL
1971 Triumph Spitfire MkIV "Spitie"
1974 Triumph Stag "Staggy"
Up date on progress of the Tri/Dat R160 conversion Kit

http://www.triumphexp.com/phorum/read.php?5,1258128

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