Fiat coupe/Alfa gear set interchangability?

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Infectus-Guy
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Fiat coupe/Alfa gear set interchangability?

Post by Infectus-Guy »

Hi chaps, i wonder if anyone has, or knows of anyone who has experience with swapping gears between various Fiat/Alfa boxes. The reason i ask is that i want to build up a box for my FWD Lancia delta hf turbo i.e. hillclimb car with a tall first gear then try and bunch up the rest (2nd, 3rd, 4th, not too worried about 5th) using swapped over gear sets. I can't afford to have a custom box made up so this is my only real option, i'd like to use a coupe box with the visco drive if possible, better than no slipper at all. So i guess this will be the box i will start with, then I'm hoping if there are enough final drive options out there so that i might be able to get something sorted out.
Anyone think this is possible of have i had one lungful of waxoyl smoke too many?
Thanks,
Guy
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Brit01
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Re: Fiat coupe/Alfa gear set interchangability?

Post by Brit01 »

Not sure about compatibility but this information may be of use to you with the ratios of all Alfa gear boxes.
The 1.5 33 ratios are quite favourable. I would like to change my 1st/2nd gear ratios as the 1.7 is not my cup of tea at all. 1.7 engines with 1.5 ratios are quite common for racing.

Sud 1.5= 1:3.750 - 1:2.062

My 33 1.7 = 1:3.143 - 1:1.864

Chris
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dobromir
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Re: Fiat coupe/Alfa gear set interchangability?

Post by dobromir »

Do regulations allow using a gearbox from a different car?If yes,I have a few suggestions.Very cheap ones,indeed...
I've never really messed around that much with HF turbo FWD gearbox,though.But the Dedra Integrale 4WD gears are interchangeable with any Lancia Turbo FWD gears - Kappa,Thema,Lybra etc.In fact,more than half of the 4WD gearbox is the same as the FWD - just a thought...
Infectus-Guy
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Re: Fiat coupe/Alfa gear set interchangability?

Post by Infectus-Guy »

Thanks guys, that's some great information and ideas for me to think about. I guess im just going to have to keep my eye out for as many cheap gearboxes as possible!
Thanks,
Guy
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WhizzMan
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Re: Fiat coupe/Alfa gear set interchangability?

Post by WhizzMan »

There are two main groups of gear boxes used that are shared between a lot of Fiat/Alfa/Lancia models. There's the C503/C530 box that is used in the Evo2, Alfa V6, JTD and such. The 503 is the 5 speed, the 530 is the six speed. I don't know if many parts are interchangeable between the 503 and the 530, but the 503 has a lot of parts you can swap around between the variations. Then there's the C510 box which is lighter. It's used in the Alfa 16V TS and the Punto Turbo, to name a few examples. There are also lighter boxes used on the panda and derivatives with the 1st few generations of Fire engines, but I doubt those are of interest to you.
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fingers99
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Re: Fiat coupe/Alfa gear set interchangability?

Post by fingers99 »

Our friend HoSDo over on Fiat Forum recently blew the innards of his Rotrex supercharged, M Jet engined Mk1 Punto, so did a fair bit of research into what stronger gearbox might fit. The 510 was, he found, fitted to Punto GT, Punto TD, JTDs, MJETs and HGT. It's also to be found on the 500 Abarth (but not on any of the other T Jet cars, which all have 6 speed boxes) and the Alfa 155s and 156. People have seen in excess of 200bhp from the T Jet, so it should be a good match for your car.

The smaller FIRE boxes seem to wilt at anything over 150 bhp, so would be marginal in your application.

Good luck with it!
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Re: Fiat coupe/Alfa gear set interchangability?

Post by WhizzMan »

fingers99 wrote:The 510 was, he found, fitted to Punto GT, Punto TD, JTDs, MJETs and HGT.
Maybe on more modern three cylinder JTDs, but the 1.9 8v original JTD already had too much torque for the C510.

Be aware, it's about torque, not horsepower for gear box selection. The input shaft, the input bearing and the teeth on the gears will have to deal with torque that can break them. How much RPM they have to make is relatively trivial, since there's not that much difference in 5000 rpm and 7500 rpm redline when designing an automotive gear box. You can get a C510 box to take 250 HP on an NA 2.0 16V TwinSpark engine, but it won't take 150 HP on a 1.9 16V JTD.
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fingers99
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Re: Fiat coupe/Alfa gear set interchangability?

Post by fingers99 »

Agreed re the torque. If I had the figures, I'd have used them. But the OP isn't running a deisel.........

Given petrol, given the spec, the old 510 will do just fine (but I'd not trust one past the kind of torque a full race T Jet can make, and well below that if 1/4 mile is the intent).

I think I missed the 147 off the list.

But, lots of them about, happy hunting.
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WhizzMan
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Re: Fiat coupe/Alfa gear set interchangability?

Post by WhizzMan »

The OP is running a turbo engine, so torque is very much significant. Those easily push over the 200 or so Nm that the C510 box can take.

The stock visco is only used on the C503/530 boxes as far as I know? What is the original box used on this car? What torque figures are you expecting from the engine?
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fingers99
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Re: Fiat coupe/Alfa gear set interchangability?

Post by fingers99 »

WhizzMan wrote:The OP is running a turbo engine, so torque is very much significant. Those easily push over the 200 or so Nm that the C510 box can take.

The stock visco is only used on the C503/530 boxes as far as I know? What is the original box used on this car? What torque figures are you expecting from the engine?
The 500 Abarth is also a turbo engine, as is the Punto GT. I'd not expect a 1600 turbo to produce significantly more power or torque -- indeed, I'd expect (but would be happy to be proved wrong) it to be well down on a 500 T Jet in race spec.

Of course, if we're talking of the 2 litre engine, then all bets are off. Lots of Fiat Coupe boxes out there, and, it's said, they'll take the stiffening bracket out of the Integrale box. At that point, the visco probably becomes the weak point.
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Re: Fiat coupe/Alfa gear set interchangability?

Post by Infectus-Guy »

510 box sounds like a good step up for me then. I'm guessing there was never one of these boxes with visco drive then? Shame as LSD would be useful for hillclimb i think.
Guy
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WhizzMan
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Re: Fiat coupe/Alfa gear set interchangability?

Post by WhizzMan »

C510 box is a model family name from Fiat Power Train. I know that Quaife sells torsen diffs for the 510 and AHM has a plate LSD. There could be others as well, but I don't know of any myself.
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