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Discussion Starter #1 (Edited)
We had the Miata limited slip in our Classica, it worked okay, now testing the OSGIKEN Competition 24 Disc Limited Slip. We have used these in our higher powered Miatas for many years, this has always been our choice when putting down over 200 hp, a great choice to support our continuing development of the car. I raced the car today at BMW Autocross. Did it on street tires in STR trim, fastest street tire time of the day (got beat for overall Top Time of Day only but a few friends on Hoosiers...by about one second). Will test it again next time on set of Hoosiers. My jump in time from Rivals on the car today to Hoosiers is usually about 2 seconds, so I expect the mighty Fiat will be Top Time of Day at next BMW Club event....will see. The feel of this unit is more aggressive than stock, takes a little time to understand that you mash the throttle and need to trust that when the rear steps out at corner exit it will then lay power very effectively, reaction is a bit faster than with the conservative lockup rate of the stock unit.


 

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Mahalo for the intel...you go get them beemers!!!
 

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We had the Miata limited slip in our Classica, it worked okay, now testing the OSGIKEN Competition 24 Disc Limited Slip. We have used these in our higher powered Miatas for many years, this has always been our choice when putting down over 200 hp, a great choice to support our continuing development of the car. I raced the car today at BMW Autocross. Did it on street tires in STR trim, fastest street tire time of the day (got beat for overall Top Time of Day only but a few friends on Hoosiers...by about one second). Will test it again next time on set of Hoosiers. My jump in time from Rivals on the car today to Hoosiers is usually about 2 seconds, so I expect the mighty Fiat will be Top Time of Day at next BMW Club event....will see. The feel of this unit is more aggressive than stock, takes a little time to understand that you mash the throttle and need to trust that when the rear steps out at corner exit it will then lay power very effectively, reaction is a bit faster than with the conservative lockup rate of the stock unit.


Hi Brian
Great results!
Are you still running the 2.9 mazda gears or have you switched back to the 3.5 Fiats?

Jason
 

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OS Giken diffs are awesome. traction everywhere. It's hard to grasp how much better they are than something like a Torsten or quaife without actually trying it out. More power sooner everywhere. Very streetable (progressive) for a clutch pack when set up properly too. Expensive but one of those secret weapons I've seen the fast guys use.
 

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Discussion Starter #5
Hi Brian
Great results!
Are you still running the 2.9 mazda gears or have you switched back to the 3.5 Fiats?

Jason

Our stock rear 'Fiat' housing went all the way to Japan for OSGIKEN to engineer the new setup and then came back in pieces. We put it together with the original 3.4. Thus, our days with the Miata super tall 2.9 rear are over for now. At the autocross today the old 2.9 setup would have stayed in 2nd gear more of the time, the new setup with original stock 3.4 FDR needed third gear several places....but launched faster/harder from the tighter turns. It's a tradeoff.
 

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Wow, that'll make the decision really hard. I'm seriously considering getting a complete ND LSD rear to drop in. What you'd said about the taller gearing and not having to flip in and out of 3rd gear is right up my alley. I had to shift to 3rd on some of the bigger Midwest divisional courses in my Neon because of the insane power that car made. As we get weight out and power in our 124, I expect this to be an issue again.
 

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Discussion Starter #7
Wow, that'll make the decision really hard. I'm seriously considering getting a complete ND LSD rear to drop in. What you'd said about the taller gearing and not having to flip in and out of 3rd gear is right up my alley. I had to shift to 3rd on some of the bigger Midwest divisional courses in my Neon because of the insane power that car made. As we get weight out and power in our 124, I expect this to be an issue again.
Do your events there get to 60mph typically such that you need the 2.9 from the Miata to stay in 2nd gear?
 

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Great news for Classica and Lusso owners! Woot!!!!
 

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Discussion Starter #11 (Edited)
And hard core Abarths!
That's right, we have found the limits of the factory limited slip.

Not a factor for street drivers, but autocross/track guys can feel the difference once the torque level at the wheels is above a genuine 200 Ft/lbs. Stock unit simply not designed to handle that power. By the way, the OSGIKEN can be tuned to the power level you make. I just had them tune one for 250 ft/lbs of torque for our ND Miata. The power race is on between our ND Miatas and our Fiat 124 projects. In the Fiat 124 corner...is a turbo motor. In our Miata now...is a TVS900 Supercharger.
 

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That's right, we have found the limits of the factory limited slip.

Not a factor for street drivers, but autocross/track guys can feel the difference once the torque level at the wheels is above a genuine 200 Ft/lbs. Stock unit simply not designed to handle that power. By the way, the OSGIKEN can be tuned to the power level you make. I just had them tune one for 250 ft/lbs of torque for our ND Miata. The power race is on between our ND Miatas and our Fiat 124 projects. In the Fiat 124 corner...is a turbo motor. In our Miata now...is a TVS900 Supercharger.
If I understand correctly, you used an ND Miata LSD with a different gear ratio in the Fiat. Are you confident that the limits of the Abarth factory limited slip are the same as the limits of the ND limited slip?
 

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Discussion Starter #13
If I understand correctly, you used an ND Miata LSD with a different gear ratio in the Fiat. Are you confident that the limits of the Abarth factory limited slip are the same as the limits of the ND limited slip?
I have raced an ABARTH with our full exhaust and reflash, customer car, and the limited slip was the weak link.
 

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Discussion Starter #14
We have been fortunate enough that a number of customers have made the drive here to San Diego and I have been able to drive their installations at local events. Pics here of Kathi and her Abarth from Arizona at our last BMW CLUB event. This car has our full exhaust and other goodies and one of several that I have driven that has reached about the limit of the stock limited slip. The limited slip was a weak link even on stock tires. Another event this weekend here in San Diego at the Stadium, open event Saturday I will miss...but I plan to attend the Sunday event. Come on down even if just for a ride in whatever project car we bring. Continuing to work on the reflash, likely have our Fiat 124 at the event with latest version of the reflash for further testing Sunday.


 
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