Tranaxle
- Thread starter Ric
- Start date
pyrraxis
True Classic
There are stronger gears out there, but the cost is astronomical! Steve H would be able to tell you what can be done and how as well as the upper limits of the 4-speed vs the 5-speed gearboxes.
Bernice should have some great tips on how to make more power get to the ground reliably. Of course, the real trick is to make that power useable...
Bernice should have some great tips on how to make more power get to the ground reliably. Of course, the real trick is to make that power useable...
Dan Sarandrea (Phila)
Waitin' On Parts...
A Bit Unkind
Assuming your figure of 150HP is true, that represents 75% more HP than the most powerful stock X1/9 (the later euro X was rated at 85HP) had from the factory.
IMO something that can handle up to 75% over it's rated capacity hardly deserves to be called "glass."
I seem to recall some of our Euro friends telling us that the transmission internals from the turbo Unos are a perfect fit for the X tranny and are significantly more durable.
Assuming your figure of 150HP is true, that represents 75% more HP than the most powerful stock X1/9 (the later euro X was rated at 85HP) had from the factory.
IMO something that can handle up to 75% over it's rated capacity hardly deserves to be called "glass."
I seem to recall some of our Euro friends telling us that the transmission internals from the turbo Unos are a perfect fit for the X tranny and are significantly more durable.
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Rupunzell
Bernice Loui
Where is you "hear this, 150 bhp limit" for a stock transaxle?
HP in itself is not the problem for gears, it is torque, how much and how fast it is transferred past any gear system.
As for "Glass" this transaxle has proven to be quite durable/reliable for endurance racing when it is in good condition. This does NOT mean short club race events or autocross, this is transmitting near 130 Bhp hour after hour or hard road racing.
Why the inquiry, planning a different engine or ?
The Turbo Uno innards are reputed to be stronger, but I have no direct experience with them.
Bernice
HP in itself is not the problem for gears, it is torque, how much and how fast it is transferred past any gear system.
As for "Glass" this transaxle has proven to be quite durable/reliable for endurance racing when it is in good condition. This does NOT mean short club race events or autocross, this is transmitting near 130 Bhp hour after hour or hard road racing.
Why the inquiry, planning a different engine or ?
The Turbo Uno innards are reputed to be stronger, but I have no direct experience with them.
Bernice
Old Fiat Driver
Old Fiat Driver
I agree with Rupunzell
I've been autocrossing these transaxles ( 4 speeds ) for 35 years and have never broke any gears. I have seen 148 HP on the PBS dyno out of a 1500 with 45 DCOE'S. My engine is a 1650 CC with duel 40 MM TWM throttle bodies which flow slightly more 45 DCOE's with 36 chokes. My engine is also pumped up in every way you can imagine so I don't think you will have a problem with 150 HP. I do remember PBS haveing trouble with 5th gear when they were road racing but I think that was due to an oiling problem and the fact that 5th gear is in single shear. Also the 5 speed differential is a little suspect if you wind up the RPM'S and drop the clutch such as Pro Solo. Other than that you should be good.
Charlie
I've been autocrossing these transaxles ( 4 speeds ) for 35 years and have never broke any gears. I have seen 148 HP on the PBS dyno out of a 1500 with 45 DCOE'S. My engine is a 1650 CC with duel 40 MM TWM throttle bodies which flow slightly more 45 DCOE's with 36 chokes. My engine is also pumped up in every way you can imagine so I don't think you will have a problem with 150 HP. I do remember PBS haveing trouble with 5th gear when they were road racing but I think that was due to an oiling problem and the fact that 5th gear is in single shear. Also the 5 speed differential is a little suspect if you wind up the RPM'S and drop the clutch such as Pro Solo. Other than that you should be good.
Charlie
Rupunzell
Bernice Loui
+1
The early 5 speed 5th gears were key driven, later ones went to spline drive and the problem with shearing off 5th gear went away.
If this transaxle can stand over a hundred hours of LeMons racing with 100+ Bhp at the rear wheels, it will live well for years and years of track days, autocross and most any road car.
These transaxles are not as fragile as some would believe. If they do have problems, it is due to other factors, not it's innate design.
I'm still wanting to know where this number of 150 BHP being the limit came from.
Bernice
The early 5 speed 5th gears were key driven, later ones went to spline drive and the problem with shearing off 5th gear went away.
If this transaxle can stand over a hundred hours of LeMons racing with 100+ Bhp at the rear wheels, it will live well for years and years of track days, autocross and most any road car.
These transaxles are not as fragile as some would believe. If they do have problems, it is due to other factors, not it's innate design.
I'm still wanting to know where this number of 150 BHP being the limit came from.
Bernice
Glass and 150
This is what I've read on other forums. Still learning, seems most the really in the know hang hear, But at the same time I am trying to figure out when I get an X do I turbo or swap. I've had plenty of cars that have had "weak" trans 2 5.0's and a couple DSM's the mustangs couldn't handle much more than stock. The eclipse had 400hp so that's 2x the hp and torque. Just don't be dumb and dump the cluch.
This is what I've read on other forums. Still learning, seems most the really in the know hang hear, But at the same time I am trying to figure out when I get an X do I turbo or swap. I've had plenty of cars that have had "weak" trans 2 5.0's and a couple DSM's the mustangs couldn't handle much more than stock. The eclipse had 400hp so that's 2x the hp and torque. Just don't be dumb and dump the cluch.
Old Fiat Driver
Old Fiat Driver
Turbos make a lot of torque
That could be a problem. If you pump up tot say 12 PSI you will certinally compromise the clutch which will need to be upgraded also depending on the torque you are talking about, the transaxle could become a problem. It's difficult to say how much torque you could make before having a problem. It all depends how it's driven or raced. On my other autocross car that's exactly why I went to a Lancia transaxle with a larger clutch. It's a 2 liter twin cam turbo with a lot of head work, big cams and a bunch of engine mods and there's no way the x's transaxle would handel the extra torque of this motor. Engine swaps with turbos require a lot of research. good luck.
Charlie
That could be a problem. If you pump up tot say 12 PSI you will certinally compromise the clutch which will need to be upgraded also depending on the torque you are talking about, the transaxle could become a problem. It's difficult to say how much torque you could make before having a problem. It all depends how it's driven or raced. On my other autocross car that's exactly why I went to a Lancia transaxle with a larger clutch. It's a 2 liter twin cam turbo with a lot of head work, big cams and a bunch of engine mods and there's no way the x's transaxle would handel the extra torque of this motor. Engine swaps with turbos require a lot of research. good luck.
Charlie
Rooster
piccole ma cattive
LOL, you gotta take what you read on the web with a grain of salt. The term "glassbox" is slung around alot for my 2002 Subaru WRX as well. Yeah they shatter, but it's usually people doing clutch dumps and all out abusing the drivetrain. I've autoX'd my WRX alot and never had a single transmission problem with it (and its at 300hp).
As for the X-1/9 trans, I have 2 X-1/9's, one's got a turbo at about 105hp at stock boost, and the RaceX is a fully prepped motor (still in process of building) at about 130hp, I have no worries about the trans.
Rupunzell
Bernice Loui
Yea, there are "Glass transmissions" out there. Recently on the table would be the Nisssan GT-R, apparently bust under factory launch control starts resulting in a $30,000+ replacement. Or, dispute with Nissan over the current class action law suite..
http://jalopnik.com/?_escaped_fragm...issan-claims-issue-not-covered-under-warranty
Bernice
http://jalopnik.com/?_escaped_fragm...issan-claims-issue-not-covered-under-warranty
Bernice
Rupunzell
Bernice Loui
Get the chassis working well initially way before adding any more power.
Beyond 150 Bhp at the rear wheels will need a LSD to put that power to the ground. LSD's for the stock transaxle is limited in selection or something custom get's made.
Turbo = higher torque or significantly more stress on the transaxle. More HP (to about 170 Bhp) alone is not going to be much of a problem. Much higher torque will be.
The real question is, how fast do you wanna go and what is this X intended for? Set your goals, do the ground work well before trying to make it happen.
Bernice
Beyond 150 Bhp at the rear wheels will need a LSD to put that power to the ground. LSD's for the stock transaxle is limited in selection or something custom get's made.
Turbo = higher torque or significantly more stress on the transaxle. More HP (to about 170 Bhp) alone is not going to be much of a problem. Much higher torque will be.
The real question is, how fast do you wanna go and what is this X intended for? Set your goals, do the ground work well before trying to make it happen.
Bernice
http://xwebforums.com/forum/index.php?threads/9361/
safe to say it has more than 200bhp (our dyno is currently not reading power output) with a 5spd gearbox
safe to say it has more than 200bhp (our dyno is currently not reading power output) with a 5spd gearbox
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