Hokay, I will preface this by saying that I have spent considerable time trying to get down to hard facts, get straight answers from manufacturers, and opinions from as many shops that I can. That said, I have about 17 different explanations for what's going on and that's no help.
Background:
Car is my 91 7M powered Supra. Latest power output was 788hp and 674 lb-ft of torque. R-154 is the transmission, it has a 3.5" Aluminum driveshaft, a 3.91 LSD, and a Spec super twin P-trim.
Main use of the car is drag racing and street driving, but mild road racing will be done when I get it to a state where I feel it's ready.
The Issue:
While on the dyno tuning the engine, we cracked the 3-4 synchro sleeve. It was brand new 1 year ago and the car has seen less than 1000miles. While it's possible it was a factory defect, I think it's unlikely.
As far as I can tell, there has been no additional damage to the transmission aside from this. I'm replacing the shift fork and some of the bearings to prevent future failure, so the trans will be fixed.
The question:
What caused this, and what can I do to prevent it/mitigate some of the risk moving forward? There are 2 schools of thought at this time from those who I've talked to as of yet.
1: Too much power/torque for the transmission to handle.
2: Solid hub clutch discs increased the shock load on the transmission during events such as hitting rev limiter and lifting after a hard pull.
Talking with Spec, they used to offer the clutches with only solid hubs, but have started to include 1 solid hub and 1 damped hub. Though I would greatly desire it, they do not offer dual damped discs, citing they may not fit and it would only add weight and noise. Am I right or wrong to want the discs to both be damped? My thought is that if we reduce the back-and-forth shock loads, the transmission may be less stressed during shifts and hitting the limiter, which could lead to this failure not occurring again. I'm not all that concerned with the noise, and disc weight just demands more frequent rebuilds due to blocker ring wear. At the same time, I feel that having 1 disc damped and the other solid doesn't address the main problem, and actually makes more issues (uneven disc loading for one). Am I on-point, or way out of line? I loved my Spec 3+, but it just doesn't hold the power like I need it to.
If anyone has expertise dealing with multi-plate clutches, or has dealt with this situation, feel free to chime in!
Note/edit: We recently moved into a new house and have yet to be able to get our internet connected- my only source of internet is work, so I will be able to read and respond during business hours in MN. I <3 Comcast... :nono:
Background:
Car is my 91 7M powered Supra. Latest power output was 788hp and 674 lb-ft of torque. R-154 is the transmission, it has a 3.5" Aluminum driveshaft, a 3.91 LSD, and a Spec super twin P-trim.
Main use of the car is drag racing and street driving, but mild road racing will be done when I get it to a state where I feel it's ready.
The Issue:
While on the dyno tuning the engine, we cracked the 3-4 synchro sleeve. It was brand new 1 year ago and the car has seen less than 1000miles. While it's possible it was a factory defect, I think it's unlikely.
As far as I can tell, there has been no additional damage to the transmission aside from this. I'm replacing the shift fork and some of the bearings to prevent future failure, so the trans will be fixed.
The question:
What caused this, and what can I do to prevent it/mitigate some of the risk moving forward? There are 2 schools of thought at this time from those who I've talked to as of yet.
1: Too much power/torque for the transmission to handle.
2: Solid hub clutch discs increased the shock load on the transmission during events such as hitting rev limiter and lifting after a hard pull.
Talking with Spec, they used to offer the clutches with only solid hubs, but have started to include 1 solid hub and 1 damped hub. Though I would greatly desire it, they do not offer dual damped discs, citing they may not fit and it would only add weight and noise. Am I right or wrong to want the discs to both be damped? My thought is that if we reduce the back-and-forth shock loads, the transmission may be less stressed during shifts and hitting the limiter, which could lead to this failure not occurring again. I'm not all that concerned with the noise, and disc weight just demands more frequent rebuilds due to blocker ring wear. At the same time, I feel that having 1 disc damped and the other solid doesn't address the main problem, and actually makes more issues (uneven disc loading for one). Am I on-point, or way out of line? I loved my Spec 3+, but it just doesn't hold the power like I need it to.
If anyone has expertise dealing with multi-plate clutches, or has dealt with this situation, feel free to chime in!
Note/edit: We recently moved into a new house and have yet to be able to get our internet connected- my only source of internet is work, so I will be able to read and respond during business hours in MN. I <3 Comcast... :nono:
