You also have to add the 5% gain through your drivetrain, I think it's a 20% loss for awd and 15% for rwd.

 

right...more hard to control power to the tires...my 930 was a handful at 470 rwhp. Fun car going straight, but thats about it. If you chickened out in a fast corner...all bets were off. I bought my car because it was awd. I figured it would be my 930 with awd...pretty close.

 

I concur with most of this. When I bought mine earlier this year, it already had RWD conversion but ROW suspension (barely better than stock). I didn't like the way it handled and was bouncy under acceleration on long sweeping roads/exits. I had the PSS10s and sway bars installed and a fairly aggressive street alignment done and it is wayy better and more stable under these conditions, which seems safer to me.

I really like it and the fact it frees up 5%+ more horsepower, but I am not a road racer guy either.

 

as for hp loss, I hear people on this very forum with lots of experience say that the AWD systems in these cars do not loose that much power compared to rwd. I have seen figures closer to 14-15% loss for awd and 12% for rwd. I am not trying to hijack my own thread, but I think that a 5% gain in power is a good reason to make rwd work, whereas a 2% gain isn't, imo

 

I plan on doing suspension and an LSD in the spring, but STAYING AWD. (oh and by the way, I have tuned my car on a mustang dyno and I had a 19% driveline loss.)

 

did you disconnect the front and dyno again? is that how you got the number? Not sure I understand how you know your loss unless you knew the brake hp beforehand.

 

yes, we baselined my car, in AWD, on a mustang dyno.

 

19% to 12/13% seems like a big difference, and 70+ lbs is a rather big weight reduction... not too many places you can lose that much weight... but considering you lose it on the wrong side.. not sure that's ideal.

 

25-30whp at 13% loss? You could leave it AWD and turn up the boost 1psi or so and make up for that...

 

There are some many factors in racing that I don't think one should make a decision based on what they are reading in this thread regarding RWD to AWD. 5%, 2% drivetrain loss, etc, etc. I have no interest in reading dyno #s on my car because there are so many variables. 1/4 mile times and 60-130mph times are a better indicator of power and even then it is hard to isolate variables to see a difference between AWD and RWD.

I would speculate that the RWD would shine at higher speeds over the AWD given the weight damage. Out of the hole, it might actually hurt you as a result of less traction. I think the better question is whether or not it is possible to convert our AWD into a true AWD system.

 

I disagree. I think a lot can be gathered from what people on this thread have said. IF you are strictly racing, then this is meaningless as you have a gutted car. However, I think that one thing is clear, unless you are willing to do the conversion correctly and completely, it's not worth it for 70 lbs and unstable handling.

I agree that dyno's don't tell the whole story.

I'd bet that at higher speeds awd is better and much more secure.

 

Just curious...it seems like a lot of people are concerned with the 70lb reduction in weight on the front throwing off the balance. If that's the case then why not leave all the parts and just remove the front drive shaft to keep the balance the same?

I just have a UMW flash and exhaust, and my car felt quick in AWD. Then I removed the front drive shaft for 6 months, and the car felt scary fast in RWD mode! It pulled so much harder that I would only dare floor it going in a straight line. Flooring it on any slight bend would make my traction control light flash on and off.

Then I put the front drive shaft back in, and the car just feels quick... no more scary fast. I plan on removing it again after the winter rainy season

 

very interesting. of course you had to bring in another option. I like this idea along with LSD rear, might just work.

 

I dont think that is the proper way to test for drivetrain losses. It's going to take more power to spin two drums instead of one as it is. The only proper way is to do an engine dyno and a bhp dyno using the same equipment.

 

I think what TTBoost is saying is before he did his mods, he got a baseline figure and from that he calculated driveline loss.

Before I did any work on my car, I thew it on Tony's mustang dyno bone stock and did 334 at all 4 wheels. Assuming the factory 416 is correct, my math says I'm making 80% of the crank power at the wheels, hence a 20% driveline loss.

At very least, this is my driveline loss as measured ON THAT DYNO. Some dynos measure stock cars in the 370 range, so obviously it's not apples to apples.