250 WHP Supernatural 3.4 Build (Page 10/47) Boot NOV 06, 01:00 PM quote Originally posted by La fiera: I have driven it plenty and the one thing I love about having the welded diff is the amount of grip that the rear obtained. The car had a tendency to oversteer easy after I added the fiero store rear swaybar with the open diff. I then upgraded the swaybars with adjustable NASCAR style fully adjustable and 350# springs and I was able to adjust the car better but I couldn't get the predictability I was looking for. After I welded the diff high speed braking improved a lot and I can throttle steer it in a very predictable way. I feel more comfortable driving it with the welded diff than without it, I would never go back to an open diff. The 11 and 12 of this month I'm going to shake down the car and I will be able to really drive it safely How do you think it compares to say, the same car with an LSD? I know you cant get an LSD for those transmissions, but lets talk theoretically. Everyone Ive talked to about it thinks that with the welded diff it'll just understeer or snap oversteer unless you go fast enough to lift the inside rear like on a kart. That makes sense to me, too. Is that what you're doing? Or is the understeer and oversteer a non issue? Also, how stiff is the front setup compared to the rear? La fiera NOV 06, 08:51 PM quote Originally posted by Boot: How do you think it compares to say, the same car with an LSD? I know you cant get an LSD for those transmissions, but lets talk theoretically. Everyone Ive talked to about it thinks that with the welded diff it'll just understeer or snap oversteer unless you go fast enough to lift the inside rear like on a kart. That makes sense to me, too. Is that what you're doing? Or is the understeer and oversteer a non issue? Also, how stiff is the front setup compared to the rear? Well, from an experienced Porsche and kart driver I will tell you that is just perfect. Now, if someone is doing these mods to their Fiearo with no driver experience, he or she will be very disappointed because they are lacking the experience. The rear grip increase is due to the lack of front turn in grip but as soon as you apply throttle the understeer disappears. You literately drive the Fiero with the throttle and to do that it takes some experience. WIth practice and patience anybody can do it and once you experience that, you'll never go back to your old stock settings. La fiera NOV 06, 09:01 PM Boot, I can fine tune how I want the car to behave at a specific track. The front has the same set up. I can change the swaybar thickness front and rear and can also can interchange front and rear bars. They have the same spline. It's very tuner friendly! Blacktree NOV 06, 09:11 PM Now THAT is a sway bar! La fiera NOV 08, 01:52 PM quote Originally posted by Blacktree: Now THAT is a sway bar! Right now it has a 38mm rear bar and a 29mm up front. In a regular Fiero set up the bars order would be the opposite, but having the welded diff the bigger rear and smaller front bar complements the extra grip provided by the welded diff. I can throttle steer it easy and I have complete control of the drift at mid and slow speeds. At hi speed, well; I'll try that this weekend at the track. When I said my Fiero handles like my kart, believe me ; it does! Will NOV 12, 01:56 PM quote Originally posted by La fiera: 225/50/15 front 235/50/15 rear I'll check fiero warehouse, thank you for the sugestion! Oh, ok. You have low offset wheels rather than ridiculously wide tires. La fiera NOV 12, 07:17 PM quote Originally posted by Will: Oh, ok. You have low offset wheels rather than ridiculously wide tires. yes sir La fiera NOV 12, 07:48 PM Well guys, I couldn't make it to the track this weekend. I took the car to the dyno friday morning to simulate a couple of laps on it, that way I can concentrate on the driving instead of tuning the car. Just to make sure that the fuel and ignition maps are good. I did some tuning at the mid range to fix the big dip that the previous dyno sheet shows. It did fantastic! I picked up 50 lbs/ft of torque and 13hp at 2800rpm. The simulation went very well, I was not tuning for ultimate hp but the owner of the dyno told me that I broke into the 250WHP in the 1st try, so I was excited. My main goal was that the engine responded well at all RPMS, so I concentrated on that, so I ran on the dyno for 30 minutes as hard as I could, playing in my mind the roadcourse and accelerating and decelerating accordingly, no problems at all! At 4:00pm friday and I haven't got my hood and decklid back from the bodyshop! I bring the car back home and suddenly I see a spot of oil on the floor! The driver side driveshaft seal is leaking! No big deal, I raised the back end to inspected. There is some rotational play between the rear wheels!! I took the speed sensor off and drained the trans oil to inspect it with my bore scope and I can see some welds on the spider gears missing!!!! The hood and decklid showed up, also my friend with the trailer to take my car to the track showed up. But my gut feeling told me not to go and I just went with my gut. I also checked the play on the axles and they are sooo worned out!! The car drives fine, both rear wheels are still locked. I have to do a cradle change and some upgrades on the engine, I'll just wait until I get my new cradle and engine upgrade to fix the diff. I think I got a print of one of the passes while on the dyno, I'll try to find it and post it. wftb NOV 12, 10:12 PM Too bad, was looking forward to some in car vid. Good luck with the fixes. Will NOV 13, 12:16 PM quote Originally posted by La fiera: The driver side driveshaft seal is leaking! No big deal, I raised the back end to inspected. There is some rotational play between the rear wheels!! I took the speed sensor off and drained the trans oil to inspect it with my bore scope and I can see some welds on the spider gears missing!!!! The hood and decklid showed up, also my friend with the trailer to take my car to the track showed up. But my gut feeling told me not to go and I just went with my gut. I also checked the play on the axles and they are sooo worned out!! The car drives fine, both rear wheels are still locked. I have to do a cradle change and some upgrades on the engine, I'll just wait until I get my new cradle and engine upgrade to fix the diff. I was wondering if you were going to have durability issues in that regard. The GM FWD axle form factor is not suited to the abuse of driving with locked diff and a lot of traction. The inner CV joint splines in the transmission are the second weak point in the axles... following the outer CV joint splines in the wheel hubs.