After racing last night (7 passes) and using the nitrous most of the runs my tranny has been surging. When it shifts at 1500rpm it surges to 2500 and then shifts. Again at 2000 when the next shift happens it surges another 300 or so before shifting. Any ideas?
best tiem was 9.6 in the 1/8th. the car was hestitating but I'm guessing it was the tranny. but yea, very happy. the track was so slippery, very dusty.
I asked around a little, looks like when there is a tugging and surging during shifts that can be the transmission slipping. I'm gonna see how much it'll cost to rebuild it, it might be a fun thing to do myself and then sell it.
Hmmm. I have been watching you, and now worry about using the nitrous. But then i was pulling 9.3s on my old engine without nitrous, so I am guessing your trans is just worn.
I am curious, How much engine and how much nitrous are we talking here. Am I to understand that this is with a STOCK C4? Now my comments on nitrous and the C4. When deciding how I will build a C4 when nitrous is involved I take motor HP + twice the amount of power that the nitrous will provide. For a 350 NA HP engine with a 200 nitrous shot I build the engine for 750 HP not 550 hp. Why? Isn't HP the same whether it comes from the engine or the bottle? NO! it is very different. The engine builds its power in a curve - the transmission never has to absorb all the torque but when you push that button it all happens at once. Like building a shelf that will hold 15 pounds, setting a 10 pound bag of flour on it - Then drop a 5 pound bag of flour from one foot above the shelf. The shelf is going to give under the rapid application of force even though if you had carefully placed that bag on the shelf it would have held it just fine. Everytime you hit that button you are hitting your transmission with a sledge hammer. The 750 hp C4s use all roller thrust bearings to eliminate friction (heat), billet steel planet carriers with 4 pinions, at least 6 clutches in BOTH packs, Welded or ridgid front band, "H" servo or larger, deep sump pan and pick-up, a torque converter with more stall than it would need for the engine alone (to help cushion the hit) and a very large (or two large) coolers. The valve body should be a full manual control with at least 190 PSI line pressure. Now, what are you guys running?
ummm, so my C4 is pretty close to what you describing minus all the stuff that you mentioned! my C4 was the stock one I had behind my 6cyl. My motor make 185 at the wheels and I had a 125hp shot to it.
Mashori, The gear train should hold with your application but you need to increase line pressure and speed the shifts up just a bit. I would recommend that you install a TransGo 40-2 kit in it at the highest level. That should help keep the new parts from slipping in the future (after the rebuild) Make sure you are using a "C", "H", "A"< or "R" front servo - the rest are too weak to hold.
