biggjimm

Hello all. I think this forum is absolutely great. I have never found a place where so many knowledgable people are so eager to help. With that being said, I have a couple of questions or concerns about my car. My setup is in my signature. I dont have my shifter dialed in yet so I can not manually get the tranny in 2nd or 1st gear, only drive. When I take off (WOT) it shifts into 2nd gear at 5800 RPM and then into 3rd at 4500 RPM. I dont know the speed as I was watching the tach and holding on. I dont have much room to run it until I get her legal and take it out on the highway. Now I'm thinking if I can manually hold it in 1st gear, I can probable get up to about 6200 or so, maybe more, I dont know. It is still making power like crazy at 5800. Now it is supposed to have 3.36's in the rear. Although it feels like 4.11's or something. I dont know. Is there anyway to tell without tearing the rear end down? Assuming they are 3.36 and I change to 4.11 or 4.56 what is going to happen when I run it up in 1st gear? I want to get all the power I can without overrevving the engine? I dont know what kind of RPM's I can get out of it, but it is pulling like a cummings diesel at 5800. I am not going to change anything until I get the shifter finished and get it out and run it and see how it does. I dont want to change gears and then have to do it again. It doesnt look like an easy job. How do I tell what ratio's my 350 tranny is? I think the tires on the rear are 235 60 15. I dont know how to compute all this. We are going to run it on the strip and I need to get all the power I can out of it. thats all I can think of now. Thanks in advance guys. Biggjimm

biggjimm

Did I say DIESEL? :U

Jvette73

Heres a link with a chart that has the trans ratios listed. The second link is to a calculator where you can enter different variables and see the results. To find yur aprox gear ratio you could use data you collect from a test drive and enter it into the calculator. Or you could jack up the rear tires and rotate them 1 full revolution of the rear tire, and count how many rotations of the driveshaft. IE: If yur driveshaft turns aprox 3 3/4 turns to one tire revolution, assume 3.70. if yur drive turns just over 4 revolutions, assume 4.11 and so on. its best to mark the tire and driveshaft with chalk to aid in the counting process.
http://www.bhrmotorsports.com/data.htm
http://www.prestage.com/carmath/calc_Gears.asp


[Modified by Jvette73, 8:38 AM 3/23/2003]

Ganey

Was going to say "pulling like a cummings diesel at 5800" doesn't sound like much. J/K See you already corrected. :cheers:

TH350 1st 2.52 2nd 1.52 3rd 1:1

Drag rear gears are selected to get you to top speed at the end of the 1/4 then fine tuned w/ tire diameter.

biggjimm

Thank you both Jvette and Ganey for your help and the links, I think they will prove to be very helpful when I get ready to do the gears. Yeah sorry about the diesel thing Ganey :smash: I was under the influence of pain medicine. :lolg: :jester But on a serious note, It is so strong at those RPM's it is unbelievable. I dont think I mentioned it before but I want this car to be streetable also. I guess I want the best of both worlds :steering: :D