how much RPM have you lost at the stripe or any at all with the slip? Interesting the shift drop RPM has not changed, with the slip I would think oyu are blowing through the converter or you just do not have enough rear gear..
That's not alot of rear gear for sure, I would be leery of having it there for such an engine. With a 655ish deal likely be not as big of a concern. At least on our 655 that dont seem to care so much where its shifted
Thanks for the replies
I don't appear to have lost too much rpm at the stripe, maybe 200 rpm, unfortunately we never logged DS rpm or indeed used a Racepak prior to the gear change. So it's really a bit unknown as the tach (also changed) may have been inaccurate, though IIRC wasn't too bad compared to the Grid RPM. However with the previous logging tach, the same converter would flash to 5200 consistently with the 4:10 rear.
We changed the rear ratio as we just couldn't control the wheelstands, one weekend we'd be struggling to tune out wheelspin, the next time out car would dead hook and we'd bend stuff at both ends, it got expensive and after the 4th time we decided to do something drastic. The lack of available ratio's for a Dana 60 forced our hand somewhat and we ended with 3.73's (we would have preferred 3.90's), we use a radial slick BTW.
Car seems more consistent but slower, which I feel is a backward step
We're back out in 9 days for our last race meeting but I don't think I'll have time to change the T/C as we are in the process of a house move and next season we'll likely have the 655 back in
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Have you tried shifting it higher to see if the motor it likes it or not?
If not, I would, maybe 300 and then 500 higher RPM shift point.
Please try that and let us know your results
We upped the shift from 6700 to 6900, picked up a 10th. motor seems to start to nose over after 7000
