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View Full Version : RPM diff. from runnin a 7.00 and 7.33


jeremy_wells77
06-14-2011, 01:03 PM
Im mainly running 1/4 mile tracks and am not getting the kinda rpm's i should be getting. I am currently running a 7.00 final gear now and was wandering how many more rpm's i can get by switching over to a 7.33?
rubbinsracin
06-14-2011, 01:26 PM
what are you turning now?
jeremy_wells77
06-14-2011, 01:37 PM
depending on track conditions 5900 to 6200
jeremy_wells77
06-14-2011, 01:39 PM
what are you turning now?

depending on track conditions 5900 to 6200
gadirtracer
06-14-2011, 02:10 PM
RPM/Current Gear x New Gear=New RPM
6,200/7.00x7.33=6,492
Or each .1 is usually close to 100 RPM.
rubbinsracin
06-14-2011, 02:19 PM
hmmm...i dont know all that math stuff....lol but when we go up 33 points we have usually gained about 200-300 rpm depending on
cassellracing24
06-14-2011, 02:23 PM
depending on track conditions 5900 to 6200

With a 7.00 !! Are you sure your distributer is good ?? Try a MSD or DUI coil & modual before buying another gear. Assuming your on a 4412 2bbl, 3200ibs car with 86" roll out you should turn about 7500 with a 7.00. Something is deff wrong....Like post above every .1 is around 100 rpm.
jeremy_wells77
06-14-2011, 03:09 PM
With a 7.00 !! Are you sure your distributer is good ?? Try a MSD or DUI coil & modual before buying another gear. Assuming your on a 4412 2bbl, 3200ibs car with 86" roll out you should turn about 7500 with a 7.00. Something is deff wrong....Like post above every .1 is around 100 rpm.

we just ran sunday at shepps with a MSD distributor and module to see if that would help and still only got 58, had the same problem with last years motor also and this motor is a much better piece. we are dumbfounded. we ran the car at lincoln a few weeks ago and got 66 out of it but that was it. its been frustrating
ToddSmith16
06-14-2011, 03:23 PM
...there is something wrong with engine. Valve lash to tight, ignition, timing, etc... I ran a 7.0 at lincoln and truned close to 7200-7400. Ran 7.00, 7.16 and 7.33 at Shepps and was well over 6300...your missing approximately 500 rpms! Good luck!
Egoracing
06-15-2011, 06:54 AM
Is it the same tach as last year? I had an Autometer that went bad and I could only get 6000 out of the engine. We swapped deistibutor, MSD, Battery, valve springs, plugs and wires and I went out and it was great in the heat race but we forgot to plug in the tach. We plugged it in for the feature and when I hit the gas all the car would do was 6000. Under caution I go ahold of the wire on the tach and ripped it out and the engine came right back.
cassellracing24
06-16-2011, 05:39 AM
Is it the same tach as last year? I had an Autometer that went bad and I could only get 6000 out of the engine. We swapped deistibutor, MSD, Battery, valve springs, plugs and wires and I went out and it was great in the heat race but we forgot to plug in the tach. We plugged it in for the feature and when I hit the gas all the car would do was 6000. Under caution I go ahold of the wire on the tach and ripped it out and the engine came right back.

As Ego said....That was my next ???
cassellracing24
06-16-2011, 05:42 AM
...there is something wrong with engine. Valve lash to tight, ignition, timing, etc... I ran a 7.0 at lincoln and truned close to 7200-7400. Ran 7.00, 7.16 and 7.33 at Shepps and was well over 6300...your missing approximately 500 rpms! Good luck!

Todd: Is Shepps that much smaller than Lincoln that you loose 800rpm with same gear ??