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FE Power Forums => FE Technical Forum => Topic started by: Jim Comet on May 28, 2025, 08:20:45 PM

Title: drive train losses
Post by: Jim Comet on May 28, 2025, 08:20:45 PM
A year and a half ago my 416FE dropped a valve forcing a rebuild and 3 sleeves. Up to that time my best ET was 10.70 @125mph. To do this I had been spinning the motor to 7500rpm's or more through the traps running 4.71 gears and a rollerized C6 trans and aluminum driveshaft. When I did the rebuild I found the distributor drive gear on the cam was trashed most likely due to me installing my distributor gear wrong. I decided to lower my rpm's through the traps after the rebuild in hopes of not breaking any more tool steel retainers (which I had broken 2) and dropping more valves. First I switched to 4.10 gears. I then was able to purchase a Powerglide trans with a brake to replace the C6. The Powerglide is shorter than the C6 so in talking with PST drivetrain they said to avoid driveshaft issues, I should switch to a carbon fiber shaft. I had Neal Chance do a converter to fit the swap. I had Lykins spec a cam which peaked at 6300 rpms which has me shifting at 6500 and I now go through the traps at 6900 rpms. Previous hp with on the original build was 605hp. With the new cam the motor came in at 540hp. So with all these changes I ended up running 10.70's at 126mph last weekend. I did go from 1.45 60ft times with the original set up to 1.58 60ft with the new. The new lighter drivetrain is allowing the car to make up the difference on the top end. Jim
Title: Re: drive train losses
Post by: e philpott on May 28, 2025, 09:00:45 PM
10.70 at 105 mph ? That’s either a good et for that mph or a bad mph that et
Title: Re: drive train losses
Post by: Jim Comet on May 28, 2025, 09:08:02 PM
Thank you for catching that. I changed it to correctly read 125 and 126mph. Jim
Title: Re: drive train losses
Post by: galaxiex on May 28, 2025, 09:31:57 PM
Even a rollerized C6 is still an energy vampire, tho the roller bearing do help.
Heavy internal rotating parts. (clutch drums)
There are light weight billet aluminum drums but $$$$$$.
Even just a stock C6 is almost bullet proof, but heavy.

Hard to beat the PG for drag racing.
Tons of development for it.
Title: Re: drive train losses
Post by: 4twennyAint on May 29, 2025, 01:18:49 PM
Fantastic!  All the parts made a difference - C6 to 'glide being the biggest, switching to a Neal Chance convertor likely was the next biggest. Carbon fiber driveshafts have shown up to 10 rear wheel HP; same for numerically lower ring & pinion on a Dyno Jet.   
Title: Re: drive train losses
Post by: Stangman on May 29, 2025, 11:13:12 PM
Wow that’s great and 600 RPMs less will be much better on the motor.