FrontEngineDragsters.Org Forum

Technical => Dan Dishon's Transmission Den => Topic started by: spitzerscott on September 20, 2018, 04:07:04 PM

Title: sprag or spragless?
Post by: spitzerscott on September 20, 2018, 04:07:04 PM

 Here it is , I'm looking at converters.  We have a 1500# R.E.D.  336 c.i. chevy, we are going to leave the line at 5000-5500, we have a 4:10 gear, so let's hear it.  Sprag or Spragless. We do drive the car to the lanes and back to the pits.  Let me have it!!!!

Title: Re: sprag or spragless?
Post by: jeff/21 on September 20, 2018, 05:45:35 PM

how big are your tires ? your running 366" and only 4:10 gears? as for the converter talk to your guy I have only run sprag type with small motors.

Title: Re: sprag or spragless?
Post by: BK on September 21, 2018, 05:28:36 AM

I would think sprag. Your going to need all the torque multiplication you can get.

Title: Re: sprag or spragless?
Post by: gregm784 on September 21, 2018, 08:57:27 AM

I've run 331 - 387" blown motors.  4.10 gear, 32" tire, 1910# car.   Every converter guy i know says i don't need a spragless.  I took the sprag out years ago, saw no change in performance.  It repeats very well without it. 

we run a 7.60 index btw.

Title: Re: sprag or spragless?
Post by: JrFuel Hayden on September 21, 2018, 09:35:51 AM

Yes, our coverter people have said don't run spragless. We run 7.0's @ 188-190 mph with injected alky 400 ci SBC, weighing 1435 lbs
Greg I did not know you are at 1910 lbs, and don't you run the 12" NTF tires, are they only 32" tall ?
Hope to see you at CHRR.

Jon

Title: Re: sprag or spragless?
Post by: spitzerscott on September 21, 2018, 04:56:04 PM

Tires are 14.5x32 and the 4.10 gear is what was in it.  Most good race converters say, heavy duty sprag.    Thanks Guys.

Title: Re: sprag or spragless?
Post by: bikeguy307 on September 21, 2018, 07:31:06 PM

Every combo is different. Some work better with some without and some it seems to make no difference. Talk to your converter people and see what they say. In a perfect world we could try both and see what works best.

Title: Re: sprag or spragless?
Post by: gregm784 on September 23, 2018, 08:45:18 AM

Quote from: JrFuel Hayden on September 21, 2018, 09:35:51 AM

Yes, our coverter people have said don't run spragless. We run 7.0's @ 188-190 mph with injected alky 400 ci SBC, weighing 1435 lbs
Greg I did not know you are at 1910 lbs, and don't you run the 12" NTF tires, are they only 32" tall ?
Hope to see you at CHRR.

Jon

I have the 13.00x16 NTF tire, it's 101", works out to about 32" tall.

Title: Re: sprag or spragless?
Post by: jeff/21 on September 23, 2018, 05:05:45 PM

spitzerscott is your 336 blown or NA?

Title: Re: sprag or spragless?
Post by: spitzerscott on September 29, 2018, 07:15:04 AM

jeff21,  N/A  850 Quick Fuel alcohol carb.

Title: Re: sprag or spragless?
Post by: jeff/21 on September 29, 2018, 08:30:55 PM

ran 160 " fed 406 sbc with a 850 33x10.5 hoosiers ran 4.86 gears slowed when we changed to 4.10 now changed from the carb to injection have yet to race it since the  need a new block cracked in the rear camshaft and life has gotten in the way. all the big blocks ran 4.10 or 3.90 gears

Title: Re: sprag or spragless?
Post by: gregm784 on October 01, 2018, 03:22:10 PM

I broke a stator last month in my old trusty converter, so i had it cut apart to take a peak. 

Years ago, i had PDQ converters in Sacramento remove the sprag and go spragless.

Found out Friday, that they never did what i paid them to do, and my sprag was indeed slipping. 

PDQ sux.