FrontEngineDragsters.Org Forum

Technical => Spud Miller's Cave => Topic started by: wideopen231 on October 19, 2020, 05:05:17 AM

Title: shift point with small load
Post by: wideopen231 on October 19, 2020, 05:05:17 AM

 Wondering if need to move shift point up little when running small load of nitro.
 Knowing the stall will go up some,been told about 500 for 25%. Would moving shift up help with fall back. Example my car stall is 6600 ,so 7000 to 7100 with 25%. Normal shift is 7500. Would bumping it to say 7800 to 8000 help when it falls back to keep it where fall back is right at stall rpm? Any thoughts on stage rpm change?  Just me wondering stuff as always. LMAO

Title: Re: shift point with small load
Post by: masracingtd1167 on October 19, 2020, 02:15:06 PM

Chris I tried lowering mine about 400 rpm and saw nothing ! Normally shift it at 9200 !

Title: Re: shift point with small load
Post by: wideopen231 on October 19, 2020, 02:55:50 PM

Bill,

 Have you tried raising it some.Then again you are already in totally different zone than I will be. Pretty sure my motor can handle the one you are in,use to about 1000 more,but sure worked on valve springs. Hey I am just a bracket car not in the fast brackets like you are.

Title: Re: shift point with small load
Post by: Curly1 on October 19, 2020, 06:41:45 PM

Have you tried to make any more passes with it?

Title: Re: shift point with small load
Post by: wideopen231 on October 21, 2020, 04:55:17 PM

Yes. Few T-N-T nights and getting close to solid pass'. Best so far was 4.82 with medium shake about 20 to 30 feet out.  Did get little hairy on top end last shot. Track was getting slick and back got loose about 100 ft from finish and think I shut it down too quick which just added so,e bounce to the fun meter.  Hopefully getting out next week and if tnt goes decent going to local bracket deal Sat. Figure next x\challenge is tuning old fart in the seat and thats always tough. LMAO

Title: Re: shift point with small load
Post by: wideopen231 on October 21, 2020, 04:56:45 PM

Probably not good idea to test that extra load thing yet? Then might get rid of shake with little more tq.

Title: Re: shift point with small load
Post by: masracingtd1167 on October 22, 2020, 10:13:18 AM

Chris From what I have found using a small amount of nitro is to keep everything the same as far as converter and gearing ! I tried a tighter converter thinking the extra torque would help and it was slower !

Title: Re: shift point with small load
Post by: wideopen231 on October 22, 2020, 01:34:05 PM

How much nitro and how much more stall? According to SPuds calculator and FTI with 25% load I should gain about 600 rpm stall putting me right around 7200 rpm. My fall back estimating is 6600 now.No data acquisition ,YET. Shifting at about 7500,using time instead of rpm. Might reset and try rpm since I said that. Right now getting input for when I do open one of the blue jugs. If I can get 3 or 4 consistent runs and time allowing I am going to drop 10 to 15% load in BIWT.